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Kallet RH, Lipnick MS. Pressure Control Surrogate Formula for Estimating Mechanical Power in ARDS Is Associated With Mortality. Respir Care 2025:respcare.12269. [PMID: 39242173 DOI: 10.4187/respcare.12269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Accepted: 09/01/2024] [Indexed: 09/09/2024]
Abstract
Background: Mechanical power (MP) applied to the respiratory system (MPRS) is associated with ventilator-induced lung injury (VILI) and ARDS mortality. Absent automated ventilator MPRS measurements, the alternative is clinically unwieldy equations. However, simplified surrogate formulas are now available and accurately reflect values produced by airway pressure-volume curves. This retrospective, observational study examined whether the surrogate pressure -control equation alone could accurately assess mortality risk in subjects with ARDS managed almost exclusively with volume control (VC) ventilation. Methods: Nine hundred and forty-eight subjects were studied in whom invasive mechanical ventilation and implementation of ARDS Network ventilator protocols commenced ≤ 24 h after ARDS onset and who survived > 24 h. MPRS was calculated as 0.098 x breathing frequency x tidal volume x (PEEP + driving pressure). MPRS was assessed as a risk factor for hospital mortality and compared between non-survivors and survivors across Berlin definition classifications. In addition, mortality was compared across 4 MPRS thresholds associated with VILI or mortality (ie, 15, 20, 25, and 30 J/min). Results: MPRS was associated with increased mortality risk: odds ratio (95% CI) of 1.06 (1.04-1.07) J/min (P < .001). Median MPRS differentiated non-survivors from survivors in mild (24.7 J/min vs 18.5 J/min, respectively, P = .034), moderate (25.7 J/min vs 21.3 J/min, respectively, P < .001), and severe ARDS (28.7 J/min vs 23.5 J/min, respectively, P < .001). Across 4 MPRS thresholds, mortality increased from 23-29% when MPRS was ≤ threshold versus 38-51% when MPRS was > threshold (P < .001). In the > cohort, the odds ratio (95% CI) increased from 2.03 (1.34-3.12) to 2.51 (1.87-3.33). Conclusion: The pressure control surrogate formula is sufficiently accurate to assess mortality in ARDS, even when using VC ventilation. In our subjects when MPRS exceeds established cutoff values for VILI or mortality risk, we found mortality risk consistently increased by a factor of > 2.0.
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Affiliation(s)
- Richard H Kallet
- Mr. Kallet and Dr. Lipnick are affiliated with Department of Anesthesia and Perioperative Care, University of California, San Francisco at San Francisco General Hospital, San Francisco, California
| | - Michael S Lipnick
- Mr. Kallet and Dr. Lipnick are affiliated with Department of Anesthesia and Perioperative Care, University of California, San Francisco at San Francisco General Hospital, San Francisco, California
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Qiu K, Lu J, Guo H, Du C, Liu J, Li A. Study on Respiratory Function and Hemodynamics of AIDS Patients with Respiratory Failure. Infect Drug Resist 2023; 16:6941-6950. [PMID: 37928608 PMCID: PMC10624180 DOI: 10.2147/idr.s376752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 09/27/2023] [Indexed: 11/07/2023] Open
Abstract
Objective We performed a comparative analysis of respiratory function and hemodynamics among patients with Acquired Immunodeficiency Syndrome (AIDS)-associated respiratory failure and those with non-AIDS-associated respiratory failure. Methods Data were collected from critically ill patients diagnosed with Acquired Immunodeficiency Syndrome who were admitted to the Intensive Care Unit (ICU) of Beijing Ditan Hospital, affiliated with Capital Medical University, between January 1, 2019, and December 31, 2019. We simultaneously gathered data from non-AIDS patients admitted to the ICU of Beijing Liangxiang Hospital within the same timeframe. A comparative study was performed to analyze clinical data from these two patient groups, encompassing parameters related to respiratory mechanics and hemodynamic indicators. Results A total of 12 patients diagnosed with Acquired Immunodeficiency Syndrome (AIDS) and experiencing respiratory failure, along with 23 patients with respiratory failure independent of AIDS, were included in our study. Subsequently, a comparative analysis of clinical information was conducted between the two patient cohorts. Our findings demonstrate non-statistically significant differences between the two patient groups when assessing various indicators, encompassing peak airway pressure, plateau pressure, mean pressure, compliance, oxygenation index, and arterial partial pressure of carbon dioxide (P>0.05). Additionally, the comparison of multiple indicators encompassing mean arterial pressure, central venous pressure, cardiac output index, intrathoracic blood volume index, global end-diastolic volume index, extravascular lung water content, and pulmonary vascular permeability index revealed no statistically significant differences between the two patient groups (P>0.05). Ultimately, the Galileo respiratory system was utilized to assess the pressure-volume (P-V) curve of the experimental cohort, revealing a consistent and seamless trajectory devoid of noticeable points of inflection. Conclusion No statistically significant differences were found in the respiratory function and hemodynamic profiles between patients diagnosed with AIDS presenting respiratory failure and those experiencing respiratory failure unrelated to AIDS. Additionally, the pressure-volume curve of individuals diagnosed with AIDS presenting respiratory failure displayed a seamless and uninterrupted trajectory devoid of discernible points of inflection. Hence, there might be constraints when utilizing P-V curve-based adjustments for positive end-expiratory pressure (PEEP) during mechanical ventilation in individuals diagnosed with AIDS presenting respiratory failure.
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Affiliation(s)
- Kai Qiu
- Department of Critical Care Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China
- Department of Intensive Care Medicine, Liangxiang Hospital of Beijing Fangshan District, Beijing, People’s Republic of China
| | - Jiaqi Lu
- Department of Critical Care Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Hebing Guo
- Department of Critical Care Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Chunjing Du
- Department of Critical Care Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Jingyuan Liu
- Department of Critical Care Medicine, Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Ang Li
- Beijing Ditan Hospital, Capital Medical University, Beijing, People’s Republic of China
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Kock KDS, Maurici R. Respiratory mechanics, ventilator-associated pneumonia and outcomes in intensive care unit. World J Crit Care Med 2018; 7:24-30. [PMID: 29430405 PMCID: PMC5797973 DOI: 10.5492/wjccm.v7.i1.24] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 11/05/2017] [Accepted: 12/04/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To evaluate the predictive capability of respiratory mechanics for the development of ventilator-associated pneumonia (VAP) and mortality in the intensive care unit (ICU) of a hospital in southern Brazil.
METHODS A cohort study was conducted between, involving a sample of 120 individuals. Static measurements of compliance and resistance of the respiratory system in pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV) modes in the 1st and 5th days of hospitalization were performed to monitor respiratory mechanics. The severity of the patients’ illness was quantified by the Acute Physiology and Chronic Health Evaluation II (APACHE II). The diagnosis of VAP was made based on clinical, radiological and laboratory parameters.
RESULTS The significant associations found for the development of VAP were APACHE II scores above the average (P = 0.016), duration of MV (P = 0.001) and ICU length of stay above the average (P = 0.003), male gender (P = 0.004), and worsening of respiratory resistance in PCV mode (P = 0.010). Age above the average (P < 0.001), low level of oxygenation on day 1 (P = 0.003) and day 5 (P = 0.004) and low lung compliance during VCV on day 1 (P = 0.032) were associated with death as the outcome.
CONCLUSION The worsening of airway resistance in PCV mode indicated the possibility of early diagnosis of VAP. Low lung compliance during VCV and low oxygenation index were death-related prognostic indicators.
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Affiliation(s)
- Kelser de Souza Kock
- Department of Physiotherapy, University of South of Santa Catarina, Tubarão, SC 88704-001, Brazil
| | - Rosemeri Maurici
- Graduate Program in Medical Sciences, Federal University of Santa Catarina, Florianópolis, SC 88700-000, Brazil
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Risk Factors for the Mortality of Pneumocystis jirovecii Pneumonia in Non-HIV Patients Who Required Mechanical Ventilation: A Retrospective Case Series Study. BIOMED RESEARCH INTERNATIONAL 2017; 2017:7452604. [PMID: 28567422 PMCID: PMC5439059 DOI: 10.1155/2017/7452604] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/09/2017] [Accepted: 04/20/2017] [Indexed: 01/15/2023]
Abstract
Background The risk factors for the mortality rate of Pneumocystis jirovecii pneumonia (PCP) who required mechanical ventilation (MV) remained unknown. Methods A retrospective chart review was performed of all PCP patients admitted to our intensive care unit and treated for acute hypoxemic respiratory failure to assess the risk factors for the high mortality. Results Twenty patients without human immunodeficiency virus infection required mechanical ventilation; 19 received noninvasive ventilation; and 11 were intubated. PEEP was incrementally increased and titrated to maintain FIO2 as low as possible. No mandatory ventilation was used. Sixteen patients (80%) survived. Pneumothorax developed in one patient with rheumatoid arthritis (RA). Median PEEP level in the first 5 days was 10.0 cmH2O and not associated with death. Multivariate analysis showed the association of incidence of interstitial lung disease and increase in serum KL-6 with 90-day mortality. Conclusions We found MV strategies to prevent pneumothorax including liberal use of noninvasive ventilation, and PEEP titration and disuse of mandatory ventilation may improve mortality in this setting. Underlying disease of interstitial lung disease was a risk factor and KL-6 may be a useful predictor associated with mortality in patients with RA. These findings will need to be validated in larger studies.
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Kock KDS, Rosa BCD, Martignago N, Reis C, Maurici R. Comparison of respiratory mechanics measurements in the volume cycled ventilation (VCV) and pressure controlled ventilation (PCV). FISIOTERAPIA EM MOVIMENTO 2016. [DOI: 10.1590/0103-5150.029.002.ao02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Abstract Introduction Monitoring respiratory mechanics may provide important information for the intensivist, assisting in the early detection of pulmonary function changes of patients hospitalized in ICU. Objective: To compare measurements of respiratory mechanics in VCV and PCV modes, and correlate them with age and oxygenation index. Materials and methods: Cross-sectional study conducted in the adult ICU of the Hospital Nossa Senhora da Conceição, in Tubarão - SC. A hundred and twenty individuals were selected between March and August 2013. The respiratory mechanics measurements were evaluated using compliance and resistance static measures of the respiratory system in PCV and VCV modes between the 1st and 5th day of hospitalization. Simultaneously, the oxygenation index PaO2/FiO2 was collected. Results: The obtained results were: compliance (VCV) = 40.9 ± 12.8 mL/cmH2O, compliance (PCV) = 35.0 ± 10.0 mL/cmH2O, resistance (VCV) = 13.2 ± 4.9 cmH2O/L/s, resistance (PCV) = 27.3 ± 16.2 cmH2O/L/s and PaO2/FiO2 = 236.0 ± 97.6 mmHg. There was statistical difference (p < 0.001) between the compliance and resistance measures in VCV and PCV modes. The correlations between the oxygenation index and compliance in VCV and PCV modes and resistance in VCV and PCV modes were, respectively, r = 0.381 (p < 0.001), r = 0.398 (p < 0.001), r = -0.188 (p = 0.040), r = -0.343 (p < 0.001). Conclusion: Despite the differences between the respiratory mechanics measurements the monitoring using VCV and PCV modes seems to show complementary aspects.
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How large is the lung recruitability in early acute respiratory distress syndrome: a prospective case series of patients monitored by computed tomography. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:R4. [PMID: 22226331 PMCID: PMC3396229 DOI: 10.1186/cc10602] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 10/30/2011] [Accepted: 01/08/2012] [Indexed: 12/28/2022]
Abstract
Introduction The benefits of higher positive end expiratory pressure (PEEP) in patients with acute respiratory distress syndrome (ARDS) have been modest, but few studies have fully tested the "open-lung hypothesis". This hypothesis states that most of the collapsed lung tissue observed in ARDS can be reversed at an acceptable clinical cost, potentially resulting in better lung protection, but requiring more intensive maneuvers. The short-/middle-term efficacy of a maximum recruitment strategy (MRS) was recently described in a small physiological study. The present study extends those results, describing a case-series of non-selected patients with early, severe ARDS submitted to MRS and followed until hospital discharge or death. Methods MRS guided by thoracic computed tomography (CT) included two parts: a recruitment phase to calculate opening pressures (incremental steps under pressure-controlled ventilation up to maximum inspiratory pressures of 60 cmH2O, at constant driving-pressures of 15 cmH2O); and a PEEP titration phase (decremental PEEP steps from 25 to 10 cmH2O) used to estimate the minimum PEEP to keep lungs open. During all steps, we calculated the size of the non-aerated (-100 to +100 HU) compartment and the recruitability of the lungs (the percent mass of collapsed tissue re-aerated from baseline to maximum PEEP). Results A total of 51 severe ARDS patients, with a mean age of 50.7 years (84% primary ARDS) was studied. The opening plateau-pressure was 59.6 (± 5.9 cmH2O), and the mean PEEP titrated after MRS was 24.6 (± 2.9 cmH2O). Mean PaO2/FiO2 ratio increased from 125 (± 43) to 300 (± 103; P < 0.0001) after MRS and was sustained above 300 throughout seven days. Non-aerated parenchyma decreased significantly from 53.6% (interquartile range (IQR): 42.5 to 62.4) to 12.7% (IQR: 4.9 to 24.2) (P < 0.0001) after MRS. The potentially recruitable lung was estimated at 45% (IQR: 25 to 53). We did not observe major barotrauma or significant clinical complications associated with the maneuver. Conclusions MRS could efficiently reverse hypoxemia and most of the collapsed lung tissue during the course of ARDS, compatible with a high lung recruitability in non-selected patients with early, severe ARDS. This strategy should be tested in a prospective randomized clinical trial.
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Acute clinical benefits of chest wall-stretching exercise on expired tidal volume, dyspnea and chest expansion in a patient with chronic obstructive pulmonary disease: A single case study. J Bodyw Mov Ther 2009; 13:338-43. [DOI: 10.1016/j.jbmt.2008.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 10/23/2008] [Accepted: 11/02/2008] [Indexed: 11/18/2022]
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History of mechanical ventilation may affect respiratory mechanics evolution in acute respiratory distress syndrome. J Crit Care 2009; 24:626.e1-6. [PMID: 19427758 DOI: 10.1016/j.jcrc.2009.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 02/03/2009] [Accepted: 02/16/2009] [Indexed: 12/17/2022]
Abstract
PURPOSE The aim of this study was to investigate the effect of mechanical ventilation (MV) before acute respiratory distress syndrome (ARDS) on subsequent evolution of respiratory mechanics and blood gases in protectively ventilated patients with ARDS. METHODS Nineteen patients with ARDS were stratified into 2 groups according to ARDS onset relative to the onset of MV: In group A (n = 11), MV was applied at the onset of ARDS; in group B (n = 8), MV had been initiated before ARDS. Respiratory mechanics and arterial blood gas were assessed in early (<or=3 days) and late (8-11 days) ARDS, on zero positive end-expiratory pressure and positive end-expiratory pressure of 10 cm H(2)O. RESULTS In group A, Pao(2)/fractional inspired oxygen concentration increased (121 +/- 43 vs 161 +/- 60 mm Hg) and minimal resistance of respiratory system decreased (8.3 +/- 1.8 vs 6.0 +/- 2.1 cm H(2)O L(-1) s(-1)) from early to late ARDS. In group B, static elastance of respiratory system increased in the late stage (30.4 +/- 7.8 vs 36.4 +/- 9.9 cm H(2)O/L). In both groups, positive end-expiratory pressure application resulted in Pao(2)/fractional inspired oxygen concentration improvement and minimal resistance of respiratory system decreases in both stages. CONCLUSION In protectively ventilated patients with ARDS, late alteration of respiratory mechanics occurs more commonly in patients who have been ventilated before ARDS onset, suggesting that the history of MV affects the subsequent progress of ARDS even when using protective ventilation.
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Davis JL, Morris A, Kallet RH, Powell K, Chi AS, Bensley M, Luce JM, Huang L. Low tidal volume ventilation is associated with reduced mortality in HIV-infected patients with acute lung injury. Thorax 2008; 63:988-93. [PMID: 18535118 DOI: 10.1136/thx.2008.095786] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Respiratory failure remains the leading indication for admission to the intensive care unit (ICU) and a leading cause of death for HIV-infected patients in spite of overall improvements in ICU mortality. It is unclear if these improvements are due to combination anti-retroviral therapy, low tidal volume ventilation for acute lung injury, or both. A study was undertaken to identify therapies and clinical factors associated with mortality in acute lung injury among HIV-infected patients with respiratory failure in the period 1996-2004. A secondary aim was to compare mortality before and after introduction of a low tidal volume ventilation protocol in 2000. METHODS A retrospective cohort study was performed of 148 consecutive HIV-infected adults admitted to the ICU at San Francisco General Hospital with acute lung injury requiring mechanical ventilation. Demographic and clinical information including data on mechanical ventilation was abstracted from medical records and analysed by multivariate analysis using logistic regression. RESULTS In-hospital mortality was similar before and after introduction of a low tidal volume ventilation protocol, although the study was not powered to exclude a clinically significant difference (risk difference -5.4%, 95% CI -21% to 11%, p = 0.51). Combination antiretroviral therapy was not clearly associated with mortality, except in patients with Pneumocystis pneumonia. Among all those with acute lung injury, lower tidal volume was associated with decreased mortality (adjusted odds ratio 0.76 per 1 ml/kg decrease, 95% CI 0.58 to 0.99, p = 0.043), after controlling for Pneumocystis pneumonia, serum albumin, illness severity, gas exchange impairment and plateau pressure. CONCLUSIONS Lower tidal volume ventilation is independently associated with reduced mortality in HIV-infected patients with acute lung injury and respiratory failure.
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Affiliation(s)
- J L Davis
- Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, California 94110, USA.
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Hypoventilation and Respiratory Muscle Dysfunction. Crit Care Med 2008. [DOI: 10.1016/b978-032304841-5.50043-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Peres e Serra A, Parra ER, Eher E, Capelozzi VL. Nonhomogeneous immunostaining of hyaline membranes in different manifestations of diffuse alveolar damage. Clinics (Sao Paulo) 2006; 61:497-502. [PMID: 17187083 DOI: 10.1590/s1807-59322006000600002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2006] [Accepted: 07/18/2006] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To determine the nature of hyaline membranes in different manifestations of diffuse alveolar damage, [pulmonary and extrapulmonary acute respiratory distress syndrome], and idiopathic [acute interstitial pneumonia]. MATERIALS AND METHODS Pulmonary specimens were obtained from 17 patients with acute respiratory distress syndrome and 9 patients with acute interstitial pneumonia. They were separated into 3 different groups: (a) pulmonary diffuse alveolar damage (pDAD) (n = 8), consisting only of pneumonia cases; (b) extrapulmonary diffuse alveolar damage (expDAI) (n = 9), consisting of sepsis and septic shock cases; and (c) idiopathic diffuse alveolar damage (iDAD) (n = 9), consisting of idiopathic cases (acute interstitial pneumonia). Hyaline membranes, the hallmark of the diffuse alveolar damage histological pattern, were examined using various kinds of antibodies. The antibodies used were against surfactant apoprotein-A (SP-A), cytokeratin 7 (CK7), cytokeratin 8 (CK8), alpha smooth muscle actin (alpha-SMA), cytokeratin AE1/AE3 (AE1/AE3), and factor VIII-related antigen (factor VIII). RESULTS Pulmonary diffuse alveolar damage showed the largest quantity of hyaline membranes (12.65% +/- 3.24%), while extrapulmonary diffuse alveolar damage (9.52% +/- 3.64%) and idiopathic diffuse alveolar damage (7.34% +/- 2.11%) showed intermediate and lower amounts, respectively, with the difference being statistically significant between pulmonary and idiopathic diffuse alveolar damage (P < 0.05). No significant difference was found for hyaline membranes Sp-A immunostaining among pulmonary (15.36% +/- 3.12%), extrapulmonary (16.12% +/- 4.58%), and idiopathic (13.74 +/- 4.20%) diffuse alveolar damage groups. Regarding factor VIII, we found that idiopathic diffuse alveolar damage presented larger amounts of immunostained hyaline membranes (14.12% +/- 6.25%) than extrapulmonary diffuse alveolar damage (3.93% +/- 2.86%), with this difference being statistically significant (P < 0.001). Equally significant was the difference for progressive decrease of cytokeratin AE1/AE3 immunostaining in hyaline membranes present in the extrapulmonary diffuse alveolar damage (5.42% +/- 2.80%) and idiopathic diffuse alveolar damage (0.47% +/- 0.81%) groups (P < 0.001). None of the groups stained for cytokeratin CK-7, CK-8, vimentin, or a anti-smooth muscle actin. CONCLUSIONS This study showed that only the epithelial/endothelial components (SP-A, factor VIII, and AE1/AE3) of the alveolar/capillary barrier are present in hyaline membranes formation in the 3 groups of patients with diffuse alveolar damage. The significant difference in the expression of factor VIII-related antigen and cytokeratin AE1/AE3 in the expDA versus iDAD groups as well as the significant difference in the amount of hyaline membranes present in the pDAD versus iDAD groups are suggestive of a local and specific lesion with different pathways (direct, indirect, or idiopathic), depending on the type of diffuse alveolar damage.
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Affiliation(s)
- André Peres e Serra
- Department of Pathology, São Paulo University Medical School, São Paulo, SP, Brazil
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Borges JB, Okamoto VN, Matos GFJ, Caramez MPR, Arantes PR, Barros F, Souza CE, Victorino JA, Kacmarek RM, Barbas CSV, Carvalho CRR, Amato MBP. Reversibility of lung collapse and hypoxemia in early acute respiratory distress syndrome. Am J Respir Crit Care Med 2006; 174:268-78. [PMID: 16690982 DOI: 10.1164/rccm.200506-976oc] [Citation(s) in RCA: 322] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
RATIONALE The hypothesis that lung collapse is detrimental during the acute respiratory distress syndrome is still debatable. One of the difficulties is the lack of an efficient maneuver to minimize it. OBJECTIVES To test if a bedside recruitment strategy, capable of reversing hypoxemia and collapse in > 95% of lung units, is clinically applicable in early acute respiratory distress syndrome. METHODS Prospective assessment of a stepwise maximum-recruitment strategy using multislice computed tomography and continuous blood-gas hemodynamic monitoring. MEASUREMENTS AND MAIN RESULTS Twenty-six patients received sequential increments in inspiratory airway pressures, in 5 cm H(2)O steps, until the detection of Pa(O(2)) + Pa(CO(2)) >or= 400 mm Hg. Whenever this primary target was not met, despite inspiratory pressures reaching 60 cm H(2)O, the maneuver was considered incomplete. If there was hemodynamic deterioration or barotrauma, the maneuver was to be interrupted. Late assessment of recruitment efficacy was performed by computed tomography (9 patients) or by online continuous monitoring in the intensive care unit (15 patients) up to 6 h. It was possible to open the lung and to keep the lung open in the majority (24/26) of patients, at the expense of transient hemodynamic effects and hypercapnia but without major clinical consequences. No barotrauma directly associated with the maneuver was detected. There was a strong and inverse relationship between arterial oxygenation and percentage of collapsed lung mass (R = - 0.91; p < 0.0001). CONCLUSIONS It is often possible to reverse hypoxemia and fully recruit the lung in early acute respiratory distress syndrome. Due to transient side effects, the required maneuver still awaits further evaluation before routine clinical application.
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Affiliation(s)
- João B Borges
- Respiratory Intensive Care Unit, Pulmonary Department, and General Intensive Care Unit, Emergency Clinics Division, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil
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Rusca M, Oddo M, Schaller MD, Liaudet L. Carboxyhemoglobin formation as an unexpected side effect of inhaled nitric oxide therapy in severe acute respiratory distress syndrome. Crit Care Med 2004; 32:2537-9. [PMID: 15599162 DOI: 10.1097/01.ccm.0000148012.80245.fc] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To report an unexpected cause of carboxyhemoglobinemia associated with inhaled nitric oxide therapy in severe acute respiratory distress syndrome. DESIGN Case report. SETTING Medical critical care unit at Lausanne University Hospital. PATIENT One female patient with acute respiratory distress syndrome treated with inhaled nitric oxide, who developed a simultaneous increase in blood methemoglobin and carboxyhemoglobin. CONCLUSIONS Potential pathophysiologic mechanisms linking acute respiratory distress syndrome, inhaled nitric oxide, methemoglobin, and carboxyhemoglobin are discussed. Since carboxyhemoglobin has a negative influence on oxygen-carrying capacity, this effect may potentially offset the beneficial influence (if any) of inhaled nitric oxide on arterial PO2. This observation does not support the use of inhaled nitric oxide in the treatment of acute respiratory distress syndrome.
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Affiliation(s)
- Marco Rusca
- Division of Critical Care, Department of Internal Medicine, University Hospital, Lausanne, Switzerland
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Erkrankungen im Kindesalter. Thorax 2003. [DOI: 10.1007/978-3-642-55830-6_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Pelosi P, Gattinoni L. Acute respiratory distress syndrome of pulmonary and extra-pulmonary origin: fancy or reality? Intensive Care Med 2001; 27:457-60. [PMID: 11355111 DOI: 10.1007/s001340100879] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hoelz C, Negri EM, Lichtenfels AJ, Conceição GM, Barbas CS, Saldiva PH, Capelozzi VL. Morphometric Differences in Pulmonary Lesions in Primary and Secondary ARDS. Pathol Res Pract 2001. [DOI: 10.1078/0344-0338-00122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Nava S, Compagnoni ML. Controlled short-term trial of fluticasone propionate in ventilator-dependent patients with COPD. Chest 2000; 118:990-9. [PMID: 11035668 DOI: 10.1378/chest.118.4.990] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND There is no agreement about the efficacy of systemic corticosteroids in patients with COPD, but corticosteroids often are employed during exacerbations of the disease. The use of systemic or inhaled corticosteroids in patients in stable condition is even more controversial, even though the more severely affected patients seem to respond better. Unfortunately, in this subset of patients, the use of forced expiratory maneuvers frequently fails to detect significant functional response. STUDY OBJECTIVES We evaluated the short-term effects of an inhaled corticosteroid, fluticasone propionate (FP), on FEV(1) and on the mechanical properties of patients in stable condition with severe COPD and chronic hypercapnic respiratory failure who were receiving long-term ventilatory support. This allowed us to measure respiratory mechanics (RM) passively, thereby avoiding any problems linked with voluntary maneuvers. DESIGN Randomized, placebo-controlled, crossover study. SETTING A respiratory ICU. PATIENTS Twelve hypercapnic COPD patients (mean [+/- SD] PaCO(2), 60+/-11 mm Hg; mean FEV(1), 13+/-5% predicted; and mean FEV(1)/FVC, 31 +/- 7%) were enrolled. INTERVENTIONS A daily dose of 2,000 microg FP or placebo was administered via metered-dose inhaler during mechanical ventilation for 5 consecutive days. A washout of 72 h was allowed between regimens. MEASUREMENTS End-expiratory and end-inspiratory airway occlusions were performed to assess static intrinsic positive end-expiratory pressure (PEEPi,st), static compliance of the respiratory system (Cst,rs), maximal respiratory resistance (Rmax, rs), and minimal respiratory resistance (Rmin,rs). The bronchodilator response also was assessed by FEV(1) level. RESULTS No significant changes were found in RM after administration of the placebo. By day 6, FP had induced the following significant decreases: PEEPi,st, 4.3+/-2.4 to 3.1+/-1.7 cm H(2)O (p<0.01); Rmax,rs, 19.0+/-6.5 to 14.6+/-6 cm H(2)O/L/s (p<0.001); and Rmin,rs, 14.8+/-4.2 to 10.5+/-3.4 cm H(2)O/L/s (p<0.001). The Cst,rs and the effective additional resistance of the respiratory system did not change significantly, the latter suggesting that the major effect of FP was on the airway caliber (Rmin,rs). FEV(1) changes significantly (p<0.01) underestimated the bronchodilator response, as compared with changes in Rmin,rs. CONCLUSIONS We conclude that in patients in stable condition with severe COPD and chronic hypercapnic respiratory failure, a brief trial of FP may induce a bronchodilator response, mainly related to a reduction in airway resistances, that is not detected by the usual pulmonary function tests.
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Affiliation(s)
- S Nava
- Respiratory Intensive Care Unit, Fondazione S. Mougeri, Istituto Scientifico di Pavia, FRCCS, Pavia, Italy.
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Nava S, Rubini F. Lung and chest wall mechanics in ventilated patients with end stage idiopathic pulmonary fibrosis. Thorax 1999; 54:390-5. [PMID: 10212101 PMCID: PMC1763791 DOI: 10.1136/thx.54.5.390] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Idiopathic pulmonary fibrosis is an inflammatory disease which leads to chronic ventilatory insufficiency and is characterised by a reduction in pulmonary static and dynamic volumes. It has been suggested that lung elastance may also be abnormally increased, particularly in end stage disease, but this has not been systematically tested. The aim of this study was to assess the respiratory mechanics during mechanical ventilation in patients affected by end stage disease. METHODS Respiratory mechanics were monitored in seven patients with idiopathic pulmonary fibrosis being ventilated for acute respiratory failure (PaO2/FiO2 5.8 (0.3); pH 7. 28 (0.02); PaCO2 8.44 (0.82) kPa; tidal volume 3.4 (0.2) ml/kg; respiratory rate 35.1 (8.8) breaths/min) using an oesophageal balloon and airway occlusion during constant flow inflation. The total respiratory system mechanics (rs) was partitioned into lung (L) and chest wall (w) mechanics to measure static intrinsic positive end expiratory pressure (PEEPi), static (Est) and dynamic (Edyn) elastances, total respiratory resistance (Rrs), interrupter respiratory resistance (Rint,rs), and additional respiratory resistance (DeltaRrs). RESULTS PEEPi was negligible in all patients. Edyn,rs and Est,rs were markedly increased (60.9 (7.3) and 51.9 (8. 0) cm H2O/l, respectively), and this was due to abnormal lung elastance (dynamic 53.9 (8.0) cm H2O/l, static 46.1 (8.1) cm H2O/l) while chest wall elastance was only slightly increased. Rrs and Rint, rs were also increased above the normal range (16.7 (4.5) and 13.7 (3.5) cm H2O/l/s, respectively). RL and Rint,L contributed 88% and 89%, on average, to the total. Edyn,rs, Est,rs, Rrs and Rint,rs were significantly correlated with the degree of hypercapnia (r = 0.64 (p<0.01), r = 0.54 (p<0.05), r = 0.84 (p<0.001), and r = 0.72 (p<0. 001), respectively). CONCLUSIONS The elastances and resistances of the respiratory system are significantly altered in ventilated patients with end stage idiopathic pulmonary fibrosis. These features are almost totally due to abnormalities in lung mechanics. These profound alterations in elastic and resistive mechanical properties at this stage of the disease may be responsible for the onset of hypercapnia.
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Affiliation(s)
- S Nava
- Respiratory Intensive Care Unit, Fondazione S. Maugeri, Centro Medico di Montescano, 27040 Montescano (PV), Italy
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Pelosi P, Cadringher P, Bottino N, Panigada M, Carrieri F, Riva E, Lissoni A, Gattinoni L. Sigh in acute respiratory distress syndrome. Am J Respir Crit Care Med 1999; 159:872-80. [PMID: 10051265 DOI: 10.1164/ajrccm.159.3.9802090] [Citation(s) in RCA: 211] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Mechanical ventilation with plateau pressure lower than 35 cm H2O and high positive end-expiratory pressure (PEEP) has been recommended as lung protective strategy. Ten patients with ARDS (five from pulmonary [p] and five from extrapulmonary [exp] origin), underwent 2 h of lung protective strategy, 1 h of lung protective strategy with three consecutive sighs/min at 45 cm H2O plateau pressure, and 1 h of lung protective strategy. Total minute ventilation, PEEP (14.0 +/- 2.2 cm H2O), inspiratory oxygen fraction, and mean airway pressure were kept constant. After 1 h of sigh we found that: (1) PaO2 increased (from 92.8 +/- 18.6 to 137.6 +/- 23.9 mm Hg, p < 0.01), venous admixture and PaCO2 decreased (from 38 +/- 12 to 28 +/- 14%, p < 0.01; and from 52.7 +/- 19.4 to 49.1 +/- 18.4 mm Hg, p < 0.05, respectively); (2) end-expiratory lung volume increased (from 1.49 +/- 0.58 to 1.91 +/- 0.67 L, p < 0.01), and was significantly correlated with the oxygenation (r = 0.82, p < 0.01) and lung elastance (r = 0.76, p < 0.01) improvement. Sigh was more effective in ARDSexp than in ARDSp. After 1 h of sigh interruption, all the physiologic variables returned to baseline. The derecruitment was correlated with PaCO2 (r = 0.86, p < 0.01). We conclude that: (1) lung protective strategy alone at the PEEP level used in this study may not provide full lung recruitment and best oxygenation; (2) application of sigh during lung protective strategy may improve recruitment and oxygenation.
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Affiliation(s)
- P Pelosi
- Istituto di Anestesia e Rianimazione, Università di Milano and Servizio di Anestesia e Rianimazione, Ospedale Maggiore IRCCS, Milano, Italy
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