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Lindholm E, Martus G, Öberg CM, Bergling K. Determining the residual volume in peritoneal dialysis using low molecular weight markers. Perit Dial Int 2024:8968608241260024. [PMID: 39091083 DOI: 10.1177/08968608241260024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024] Open
Abstract
BACKGROUND Variation in residual volume between peritoneal dialysis dwells creates uncertainty in ultrafiltration determination, dialysis efficiency, and poses a risk of overfill if the residual volume is large. Measuring the dilution of a marker molecule during fluid fill offers a convenient approach, however, estimation accuracy depends on the choice of dilution marker. We here evaluate the feasibility of creatinine and urea as dilution markers compared to albumin-based residual volumes and three-pore model estimations. METHOD This clinical, retrospective analysis comprises 56 residual volume estimations from 20 individuals, based on the dilution of pre-fill dialysate creatinine, urea and albumin concentrations during the dialysis fluid fill phase. Outcomes were compared individually. Bias induced by ultrafiltration, marker molecule mass-transfer and influence of fluid glucose contents was quantified using the three-pore model. Linear regression established conversion factors enabling conversion between the various marker molecules. RESULTS Creatinine-based calculations overestimated residual volumes by 115 mL (IQR 89-149) in 1.5% dwells and 252 mL (IQR 179-313) in 4.25% glucose dwells. In hypertonic dwells, ultrafiltration was 52 mL (IQR 38-66), while intraperitoneal creatinine mass increased by 67% during fluid fill, being the leading cause of overestimation. Albumin-based volumes conformed strongly with three-pore model estimates. Correction factors effectively enabled marker molecule interchangeability. CONCLUSIONS Mass-transfer of low molecular weight marker molecules is associated with residual volume overestimation. However, by applying correction factors, creatinine and urea dilution can still provide reasonable estimates, particularly when the purpose is to exclude the presence of a very large residual volume.
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Affiliation(s)
- Elin Lindholm
- Department of Clinical Sciences Lund, Skane University Hospital, Lund University, Lund, Sweden
| | - Giedre Martus
- Department of Clinical Sciences Lund, Skane University Hospital, Lund University, Lund, Sweden
| | - Carl M Öberg
- Department of Clinical Sciences Lund, Skane University Hospital, Lund University, Lund, Sweden
| | - Karin Bergling
- Department of Clinical Sciences Lund, Skane University Hospital, Lund University, Lund, Sweden
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Morelle J, Lambie M, Öberg CM, Davies S. The Peritoneal Membrane and Its Role in Peritoneal Dialysis. Clin J Am Soc Nephrol 2024; 19:244-253. [PMID: 37616463 PMCID: PMC10861113 DOI: 10.2215/cjn.0000000000000282] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 08/03/2023] [Indexed: 08/26/2023]
Abstract
A healthy and functional peritoneal membrane is key to achieving sufficient ultrafiltration and restoring fluid balance, a major component of high-quality prescription in patients treated with peritoneal dialysis (PD). Variability in membrane function at the start of PD or changes over time on treatment influence dialysis prescription and outcomes, and dysfunction of the peritoneal membrane contributes to fluid overload and associated complications. In this review, we summarize the current knowledge about the structure, function, and pathophysiology of the peritoneal membrane with a focus on clinical implications for patient-centered care. We also discuss the molecular and genetic mechanisms of solute and water transport across the peritoneal membrane, including the role of aquaporin water channels in crystalloid versus colloid osmosis; why and how to assess membrane function using peritoneal equilibration tests; the etiologies of membrane dysfunction and their specific management; and the effect of genetic variation on membrane function and outcomes in patients treated with PD. This review also identifies the gaps in current knowledge and perspectives for future research to improve our understanding of the peritoneal membrane and, ultimately, the care of patients treated with PD.
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Affiliation(s)
- Johann Morelle
- Division of Nephrology, Cliniques universitaires Saint-Luc, Brussels, Belgium
- UCLouvain School of Medicine, UCLouvain, Brussels, Belgium
| | - Mark Lambie
- Faculty of Medicine and Health Sciences, Keele University, Keele, United Kingdom
| | - Carl M. Öberg
- Division of Nephrology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Simon Davies
- Faculty of Medicine and Health Sciences, Keele University, Keele, United Kingdom
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Helman J, Wahlgren H, Andersson L, Morelle J, Öberg CM. Quantifying Ultrafiltration in Peritoneal Dialysis Using the Sodium Dip. KIDNEY360 2024; 5:195-204. [PMID: 38236202 PMCID: PMC10914194 DOI: 10.34067/kid.0000000000000358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 01/10/2024] [Indexed: 01/19/2024]
Abstract
Key Points Ultrafiltration (UF) is a key component of clinical peritoneal dialysis prescription, but the traditional method to assess UF is hampered by large inaccuracies. Here we propose a novel method, based on a computational model and on a single dialysate sodium measurement, to accurately estimate UF and osmotic conductance to glucose in patients on peritoneal dialysis. Background Volume overload is highly prevalent among patients treated with peritoneal dialysis (PD), contributes to hypertension, and is associated with an increased risk of cardiovascular events and death in this population. As a result, optimizing peritoneal ultrafiltration (UF) is a key component of high-quality dialysis prescription. Osmotic conductance to glucose (OCG) reflects the water transport properties of the peritoneum, but measuring it requires an accurate quantification of UF, which is often difficult to obtain because of variability in catheter patency and peritoneal residual volume. Methods In this study, we derived a new mathematical model for estimating UF during PD, on the basis of sodium sieving, using a single measure of dialysate sodium concentration. The model was validated experimentally in a rat model of PD, using dialysis fluid with two different sodium concentrations (125 and 134 mmol/L) and three glucose strengths (1.5%, 2.3%, and 4.25%). Then, the same model was tested in a cohort of PD patients to predict UF. Results In experimental and clinical conditions, the sodium-based estimation of UF rate correlated with UF rate measurements on the basis of volumetry and albumin dilution, with a R 2 =0.35 and R 2 =0.76, respectively. UF on the basis of sodium sieving was also successfully used to calculate OCG in the clinical cohort, with a Pearson r of 0.77. Conclusions Using the novel mathematical models in this study, the sodium dip can be used to accurately estimate OCG, and therefore, it is a promising measurement method for future clinical use.
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Affiliation(s)
- Jakob Helman
- Department of Clinical Sciences Lund, Skåne University Hospital, Lund, Sweden
| | - Hedda Wahlgren
- Department of Clinical Sciences Lund, Skåne University Hospital, Lund, Sweden
| | - Linn Andersson
- Department of Clinical Sciences Lund, Skåne University Hospital, Lund, Sweden
| | - Johann Morelle
- Division of Nephrology, Cliniques universitaires Saint-Luc, Brussels, Belgium
- UCLouvain School of Medicine, Université catholique de Louvain, Brussels, Belgium
| | - Carl M. Öberg
- Department of Clinical Sciences Lund, Skåne University Hospital, Lund, Sweden
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Falcao L, Gago LG, Astudillo D, Magariños CR, Pardo MB, Rodríguez-Carmona A, Fontán MP. Influence of peritoneal residual volume on the results of the peritoneal equilibration test. Prospective study. Nefrologia 2023; 43:189-196. [PMID: 37442712 DOI: 10.1016/j.nefroe.2021.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 07/24/2021] [Indexed: 07/15/2023] Open
Abstract
BACKGROUND Categorization of the capacity of ultrafiltration during a peritoneal equilibration test (PET) is a usual step during the monitoring of peritoneal transport characteristics of Peritoneal Dialysis (PD) patients. Quantifying the peritoneal residual volume (Vr) after the dwell preceding the PET (Vrpre) and at the end of the test (Vrpost) could help to improve the accuracy of the estimation of this variable. METHOD Following a prospective design, we calculated Vrpre and Vrpost in 116 patients, incident or prevalent on DP, who underwent one or two (n = 27) PET with 3,86/4,25% glucose-based PD solutions and complete drainage at 60 min. We evaluated the consistency of Vr by comparing Vrpre and Vrpost, as also these two parameters in repeated tests. We scrutinized potential associations between demographic and clinical factors, on one side, and the amount of Vr on the other, as also the impact of correcting ultrafiltration during PET for Vr on the categorization of the capacity of ultrafiltration. RESULTS As a mean, Vrpost was larger than Vrpre. Consequently, correction of ultrafiltration for Vr resulted in significantly higher values than those obtained according to the standard procedure (494 vs. 449 mL, p < 0,0005). We disclosed marked inconsistencies for different estimations of Vr in the same patients (Vrpre vs Vrpost and repeated PET studies). Moreover, no demographic or clinical variable was able to predict the amount of Vr. We observed a significant deviation (>200 mL) between both methods of estimation of the capacity of utrafiltration in only 12,9% of the patients. However, 21,1% of the patients categorized as cases of ultrafiltration failure according to the standard procedure did not maintain this condition after correction for Vr. CONCLUSIONS Correction for Vr of the capacity of ultrafiltration during a PET carries, as a mean, a minor impact on the categorization of this parameter. However, the results of the test can be significantly affected in 12,9% of the cases. We have been unable to detect demographic or clinical predictors of Vr, which suggests a random component for the mechanics of single peritoneal exchanges. We suggest that Vr should be estimated at the time of categorizing the capacity of ultrafiltration, whenever inconsistencies during serial PET studies are detected.
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Affiliation(s)
- Luis Falcao
- Servicio de Nefrología, Hospital Beatriz Angelo, Loures, Portugal
| | - Leticia García Gago
- Servicio de Nefrología, Hospital Universitario de A Coruña, La Coruña, Spain
| | - Daniela Astudillo
- Servicio de Nefrología, Hospital Universitario de A Coruña, La Coruña, Spain
| | | | - Marta Blanco Pardo
- Servicio de Nefrología, Hospital Universitario de A Coruña, La Coruña, Spain
| | | | - Miguel Pérez Fontán
- Servicio de Nefrología, Hospital Universitario de A Coruña, La Coruña, Spain; Facultad de Ciencias de la Salud, Universidad de A Coruña, La Coruña, Spain.
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Falcao L, García Gago L, Astudillo D, Rodríguez Magariños C, Blanco Pardo M, Rodríguez-Carmona A, Pérez Fontán M. Influencia del volumen peritoneal residual en los resultados de la prueba de equilibrio peritoneal. Estudio prospectivo. Nefrologia 2021. [DOI: 10.1016/j.nefro.2021.07.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Verger C, Dratwa M. Traduction des Recommandations de l'ISPD pour l'évaluation du dysfonctionnement de la membrane péritonéale chez l'adulte. BULLETIN DE LA DIALYSE À DOMICILE 2021. [DOI: 10.25796/bdd.v4i3.62673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Informations concernant cette traductionDans le cadre d’un accord de partenariat entre l’ISPD et le RDPLF, le RDPLF est le traducteur français officiel des recommandations de l’ISPD. La traduction ne donne lieu à aucune compensation financière de la part de chaque société et le RDPLF s’est engagé à traduire fidèlement le texte original sous la responsabilité de deux néphrologues connus pour leur expertise dans le domaine. Avant publication le texte a été soumis à l’accord de l’ISPD. La traduction est disponible sur le site de l’ISPD et dans le Bulletin de la Dialyse à Domicile.Le texte est, comme l’original, libremement téléchargeable sous licence copyright CC By 4.0https://creativecommons.org/licenses/by/4.0/Cette traduction est destinée à aider les professionnels de la communauté francophone à prendre connaissance des recommandations de l’ISPD dans leur langue maternelle.
Toute référence dans un article doit se faire au texte original en accès libre :Peritoneal Dialysis International https://doi.org/10.1177/0896860820982218
Dans les articles rédigés pour des revues françaises, conserver la référence à la version originale anglaise ci dessus, mais ajouter «version française https://doi.org/10.25796/bdd.v4i3.62673"»TraducteursDr Christian Verger, néphrologue, président du RDPLFRDPLF, 30 rue Sere Depoin, 95300 Pontoise – FranceProfesseur Max Dratwa, néphrologueHôpital Universitaire Brugmann – Bruxelles – Belgique
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Morelle J, Stachowska-Pietka J, Öberg C, Gadola L, La Milia V, Yu Z, Lambie M, Mehrotra R, de Arteaga J, Davies S. ISPD recommendations for the evaluation of peritoneal membrane dysfunction in adults: Classification, measurement, interpretation and rationale for intervention. Perit Dial Int 2021; 41:352-372. [DOI: 10.1177/0896860820982218] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lay summary Peritoneal dialysis (PD) uses the peritoneal membrane for dialysis. The peritoneal membrane is a thin layer of tissue that lines the abdomen. The lining is used as a filter to help remove extra fluid and poisonous waste from the blood. Everybody is unique. What is normal for one person’s membrane may be very different from another person’s. The kidney care team wants to provide each person with the best dialysis prescription for them and to do this they must evaluate the person’s peritoneal lining. Sometimes dialysis treatment itself can cause the membrane to change after some years. This means more assessments (evaluations) will be needed to determine whether the person’s peritoneal membrane has changed. Changes in the membrane may require changes to the dialysis prescription. This is needed to achieve the best dialysis outcomes. A key tool for these assessments is the peritoneal equilibration test (PET). It is a simple, standardized and reproducible tool. This tool is used to measure the peritoneal function soon after the start of dialysis. The goal is to understand how well the peritoneal membrane works at the start of dialysis. Later on in treatment, the PET helps to monitor changes in peritoneal function. If there are changes between assessments causing problems, the PET data may explain the cause of the dysfunction. This may be used to change the dialysis prescription to achieve the best outcomes. The most common problem with the peritoneal membrane occurs when fluid is not removed as well as it should be. This happens when toxins (poisons) in the blood cross the membrane more quickly than they should. This is referred to as a fast peritoneal solute transfer rate (PSTR). Since more efficient fluid removal is associated with better outcomes, developing a personal PD prescription based on the person’s PSTR is critically important. A less common problem happens when the membrane fails to work properly (also called membrane dysfunction) because the peritoneal membrane is less efficient, either at the start of treatment or developing after some years. If membrane dysfunction gets worse over time, then this is associated with progressive damage, scarring and thickening of the membrane. This problem can be identified through another change of the PET. It is called reduced ‘sodium dip’. Membrane dysfunction of this type is more difficult to treat and has many implications for the individual. If the damage is major, the person may need to stop PD. They would need to begin haemodialysis treatment (also spelled hemodialysis). This is a very important and emotional decision for individuals with kidney failure. Any decision that involves stopping PD therapy or transitioning to haemodialysis therapy should be made jointly between the clinical team, the person on dialysis and a caregiver, if requested. Although evidence is lacking about how often tests should be performed to determine peritoneal function, it seems reasonable to repeat them whenever there is difficulty in removing the amount of fluid necessary for maintaining the health and well-being of the individual. Whether routine evaluation of membrane function is associated with better outcomes has not been studied. Further research is needed to answer this important question as national policies in many parts of the world and the COVID-19 has placed a greater emphasis and new incentives encouraging the greater adoption of home dialysis therapies, especially PD. For Chinese and Spanish Translation of the Lay Summary, see Online Supplement Appendix 1. Key recommendations Guideline 1: A pathophysiological taxonomy: A pathophysiological classification of membrane dysfunction, which provides mechanistic links to functional characteristics, should be used when prescribing individualized dialysis or when planning modality transfer (e.g. to automated peritoneal dialysis (PD) or haemodialysis) in the context of shared and informed decision-making with the person on PD, taking individual circumstances and treatment goals into account. (practice point) Guideline 2a: Identification of fast peritoneal solute transfer rate (PSTR): It is recommended that the PSTR is determined from a 4-h peritoneal equilibration test (PET), using either 2.5%/2.27% or 4.25%/3.86% dextrose/glucose concentration and creatinine as the index solute. (practice point) This should be done early in the course dialysis treatment (between 6 weeks and 12 weeks) (GRADE 1A) and subsequently when clinically indicated. (practice point) Guideline 2b: Clinical implications and mitigation of fast solute transfer: A faster PSTR is associated with lower survival on PD. (GRADE 1A) This risk is in part due to the lower ultrafiltration (UF) and increased net fluid reabsorption that occurs when the PSTR is above the average value. The resulting lower net UF can be avoided by shortening glucose-based exchanges, using a polyglucose solution (icodextrin), and/or prescribing higher glucose concentrations. (GRADE 1A) Compared to glucose, use of icodextrin can translate into improved fluid status and fewer episodes of fluid overload. (GRADE 1A) Use of automated PD and icodextrin may mitigate the mortality risk associated with fast PSTR. (practice point) Guideline 3: Recognizing low UF capacity: This is easy to measure and a valuable screening test. Insufficient UF should be suspected when either (a) the net UF from a 4-h PET is <400 ml (3.86% glucose/4.25% dextrose) or <100 ml (2.27% glucose /2.5% dextrose), (GRADE 1B) and/or (b) the daily UF is insufficient to maintain adequate fluid status. (practice point) Besides membrane dysfunction, low UF capacity can also result from mechanical problems, leaks or increased fluid absorption across the peritoneal membrane not explained by fast PSTR. Guideline 4a: Diagnosing intrinsic membrane dysfunction (manifesting as low osmotic conductance to glucose) as a cause of UF insufficiency: When insufficient UF is suspected, the 4-h PET should be supplemented by measurement of the sodium dip at 1 h using a 3.86% glucose/4.25% dextrose exchange for diagnostic purposes. A sodium dip ≤5 mmol/L and/or a sodium sieving ratio ≤0.03 at 1 h indicates UF insufficiency. (GRADE 2B) Guideline 4b: Clinical implications of intrinsic membrane dysfunction (de novo or acquired): in the absence of residual kidney function, this is likely to necessitate the use of hypertonic glucose exchanges and possible transfer to haemodialysis. Acquired membrane injury, especially in the context of prolonged time on treatment, should prompt discussions about the risk of encapsulating peritoneal sclerosis. (practice point) Guideline 5: Additional membrane function tests: measures of peritoneal protein loss, intraperitoneal pressure and more complex tests that estimate osmotic conductance and ‘lymphatic’ reabsorption are not recommended for routine clinical practice but remain valuable research methods. (practice point) Guideline 6: Socioeconomic considerations: When resource constraints prevent the use of routine tests, consideration of membrane function should still be part of the clinical management and may be inferred from the daily UF in response to the prescription. (practice point)
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Affiliation(s)
- Johann Morelle
- Division of Nephrology, Cliniques universitaires Saint-Luc, and Institut de Recherche Expérimentale et Clinique, UCLouvain, Brussels, Belgium
| | - Joanna Stachowska-Pietka
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Carl Öberg
- Division of Nephrology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Liliana Gadola
- Centro de Nefrología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | | | - Zanzhe Yu
- Department of Nephrology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Mark Lambie
- Faculty of Medicine and Health Sciences, Keele University, Keele, UK
| | - Rajnish Mehrotra
- Division of Nephrology, Department of Medicine, University of Washington, Seattle, Washington DC, USA
| | - Javier de Arteaga
- Servicio de Nefrología, Hospital Privado Universitario de Córdoba, Universidad Católica de Córdoba, Córdoba, Argentina
| | - Simon Davies
- Faculty of Medicine and Health Sciences, Keele University, Keele, UK
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Martus G, Bergling K, Simonsen O, Goffin E, Morelle J, Öberg CM. Novel Method for Osmotic Conductance to Glucose in Peritoneal Dialysis. Kidney Int Rep 2020; 5:1974-1981. [PMID: 33163718 PMCID: PMC7610002 DOI: 10.1016/j.ekir.2020.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 08/17/2020] [Accepted: 09/01/2020] [Indexed: 01/30/2023] Open
Abstract
Introduction The osmotic conductance to glucose (OCG) is a crucial determinant of ultrafiltration (UF) in peritoneal dialysis (PD) patients and can be used to monitor membrane integrity in patients on long-term PD. It has been proposed that OCG can be assessed based on drained volumes in 2 consecutive 1-hour glucose dwells, usually 1.5% and 4.25% glucose, in a so-called double mini-peritoneal equilibration test (dm-PET). However, recent data indicated that the dm-PET provides a poor estimate of OCG unless the residual volume (RV) is taken into account. We introduce an easy, robust, and accurate method to measure OCG and compare it with conventional methods. Methods In a prospective cohort of 21 PD patients, a modified version of the dm-PET was performed, along with the determination of RV before, between, and after dwells. Based on computer simulations derived from the 3-pore model (TPM) for membrane permeability, we developed and validated a novel single-dwell method to estimate OCG. We next validated the equation in an independent cohort consisting of 32 PD patients. Results Single-dwell OCG correlated more closely with actual UF (r = 0.94 vs. r = 0.07 for conventional dm-PET), sodium sieving, and free water transport (FWT) compared with other methods. These findings were replicated in the validation cohort in which OCG calculated using the single-dwell method closely correlated with parameters of osmotic water transport, even when RV was not taken into account, using only drained volumes. Conclusion We propose a novel, easy, and robust single-dwell method to determine OCG in individual patients and to monitor membrane integrity over time on PD.
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Affiliation(s)
- Giedre Martus
- Department of Clinical Sciences Lund, Nephrology Division, Skane University Hospital, Lund University, Lund, Sweden
| | - Karin Bergling
- Department of Clinical Sciences Lund, Nephrology Division, Skane University Hospital, Lund University, Lund, Sweden
| | - Ole Simonsen
- Department of Clinical Sciences Lund, Nephrology Division, Skane University Hospital, Lund University, Lund, Sweden
| | - Eric Goffin
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.,Institut de Recherche Expérimentale et Clinique, UCLouvain, Brussels, Belgium
| | - Johann Morelle
- Division of Nephrology, Cliniques Universitaires Saint-Luc, Brussels, Belgium.,Institut de Recherche Expérimentale et Clinique, UCLouvain, Brussels, Belgium
| | - Carl M Öberg
- Department of Clinical Sciences Lund, Nephrology Division, Skane University Hospital, Lund University, Lund, Sweden
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Öberg CM, Martuseviciene G. Computer Simulations of Continuous Flow Peritoneal Dialysis Using the 3-Pore Model-A First Experience. Perit Dial Int 2019; 39:236-242. [PMID: 30846606 DOI: 10.3747/pdi.2018.00225] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 12/28/2018] [Indexed: 11/15/2022] Open
Abstract
Background:Continuous flow peritoneal dialysis (CFPD) is performed using a continuous flux of dialysis fluid via double or dual-lumen PD catheters, allowing a higher dialysate flow rate (DFR) than conventional treatments. While small clinical studies have revealed greatly improved clearances using CFPD, the inability to predict ultrafiltration (UF) may confer a risk of potentially harmful overfill. Here we performed physiological studies of CFPD in silico using the extended 3-pore model.Method:A 9-h CFPD session was simulated for: slow (dialysate to plasma creatinine [D/P crea] < 0.6), fast (D/P crea > 0.8) and average (0.6 ≤ D/P crea ≤ 0.8) transporters using 1.36%, 2.27%, or 3.86% glucose solutions. To avoid overfill, we applied a practical equation, based on the principle of mass-balance, to predict the UF rate during CFPD treatment.Results:Increasing DFR > 100 mL/min evoked substantial increments in small- and middle-molecule clearances, being 2 - 5 times higher compared with a 4-h continuous ambulatory PD (CAPD) exchange, with improvements typically being smaller for average and slow transporters. Improved UF rates, exceeding 10 mL/min, were achieved for all transport types. The β2-microglobulin clearance was strongly dependent on the UF rate and increased between 60% and 130% as a function of DFR. Lastly, we tested novel intermittent-continuous regimes as an alternative strategy to prevent overfill, being effective for 1.36% and 2.27%, but not for 3.86% glucose.Conclusion:While we find substantial increments in solute and water clearance with CFPD, previous studies have shown similar improvements using high-volume tidal automated PD (APD). Lastly, the current in silico results need confirmation by studies in vivo.
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Affiliation(s)
- Carl M Öberg
- Renal Physiology and Peritoneal Dialysis Group, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Giedre Martuseviciene
- Renal Physiology and Peritoneal Dialysis Group, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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