|
1
|
Novokhodko A, Du N, Hao S, Wang Z, Shu Z, Ahmad S, Gao D. Predicting the Impact of Polysulfone Dialyzers and Binder Dialysate Flow Rate on Bilirubin Removal. Bioengineering (Basel) 2024; 11:1262. [PMID: 39768080 PMCID: PMC11673171 DOI: 10.3390/bioengineering11121262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2024] [Revised: 12/05/2024] [Accepted: 12/11/2024] [Indexed: 01/03/2025] Open
Abstract
Liver failure is the 12th leading cause of death worldwide. Protein-bound toxins such as bilirubin are responsible for many complications of the disease. Binder dialysis systems use albumin or another binding molecule in dialysate and detoxifying sorbent columns to remove these toxins. Systems like the molecular adsorbent recirculating system and BioLogic-DT have existed since the 1990s, but survival benefits in randomized controlled trials have not been consistent. New binder dialysis systems, including open albumin dialysis and the Advanced Multi-Organ Replacement system, are being developed. Optimal conditions for binder dialysis have not been established. We developed and validated a computational model of bound solute dialysis. It predicted the impact of changing between two test setups using different polysulfone dialyzers (F3 and F6HPS). We then predicted the impact of varying the dialysate flow rate on toxin removal. We found that bilirubin removal declines with dialysate flow rate. This can be explained through a linear decline in free bilirubin membrane permeability. Our model quantifies this decline through a single parameter (polysulfone dialyzers). Validation for additional dialyzers and flow rates will be needed. This model will benefit clinical trials by predicting optimal dialyzer and flow rate conditions. Accounting for toxin adsorption onto the dialyzer membrane may improve results further.
Collapse
Affiliation(s)
- Alexander Novokhodko
- Mechanical Engineering, University of Washington (Seattle), 3900 E Stevens Way NE, Seattle, WA 98195-0001, USA; (A.N.); (N.D.); (S.H.); (Z.W.)
| | - Nanye Du
- Mechanical Engineering, University of Washington (Seattle), 3900 E Stevens Way NE, Seattle, WA 98195-0001, USA; (A.N.); (N.D.); (S.H.); (Z.W.)
| | - Shaohang Hao
- Mechanical Engineering, University of Washington (Seattle), 3900 E Stevens Way NE, Seattle, WA 98195-0001, USA; (A.N.); (N.D.); (S.H.); (Z.W.)
| | - Ziyuan Wang
- Mechanical Engineering, University of Washington (Seattle), 3900 E Stevens Way NE, Seattle, WA 98195-0001, USA; (A.N.); (N.D.); (S.H.); (Z.W.)
| | - Zhiquan Shu
- School of Engineering and Technology, University of Washington (Tacoma), 1900 Commerce Street, Tacoma, WA 98402-3100, USA;
| | - Suhail Ahmad
- School of Medicine, University of Washington (Seattle), 1959 N.E. Pacific Street-Box 356340, Seattle, WA 98195-6340, USA
| | - Dayong Gao
- Mechanical Engineering, University of Washington (Seattle), 3900 E Stevens Way NE, Seattle, WA 98195-0001, USA; (A.N.); (N.D.); (S.H.); (Z.W.)
| |
Collapse
|
|
2
|
Abstract
Introduction Abnormalities in blood bicarbonates (HCO3–) concentration are a common finding in patients with chronic kidney disease, especially at the end-stage renal failure. Initiating of hemodialysis does not completely solve this problem. The recommendations only formulate the target concentration of ≥22 mmol/L before hemodialysis but do not guide how to achieve it. The aim of the study was to assess the acid–base balance in everyday practice, the effect of hemodialysis session and possible correlations with clinical and biochemical parameters in stable hemodialysis patients. Material and methods We enrolled 75 stable hemodialysis patients (mean age 65.5 years, 34 women), from a single Department of Nephrology. We assessed blood pressure, and acid–base balance parameters before and after mid-week hemodialysis session. Results We found significant differences in pH, HCO3– pCO2, lactate before and after HD session in whole group (p < 0.001; p < 0.001; p < 0.001; p = 0.001, respectively). Buffer bicarbonate concentration had only statistically significant effect on the bicarbonate concentration after dialysis (p < 0.001). Both pre-HD acid–base parameters and post-HD pH were independent from buffer bicarbonate content. We observed significant inverse correlations between change in the serum bicarbonates and only two parameters: pH and HCO3– before hemodialysis (p = 0.013; p < 0.001, respectively). Conclusions Despite the improvement in hemodialysis techniques, acid–base balance still remains a challenge. The individual selection of bicarbonate in bath, based on previous single tests, does not improve permanently the acid–base balance in the population of hemodialysis patients. New guidelines how to correct acid–base disorders in hemodialysis patients are needed to have less ‘acidotic’ patients before hemodialysis and less ‘alkalotic’ patients after the session.
Collapse
Affiliation(s)
- Monika Wieliczko
- Department of Nephrology, Dialysis and Internal Disease, Medical University of Warsaw, Warsaw, Poland
| | - Jolanta Małyszko
- Department of Nephrology, Dialysis and Internal Disease, Medical University of Warsaw, Warsaw, Poland
| |
Collapse
|
|
3
|
Bem D, Sugrue D, Wilding B, Zile I, Butler K, Booth D, Tafesse E, McEwan P. The effect of hyperkalemia and long inter-dialytic interval on morbidity and mortality in patients receiving hemodialysis: a systematic review. Ren Fail 2021; 43:241-254. [PMID: 33478329 PMCID: PMC7833048 DOI: 10.1080/0886022x.2020.1871012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/18/2020] [Accepted: 12/26/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Patients with chronic kidney disease, especially those receiving hemodialysis (HD), are at risk of hyperkalemia (HK). This systematic review aimed to evaluate the prevalence of HK in patients with renal disease receiving HD and collate evidence on the effect of HK and differing HD patterns (i.e., long vs. short inter-dialytic intervals [LIDI and SIDI, respectively] in a thrice weekly schedule) on mortality. METHODS Comprehensive searches were conducted across six databases and selected conference proceedings by two independent reviewers up to September 2020. A hundred and two studies reporting frequency of HK, mortality, or cardiovascular (CV) outcomes in adult patients with acute, chronic or end-stage renal disease in receipt of HD were included. Narrative synthesis of results was undertaken with key findings presented in tables and figures. RESULTS Median prevalence of HK in patients with renal disease receiving HD was 21.6% and increased in patients receiving concomitant medications - mainly renin-angiotensin-aldosterone system inhibitors and potassium-sparing diuretics. Associations between elevated potassium levels and increased risk of both all-cause and CV mortality in the HD population were consistent across the included studies. In addition, there was a rise in all-cause and CV mortality on the day following LIDI compared with the day after the two SIDIs in patients on HD. CONCLUSIONS Evidence identified in this systematic review indicates a relationship between HK and LIDI with mortality in patients with renal disease receiving HD, emphasizing the need for effective monitoring and management to control potassium levels both in emergency and chronic HD settings.
Collapse
Affiliation(s)
- Danai Bem
- Health Economics and Outcomes Research Ltd, Birmingham, UK
| | - Daniel Sugrue
- Health Economics and Outcomes Research Ltd, Cardiff, UK
| | - Ben Wilding
- Health Economics and Outcomes Research Ltd, Cardiff, UK
| | - Ina Zile
- Health Economics and Outcomes Research Ltd, Cardiff, UK
| | - Karin Butler
- Health Economics and Outcomes Research Ltd, Cardiff, UK
| | - David Booth
- Health Economics and Outcomes Research Ltd, Cardiff, UK
| | | | - Phil McEwan
- Health Economics and Outcomes Research Ltd, Cardiff, UK
- Swansea University, Swansea, UK
| |
Collapse
|
|
4
|
Butea-Bocu MC, Müller G, Brock O, Otto U. [Metabolic acidosis in neobladder patients : Risk factors and treatment options]. Urologe A 2021; 60:617-623. [PMID: 33884463 DOI: 10.1007/s00120-021-01523-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND In cystectomy patients who underwent neobladder creation, the intestinal mucosa of the neobladder is in constant contact with urine, which may result in chronic metabolic acidosis (CMA) due to specific absorption capabilities of the intestinal mucosa. Despite being a prevalent comorbidity, the risk factors for CMA and its diagnostic parameters are poorly understood. OBJECTIVES This review examines the risk factors associated with the development of CMA and their prevalence in patients with a neobladder. MATERIALS AND METHODS We conducted a systematic literature search using the PubMed database to detect studies about the topics CMA and neobladder that were published between 2000 and 2020. The prevalence and risk factors for CMA in neobladder patients were assessed by reviewing 23 studies. RESULTS Acidosis is most prevalent during the first year after surgery (25-70%). Risk factors are renal failure, high continence, old age and diabetes mellitus. CONCLUSIONS The prevalence of CMA is at its highest during the early postoperative period for neobladder patients, so for this time period, weekly diagnostic investigations are recommended according to the German S3-guidelines for the "Früherkennung, Diagnose, Therapie und Nachsorge des Harnblasenkarzinomsent für Neoblasepatienten". Blood gas tests should not only be used to analyze the pH value but also to detect and counteract acid-base imbalance issues in time. The recommended normalization of serum bicarbonate levels with oral bicarbonate follows patient-specific therapy strategies.
Collapse
Affiliation(s)
- Marius Cristian Butea-Bocu
- Urologisches Kompetenzzentrum für die Rehabilitation - UKR, Kliniken Hartenstein, Dr.-Herbert-Kienle-Str. 6, 34537, Bad Wildungen, Deutschland.
| | - Guido Müller
- Urologisches Kompetenzzentrum für die Rehabilitation - UKR, Kliniken Hartenstein, Dr.-Herbert-Kienle-Str. 6, 34537, Bad Wildungen, Deutschland
| | - Oliver Brock
- Urologisches Kompetenzzentrum für die Rehabilitation - UKR, Kliniken Hartenstein, Dr.-Herbert-Kienle-Str. 6, 34537, Bad Wildungen, Deutschland
| | - Ullrich Otto
- Urologisches Kompetenzzentrum für die Rehabilitation - UKR, Kliniken Hartenstein, Dr.-Herbert-Kienle-Str. 6, 34537, Bad Wildungen, Deutschland
| |
Collapse
|
|
5
|
Almeida LLSD, Sette LHBC, Fonseca FLA, Bezerra LSVDS, Oliveira Júnior FH, Bérgamo RR. Metabolic and volume status evaluation of hemodialysis patients with and without residual renal function in the long interdialytic interval. ACTA ACUST UNITED AC 2020; 41:481-491. [PMID: 30620775 PMCID: PMC6979571 DOI: 10.1590/2175-8239-jbn-2018-0171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 10/14/2018] [Indexed: 11/22/2022]
Abstract
Introduction: It is unclear whether residual renal function (RRF) in dialysis patients can
attenuate the metabolic impact of the long 68-hour interdialytic interval,
in which water, acid, and electrolyte accumulation occurs. Objective: to evaluate serum electrolyte levels, water balance, and acid-base status in
dialytic patients with and without RRF over the long interdialytic interval
(LII). Methodology: this was a single-center, cross-sectional, and analytical study that compared
patients with and without RRF, defined by diuresis above 200 mL in 24 hours.
Patients were weighed and serum samples were collected for biochemical and
gasometric analysis at the beginning and at the end of the LII. Results: 27 and 24 patients with and without RRF were evaluated, respectively.
Patients without RRF had a higher increase in serum potassium during the LII
(2.67 x 1.14 mEq/L, p < 0.001), reaching higher values
at the end of the study (6.8 x 5.72 mEq/L, p < 0.001)
and lower pH value at the beginning of the interval (7.40 x 7.43,
p = 0.018). More patients with serum bicarbonate <
18 mEq/L (50 x 14.8%, p = 0.007) and mixed acid-base
disorder (57.7 x 29.2%, p = 0.042), as well as greater
interdialytic weight gain (14.67 x 8.87 mL/kg/h, p <
0.001) and lower natremia (137 x 139 mEq/L, p = 0.02) at
the end of the interval. Calcemia and phosphatemia were not different
between the groups. Conclusion: Patients with RRF had better control of serum potassium, sodium, acid-base
status, and volemia throughout the LII.
Collapse
|
|
6
|
|
|
7
|
Woodell TB, Rifkin DE, Ellison DH, Negoianu D, Weiss JW. Serum Bicarbonate as a Surrogate for pH in Hemodialysis: A Pilot Study. Kidney Med 2019; 2:42-48. [PMID: 33015611 PMCID: PMC7525140 DOI: 10.1016/j.xkme.2019.08.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Rationale & Objective Excess morbidity and mortality are associated with both high and low serum bicarbonate levels in epidemiologic studies of patients with end-stage kidney disease (ESKD) receiving hemodialysis. The Kidney Disease Outcomes Quality Initiative (KDOQI) recommends modifying dialysate bicarbonate concentration to achieve a predialysis serum bicarbonate level ≥ 22 mmol/L, measured as total carbon dioxide (CO2). This practice assumes that total CO2 is an adequate surrogate for acid-base status, yet its surrogacy performance is unknown in ESKD. We determined acid-base status at the beginning and end of hemodialysis using total CO2 and pH and tested whether total CO2 is an appropriate surrogate for acid-base status. Study Design Pilot study. Setting & Participants 25 veterans with ESKD receiving outpatient hemodialysis. Tests Compared pH, calculated bicarbonate level, and total CO2. Outcomes The proportion of paired samples for which total CO2 misclassified acid-base status according to pH was determined. Bias of total CO2 was evaluated using Bland-Altman plots, comparing it to calculated bicarbonate. Results Among 71 samples, mean pH was 7.41 ± 0.03 predialysis and 7.48 ± 0.05 postdialysis. Compared with interpretation of full blood gas profiles, 9 of 25 (36%) participants were misclassified as acidemic using predialysis total CO2 measures alone (total CO2 < 22 mmol/L but pH ≥ 7.38); 1 (4%) participant was misclassified as alkalemic (total CO2 > 26 mmol/L but pH ≤ 7.42). Among paired samples in which predialysis total CO2 was < 22 mmol/L, the corresponding pH was acidemic (< 7.38) in just 3 of 13 (23%) instances. Limitations Small, single-center, entirely male cohort. Conclusions A majority of participants became alkalemic during routine hemodialysis despite arriving with normal pH. 10 of 25 (40%) participants' acid-base status was misclassified using total CO2 measurements alone; the majority of predialysis total CO2 values that would trigger therapeutic modification according to practice guidelines did not have acidemia when assessed using pH. Efforts to improve dialysis prescription require recognition that total CO2 may not be reliable for interpreting acid-base status in hemodialysis patients.
Collapse
Affiliation(s)
| | - Dena E Rifkin
- University of California, San Diego, La Jolla, CA.,Veterans' Administration Healthcare System, San Diego, CA
| | - David H Ellison
- Oregon Health & Science University, Portland, OR.,Veterans' Administration Healthcare System, Portland, OR
| | | | - Jessica W Weiss
- Oregon Health & Science University, Portland, OR.,Veterans' Administration Healthcare System, Portland, OR
| |
Collapse
|
|
8
|
Acid-Base Status Disturbances in Patients on Chronic Hemodialysis at High Altitudes. Int J Nephrol 2018; 2018:2872381. [PMID: 30581623 PMCID: PMC6276435 DOI: 10.1155/2018/2872381] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 10/31/2018] [Indexed: 12/23/2022] Open
Abstract
Background Acid-base disorders have been previously described in patients with chronic hemodialysis, with metabolic acidosis being the most important of them; however, little is known about the potential changes in acid-base status of patients on dialysis living at high altitudes. Methods Cross-sectional study including 93 patients receiving chronic hemodialysis on alternate days and living in Bogotá, Colombia, at an elevation of 2,640 meters (8,661 feet) over sea level (m.o.s.l.). Measurements of pH, PaCO2, HCO3, PO2, and base excess were made on blood samples taken from the arteriovenous fistula (AVF) during the pre- and postdialysis periods in the midweek hemodialysis session. Normal values for the altitude of Bogotá were taken into consideration for the interpretation of the arterial blood gases. Results 43% (n= 40) of patients showed predialysis normal acid-base status. The most common acid-base disorder in predialysis period was metabolic alkalosis with chronic hydrogen ion deficiency in 19,3% (n=18). Only 9,7% (n=9) had predialysis metabolic acidosis. When comparing pre- and postdialysis blood gas analysis, higher postdialysis levels of pH (7,41 versus 7,50, p<0,01), bicarbonate (21,7mmol/L versus 25,4mmol/L, p<0,01), and base excess (-2,8 versus 2,4, p<0,01) were reported, with lower levels of partial pressure of carbon dioxide (34,9 mmHg versus 32,5 mmHg, p<0,01). Conclusion At an elevation of 2,640 m.o.s.l., a large percentage of patients are in normal acid-base status prior to the dialysis session (“predialysis period”). Metabolic alkalosis is more common than metabolic acidosis in the predialysis period when compared to previous studies. Paradoxically, despite postdialysis metabolic alkalosis, PaCO2 levels are lower than those found in the predialysis period.
Collapse
|
|
9
|
Lugon J, Pereira G, Strogoff-de-Matos J, Peixoto A. Kinetics of acid-base parameters in conventional hemodialysis. Braz J Med Biol Res 2018; 52:e7974. [PMID: 30539970 PMCID: PMC6301264 DOI: 10.1590/1414-431x20187974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 10/22/2018] [Indexed: 11/22/2022] Open
Abstract
Details about the acid-base changes in hemodialysis are scarce in the literature but are potentially relevant to adequate management of patients. We addressed the acid-base kinetics during hemodialysis and throughout the interdialytic period in a cross-sectional study of adults undergoing conventional hemodialysis. Samples for blood gas analysis were obtained from the arterial limb of the arteriovenous fistula before the first session of the week (HD1), immediately at the end of HD1, and on sequential collections at 15, 30, 45, 60, and 120 min post-HD1. Additional blood samples were collected after ∼20 h following the end of the first dialysis and immediately prior to the initiation of the second dialysis of the week. Thirty adult patients were analyzed (55±15 years, 50% men, 23% diabetic; dialysis vintage 69±53 months). Mean serum bicarbonate levels increased at the end of HD1 (22.3±2.7 mEq/L vs 17.5±2.3 mEq/L, P<0.001) and remained stable until 20 h after the end of the session. The mean values of pCO2 before HD1 were below reference and at 60 and 120 min post-HD1 were significantly lower than at the start (31.3±2.7 mmHg and 30.9±3.7 mmHg vs 34.3±4.1 mmHg, P=0.041 and P=0.010, respectively). The only point of collection in which mean values of pCO2 were above 35 mmHg was 20 h post-dialysis. Serum bicarbonate levels remained stable for at least 20 h after the dialysis sessions, a finding that may have therapeutic implications. During dialysis, the respiratory response for correction of metabolic acidosis (i.e., pCO2 elevation) was impaired.
Collapse
Affiliation(s)
- J.R. Lugon
- Divisão de Nefrologia, Departamento de Medicina, Faculdade de Medicina, Universidade Federal Fluminense, Niteroi, RJ, Brasil
| | - G.R.M. Pereira
- Curso de Pós-Graduação em Ciências Médicas, Faculdade de Medicina, Universidade Federal Fluminense, Niteroi, RJ, Brasil
| | - J.P. Strogoff-de-Matos
- Divisão de Nefrologia, Departamento de Medicina, Faculdade de Medicina, Universidade Federal Fluminense, Niteroi, RJ, Brasil
| | - A.J. Peixoto
- Section of Nephrology, Yale University School of Medicine, New Haven, CT, USA
| |
Collapse
|
|
10
|
Abstract
The optimal approach to managing acid-base balance is less well defined for patients receiving hemodialysis than for those receiving peritoneal dialysis. Interventional studies in hemodialysis have been limited and inconsistent in their findings, whereas more compelling data are available from interventional studies in peritoneal dialysis. Both high and low serum bicarbonate levels associate with an increased risk of mortality in patients receiving hemodialysis, but high values are a marker for poor nutrition and comorbidity and are often highly variable from month to month. Measurement of pH would likely provide useful additional data. Concern has arisen regarding high-bicarbonate dialysate and dialysis-induced alkalemia, but whether these truly cause harm remains to be determined. The available evidence is insufficient for determining the optimal target for therapy at this time.
Collapse
Affiliation(s)
- Matthew K Abramowitz
- Division of Nephrology, Department of Medicine, and
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
|
11
|
Marano M, D’Amato A, Cantone A. Carbon dioxide: Global warning for nephrologists. World J Nephrol 2016; 5:429-36. [PMID: 27648406 PMCID: PMC5011249 DOI: 10.5527/wjn.v5.i5.429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 08/02/2016] [Accepted: 08/17/2016] [Indexed: 02/06/2023] Open
Abstract
The large prevalence of respiratory acid-base disorders overlapping metabolic acidosis in hemodialysis population should prompt nephrologists to deal with the partial pressure of carbon dioxide (pCO2) complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients' bloodstream every hemodialysis treatment and "acidosis by dialysate" may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the filter reenters arterial needle.
Collapse
|