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Magnet I, Stommel AM, Schriefl C, Mueller M, Poppe M, Grafeneder J, Testori C, Janata A, Schober A, Grassmann D, Behringer W, Weihs W, Holzer M, Hoegler S, Ettl F. Neuroprotection with hypothermic reperfusion and extracorporeal cardiopulmonary resuscitation - A randomized controlled animal trial of prolonged ventricular fibrillation cardiac arrest in rats. J Cereb Blood Flow Metab 2025; 45:476-485. [PMID: 39246100 PMCID: PMC11574926 DOI: 10.1177/0271678x241281485] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 07/31/2024] [Accepted: 08/15/2024] [Indexed: 09/10/2024]
Abstract
Extracorporeal cardiopulmonary resuscitation (ECPR) facilitates resuscitation with immediate and precise temperature control. This study aimed to determine the optimal reperfusion temperature to minimize neurological damage after ventricular fibrillation cardiac arrest (VFCA). Twenty-four rats were randomized (n = 8 per group) to normothermia (NT = 37°C), mild hypothermia (MH = 33°C) or moderate hypothermia (MOD = 27°C). The rats were subjected to 10 minutes of VFCA, before 15 minutes of ECPR at their respective target temperature. After ECPR weaning, rats in the MOD group were rapidly rewarmed to 33°C, and temperature maintained at 33°C (MH/MOD) or 37°C (NT) for 12 hours before slow rewarming to normothermia (MH/MOD). The primary outcome was 30-day survival with overall performance category (OPC) 1 or 2 (1 = normal, 2 = slight disability, 3 = severe disability, 4 = comatose, 5 = dead). Secondary outcomes included awakening rate (OPC ≤ 3) and neurological deficit score (NDS, from 0 = normal to 100 = brain dead). The survival rate did not differ between reperfusion temperatures (NT = 25%, MH = 63%, MOD = 38%, p = 0.301). MH had the lowest NDS (NT = 4[IQR 3-4], MH = 2[1-2], MOD = 5[3-5], p = 0.044) and highest awakening rate (NT = 25%, MH = 88%, MOD = 75%, p = 0.024). In conclusion, ECPR with 33°C reperfusion did not statistically significantly improve survival after VFCA when compared with 37°C or 27°C reperfusion but was neuroprotective as measured by awakening rate and neurological function.
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Affiliation(s)
- Ingrid Magnet
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | | | - Christoph Schriefl
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Matthias Mueller
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Michael Poppe
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Juergen Grafeneder
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Christoph Testori
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Andreas Janata
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Andreas Schober
- Department of Cardiology, Klinik Floridsdorf, Vienna, Austria
| | | | - Wilhelm Behringer
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Weihs
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Michael Holzer
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Sandra Hoegler
- Unit of Laboratory Animal Pathology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Florian Ettl
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
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Stommel AM, Högler S, Mueller M, Magnet IAM, Kodajova P, Ullram B, Szinovatz A, Panzer FP, Engenhart-Seyrl A, Kaschmekat J, Schütz T, Holzer M, Weihs W. A ventricular fibrillation cardiac arrest model with extracorporeal cardiopulmonary resuscitation in rats: 8 minutes arrest time leads to increased myocardial damage but does not increase neuronal damage compared to 6 minutes. Front Vet Sci 2023; 10:1276588. [PMID: 38026669 PMCID: PMC10655001 DOI: 10.3389/fvets.2023.1276588] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging strategy in highly selected patients with refractory cardiac arrest (CA). Animal models can help to identify new therapeutic strategies to improve neurological outcome and cardiac function after global ischemia in CA. Aim of the study was to establish a reproducible ECPR rat model of ventricular fibrillation CA (VFCA) that leads to consistent neuronal damage with acceptable long-term survival rates, which can be used for future research. Materials and methods Male Sprague Dawley rats were resuscitated with ECPR from 6 min (n = 15) and 8 min (n = 16) VFCA. Animals surviving for 14 days after return of spontaneous resuscitation (ROSC) were compared with sham operated animals (n = 10); neurological outcome was assessed daily until day 14. In the hippocampal cornu ammonis 1 region viable neurons were counted. Microglia and astrocyte reaction was assessed by Iba1 and GFAP immunohistochemistry, and collagen fibers in the myocardium were detected in Azan staining. QuPath was applied for quantification. Results Of the 15 rats included in the 6 min CA group, all achieved ROSC (100%) and 10 (67%) survived to 14 days; in the 8 min CA group, 15 (94%) achieved ROSC and 5 (31%) reached the endpoint. All sham animals (n = 10) survived 2 weeks. The quantity of viable neurons was significantly decreased, while the area displaying Iba1 and GFAP positive pixels was significantly increased in the hippocampus across both groups that experienced CA. Interestingly, there was no difference between the two CA groups regarding these changes. The myocardium in the 8 min CA group exhibited significantly more collagen fibers compared to the sham animals, without differences between 6- and 8-min CA groups. However, this significant increase was not observed in the 6 min CA group. Conclusion Our findings indicate a uniform occurrence of neuronal damage in the hippocampus across both CA groups. However, there was a decrease in survival following an 8-min CA. Consequently, a 6-min duration of CA resulted in predictable neurological damage without significant cardiac damage and ensured adequate survival rates up to 14 days. This appears to offer a reliable model for investigating neuroprotective therapies.
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Affiliation(s)
| | - Sandra Högler
- Department of Pathobiology, Unit of Laboratory Animal Pathology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Matthias Mueller
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | | | - Petra Kodajova
- Department of Pathobiology, Unit of Laboratory Animal Pathology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Benjamin Ullram
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Alexander Szinovatz
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Felix Paul Panzer
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | | | - Julia Kaschmekat
- Department of Pathobiology, Unit of Laboratory Animal Pathology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Tamara Schütz
- Center for Biomedical Research and Translational Surgery, Medical University of Vienna, Vienna, Austria
| | - Michael Holzer
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Weihs
- Department of Emergency Medicine, Medical University of Vienna, Vienna, Austria
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Jakobsen RP, Nielsen TH, Mølstrøm S, Nordström CH, Granfeldt A, Toft P. Moderately prolonged permissive hypotension results in reversible metabolic perturbation evaluated by intracerebral microdialysis - an experimental animal study. Intensive Care Med Exp 2019; 7:67. [PMID: 31802303 PMCID: PMC6892994 DOI: 10.1186/s40635-019-0282-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/13/2019] [Indexed: 12/28/2022] Open
Abstract
Background Damage control resuscitation (DCR) and damage control surgery (DCS) is the main strategy in patients with uncontrollable hemorrhagic shock. One aspect of DCR is permissive hypotension. However, the duration of hypotension that can be tolerated without affecting the brain is unknown. In the present study we investigate the effect of 60 min severe hypotension on the brain’s energy metabolism and seek to verify earlier findings that venous cerebral blood can be used as a marker of global cerebral energy state. Material and methods Ten pigs were anaesthetized, and vital parameters recorded. Microdialysis catheters were placed in the left parietal lobe, femoral artery, and superior sagittal sinus for analysis of lactate, pyruvate, glucose, glycerol, and glutamate. Hemorrhagic shock was induced by bleeding the animal until mean arterial pressure (MAP) of 40 mmHg was achieved. After 60 min the pigs were resuscitated with autologous blood and observed for 3 h. Results At baseline the lactate to pyruvate ratios (LP ratio) in the hemisphere, artery, and sagittal sinus were (median (interquartile range)) 13 (8–16), 21 (18–24), and 9 (6–22), respectively. After induction of hemorrhagic shock, the LP ratio from the left hemisphere in 9 pigs increased to levels indicating a reversible perturbation of cerebral energy metabolism 19 (12–30). The same pattern was seen in LP measurements from the femoral artery 28 (20–35) and sagittal sinus 22 (19–26). At the end of the experiment hemisphere, artery and sinus LP ratios were 16 (10–23), 17 (15–25), and 17 (10–27), respectively. Although hemisphere and sinus LP ratios decreased, they did not reach baseline levels (p < 0.05). In one pig hemisphere LP ratio increased to a level indicating irreversible metabolic perturbation (LP ratio > 200). Conclusion During 60 min of severe hypotension intracerebral microdialysis shows signs of perturbations of cerebral energy metabolism, and these changes trend towards baseline values after resuscitation. Sagittal sinus microdialysis values followed hemisphere values but were not distinguishable from systemic arterial values. Venous (jugular bulb) microdialysis might have a place in monitoring conditions where global cerebral ischemia is a risk.
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Affiliation(s)
- Rasmus Peter Jakobsen
- Department of Anesthesia and Intensive Care, Odense University Hospital, J.B. Winsløws Vej 4, Indgang 8, 20, 201, 5000, Odense C, Denmark.
| | - Troels Halfeld Nielsen
- Department of Neurosurgery, Odense University Hospital, Kløvervænget 47, Indgang 44, 1. etage, 5000, Odense C, Denmark
| | - Simon Mølstrøm
- Department of Anesthesia and Intensive Care, Odense University Hospital, J.B. Winsløws Vej 4, Indgang 8, 20, 201, 5000, Odense C, Denmark
| | - Carl-Henrik Nordström
- Department of Neurosurgery, Odense University Hospital, Kløvervænget 47, Indgang 44, 1. etage, 5000, Odense C, Denmark
| | - Asger Granfeldt
- Department of Intensive Care, Aarhus University Hospital, Palle Juul-Jensens Blvd. 99 G304, 8200, Aarhus, Denmark
| | - Palle Toft
- Department of Anesthesia and Intensive Care, Odense University Hospital, J.B. Winsløws Vej 4, Indgang 8, 20, 201, 5000, Odense C, Denmark
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Janata A, Magnet IAM, Schreiber KL, Wilson CD, Stezoski JP, Janesko-Feldman K, Kochanek PM, Drabek T. Minocycline fails to improve neurologic and histologic outcome after ventricular fibrillation cardiac arrest in rats. World J Crit Care Med 2019; 8:106-119. [PMID: 31853446 PMCID: PMC6918046 DOI: 10.5492/wjccm.v8.i7.106] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 09/17/2019] [Accepted: 10/27/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Prolonged cardiac arrest (CA) produces extensive neuronal death and microglial proliferation and activation resulting in neuro-cognitive disabilities. Among other potential mechanisms, microglia have been implicated as triggers of neuronal death after hypoxic-ischemic insults. Minocycline is neuroprotective in some brain ischemia models, either by blunting the microglial response or by a direct effect on neurons. AIM To improve survival, attenuate neurologic deficits, neuroinflammation, and histological damage after ventricular fibrillation (VF) CA in rats. METHODS Adult male isoflurane-anesthetized rats were subjected to 6 min VF CA followed by 2 min resuscitation including chest compression, epinephrine, bicarbonate, and defibrillation. After return of spontaneous circulation (ROSC), rats were randomized to two groups: (1) Minocycline 90 mg/kg intraperitoneally (i.p.) at 15 min ROSC, followed by 22.5 mg/kg i.p. every 12 h for 72 h; and (2) Controls, receiving the same volume of vehicle (phosphate-buffered saline). The rats were kept normothermic during the postoperative course. Neurologic injury was assessed daily using Overall Performance Category (OPC; 1 = normal, 5 = dead) and Neurologic Deficit Score (NDS; 0% = normal, 100% = dead). Rats were sacrificed at 72 h. Neuronal degeneration (Fluoro-Jade C staining) and microglia proliferation (anti-Iba-1 staining) were quantified in four selectively vulnerable brain regions (hippocampus, striatum, cerebellum, cortex) by three independent reviewers masked to the group assignment. RESULTS In the minocycline group, 8 out of 14 rats survived to 72 h compared to 8 out of 19 rats in the control group (P = 0.46). The degree of neurologic deficit at 72 h [median, (interquartile range)] was not different between survivors in minocycline vs controls: OPC 1.5 (1-2.75) vs 2 (1.25-3), P = 0.442; NDS 12 (2-20) vs 17 (7-51), P = 0.328) or between all studied rats. The number of degenerating neurons (minocycline vs controls, mean ± SEM: Hippocampus 58 ± 8 vs 76 ± 8; striatum 121 ± 43 vs 153 ± 32; cerebellum 20 ± 7 vs 22 ± 8; cortex 0 ± 0 vs 0 ± 0) or proliferating microglia (hippocampus 157 ± 15 vs 193 cortex 0 ± 0 vs 0 ± 0; 16; striatum 150 ± 22 vs 161 ± 23; cerebellum 20 ± 7 vs 22 ± 8; cortex 26 ± 6 vs 31 ± 7) was not different between groups in any region (all P > 0.05). Numerically, there were approximately 20% less degenerating neurons and proliferating microglia in the hippocampus and striatum in the minocycline group, with a consistent pattern of histological damage across the individual regions of interest. CONCLUSION Minocycline did not improve survival and failed to confer substantial benefits on neurologic function, neuronal loss or microglial proliferation across multiple brain regions in our model of rat VF CA.
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Affiliation(s)
- Andreas Janata
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
- Emergency Department, KA Rudolfstiftung, Vienna 1030, Austria
| | - Ingrid AM Magnet
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Department of Emergency Medicine, Vienna General Hospital, Medical University of Vienna, Vienna 1090, Austria
| | - Kristin L Schreiber
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, United States
| | - Caleb D Wilson
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Wyoming Otolaryngology, Wyoming Medical Center, Casper, WY 82604, United States
| | - Jason P Stezoski
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
| | - Keri Janesko-Feldman
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
| | - Patrick M Kochanek
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
| | - Tomas Drabek
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, United States
- Department of Anesthesiology and Perioperative Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, United States
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5
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Mihara R, Takasu A, Maemura K, Minami T. Prolonged severe hemorrhagic shock at a mean arterial pressure of 40 mmHg does not lead to brain damage in rats. Acute Med Surg 2018; 5:350-357. [PMID: 30338081 PMCID: PMC6167391 DOI: 10.1002/ams2.361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 06/24/2018] [Indexed: 11/17/2022] Open
Abstract
Aim To examine whether prolonged hemorrhagic shock (HS) at a mean arterial pressure (MAP) of 40 mmHg leads to brain damage. Methods Rats were anesthetized with sevoflurane. The HS model consisted of the following phases: I, pressure‐controlled HS at a MAP of 40 mmHg; II, fluid resuscitation to normalize blood pressure; III, observations with outcome evaluations in terms of survival, overall performance categories, and neurological deficit scores, as well as evaluation of apoptosis in the hippocampus at 96 h. Each group of six rats was randomized into 60 min (group 1) or 75 min (group 2) each of phases I and II. Three sham rats were anesthetized for 150 min, and then awakened during phase III. Results The three sham rats as well as five and two of the six rats in groups 1 and 2 (P < 0.05), respectively, survived for up to 96 h. All survivors were functionally normal with overall performance category = 1 and neurological deficit score = 0 at 96 h. Apoptotic neurons were not found in the hippocampus. Conclusions The higher mortality in group 2 suggested a more profound effect of HS compared with group 1. However, prolonged HS for 60 or 75 min did not cause functional damage or apoptosis in the hippocampus. These findings suggest that prolonged HS at a MAP of 40 mmHg, as a level at which cerebral blood flow seems preserved by autoregulatory mechanisms, does not lead to brain damage.
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Affiliation(s)
- Ryosuke Mihara
- Department of Emergency Medicine Osaka Medical College Osaka Japan.,Department of Anesthesiology Osaka Medical College Osaka Japan
| | - Akira Takasu
- Department of Emergency Medicine Osaka Medical College Osaka Japan
| | | | - Toshiaki Minami
- Department of Anesthesiology Osaka Medical College Osaka Japan
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Treatment of combined traumatic brain injury and hemorrhagic shock with fractionated blood products versus fresh whole blood in a rat model. Eur J Trauma Emerg Surg 2018; 45:263-271. [PMID: 29344708 DOI: 10.1007/s00068-018-0908-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 01/12/2018] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Treatment of combined traumatic brain injury and hemorrhagic shock, poses a particular challenge due to the possible conflicting consequences. While restoring diminished volume is the treatment goal for hypovolemia, maintaining adequate cerebral perfusion pressure and avoidance of secondary damage remains a treatment goal for the injured brain. Various treatment modalities have been proposed, but the optimal resuscitation fluid and goals have not yet been clearly defined. A growing body of evidence suggests that in hypovolemic shock, resuscitation with fresh whole blood (FWB) may be superior to component therapy without platelets (which are likely to be unavailable in the pre-hospital setting). Nevertheless, the effects of this approach have not been studied in the combined injury. Previously, in a rat model of combined injury we have found that mild resuscitation to MABP of 80 mmHg with FWB is superior to fluid resuscitation or aggressive resuscitation with FWB. In this study, we investigate the physiological and neurological outcomes in a rat model of combined traumatic brain injury (TBI) and hypovolemic shock, submitted to treatment with varying amounts of FWB, compared to similar resuscitation goals with fractionated blood products-red blood cells (RBCs) and plasma in a 1:1 ratio regimen. MATERIALS AND METHODS 40 male Lewis rats were divided into control and treatment groups. TBI was inflicted by a free-falling rod on the exposed cranium. Hypovolemia was induced by controlled hemorrhage of 30% blood volume. Treatment groups were treated either with fresh whole blood or with RBC + plasma in a 1:1 ratio, achieving a resuscitation goal of a mean arterial blood pressure (MAP) of 80 mmHg at 15 min. MAP was assessed at 60 min, and neurological outcomes and mortality in the subsequent 24 h. RESULTS At 60 min, hemodynamic parameters were improved compared to controls, but not significantly different between treatment groups. Survival rates at 48 h were 100% for both of the mildly resuscitated groups (MABP 80 mmHg) with FWB and RBC + plasma. The best neurological outcomes were found in the group mildly resuscitated with FWB and were better when compared to resuscitation with RBC + plasma to the same MABP goal (FWB: Neurological Severity Score (NSS) 6 ± 2, RBC + plasma: NSS 10 ± 2, p = 0.02). CONCLUSIONS In this study, we find that mild resuscitation with goals of restoring MAP to 80 mmHg (which is lower than baseline) with FWB, provided better hemodynamic stability and survival. However, the best neurological outcomes were found in the group resuscitated with FWB. Thus, we suggest that resuscitation with FWB is a feasible modality in the combined TBI + hypovolemic shock scenario, and may result in improved outcomes compared to platelet-free component blood products.
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7
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Nora GJ, Harun R, Fine DF, Hutchison D, Grobart AC, Stezoski JP, Munoz MJ, Kochanek PM, Leak RK, Drabek T, Wagner AK. Ventricular fibrillation cardiac arrest produces a chronic striatal hyperdopaminergic state that is worsened by methylphenidate treatment. J Neurochem 2017; 142:305-322. [PMID: 28445595 DOI: 10.1111/jnc.14058] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 04/19/2017] [Accepted: 04/20/2017] [Indexed: 01/21/2023]
Abstract
Cardiac arrest survival rates have improved with modern resuscitation techniques, but many survivors experience impairments associated with hypoxic-ischemic brain injury (HIBI). Currently, little is understood about chronic changes in striatal dopamine (DA) systems after HIBI. Given the common empiric clinical use of DA enhancing agents in neurorehabilitation, investigation evaluating dopaminergic alterations after cardiac arrest (CA) is necessary to optimize rehabilitation approaches. We hypothesized that striatal DA neurotransmission would be altered chronically after ventricular fibrillation cardiac arrest (VF-CA). Fast-scan cyclic voltammetry was used with median forebrain bundle (MFB) maximal electrical stimulations (60Hz, 10s) in rats to characterize presynaptic components of DA neurotransmission in the dorsal striatum (D-Str) and nucleus accumbens 14 days after a 5-min VF-CA when compared to Sham or Naïve. VF-CA increased D-Str-evoked overflow [DA], total [DA] released, and initial DA release rate versus controls, despite also increasing maximal velocity of DA reuptake (Vmax ). Methylphenidate (10 mg/kg), a DA transporter inhibitor, was administered to VF-CA and Shams after establishing a baseline, pre-drug 60 Hz, 5 s stimulation response. Methylphenidate increased initial evoked overflow [DA] more-so in VF-CA versus Sham and reduced D-Str Vmax in VF-CA but not Shams; these findings are consistent with upregulated striatal DA transporter in VF-CA versus Sham. Our work demonstrates that 5-min VF-CA increases electrically stimulated DA release with concomitant upregulation of DA reuptake 2 weeks after brief VF-CA insult. Future work should elucidate how CA insult duration, time after insult, and insult type influence striatal DA neurotransmission and related cognitive and motor functions.
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Affiliation(s)
- Gerald J Nora
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rashed Harun
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - David F Fine
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Daniel Hutchison
- Mylan School of Pharmacy, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Adam C Grobart
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jason P Stezoski
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Miranda J Munoz
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Patrick M Kochanek
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Rehana K Leak
- Mylan School of Pharmacy, Duquesne University, Pittsburgh, Pennsylvania, USA
| | - Tomas Drabek
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Anesthesiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Amy K Wagner
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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8
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Karmacharya MB, Kim KH, Kim SY, Chung J, Min BH, Park SR, Choi BH. Low intensity ultrasound inhibits brain oedema formation in rats: potential action on AQP4 membrane localization. Neuropathol Appl Neurobiol 2016; 41:e80-94. [PMID: 25201550 DOI: 10.1111/nan.12182] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 09/03/2014] [Indexed: 12/23/2022]
Abstract
AIMS Brain oedema is a major contributing factor to the morbidity and mortality of a variety of brain disorders. Although there has been considerable progress in our understanding of pathophysiological and molecular mechanisms associated with brain oedema so far, more effective treatment is required and is still awaited. Here we intended to study the effects of low intensity ultrasound (LIUS) on brain oedema. METHODS We prepared the rat hippocampal slice in vitro and acute water intoxication in vivo models of brain oedema. We applied LIUS stimulation in these models and studied the molecular mechanisms of LIUS action on brain oedema. RESULTS We found that LIUS stimulation markedly inhibited the oedema formation in both of these models. LIUS stimulation significantly reduced brain water content and intracranial pressure resulting in increased survival of the rats. Here, we showed that the AQP4 localization was increased in the astrocytic foot processes in the oedematous hippocampal slices, while it was significantly reduced in the LIUS-stimulated hippocampal slices. In the in vivo model too, AQP4 expression was markedly increased in the microvessels of the cerebral cortex and hippocampus after water intoxication but was reduced in the LIUS-stimulated rats. CONCLUSIONS These data show that LIUS has an inhibitory effect on cytotoxic brain oedema and suggest its therapeutic potential to treat brain oedema. We propose that LIUS reduces the AQP4 localization around the astrocytic foot processes thereby decreasing water permeability into the brain tissue.
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Affiliation(s)
| | - Kil Hwan Kim
- Department of Physiology, Inha University College of Medicine, Incheon, Korea
| | - See Yoon Kim
- Department of Physiology, Inha University College of Medicine, Incheon, Korea
| | - Joonho Chung
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea
| | - Byoung-Hyun Min
- Department of Orthopaedic Surgery, School of Medicine, Ajou University, Suwon, Korea
| | - So Ra Park
- Department of Physiology, Inha University College of Medicine, Incheon, Korea
| | - Byung Hyune Choi
- Department of Biomedical Sciences, Inha University College of Medicine, Incheon, Korea
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9
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Simon DW, Vagni VM, Kochanek PM, Clark RSB. Combined Neurotrauma Models: Experimental Models Combining Traumatic Brain Injury and Secondary Insults. Methods Mol Biol 2016; 1462:393-411. [PMID: 27604730 DOI: 10.1007/978-1-4939-3816-2_22] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Patients with severe traumatic brain injury (TBI) frequently present with concomitant injuries that may cause secondary brain injury and impact outcomes. Animal models have been developed that combine contemporary models of TBI with a secondary neurologic insult such as hypoxia, shock, long bone fracture, and radiation exposure. Combined injury models may be particularly useful when modeling treatment strategies and in efforts to map basic research to a heterogeneous patient population. Here, we review these models and their collective contribution to the literature on TBI. In addition, we provide protocols and notes for two well-characterized models of TBI plus hemorrhagic shock.
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Affiliation(s)
- Dennis W Simon
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA, 15224, USA
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Vincent M Vagni
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Patrick M Kochanek
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA, 15224, USA
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Department of Anesthesiology, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Robert S B Clark
- Department of Critical Care Medicine, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, 4401 Penn Avenue, Pittsburgh, PA, 15224, USA.
- Department of Pediatrics, Children's Hospital of Pittsburgh of UPMC, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- The Clinical and Translational Science Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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10
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Palmer L, Martin L. Traumatic coagulopathy--part 2: Resuscitative strategies. J Vet Emerg Crit Care (San Antonio) 2014; 24:75-92. [PMID: 24393363 DOI: 10.1111/vec.12138] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 11/10/2013] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To discuss the current resuscitative strategies for trauma-induced hemorrhagic shock and acute traumatic coagulopathy (ATC). ETIOLOGY Hemorrhagic shock can be acutely fatal if not immediately and appropriately treated. The primary tenets of hemorrhagic shock resuscitation are to arrest hemorrhage and restore the effective circulating volume. Large volumes of isotonic crystalloids have been the resuscitative strategy of choice; however, data from experimental animal models and retrospective human analyses now recognize that large-volume fluid resuscitation in uncontrolled hemorrhage may be deleterious. The optimal resuscitative strategy has yet to be defined. In human trauma, implementing damage control resuscitation with damage control surgery for controlling ongoing hemorrhage, acidosis, and hypothermia; managing ATC; and restoring effective circulating volume is emerging as a more optimal resuscitative strategy. With hyperfibrinolysis playing an integral role in the manifestation of ATC, the use of antifibrinolytics (eg, tranexamic acid and aminocaproic acid) may also serve a beneficial role in the early posttraumatic period. Considering the sparse information regarding these resuscitative techniques in veterinary medicine, veterinarians are left with extrapolating information from human trials and experimental animal models. DIAGNOSIS Viscoelastic tests integrated with predictive scoring systems may prove to be the most reliable methods for early detection of ATC as well as for guiding transfusion requirements. SUMMARY Hemorrhage accounts for up to 40% of human trauma-related deaths and remains the leading cause of preventable death in human trauma. The exact proportion of trauma-related deaths due to exsanguinations in veterinary patients remains uncertain. Survivability depends upon achieving rapid definitive hemostasis, early attenuation of posttraumatic coagulopathy, and timely restoration of effective circulating volume. Early institution of damage control resuscitation in severely injured patients with uncontrolled hemorrhage has the ability to curtail posttraumatic coagulopathy and the exacerbation of metabolic acidosis and hypothermia and improve survival until definitive hemostasis is achieved.
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Affiliation(s)
- Lee Palmer
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849
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11
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Yeung PKK, Shen J, Chung SSM, Chung SK. Targeted over-expression of endothelin-1 in astrocytes leads to more severe brain damage and vasospasm after subarachnoid hemorrhage. BMC Neurosci 2013; 14:131. [PMID: 24156724 PMCID: PMC3815232 DOI: 10.1186/1471-2202-14-131] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 10/15/2013] [Indexed: 01/15/2023] Open
Abstract
Background Endothelin-1 (ET-1) is a potent vasoconstrictor, and astrocytic ET-1 is reported to play a role in the pathogenesis of cerebral ischemic injury and cytotoxic edema. However, it is still unknown whether astrocytic ET-1 also contributes to vasogenic edema and vasospasm during subarachnoid hemorrhage (SAH). In the present study, transgenic mice with astrocytic endothelin-1 over-expression (GET-1 mice) were used to investigate the pathophysiological role of ET-1 in SAH pathogenesis. Results The GET-1 mice experienced a higher mortality rate and significantly more severe neurological deficits, blood–brain barrier breakdown and vasogenic edema compared to the non-transgenic (Ntg) mice following SAH. Oral administration of vasopressin V1a receptor antagonist, SR 49059, significantly reduced the cerebral water content in the GET-1 mice. Furthermore, the GET-1 mice showed significantly more pronounced middle cerebral arterial (MCA) constriction after SAH. Immunocytochemical analysis showed that the calcium-activated potassium channels and the phospho-eNOS were significantly downregulated, whereas PKC-α expression was significantly upregulated in the MCA of the GET-1 mice when compared to Ntg mice after SAH. Administration of ABT-627 (ETA receptor antagonist) significantly down-regulated PKC-α expression in the MCA of the GET-1 mice following SAH. Conclusions The present study suggests that astrocytic ET-1 involves in SAH-induced cerebral injury, edema and vasospasm, through ETA receptor and PKC-mediated potassium channel dysfunction. Administration of ABT-627 (ETA receptor antagonist) and SR 49059 (vasopressin V1a receptor antagonist) resulted in amelioration of edema and vasospasm in mice following SAH. These data provide a strong rationale to investigate SR 49059 and ABT-627 as therapeutic drugs for the treatment of SAH patients.
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Affiliation(s)
| | | | | | - Sookja K Chung
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
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MRI assessment of cerebral blood flow after experimental traumatic brain injury combined with hemorrhagic shock in mice. J Cereb Blood Flow Metab 2013; 33:129-36. [PMID: 23072750 PMCID: PMC3597358 DOI: 10.1038/jcbfm.2012.145] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Secondary insults such as hypotension or hemorrhagic shock (HS) can greatly worsen outcome after traumatic brain injury (TBI). We recently developed a mouse combined injury model of TBI and HS using a controlled cortical impact (CCI) model and showed that 90 minutes of HS can exacerbate neuronal death in hippocampus beneath the contusion. This combined injury model has three clinically relevant phases, a shock, pre hospital, and definitive care phases. Mice were randomly assigned to four groups, shams as well as a CCI only, an HS only, and a CCI+HS groups. The CCI and HS reduced cerebral blood flow (CBF) in multiple regions of interest (ROIs) in the hemisphere ipsilateral and contralateral to injury. Hemorrhagic shock to a level of ∼30 mm Hg exacerbated the CCI-induced CBF reductions in multiple ROIs ipsilateral to injury (hemisphere and thalamus) and in the hemisphere contralateral to injury (hemisphere, thalamus, hippocampus, and cortex, all P<0.05 versus CCI only, HS only or both). An important effect of HS duration was also seen after CCI with maximal CBF reduction seen at 90 minutes (P<0.0001 group-time effect in ipsilateral hippocampus). Given that neuronal death in hippocampus is exacerbated by 90 minutes of HS in this model, our data suggest an important role for exacerbation of posttraumatic ischemia in mediating the secondary injury in CCI plus HS. In conclusion, the serial, non invasive assessment of CBF using ASL-MRI (magnetic resonance imaging with arterial spin labeling) is feasible in mice even in the complex setting of combined CCI+HS. The impact of resuscitation therapies and various mutant mouse strains on CBF and other outcomes merits investigation in this model.
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Hemerka JN, Wu X, Dixon CE, Garman RH, Exo JL, Shellington DK, Blasiole B, Vagni VA, Janesko-Feldman K, Xu M, Wisniewski SR, Bayır H, Jenkins LW, Clark RSB, Tisherman SA, Kochanek PM. Severe brief pressure-controlled hemorrhagic shock after traumatic brain injury exacerbates functional deficits and long-term neuropathological damage in mice. J Neurotrauma 2012; 29:2192-208. [PMID: 22738159 DOI: 10.1089/neu.2011.2303] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hypotension after traumatic brain injury (TBI) worsens outcome. We published the first report of TBI plus hemorrhagic shock (HS) in mice using a volume-controlled approach and noted increased neuronal death. To rigorously control blood pressure during HS, a pressure-controlled HS model is required. Our hypothesis was that a brief, severe period of pressure-controlled HS after TBI in mice will exacerbate functional deficits and neuropathology versus TBI or HS alone. C57BL6 male mice were randomized into four groups (n=10/group): sham, HS, controlled cortical impact (CCI), and CCI+HS. We used a pressure-controlled shock phase (mean arterial pressure [MAP]=25-27 mm Hg for 35 min) and its treatment after mild to moderate CCI including, a 90 min pre-hospital phase, during which lactated Ringer's solution was given to maintain MAP >70 mm Hg, and a hospital phase, when the shed blood was re-infused. On days 14-20, the mice were evaluated in the Morris water maze (MWM, hidden platform paradigm). On day 21, the lesion and hemispheric volumes were quantified. Neuropathology and hippocampal neuron counts (hematoxylin and eosin [H&E], Fluoro-Jade B, and NeuN) were evaluated in the mice (n=60) at 24 h, 7 days, or 21 days (n=5/group/time point). HS reduced MAP during the shock phase in the HS and CCI+HS groups (p<0.05). Fluid requirements during the pre-hospital phase were greatest in the CCI+HS group (p<0.05), and were increased in HS versus sham and CCI animals (p<0.05). MWM latency was increased on days 14 and 15 after CCI+HS (p<0.05). Swim speed and visible platform latency were impaired in the CCI+HS group (p<0.05). CCI+HS animals had increased contusion volume versus the CCI group (p<0.05). Hemispheric volume loss was increased 33.3% in the CCI+HS versus CCI group (p<0.05). CA1 cell loss was seen in CCI+HS and CCI animals at 24 h and 7 days (p<0.05). CA3 cell loss was seen after CCI+HS (p<0.05 at 24 h and 7 days). CA1 cell loss at 21 days was seen only in CCI+HS animals (p<0.05). Brief, severe, pressure-controlled HS after CCI produces robust functional deficits and exacerbates neuropathology versus CCI or HS alone.
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Affiliation(s)
- Joseph N Hemerka
- Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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14
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Navarro JC, Pillai S, Cherian L, Garcia R, Grill RJ, Robertson CS. Histopathological and behavioral effects of immediate and delayed hemorrhagic shock after mild traumatic brain injury in rats. J Neurotrauma 2012; 29:322-34. [PMID: 22077317 DOI: 10.1089/neu.2011.1979] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to investigate the increased susceptibility of the brain, after a controlled mild cortical impact injury, to a secondary ischemic insult. The effects of the duration and the timing of the secondary insult after the initial cortical injury were studied. Rats anesthetized with isoflurane underwent a 3 m/sec, 2.5-mm deformation cortical impact injury followed by hypotension to 40 mm Hg induced by withdrawing blood from a femoral vein. The duration of hypotension was varied from 40 to 60 min. The timing of 60 min of hypotension was varied from immediately post-injury to 7 days after the injury. Outcome was assessed by behavioral tasks and histological examination at 2 weeks post-injury. A separate group of animals underwent measurement of the acute physiology including mean blood pressure (MAP), intracranial pressure (ICP), and cerebral blood flow (CBF) using a laser Doppler technique. Increasing durations of hypotension resulted in marked expansion of the contusion, from 6.5±1.8 mm³ with sham hypotension to 27.1±3.9 mm³ with 60 min of hypotension. This worsening of the contusion was found only when then hypotension occurred immediately after injury or at 1 h after injury. CA3 neuron loss followed a similar pattern, but the injury group differences were not significant. Motor tasks, including beam balance and beam walking, were significantly worse following 50 and 60 min of hypotension. Performance on the Morris water maze task was also significantly related to the injury group. Studies of the acute cerebral hemodynamics demonstrated that CBF was significantly more impaired during hypotension in the animals that underwent the mild TBI compared to those that underwent sham TBI. The perfusion deficit was worst at the impact site, but also significant in the pericontusional brain. With 50 and 60 min of hypotension, CBF did not recover following resuscitation at the impact site, and recovered only transiently in the pericontusional brain. These results demonstrate that mild TBI, like more severe levels of TBI, can impair the brain's ability to maintain CBF during a period of hypotension, and result in a worse outcome.
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Abstract
PURPOSE OF REVIEW Although longstanding practice in trauma care has been to provide immediate, aggressive intravenous fluid resuscitation to injured patients with presumed internal hemorrhage, recent experimental and clinical data suggest a more discriminating approach that first considers concurrent head injury, hemodynamic stability, and the presence of potentially uncontrollable hemorrhage (e.g., deep truncal injury) versus a controllable source (e.g., distal extremity wound). RECENT FINDINGS The data suggest that rapid intravenous fluid infusions could be used for patients with isolated extremity, thermal or head injury. However, intravenous fluids should be limited in conditions with potentially uncontrollable internal hemorrhage, and particularly in patients with penetrating truncal injury being transported immediately to a trauma center. Likewise, positive pressure ventilatory support should be limited with severe hemorrhage due to the secondary reductions in venous return off-setting the effects of the fluids. For trauma patients with severe bleeding, there is growing evidence for the increased use of plasma and factor VIIa, as well as tourniquets, intra-osseus devices, and evolving monitoring techniques. SUMMARY Future research efforts in trauma should focus on the timing and rate of infusions as well as the concept of infusing alternative intravenous resuscitative fluids such as hemoglobin-based oxygen carriers (HBOCs) and the use of hemostatic agents and special blood products.
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Abstract
Hypotensive resuscitation in the trauma setting can be defined as deliberately allowing blood pressure to remain below normal until any active bleeding has been controlled. The dangers of aggressive fluid resuscitation in trauma were recognised as long ago as the First World War, in the intervening time, aggressive fluid resuscitation has become a mainstay of trauma management. More recently this trend of aggressive fluid resuscitation for trauma management seems to be reversing. Aggressive fluid resuscitation in trauma is based on animal studies from the 1950s and 1960s. These studies used models of controlled haemorrhage rather than uncontrolled haemorrhage. More recent studies using models of uncontrolled haemorrhage suggest an improved outcome with hypotensive resuscitation. Should there be a potential for uncontrolled haemorrhage a permissive hypotensive resuscitation strategy should be pursued until the haemorrhage has been controlled, but in certain types of trauma including blunt trauma and brain trauma the data is unclear as to the best fluid resuscitation strategy.
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Affiliation(s)
- J. Geoghegan
- Anaesthetics, University Hospital Birmingham, NHS Foundation Trust, Edgbaston, Birmingham, UK
| | - A. Dennis
- Anaesthetics, University Hospital Birmingham, NHS Foundation Trust, Edgbaston, Birmingham, UK
| | - M. Manji
- University Hospital Birmingham, NHS Foundation Trust, Edgbaston, Birmingham, UK,
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18
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Targeted overexpression of endothelin-1 in astrocytes leads to more severe cytotoxic brain edema and higher mortality. J Cereb Blood Flow Metab 2009; 29:1891-902. [PMID: 19707218 DOI: 10.1038/jcbfm.2009.175] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transgenic mice overexpressing endothelin-1 (ET-1) in astrocytes (GET-1) displayed more severe brain edema and neurologic dysfunction after experimental ischemic stroke. However, it was not clear whether astrocytic ET-1 contributed to cytotoxic or vasogenic edema associated with stroke. In this study, the role of astrocytic ET-1 in cytotoxic edema and brain injury was investigated. Upon acute water intoxication, the GET-1 mice had a lower survival rate and more severe neurologic deficits. Such an exacerbated condition in the GET-1 mice may be a result of a significant increase in cerebral water content and increased expression of the water channel protein, aquaporin 4 (AQP-4). The GET-1 mice treated with OPC-31260, a nonpeptide arginine vasopressin V(2) receptor antagonist, were alleviated from the cerebral water accumulation and neurologic deficit during the early time period after water intoxication. In addition, a significant reduction of AQP-4 expression was observed in astrocytic end-feet AQP-4 in the hippocampus of the GET-1 mice treated with OPC-31260. Therefore, ET-1-induced AQP-4 expression and cerebral water accumulation are the key factors in brain edema associated with acute water intoxication. The V(2) receptor antagonist, OPC-31260, may be one of the effective drugs for the early treatment of ET-1-induced cytotoxic edema and brain injury.
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Han F, Boller M, Guo W, Merchant RM, Lampe JW, Smith TM, Becker LB. A rodent model of emergency cardiopulmonary bypass resuscitation with different temperatures after asphyxial cardiac arrest. Resuscitation 2009; 81:93-9. [PMID: 19926192 DOI: 10.1016/j.resuscitation.2009.09.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 08/24/2009] [Accepted: 09/18/2009] [Indexed: 01/09/2023]
Abstract
BACKGROUND The use of emergency cardiopulmonary bypass (ECPB) resuscitation after cardiac arrest may offer hope for survival when standard ACLS therapies fail. However, whether cooling adds benefit to ECPB is unknown and we lack an ECPB rodent model for experimental studies. We sought to (a) develop a 72 h survival rodent model using ECPB to treat asphyxial cardiac arrest and (b) use this new model to evaluate early mild and moderate hypothermia versus normothermia during ECPB resuscitation. METHODS After 8 min of normothermic asphyxia, three groups of rats were resuscitated with ECPB at 37 degrees C (NORM), 34 degrees C (MILD) and 30 degrees C (MOD) for 1h (n=10 each). During the second resuscitation hour, ECPB was discontinued, ventilatory support was provided and body temperatures were maintained at 37 degrees C for NORM, 34 degrees C for MILD, and from 30 degrees C gradually up to 34 degrees C in 1h for MOD animals. From hours 3 to 8, body temperature was maintained at 37 degrees C for NORM and 34 degrees C for MILD and MOD animals. RESULTS All rats were initially resuscitated by ECPB. After 72 h, neurological outcome and survival in the MILD (60% survival) and MOD (80%) groups were significantly better than in the NORM (0%) group (p<0.05). Overall performance recovery in the MOD group was best (vs. the NORM group), while the MILD group had an intermediate outcome. CONCLUSIONS A rodent model of ECPB is feasible and useful for resuscitation studies. The addition of early mild and moderate hypothermia to ECPB resuscitation significantly improves survival compared with normothermic ECPB in rats.
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Affiliation(s)
- Fei Han
- Center for Resuscitation Science, Department of Emergency Medicine, University of Pennsylvania, Philadelphia, PA, United States
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20
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Dennis AM, Haselkorn ML, Vagni VA, Garman RH, Janesko-Feldman K, Bayir H, Clark RSB, Jenkins LW, Dixon CE, Kochanek PM. Hemorrhagic shock after experimental traumatic brain injury in mice: effect on neuronal death. J Neurotrauma 2009; 26:889-99. [PMID: 18781889 DOI: 10.1089/neu.2008.0512] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) from blast injury is often complicated by hemorrhagic shock (HS) in victims of terrorist attacks. Most studies of HS after experimental TBI have focused on intracranial pressure; few have explored the effect of HS on neuronal death after TBI, and none have been done in mice. We hypothesized that neuronal death in CA1 hippocampus would be exacerbated by HS after experimental TBI. C57BL6J male mice were anesthetized with isoflurane, mean arterial blood pressure (MAP) was monitored, and controlled cortical impact (CCI) delivered to the left parietal cortex followed by continued anesthesia (CCI-only), or either 60 or 90 min of volume-controlled HS. Parallel 60- or 90-min HS-only groups were also studied. After HS (+/-CCI), 6% hetastarch was used targeting MAP of > or =50 mm Hg during a 30-min Pre-Hospital resuscitation phase. Then, shed blood was re-infused, and hetastarch was given targeting MAP of > or =60 mm Hg during a 30-min Definitive Care phase. Neurological injury was evaluated at 24 h (fluorojade C) or 7 days (CA1 and CA3 hippocampal neuron counts). HS reduced MAP to 30-40 mm Hg in all groups, p < 0.05 versus CCI-only. Ipsilateral CA1 neuron counts in the 90-min CCI+HS group were reduced at 16.5 +/- 14.1 versus 30.8 +/- 6.8, 32.3 +/- 7.6, 30.6 +/- 2.2, 28.1 +/- 2.2 neurons/100 mum in CCI-only, 60-min HS-only, 90-min HS-only, and 60-min CCI+HS, respectively, all p < 0.05. CA3 neuron counts did not differ between groups. Fluorojade C staining confirmed neurodegeneration in CA1 in the 90-min CCI+HS group. Our data suggest a critical time window for exacerbation of neuronal death by HS after CCI and may have implications for blast injury victims in austere environments where definitive management is delayed.
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Affiliation(s)
- Alia Marie Dennis
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA
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Abstract
OBJECTIVE To hypothesize that in severe states of cardiogenic shock with profound decreases in buccal microcirculation, the cerebral microcirculation may be selectively protected. Decreases in buccal microcirculatory flow are closely associated with the severity and outcomes of circulatory shock. DESIGN We investigated the concurrent changes in cerebral and buccal microcirculation, in a rat model of cardiogenic shock caused by left ventricular failure. DESIGN Randomized prospective animal study. SETTING University-affiliated animal research laboratory. SUBJECTS Sprague-Dawley rats. INTERVENTIONS Studies were performed in ten male Sprague-Dawley rats, weighing between 450 and 550 g. After intraperitonial pentobarbital anesthesia and tracheostomy, a craniotomy exposed the parietal cortex for visualization of microcirculation. Animals then underwent thoracotomy and banding of ascending aorta producing left ventricular failure and cardiogenic shock. MEASUREMENTS AND MAIN RESULTS Over a 4-hr interval, effects on arterial pressure, cardiac output, left ventricular end-diastolic volume, and ejection fractions were measured. The cerebral and buccal microcirculations were visualized concurrently with the aid of orthogonal polarization spectral imaging. Animals were randomized to identically treated controls in which the aorta was not ligated. Mean arterial pressure, cardiac output, and ejection fraction decreased strikingly and end-diastolic left ventricular volume more than doubled within 30 mins after aortic banding. The buccal microcirculation was concurrently reduced. However, cerebral microcirculatory flow was fully preserved. CONCLUSIONS In contrast to striking reduction in cardiac output and arterial pressures together with buccal microcirculatory flow, cerebral cortical microcirculatory flow was fully preserved during cardiogenic shock. These findings further document a dissociation between the systemic and cerebral circulations and potentially explain earlier clinical and experimental observations that the brain is selectively protected during severe states of cardiogenic shock in the absence of cardiac arrest.
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Deniz T, Agalar C, Ozdogan M, Edremitlioglu M, Eryilmaz M, Devay SD, Deveci O, Agalar F. Mild Hypothermia Improves Survival During Hemorrhagic Shock Without Affecting Bacterial Translocation. J INVEST SURG 2009; 22:22-8. [DOI: 10.1080/08941930802566706] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
PURPOSE OF REVIEW The traditional approach to trauma patients with presumed internal hemorrhage has been immediate, aggressive intravenous fluid resuscitation. Recent experimental and clinical data, however, suggest a more discriminating approach that first considers concurrent head injury, hemodynamic stability and the presence of potentially uncontrollable hemorrhage (e.g. deep truncal injury) versus a controllable source (e.g. distal extremity wound) as well as the use of new techniques to inhibit bleeding and better ways to monitor the patient's condition. RECENT FINDINGS Evolving data suggest that while aggressive fluid infusions could be used for patients with isolated extremity, thermal or head injury, they should be limited in conditions with potentially uncontrollable internal hemorrhage, and particularly in patients with penetrating truncal injury being transported immediately to a trauma center. Likewise, the minute volume of positive pressure ventilatory support should be limited with potential severe hemorrhage due to the secondary reductions in venous return. For trauma patients with severe bleeding there is growing evidence for the increased use of plasma and factor VIIa, as well as tourniquets, intraosseus devices and evolving monitoring techniques. SUMMARY Owing to the growing societal threat of trauma, further research, including studies already under way, will be critical to delineate the timing and technique of infusing advantageous resuscitative fluids such as hypertonic saline and hemoglobin-based oxygen carriers as well as the use of hemostatic agents and special blood products.
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Yang R, Tan X, Kenney RJ, Thomas A, Landis M, Qureshi N, Morrison DC, Van Way CW. Hemorrhagic Shock in the Rat: Comparison of Carotid and Femoral Cannulation. J Surg Res 2008; 144:124-6. [PMID: 17560609 DOI: 10.1016/j.jss.2007.04.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 03/28/2007] [Accepted: 04/05/2007] [Indexed: 11/20/2022]
Abstract
BACKGROUND The reservoir model of rat hemorrhagic shock is widely used. In this model, either the carotid or femoral artery can be cannulated to withdraw blood and measure pressure. In animals undergoing hemorrhage using the carotid approach, we observed seizure activity during the post-shock period, suggesting some degree of brain damage. The hypothesis of the present study is that survival in a model of severe hemorrhagic shock would be higher with femoral cannulation than with carotid cannulation. MATERIALS AND METHODS All animals (n = 90) were anesthetized with isoflurane using an anesthesia vaporizer while breathing spontaneously. In group 1, the left carotid artery and jugular vein were cannulated; in group 2, the left femoral artery and vein were cannulated. Following a period of hemorrhagic shock (20 to 30 mmHg for 30, 60, or 50-90 min), resuscitation was performed through the venous cannula by giving L-lactated Ringer's (21 mL/kg) and returning the shed blood. RESULTS In the carotid cannulation group, nearly 50% of the animals had seizures after resuscitation, and most of those animals died following the seizures. The 24-h survival rate in the femoral artery cannulation group was significantly higher than in the carotid artery cannulation group. Femoral cannulated animals had no seizures following reperfusion. CONCLUSIONS Femoral artery cannulation was associated with considerably better survival than carotid artery cannulation in this rodent model of hemorrhagic shock. The occurrence of seizures in animals undergoing carotid cannulation suggests brain damage from inadequate cerebral perfusion or subsequent reperfusion damage.
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Affiliation(s)
- Rongjie Yang
- Department of Surgery, School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri 64108, USA
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Drabek T, Fisk JA, Dixon CE, Garman RH, Stezoski J, Wisnewski SR, Wu X, Tisherman SA, Kochanek PM. Prolonged deep hypothermic circulatory arrest in rats can be achieved without cognitive deficits. Life Sci 2007; 81:543-552. [PMID: 17658556 DOI: 10.1016/j.lfs.2007.06.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 06/11/2007] [Accepted: 06/16/2007] [Indexed: 02/07/2023]
Abstract
Cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) enable surgical repair of cardiovascular defects. However, neurological complications can result after both CPB and DHCA. We sought to investigate if 75 min of CPB or DHCA caused motor, cognitive or histological deficits in rats. Three groups were studied: DHCA, CPB, and sham. Rats in the DHCA group were subjected to 75 min DHCA at 15 degrees C, with a total CPB duration of 75 min. Rats in the CPB group were subjected to 75 min of normothermic CPB. Shams received the same anesthesia, cannulations and infusions. Motor function was assessed using beam testing on days 3-13. Cognitive performance was evaluated using Morris water maze tasks on days 7-13. Overall Performance Category (OPC) and Neurologic Deficit Score (NDS) were assessed daily. Histological Damage Score (HDS) was assessed in survivors on day 14. Sustained deficits on beam testing were seen only in the CPB group. Rats in the CPB and DHCA groups exhibited similar cognitive performance vs. sham. There were no differences in OPC or NDS between groups. Neuronal degeneration was present only in small foci in rats after DHCA (n=4/7). However, HDS was not different in individual brain regions or viscera between DHCA or CPB vs. sham. Surprisingly, CPB, but not DHCA was associated with motor deficits vs. sham, and no cognitive deficits were seen in either group vs. sham. Future studies with longer DHCA duration will be necessary to provide targets to assess novel preservation strategies.
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Affiliation(s)
- Tomas Drabek
- Safar Center for Resuscitation Research, University of Pittsburgh, School of Medicine, Pittsburgh PA 15260, USA.
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Kentner R, Safar P, Behringer W, Wu X, Henchir J, Ma L, Hsia CJC, Tisherman SA. Small volume resuscitation with tempol is detrimental during uncontrolled hemorrhagic shock in rats. Resuscitation 2007; 72:295-305. [PMID: 17112648 DOI: 10.1016/j.resuscitation.2006.05.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Revised: 05/26/2006] [Accepted: 05/26/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND In a previous study, titration of a hypertonic saline (HTS) solution during severe uncontrolled hemorrhagic shock (UHS) failed to reduce mortality. In a separate study, a novel antioxidant, polynitroxylated albumin (PNA) plus tempol (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl), infused during shock increased long-term survival. We hypothesized that combining potent antioxidants with a hypertonic solution during UHS would preserve the logistical advantage of small volume resuscitation and improve survival. METHODS An UHS outcome model in rats was used. UHS phase I (90 min) included blood withdrawal of 30 ml/kg over 15 min, followed by tail amputation for uncontrolled bleeding. At 20 min, rats were randomized to four groups (n=10 each) for hypotensive resuscitation from 20 to 90 min (mean arterial pressure [MAP] > or = 40 mmHg): HTS/starch group received 7.2% NaCl/10% hydroxyethyl starch; HTS/albumin group received 7.5% NaCl/20% albumin; HTS/PNA group received 7.5% NaCl/20% PNA; HTS/albumin+tempol group received 7.5% NaCl/20% albumin plus tempol. Resuscitation phase II (180 min) included hemostasis, return of shed blood and administration of fluids to restore MAP > or = 80 mmHg. Observation phase III was to 72 h. RESULTS The total amount of fluid required to maintain hypotensive MAP during HS was low and did not differ between groups (range: 3.4+/-1.9 to 5.3+/-2.5 ml/kg). The rate of fluid administration required was higher in the HTS/albumin+tempol group compared to all other groups (p=0.006). Additional uncontrolled blood loss was highest in the HTS/PNA group (16.2+/-5.7 ml/kg [p=0.01] versus 10.4+/-7.9 ml/kg in the HTS/starch group, 7.7+/-5.2 ml/kg in the HTS/albumin group and 8.2+/-7.1 ml/kg in the HTS/albumin+tempol group). MAP after start of resuscitation in phase I was lower in the HTS/albumin+tempol group than the HTS/albumin or HTS/PNA groups (p<0.01). This group was also less tachycardic. Long-term survival was low in all groups (2 of 10 after HTS/starch and 1 of 10 after HTS/albumin, 3 of 10 after HTS/PNA, 1 of 10 after HTS/albumin+tempol). Median survival time was shortest in the HTS/albumin+tempol group (72 min [CI 34-190]) compared to all other groups (p=0.01). CONCLUSIONS Despite its benefits in other model systems, free tempol is potentially hazardous when combined with hypertonic fluids. PNA abrogates these deleterious effects on acute mortality but may lead to increased blood loss in the setting of UHS.
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Affiliation(s)
- Rainer Kentner
- Safar Center for Resuscitation Research, University of Pittsburgh, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA
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Wu X, Drabek T, Kochanek PM, Henchir J, Stezoski SW, Stezoski J, Cochran K, Garman R, Tisherman SA. Induction of profound hypothermia for emergency preservation and resuscitation allows intact survival after cardiac arrest resulting from prolonged lethal hemorrhage and trauma in dogs. Circulation 2006; 113:1974-1982. [PMID: 16618818 DOI: 10.1161/circulationaha.105.587204] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Induction of profound hypothermia for emergency preservation and resuscitation (EPR) of trauma victims who experience exsanguination cardiac arrest may allow survival from otherwise-lethal injuries. Previously, we achieved intact survival of dogs from 2 hours of EPR after rapid hemorrhage. We tested the hypothesis that EPR would achieve good outcome if prolonged hemorrhage preceded cardiac arrest. METHODS AND RESULTS Two minutes after cardiac arrest from prolonged hemorrhage and splenic transection, dogs were randomized into 3 groups (n=7 each): (1) the cardiopulmonary resuscitation (CPR) group, resuscitated with conventional CPR, and the (2) EPR-I and (3) EPR-II groups, both of which received 20 L of a 2 degrees C saline aortic flush to achieve a brain temperature of 10 degrees C to 15 degrees C. CPR or EPR lasted 60 minutes and was followed in all groups by a 2-hour resuscitation by cardiopulmonary bypass. Splenectomy was then performed. The CPR dogs were maintained at 38.0 degrees C. In the EPR groups, mild hypothermia (34 degrees C) was maintained for either 12 (EPR-I) or 36 (EPR-II) hours. Function and brain histology were evaluated 60 hours after rewarming in all dogs. Cardiac arrest occurred after 124+/-16 minutes of hemorrhage. In the CPR group, spontaneous circulation could not be restored without cardiopulmonary bypass; none survived. Twelve of 14 EPR dogs survived. Compared with the EPR-I group, the EPR-II group had better overall performance, final neurological deficit scores, and histological damage scores. CONCLUSIONS EPR is superior to conventional CPR in facilitating normal recovery after cardiac arrest from trauma and prolonged hemorrhage. Prolonged mild hypothermia after EPR was critical for achieving intact neurological outcomes.
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Affiliation(s)
- Xianren Wu
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, USA
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Lin T, Koustova E, Chen H, Rhee PM, Kirkpatrick J, Alam HB. Energy Substrate-Supplemented Resuscitation Affects Brain Monocarboxylate Transporter Levels and Gliosis in a Rat Model of Hemorrhagic Shock. ACTA ACUST UNITED AC 2005; 59:1191-202; discussion 1202. [PMID: 16385299 DOI: 10.1097/01.ta.0000188646.86995.9d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Monocarboxylate (MC)-supplemented resuscitation has been shown to attenuate cellular injury after hemorrhagic shock. However, little is known about its effect on the central nervous system. The brain can use MCs such as lactate, pyruvate, and beta-hydroxybutyrate as energy substrates. The transit of MCs into the central nervous system is facilitated by the monocarboxylate transporters (MCTs), and their blockage can exacerbate neuronal damage. We examined the expression of MCT1 and markers specific for activation of astroglia and microglia in the brains of rats subjected to hemorrhagic shock and resuscitation. The hypothesis was that resuscitation with MC-based fluids would be accompanied by MCT1 up-regulation and glial response. METHODS Rats (n = 30) were subjected to volume-controlled hemorrhage. Test groups included: sham, no resuscitation, resuscitation with normal saline, resuscitation with racemic lactated Ringer's solution, resuscitation with pyruvate Ringer's solution, and resuscitation with beta-hydroxybutyrate-containing ketone Ringer's solution. Plasma levels of MC were measured serially. The brains were investigated using GFAP, CD11b, CD43, MCT1, and GLUT1 immunohistochemistry. RESULTS Rats resuscitated with MC-containing fluids had increased levels of MCT1 in brain endothelial cells and neuropil compared with sham rats. Enhanced staining was localized to the choroid plexus, astrocytic end feet, and white matter structures. None of the resuscitation treatment induced astrocytic hyperplasia, and pyruvate Ringer's solution and ketone Ringer's solution resuscitation led to hypertrophy of astrocytes. CONCLUSION In hemorrhagic shock, resuscitation with MC-based fluids increased brain MCT1 level and led to activation of astrocytes. Enhanced MC trafficking could be an essential route for energy supply to neurons under adverse circulatory conditions.
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Affiliation(s)
- Tom Lin
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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Daull P, Blouin A, Cayer J, Beaudoin M, Belleville K, Sirois P, Nantel F, Chang TMS, Battistini B. Profiling biochemical and hemodynamic markers using chronically instrumented, conscious and unrestrained rats undergoing severe, acute controlled hemorrhagic hypovolemic shock as an integrated in-vivo model system to assess new blood substitutes. Vascul Pharmacol 2005; 43:289-301. [PMID: 16253569 DOI: 10.1016/j.vph.2005.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Accepted: 09/05/2005] [Indexed: 10/25/2022]
Abstract
The aim of the present study was to assess several biochemical and physiological endpoint parameters alongside controlled hemorrhagic and recovery phases of chronically instrumented, conscious and unrestrained healthy rats. Male Sprague-Dawley rats (12-14 weeks; 430+/-20 g; n=22-18) were instrumented with a saline-perfused femoral arterial catheter and placed individually in a metabolic cage for up to 20 days, allowing instant assessments of the hemodynamic profile and blood and urine sampling for hematological profile and biochemical measurements to assess hepatic, renal and metabolic functions. In addition, body weight, food and water intake, and diuresis were monitored daily. After a 7-day stabilization period, the rats underwent severe and acute hemorrhagic shock (HS) (removal of 50% of total circulating blood volume), kept in hypovolemic shock for an ischemic period of 50 min and then resuscitated over 10 min. Gr. 1 was re-infused with autologous shed blood (AB; n=10) whereas Gr. 2 was infused 1:1 with a solution of sterile saline-albumin (SA; 7% w/v) (n=8-12). Ischemic rats recovered much more rapidly following AB re-infusion than those receiving SA. Normal hemodynamic and biochemical profiles were re-established after 24 h. Depressed blood pressure lasted 4-5 days in SA rats. The hematological profile in the SA resuscitated rats was even more drastically affected. Circulating plasma concentrations of hemoglobin (-40%), hematocrit (-50%), RBC (-40%) and platelets (-41%) counts were still severely decreased 24 h after the acute ischemic event whereas WBC counts increased 2.2-fold by day 4. It took 5-9 days for these profiles to normalize after ischemia-reperfusion with SA. Diuresis increased in both groups (by 45+/-7% on day 1) but presented distinct electrolytic profiles. Hepatic and renal functions were normal in AB rats whereas altered in SA rats. The present set of experiments enabled us to validate a model of HS in conscious rats and the use of an integrated in vivo platform as a valuable tool to characterize HS-induced stress and to test new classes of blood substitutes in real time, post-event, over days.
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Affiliation(s)
- P Daull
- Laval Hospital Research Center, Quebec Heart and Lung Institute, Department of Medicine, Faculty of Medicine, Laval University, Québec, QC, Canada
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Kentner R, Safar P, Prueckner S, Behringer W, Wu X, Henchir J, Ruemelin A, Tisherman SA. Titrated hypertonic/hyperoncotic solution for hypotensive fluid resuscitation during uncontrolled hemorrhagic shock in rats. Resuscitation 2005; 65:87-95. [PMID: 15797280 DOI: 10.1016/j.resuscitation.2004.10.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2002] [Revised: 10/19/2004] [Accepted: 10/19/2004] [Indexed: 11/23/2022]
Abstract
BACKGROUND In volume- or pressure-controlled hemorrhagic shock (HS) a bolus intravenous infusion of hypertonic/hyperoncotic solution (HHS) proved beneficial compared to isotonic crystalloid solutions. During uncontrolled HS in animals, however, HHS by bolus increased blood pressure unpredictably, and increased blood loss and mortality. We hypothesized that a titrated i.v. infusion of HHS, compared to titrated lactated Ringer's solution (LR), for hypotensive fluid resuscitation during uncontrolled HS reduces fluid requirement, does not increase blood loss, and improves survival. METHODS We used our three-phased uncontrolled HS outcome model in rats. HS phase I began with blood withdrawal of 3 ml/100g over 15 min, followed by tail amputation. Then, hydroxyethyl starch 10% in NaCl 7.2% was given i.v. to the HHS group (n=10) and LR to the control group (n=10), both titrated to prevent mean arterial pressure (MAP) from falling below 40 mmHg during HS time 20-90 min. At HS 90 min, resuscitation phase II of 180 min began with hemostasis, return of all the blood initially shed, plus fluids i.v. as needed to maintain normotension (MAP>or=70 mmHg). Liver dysoxia was monitored as increase in liver surface pCO2 during phases I and II. Observation phase III was to 72 h. RESULTS During HS, preventing a decrease in MAP below 40 mmHg required HHS 4.9+/-0.6 ml/kg (all data mean+/-S.E.M.), compared to LR 62.2+/-16.6 ml/kg (P<0.001), with no group difference in MAP. Uncontrolled blood loss during HS from the tail stump was 13.3+/-1.9 ml/kg with HHS infusion, versus 12.6+/-2.5 ml/kg with LR infusion (P=0.73). Serum sodium concentrations were moderately elevated at the end of HS in the HHS group (149+/-3 mmol/l) versus the LR group (139+/-1 mmol/l) (P=0.001), and remained elevated throughout. Liver pCO2 increased during HS in both groups equally (P<0.001 versus baseline), and tended to return to baseline levels at the end of HS. Blood gas and lactate values throughout did not differ between groups. During HS, 2 of 10 rats in the HHS group versus 0 of 10 in the LR group died (P=0.47). There was no difference between HHS and LR groups in survival rates to 72 h (3 of 10 in the HHS group versus 2 of 10 in the LR group) (P=1.0). Survival times, by life table analysis, were not different (P=0.75). CONCLUSION In prolonged uncontrolled HS, a titrated i.v. infusion of HHS can maintain controlled hypotension with only one-tenth of the volume of LR required, without increasing blood loss. This titrated HHS strategy may not increase the chance of long-term survival.
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Affiliation(s)
- Rainer Kentner
- Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA
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Abstract
This article reviews the mechanisms of brain injury associated with cardiopulmonary bypass. These include embolic injury of both a gaseous and particulate nature as well as global hypoxic ischemic injury. Ischemic injury can result from problems associated with venous drainage or with arterial inflow including a steal secondary to systemic to pulmonary collateral vessels. Modifications in the technique of cardiopulmonary bypass have reduced the risk of global hypoxic/ischemic injury. Laboratory and clinical studies have demonstrated that perfusion hematocrit should be maintained above 25% and preferably above 30%. Perfusion pH is also critically important, particularly when hypothermia is employed. An alkaline pH can limit cerebral oxygen delivery by inducing cerebral vasoconstriction as well as shifting oxyhemoglobin dissociation leftwards. If deep hypothermia is employed, it is critically important to add carbon dioxide using the so-called "pH stat" strategy. Oxygen management during cardiopulmonary bypass is also important. Although there is currently enthusiasm for using air rather than pure oxygen, ie, adding nitrogen, this does introduce a greater risk of gaseous nitrogen emboli since nitrogen is much less soluble than oxygen. The use of pure oxygen in conjunction with CO2 to apply the pH stat strategy is recommended. Many of the lessons learned from studies focusing on brain protection during cardiopulmonary bypass can be applied to the patient being supported with extracorporeal membrane oxygenation.
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Affiliation(s)
- Richard A Jonas
- Department of Cardiovascular Surgery, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
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Hachimi-Idrissi S, Yang X, Nguyen DN, Huyghens L. Combination of therapeutic mild hypothermia and delayed fluid resuscitation improved survival after uncontrolled haemorrhagic shock in mechanically ventilated rats. Resuscitation 2004; 62:303-10. [PMID: 15325450 DOI: 10.1016/j.resuscitation.2004.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2004] [Revised: 03/22/2004] [Accepted: 04/04/2004] [Indexed: 10/26/2022]
Abstract
We challenged the current management of uncontrolled haemorrhagic shock (UHS) and put forward a hypothesis that therapeutic mild hypothermia combined with delayed fluid resuscitation will improve the survival rate. After an initial blood withdrawal of 3 ml/100g for 15 min, the rat's tail was amputated up to 75% to induce UHS phase I. The mean arterial blood pressure (MAP) was maintained at 40 mmHg or 80 mmHg, according to the assigned study group. This was followed by homeostasis of the tail wound and increase of the MAP up to 100 mmHg during resuscitation phase II. Finally, phase III was an observation of phase up to 72 h. Rats were anaesthetised and randomised into four groups. Group 1 received immediate fluid resuscitation and normothermia. Group 2 received immediate fluid resuscitation and therapeutic mild hypothermia. Group 3 received limited fluid solutions to maintain MAP at 40 mmHg and normothermia. Group 4 also received limited fluid solution, but the rats were subjected to therapeutic mild hypothermia. In groups 2 and 4, the body temperature was kept at 34 degrees C throughout the UHS phase I and resuscitation phase II. At the end of the observation phase III, the brains of the animals were fixed and analysed histologically. The blood loss from the tail during the UHS phase I was significantly higher in groups 1 and 2. The survival rate was 33.3, 83.3, 58.3 and 91.7%, respectively in groups 1-4. In all surviving rats, no histological brain damage was observed. These results indicate that therapeutic mild hypothermia or delayed fluid resuscitation increase the survival rate in this model. However, when mild hypothermia and limited fluid resuscitation were combined, the survival rate was the highest.
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Affiliation(s)
- Said Hachimi-Idrissi
- Department of Critical Care Medicine and Cerebral Resuscitation Research Group, Academic Hospital, Free University of Brussels, Laarbeeklaan 101, B-1090 Brussels, Belgium.
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Miyake M, Grinberg OY, Hou H, Steffen RP, Elkadi H, Swartz HM. The Effect of RSR13, a Synthetic Allosteric Modifier of Hemoglobin, on Brain Tissue pO2 (Measured by Eproximetry) Following Severe Hemorrhagic Shock in Rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 530:319-29. [PMID: 14562728 DOI: 10.1007/978-1-4615-0075-9_30] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
RSR13 is a synthetic allosteric modifier of hemoglobin that decreases the oxygen binding affinity of hemoglobin, potentially increasing oxygen availability to hypoxic tissues. Using in vivo EPR to directly measure cortical pO2, we examined whether RSR13 would improve brain tissue pO2 following severe hemorrhagic shock in rats. Hemorrhagic shock was induced by withdrawing blood (2.7-2.8 mL/100 g/15 min). Following a 30 min shock period, resuscitation was performed by infusion with Ringer lactate plus RSR13 (150 mg/kg) or saline (control). Following hemorrhage, brain pO2 decreased by about 14 mm Hg in both groups. Following crystalloid resuscitation brain pO2 remained depressed in the control group but returned to the pre-hemorrhage values in the rats that received RSR13. RSR13 immediately increased and maintained the paO2 while controls had a very gradual increase towards pre-hemorrhage values. There was no difference in the blood pressure or heart rate between groups. RSR13 may have useful applications to decrease the effects of acute hemorrhagic hypoxemia by increasing brain oxygenation.
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Affiliation(s)
- Minoru Miyake
- EPR Center for the Study of Viable Systems, Department of Radiology, 7785 Vail Dartmouth Medical School, Hanover, NH, USA
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Abstract
Recent research efforts have demonstrated that many longstanding practices for the prehospital resuscitation of trauma patients may be inappropriate under certain circumstances. For example, traditional practices, such as application of anti-shock garments and i.v. fluid administration to raise blood pressure, may even be detrimental in certain patients with uncontrolled bleeding, particularly those with penetrating injuries. ETI, although potentially capable of transiently prolonging a patient's ability to tolerate circulatory arrest, may also be harmful if overzealous PPV further compromises cardiac output, particularly in those patients with severe hemodynamic instability. In addition, if these procedures delay patient transport, any benefit that they may offer could be outweighed by the delay in definitive care. Although traditionally taught to "hyperventilate" the patient with severe head injury, current recommendations are to avoid this tactic unless there is evidence of herniation. Even time-honored traditions, such as universal spinal precautions and CPR during circulatory arrest, are being scrutinized [2,134]. Further prospective randomized clinical trials are needed to better define the role of many overlapping therapies in prehospital trauma care. Such research must specifically address and stratify the different mechanisms of injury, anatomic areas involved, and the physiologic staging of the injury. Furthermore, the efficacy of a single intervention may be masked by a confounding variable [5]. For example, a trial of an effective new HBOC in moribund patients that indicates no advantage in the study results may have been confounded by overzealous PPV, which may have led to suboptimal outcomes. It is hoped that, in the future, EMS physicians will be able to not only better discriminate in their management of patients with major trauma but also improve outcomes as a result.
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Affiliation(s)
- Raymond Fowler
- University of Texas Southwestern Medical Center, Parkland Health and Hospital System, Dallas Metropolitan Biotel (EMS) System, Emergency Medicine, MC 8579, 5323 Harry Hines Boulevard, Dallas, TX 75390-8579, USA
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Abstract
Current reviews and consensus documents now recommend a more discriminating approach to the traditional practices of delivering liberal infusions of intravenous fluid to all major trauma patients with suspected or known major hemorrhage. The evolving evidence suggests that aggressive fluid resuscitation prior to hemostasis leads to additional bleeding through hydraulic acceleration of hemorrhage, soft clot dissolution, and dilution of clotting factors. Aggressive preoperative fluid infusion is still considered appropriate for unconscious patients without palpable blood pressure or for those with controllable hemorrhage (e.g. isolated extremity or head injury), However, the latest recommendations are to limit or delay intravenous fluid resuscitation preoperatively in those with uncontrollable hemorrhage (e.g. those with penetrating torso injuries), even if they are hypo-perfusing. Although most clinicians still generally support fluid resuscitation for multisystem blunt trauma, particularly with head injury, the most recent experimental data have begun to challenge this traditional practice as well, suggesting a 'slow infusion' approach when there is risk for uncontrolled internal bleeding. By providing oxygen delivery with slow, limited infusion, new hemoglobin-based oxygen carriers might help to resolve the current dilemma of having to limit preoperative resuscitation when there is risk of uncontrolled hemorrhage.
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Affiliation(s)
- Raymond Fowler
- University of Texas Southwestern Medical Center and The Dallas Metropolitan Area Biotel (EMS) System, Dallas, Texas 75390, USA
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Leonov Y, Safar P, Sterz F, Stezoski SW. Extending the golden hour of hemorrhagic shock tolerance with oxygen plus hypothermia in awake rats. An exploratory study. Resuscitation 2002; 52:193-202. [PMID: 11841888 DOI: 10.1016/s0300-9572(01)00453-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In a previous study of volume-controlled hemorrhagic shock (HS) in awake rats, without fluid resuscitation, either breathing of 100% oxygen or moderate hypothermia while breathing air, increased survival time. We hypothesized that combining oxygen and hypothermia can maximally extend the "golden hour" of HS from which resuscitation can be successful in terms of survival rate. Rats were prepared under light general anesthesia, breathing spontaneously via face mask, and then awakened for 2 h. Then, 3.25 ml arterial blood/100 g were withdrawn over 20 min. At the end of HS of 30, 60, 90 or 180 min duration, the shed blood was reinfused. Breathing was spontaneous. Survival endpoint was 24 h or earlier death. HS of 30 or 60 min was used for preliminary experiments; HS of 90 or 180 min for 35 definitive experiments. Control groups A-1 and B-1 had normothermia (rectal temperature 37.5 degrees C) and were breathing air. Treatment groups A-2 and B-2 had total body surface cooling during HS to rectal temperature 32 degrees C and were breathing 100% O(2). Arterial pressure during HS was higher in the hypothermia-O(2) groups. With HS of 90 min, in the normothermia-air group A-1 (n=10), none of the 10 rats survived to 3 h; while in the hypothermia-O(2) group A-2 (n=5), all rats survived to 24 h (P<0.001). With HS of 180 min, in the normothermia-air group B-1 (n=10), three of 10 rats survived to 3 h and 24 h (hypotension during HS in these three survivors was less severe than in the non-survivors); and in the hypothermia-O(2) group B-2 (n=10) all 10 rats survived to 24 h (P<0.003). We conclude that moderate hypothermia (32 degrees C) plus 100% oxygen inhalation during volume-controlled HS in awake rats mitigates hypotension and increases the chance of survival. It enables survival even after 3 h of moderate HS.
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Affiliation(s)
- Yuval Leonov
- Safar Center for Resuscitation Research (SCRR), Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh Medical Center, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA
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37
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Abstract
For the past 4 decades, the standard approach to the trauma victim who is hypotensive from presumed hemorrhage has been to infuse large volumes of fluids as early and as rapidly as possible. The goals of this treatment strategy are rapid restoration of intravascular volume and vital signs towards normal, and maintenance of vital organ perfusion. The most recent laboratory studies and the only clinical trial evaluating the efficacy of these guidelines however, suggest that in the setting of uncontrolled hemorrhage, today's practice of aggressive fluid resuscitation may be harmful, resulting in increased hemorrhage volume and subsequently greater mortality. This has been demonstrated in animal models representative of penetrating trauma as well as those representative of blunt trauma. The data strongly suggest that limited or hypotensive resuscitation may be preferable for the trauma victim with the potential for ongoing uncontrolled hemorrhage. Limited resuscitation provides a mechanism of avoiding the detrimental effects associated with early aggressive resuscitation, while maintaining a level of tissue perfusion that although decreased from the normal physiologic range is adequate for short periods. Large randomized clinical trials are necessary to confirm this new laboratory data. Future research should focus on developing resuscitation methods that may actually enhance tissue perfusion during limited resuscitation and therefore offset its potential detrimental effects.
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Affiliation(s)
- S A Stern
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan 48109-0303, USA.
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D'Hooge R, De Deyn PP. Applications of the Morris water maze in the study of learning and memory. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2001; 36:60-90. [PMID: 11516773 DOI: 10.1016/s0165-0173(01)00067-4] [Citation(s) in RCA: 1443] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Morris water maze (MWM) was described 20 years ago as a device to investigate spatial learning and memory in laboratory rats. In the meanwhile, it has become one of the most frequently used laboratory tools in behavioral neuroscience. Many methodological variations of the MWM task have been and are being used by research groups in many different applications. However, researchers have become increasingly aware that MWM performance is influenced by factors such as apparatus or training procedure as well as by the characteristics of the experimental animals (sex, species/strain, age, nutritional state, exposure to stress or infection). Lesions in distinct brain regions like hippocampus, striatum, basal forebrain, cerebellum and cerebral cortex were shown to impair MWM performance, but disconnecting rather than destroying brain regions relevant for spatial learning may impair MWM performance as well. Spatial learning in general and MWM performance in particular appear to depend upon the coordinated action of different brain regions and neurotransmitter systems constituting a functionally integrated neural network. Finally, the MWM task has often been used in the validation of rodent models for neurocognitive disorders and the evaluation of possible neurocognitive treatments. Through its many applications, MWM testing gained a position at the very core of contemporary neuroscience research.
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Affiliation(s)
- R D'Hooge
- Laboratory of Neurochemistry and Behavior, Born-Bunge Foundation, and Department of Neurology/Memory Clinic, Middelheim Hospital, University of Antwerp, Universiteitsplein 1, B-2610, Antwerp, Belgium.
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Behringer W, Kentner R, Wu X, Tisherman SA, Radovsky A, Stezoski WS, Henchir J, Prueckner S, Jackson EK, Safar P. Fructose-1,6-bisphosphate and MK-801 by aortic arch flush for cerebral preservation during exsanguination cardiac arrest of 20 min in dogs. An exploratory study. Resuscitation 2001; 50:205-16. [PMID: 11719149 DOI: 10.1016/s0300-9572(01)00337-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In our exsanguination cardiac arrest (CA) outcome model in dogs we are systematically exploring suspended animation (SA), i.e. preservation of brain and heart immediately after the onset of CA to enable transport and resuscitative surgery during CA, followed by delayed resuscitation. We have shown in dogs that inducing moderate cerebral hypothermia with an aortic arch flush of 500 ml normal saline solution at 4 degrees C, at start of CA 20 min no-flow, leads to normal functional outcome. We hypothesized that, using the same model, but with the saline flush at 24 degrees C inducing minimal cerebral hypothermia (which would be more readily available in the field), adding either fructose-1,6-bisphosphate (FBP, a more efficient energy substrate) or MK-801 (an N-methyl-D-aspartate (NMDA) receptor blocker) would also achieve normal functional outcome. Dogs (range 19-30 kg) were exsanguinated over 5 min to CA of 20 min no-flow, and resuscitated by closed-chest cardiopulmonary bypass (CPB). They received assisted circulation to 2 h, mild systemic hypothermia (34 degrees C) post-CA to 12 h, controlled ventilation to 20 h, and intensive care to 72 h. At CA 2 min, the dogs received an aortic arch flush of 500 ml saline at 24 degrees C by a balloon-tipped catheter, inserted through the femoral artery (control group, n=6). In the FBP group (n=5), FBP (total 1440 or 4090 mg/kg) was given by flush and with reperfusion. In the MK-801 group (n=5), MK-801 (2, 4, or 8 mg/kg) was given by flush and with reperfusion. Outcome was assessed in terms of overall performance categories (OPC 1, normal; 2, moderate disability; 3, severe disability; 4, coma; 5, brain death or death), neurologic deficit scores (NDS 0-10%, normal; 100%, brain death), and brain histologic damage scores (HDS, total HDS 0, no damage; >100, extensive damage; 1064, maximal damage). In the control group, one dog achieved OPC 2, one OPC 3, and four OPC 4; in the FBP group, two dogs achieved OPC 3, and three OPC 4; in the MK-801 group, two dogs achieved OPC 3, and three OPC 4 (P=1.0). Median NDS were 62% (range 8-67) in the control group; 55% (range 34-66) in the FBP group; and 50% (range 26-59) in the MK-801 group (P=0.2). Median total HDS were 130 (range 56-140) in the control group; 96 (range 64-104) in the FBP group; and 80 (range 34-122) in the MK-801 group (P=0.2). There was no difference in regional HDS between groups. We conclude that neither FBP nor MK-801 by aortic arch flush at the start of CA, plus an additional i.v. infusion of the same drug during reperfusion, can provide cerebral preservation during CA 20 min no-flow. Other drugs and drug-combinations should be tested with this model in search for a breakthrough effect.
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Affiliation(s)
- W Behringer
- Department of Anesthesiology/Critical Care Medicine, Safar Center for Resuscitation Research, University of Pittsburgh School of Medicine, 3434 Fifth Avenue, Pittsburgh, PA 15260, USA
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Takasu A, Prueckner S, Tisherman SA, Stezoski SW, Stezoski J, Safar P. Effects of increased oxygen breathing in a volume controlled hemorrhagic shock outcome model in rats. Resuscitation 2000; 45:209-20. [PMID: 10959021 DOI: 10.1016/s0300-9572(00)00183-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
It is believed that victims of traumatic hemorrhagic shock (HS) benefit from breathing 100% O(2). Supplying bottled O(2) for military and civilian first aid is difficult and expensive. We tested the hypothesis that increased FiO(2) both during severe volume-controlled HS and after resuscitation in rats would: (1) increase blood pressure; (2) mitigate visceral dysoxia and thereby prevent post-shock multiple organ failure; and (3) increase survival time and rate. Thirty rats, under light anesthesia with halothane (0. 5% throughout), with spontaneous breathing of air, underwent blood withdrawal of 3 ml/100 g over 15 min. After HS phase I of 60 min, resuscitation phase II of 180 min with normotensive intravenous fluid resuscitation (shed blood plus lactated Ringer's solution), was followed by an observation phase III to 72 h and necropsy. Rats were randomly divided into three groups of ten rats each: group 1 with FiO(2) 0.21 (air) throughout; group 2 with FiO(2) 0.5; and group 3 with FiO(2) 1.0, from HS 15 min to the end of phase II. Visceral dysoxia was monitored during phases I and II in terms of liver and gut surface PCO(2) increase. The main outcome variables were survival time and rate. PaO(2) values at the end of HS averaged 88 mmHg with FiO(2) 0.21; 217 with FiO(2) 0.5; and 348 with FiO(2) 1. 0 (P<0.001). During HS phase I, FiO(2) 0.5 increased mean arterial pressure (MAP) (NS) and kept arterial lactate lower (P<0.05), compared with FiO(2) 0.21 or 1.0. During phase II, FiO(2) 0.5 and 1. 0 increased MAP compared with FiO(2) 0.21 (P<0.01). Heart rate was transiently slower during phases I and II in oxygen groups 2 and 3, compared with air group 1 (P<0.05). During HS, FiO(2) 0.5 and 1.0 mitigated visceral dysoxia (tissue PCO(2) rise) transiently, compared with FiO(2) 0.21 (P<0.05). Survival time (by life table analysis) was longer after FiO(2) 0.5 than after FiO(2) 0.21 (P<0. 05) or 1.0 (NS), without a significant difference between FiO(2) 0. 21 and 1.0. Survival rate to 72 h was achieved by two of ten rats in FiO(2) 0.21 group 1, by four of ten rats in FiO(2) 0.5 group 2 (NS); and by four of ten rats of FiO(2) 1.0 group 3 (NS). In late deaths macroscopic necroses of the small intestine were less frequent in FiO(2) 0.5 group 2. We conclude that in rats, in the absence of hypoxemia, increasing FiO(2) from 0.21 to 0.5 or 1.0 does not increase the chance to achieve long-term survival. Breathing FiO(2) 0.5, however, might increase survival time in untreated HS, as it can mitigate hypotension, lactacidemia and visceral dysoxia.
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Affiliation(s)
- A Takasu
- Department of Anesthesiology/Critical Care Medicine, Safar Center for Resuscitation Research (SCRR), University of Pittsburgh School of Medicine, PA 15260, USA
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Manley GT, Fujimura M, Ma T, Noshita N, Filiz F, Bollen AW, Chan P, Verkman AS. Aquaporin-4 deletion in mice reduces brain edema after acute water intoxication and ischemic stroke. Nat Med 2000; 6:159-63. [PMID: 10655103 DOI: 10.1038/72256] [Citation(s) in RCA: 1199] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cerebral edema contributes significantly to morbidity and death associated with many common neurological disorders. However, current treatment options are limited to hyperosmolar agents and surgical decompression, therapies introduced more than 70 years ago. Here we show that mice deficient in aquaporin-4 (AQP4), a glial membrane water channel, have much better survival than wild-type mice in a model of brain edema caused by acute water intoxication. Brain tissue water content and swelling of pericapillary astrocytic foot processes in AQP4-deficient mice were significantly reduced. In another model of brain edema, focal ischemic stroke produced by middle cerebral artery occlusion, AQP4-deficient mice had improved neurological outcome. Cerebral edema, as measured by percentage of hemispheric enlargement at 24 h, was decreased by 35% in AQP4-deficient mice. These results implicate a key role for AQP4 in modulating brain water transport, and suggest that AQP4 inhibition may provide a new therapeutic option for reducing brain edema in a wide variety of cerebral disorders.
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Affiliation(s)
- G T Manley
- Department of Neurosurgery, University of California, San Francisco, California 94143, USA.
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