Kinetic Analysis of Peritoneal Fluid and Solute Transport with Combination of Glucose and Icodextrin as Osmotic Agents

2009 ◽  
Vol 29 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Magda Galach ◽  
Andrzej Werynski ◽  
Jacek Waniewski ◽  
Philippe Freida ◽  
Bengt Lindholm
Keyword(s):  
Mathematical Modeling ◽  
Computer Simulations ◽  
Clinical Data ◽  
Extracellular Volume ◽  
Sodium Concentration ◽  
Pore Model ◽  
Fluid Removal ◽  
Sodium Removal ◽  
Osmotic Agents ◽  
Dialysis Fluids

Background Controlling extracellular volume and plasma sodium concentration are two crucial objectives of dialysis therapy, as inadequate sodium and fluid removal by dialysis may result in extracellular volume overload, hypertension, and increased cardiovascular morbidity and mortality in end-stage renal disease patients. A new concept to enhance sodium and fluid removal during peritoneal dialysis (PD) is the use of dialysis solutions with two different osmotic agents. Aim To investigate and compare, with the help of mathematical modeling and computer simulations, fluid and solute transport during PD with conventional dialysis fluids (3.86% glucose and 7.5% icodextrin; both with standard sodium concentration) and a new combination fluid with both icodextrin and glucose (CIG; 2.6% glucose/6.8% icodextrin; low sodium concentration). In particular, this paper is devoted to improving mathematical modeling based on critical appraisal of the ability of the original three-pore model to reproduce clinical data and check its validity across different types of osmotic agents. Methods Theoretical investigations of possible causes of the improved fluid and sodium removal during PD with the combination solution (CIG) were carried out using the three-pore model. The results of computer simulations were compared with clinical data from dwell studies in 7 PD patients. To fit the model to the low net ultrafiltration (366 ± 234 mL) obtained after a 4-hour dwell with 3.86% glucose, some of the original parameters proposed in the three-pore model (Rippe & Levin. Kidney Int 2000; 57:2546-56) had to be modified. In particular, the aquaporin-mediated fractional contribution to hydraulic permeability was decreased by 25% and small pore radius increased by 18%. Results The simulations described well clinical data that showed a dramatic increase in ultrafiltration and sodium removal with the CIG fluid in comparison with the two other dialysis fluids. However, to adapt the three-pore model to the selected group of PD patients (fast transporters with small ultrafiltration capacity on average), the peritoneal pore structure had to be modified. As the mathematical model was capable of reproducing the clinical data, this shows that the enhanced ultrafiltration with the combination fluid is caused by the additive effect of the two different osmotic agents and not by a specific impact of the new dialysis fluid on the transport characteristics of the peritoneum.

Inflammation and Extracellular Volume Expansion are Related to Sodium and Water Removal in Patients on Peritoneal Dialysis

2006 ◽  
Vol 26 (5) ◽  
pp. 574-580 ◽  
Author(s):  
Marcela Ávila-Díaz ◽  
María-de-Jesús Ventura ◽  
Delfilia Valle ◽  
Marlén Vicenté-Martínez ◽  
Zuzel García-González ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Extracellular Volume ◽  
Extracellular Fluid ◽  
Cross Sectional Study ◽  
Serum Glucose ◽  
Cross Sectional ◽  
Fluid Removal ◽  
Sodium Removal ◽  
Extracellular Volume Expansion ◽  
Total Body

Background Inflammation is an important risk for mortality in dialysis patients. Extracellular fluid volume (ECFv) expansion, a condition commonly seen in peritoneal dialysis (PD) patients, may be associated with inflammation. However, published support for this relationship is scarce. Objectives To quantify the proportion of patients on PD with inflammation and to analyze the role of ECFv expansion and the factors related to these conditions. Design A prospective, multicenter cross-sectional study in six hospitals with a PD program. Patients and Methods Adult patients on PD were studied. Clinical data, body composition, and sodium and fluid intake were recorded. Biochemical analysis, C-reactive protein (CRP), and peritoneal and urinary fluid and sodium removal were also measured. Results CRP values positive (≥ 3.0 mg/L) for inflammation were found in 147 (80.3%) and negative in 36 patients. Patients with positive CRP had higher ECFv/total body water (TBW) ratio (women 47.69 ± 0.69 vs 47.36 ± 0.65, men 43.15 ± 1.14 vs 42.84 ± 0.65; p < 0.05), higher serum glucose (125.09 ± 81.90 vs 103.28 ± 43.30 mg/dL, p < 0.03), and lower serum albumin (2.86 ± 0.54 vs 3.17 ± 0.38 g/dL, p < 0.001) levels. They also had lower ultrafiltration (1003 ± 645 vs 1323 ± 413 mL/day, p < 0.005) and total fluid removal (1260 ± 648 vs 1648 ± 496 mL/day, p < 0.001), and less peritoneal (15.59 ± 162.14 vs 78.11 ± 110.70 mEq/day, p < 0.01) and total sodium removal (42.06 ± 142.49 vs 118.60 ± 69.73 mEq/day, p < 0.001). In the multivariate analysis, only ECFv/TBW was significantly ( p < 0.04) and independently associated with inflammation. ECFv/TBW was correlated with fluid removal ( r = 0.16, p < 0.03) and renal sodium removal ( r = 0.2, p < 0.01). Conclusion The data suggest that ECFv expansion may have a significant role as an inflammatory stimulus. The results disclose a relationship between the two variables, ECFv expansion and inflammation, identified as independent risk factors for mortality in PD patients.

Combination of Crystalloid (Glucose) and Colloid (Icodextrin) Osmotic Agents Markedly Enhances Peritoneal Fluid and Solute Transport during the Long PD Dwell

2007 ◽  
Vol 27 (3) ◽  
pp. 267-276 ◽  
Author(s):  
Philippe Freida ◽  
Magda Galach ◽  
Jose C. Divino Filho ◽  
Andrzej Werynski ◽  
Bengt Lindholm
Keyword(s):  
Peritoneal Dialysis ◽  
Solute Transport ◽  
Residual Renal Function ◽  
Transport Rate ◽  
Dialysis Patients ◽  
Fluid Removal ◽  
Sodium Removal ◽  
Ultra Filtration ◽  
Osmotic Agents ◽  
Peritoneal Solute Transport Rate

Background Fluid and sodium removal is often inadequate in peritoneal dialysis patients with high peritoneal solute transport rate, especially when residual renal function is declining. Method We studied the effects of using simultaneous crystalloid (glucose) and colloid (icodextrin) osmotic agents on the peritoneal transport of fluid, sodium, and other solutes during 15-hour single-dwell exchanges using 3.86% glucose, 7.5% icodextrin, and a combination fluid with 2.61% glucose and 6.8% icodextrin in 7 prevalent peritoneal dialysis patients with fast peritoneal solute transport rate. Results The combination fluid enhanced net ultrafiltration (mean 990 mL) and sodium removal (mean 158 mmol) compared with 7.5% icodextrin (mean net ultrafiltration 462 mL, mean net sodium removal 49 mmol). In contrast, the 3.86% glucose-based solution yielded negligible ultra-filtration (mean -85 mL) and sodium removal (mean 16 mmol). The combination solution resulted in significantly improved urea (+41%) and creatinine (+26%) clearances compared with 7.5% icodextrin. Conclusion A solution containing both crystalloid (glucose 2.61%) and colloid (icodextrin 6.8%) osmotic agents enhanced fluid removal by twofold and sodium removal by threefold compared with 7.5% icodextrin solution during a dwell of 15 hours, indicating that such a combination solution could represent a new treatment option for anuric peritoneal dialysis patients with high peritoneal solute transport rate.

Learning physiology from cardiac surgery patients.

1998 ◽  
Vol 274 (6) ◽  
pp. S74
Author(s):  
S Nicol ◽  
C Narkowicz
Keyword(s):  
Cardiac Surgery ◽  
Computer Simulations ◽  
Clinical Data ◽  
Great Reduction ◽  
Animal Experiments ◽  
Medical Schools ◽  
Physiological Data ◽  
Video Clips ◽  
Computer Based

A number of pressures have led to a very great reduction or complete abandonment of the use of animals in the teaching of physiology in most medical schools. Often animal experiments have been replaced by computer simulations, but a simulation is only as good as the model or algorithm on which it is based and can never contain the depth of information or unpredictability displayed by real animals or patients. We used a computer-based system to collect cardiovascular data from patients instrumented for cardiac surgery, allowing students to "replay" an operation. These recordings were annotated with notes, diagrams and video clips, and a student workbook was written. The resulting package contained a wealth of physiological data and was perceived by students to be very clinically relevant. The very wealth of information, however, tended to overwhelm students, and so a series of introductory Computer tutorials were written to provide students with the background necessary to cope with the clinical data.

A Combined Crystalloid and Colloid PD Solution as a Glucose-Sparing Strategy for Volume Control in High-Transport APD Patients: A Prospective Multicenter Study

2009 ◽  
Vol 29 (4) ◽  
pp. 433-442 ◽  
Author(s):  
Philippe Freida ◽  
Belkacem Issad ◽  
Max Dratwa ◽  
Thierry Lobbedez ◽  
LieLing Wu ◽  
...  
Keyword(s):  
Glucose Absorption ◽  
Volume Control ◽  
Continuous Exposure ◽  
University Hospitals ◽  
Percent Change ◽  
Sodium Removal ◽  
Free Glucose ◽  
Fast Transport ◽  
Glucose Exposure ◽  
Osmotic Agents

Background Evidence is accumulating that the continuous exposure to high glucose concentrations during peritoneal dialysis (PD) is an important cause of ultrafiltration (UF) failure. The cornerstone of prevention and treatment of UF failure is reduction of glucose exposure, which will also alleviate the systemic impact of significant free glucose absorption. The challenge for the future is to discover new therapeutic strategies to enhance fluid and sodium removal while diminishing glucose load and exposure using combinations of available osmotic agents. Objectives To investigate in patients on automated PD (APD) with a fast transport pattern whether there is a glucose-sparing advantage to replacing 7.5% icodextrin (ICO) during the long dwell with a mixed crystalloid and colloid PD fluid (bimodal UF) in an attempt to promote daytime UF and sodium removal while diminishing the glucose strength of the dialysate at night. Design A 2 parallel arm, 4 month, prospective nonrandomized study. Setting PD units or university hospitals in 4 French and Belgian districts. Results During the 4-month intervention period, net UF and peritoneal sodium removal during the long dwell when treated by bimodal UF was about 2-fold higher than baseline (with ICO). The estimated percent change (95% confidence interval) from baseline in net daytime UF for the bimodal solution was 150% (106% – 193%), versus 18% (–7% – 43%) for ICO ( p < 0.001). The estimated percent change from baseline in peritoneal sodium removal for the bimodal solution was 147% (112% – 183%), versus 23% (–2% – 48%) for ICO ( p < 0.001). The estimated percent change from baseline in UF efficiency (24-hour net UF divided by the amount of glucose absorbed) was significantly higher ( p < 0.001) when using the bimodal solution was 71%, versus -5% for ICO. Conclusion Prescription of bimodal UF during the day in APD patients offers the opportunity to optimize the long dwell exchange in a complete 24-hour APD cycle. The current study demonstrated that a bimodal solution based on the mixing of glucose (2.6%) and icodextrin (6.8%) achieved the double target of significantly improving UF and peritoneal sodium removal by exploring a new concept of glucose-sparing PD therapy.

scholarly journals Customization of Peritoneal Dialysis in Cardiorenal Syndrome by Optimization of Sodium Extraction

2019 ◽  
Vol 9 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Amir Kazory ◽  
Abhilash Koratala ◽  
Claudio Ronco
Keyword(s):  
Peritoneal Dialysis ◽  
Patient Population ◽  
Therapeutic Option ◽  
Free Water ◽  
Volume Overload ◽  
Cardiorenal Syndrome ◽  
Waste Products ◽  
Specific Patient ◽  
Fluid Removal ◽  
Sodium Removal

Background: Peritoneal dialysis (PD) has emerged as a mechanistically relevant therapeutic option for patients with heart failure (HF), volume overload, and varying degrees of renal dysfunction (i.e., chronic cardiorenal syndrome). Congestion has been identified as a potent ominous prognostic factor in this patient population, outperforming a number of established risk factors. As such, excess fluid removal is recognized as a relevant therapeutic target in this setting. Methods: Accumulating evidence points to the importance of sodium removal as part of any decongestive strategy because extraction of sodium-free water has little or no impact on the outcomes of these patients. Hence, optimization of sodium removal by PD should be the primary focus in the setting of HF and cardiorenal syndrome, especially if PD is started when the patient still has adequate residual renal function for clearance of waste products. Results: Herein, we provide an overview of approaches that can tailor PD treatment to the patients’ characteristics and clinical needs (e.g., choice of PD modality) to fully exploit its decongestive properties. Other methods that could prove helpful in the future will also be briefly discussed. Conclusion: While these strategies could help with efficient sodium extraction and volume optimization, future studies are needed to evaluate their impact on the outcomes of this specific patient population.

Monitoring Sodium Removal and Delivered Dialysis by Conductivity

1995 ◽  
Vol 18 (11) ◽  
pp. 716-721 ◽  
Author(s):  
F. Locatelli ◽  
S. Di Filippo ◽  
C. Manzoni ◽  
M. Corti ◽  
S. Andrulli ◽  
...  
Keyword(s):  
Kinetic Modelling ◽  
Sodium Concentration ◽  
Urea Clearance ◽  
Automatic Determination ◽  
Water Conductivity ◽  
Dialysis Dose ◽  
Sodium Removal ◽  
Routine Monitoring

As cardiovascular stability and the delivery of the prescribed dialysis “dose” seem to be the main factors in determining the morbidity and mortality of hemodialyzer patients today, it is of paramount importance to match hydro-sodium removal with interdialytic load and to verify the delivered dialysis at each session. A specially designed Biofeedback Module (BM - COT Hospal) allows the automatic determination of plasma water conductivity and effective ionic dialysance with no need for blood samples. Using BM, we evaluated the validity of “conductivity kinetic modelling” (CKM) and the possibility that this may substitute “sodium kinetic modelling”. Moreover, we evaluated the “in vivo” relationship between ionic dialysance and effective urea clearance. Our results demonstrate that: 1) CKM makes it possible to obtain programmed end-dialysis plasma water conductivity with an error of less than ± 0.14 mS/cm, roughly equivalent to a sodium concentration of ± 1.4 mEq/L. 2). Ionic dialysance and effective urea clearance are not equivalent but, as the interrelationship between these is known, the BM allows the routine monitoring of delivered dialysis.

On the change of transport parameters with dwell time during peritoneal dialysis

2020 ◽  
pp. 089686082097151
Author(s):  
Jacek Waniewski ◽  
Joanna Stachowska-Pietka ◽  
Bengt Lindholm
Keyword(s):  
Peritoneal Dialysis ◽  
Clinical Data ◽  
Dwell Time ◽  
Dialysis Fluid ◽  
Transport Parameters ◽  
Satisfactory Description ◽  
Pore Model ◽  
Vasodilatory Effect ◽  
Peritoneal Transport ◽  
Molecular Radius

The transitory change of fluid and solute transport parameters occurring during the initial phase of a peritoneal dialysis dwell is a well-documented phenomenon; however, its physiological interpretation is rather hypothetical and has been disputed. Two different explanations were proposed: (1) the prevailing view—supported by several experimental and clinical studies—is that a vasodilatory effect of dialysis fluid affects the capillary surface area available for dialysis, and (2) a recently presented alternative explanation is that the molecular radius of glucose increases due to the high glucose concentration in fresh dialysis fluid and that this change affects peritoneal transport parameters. The experimental bases for both phenomena are discussed as well as the problem of the accuracy necessary for a satisfactory description of clinical data when the three-pore model of peritoneal transport is applied. We show that the correction for the change of transport parameters with dwell time provides a better fit with clinical data when applying the three-pore model. Our conclusion is in favor of the traditional interpretation namely that the transitory change of transport parameters with dwell time during peritoneal dialysis is primarily due to the vasodilatory effect of dialysis fluids.

scholarly journals Mathematical modeling of septic shock based on clinical data

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Yukihiro Yamanaka ◽  
Kenko Uchida ◽  
Momoka Akashi ◽  
Yuta Watanabe ◽  
Arino Yaguchi ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Septic Shock ◽  
Clinical Data

scholarly journals Body Fluids in End-Stage Renal Disease: Statics and Dynamics

2018 ◽  
Vol 47 (1-3) ◽  
pp. 223-229 ◽  
Author(s):  
Jeroen P. Kooman ◽  
Frank M. van der Sande
Keyword(s):  
Cardiovascular Response ◽  
Extracellular Volume ◽  
Extracellular Fluid ◽  
Central Venous Oxygen Saturation ◽  
Tissue Perfusion ◽  
Adverse Outcomes ◽  
Fluid Distribution ◽  
Fluid Removal ◽  
Fluid Status ◽  
Statics And Dynamics

Background: Abnormalities in fluid status in hemodialysis (HD) patients are highly prevalent and are related to adverse outcomes. Summary: The inherent discontinuity of the HD procedure in combination with an often compromised cardiovascular response is a major contributor to this phenomenon. In addition, systemic inflammation and endothelial dysfunction are related to extracellular fluid overload (FO). Underlying this relation may be factors such as hypoalbuminemia and an increased capillary permeability, leading to an altered fluid distribution between the blood volume (BV) and the interstitial fluid compartments, compromising fluid removal during dialysis. Indeed, whereas estimates of extracellular volume by bioimpedance spectroscopy are highly predictive of mortality, absolute BV assessed by the saline dilution technique was predictive of intra-dialytic morbidity. Changes in relative BV during HD are positively related to ultrafiltration rate (UFR) and, at least in some studies, negatively to FO. High UFR is also related to changes in central venous oxygen saturation (ScvO2), a marker for tissue perfusion. On the one hand, high UFR and more pronounced declines in ScvO2, but on the other hand, flat relative BV curves are also predictive of mortality; the relation between outcome which statics and dynamics of fluid status appears to be complex. Key Message: While technological developments enable the clinician to monitor statics and dynamics of fluid status and hemodynamics during HD in an accessible way, the role of technology-based interventions needs further study.

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