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Biomedical subjects

B Lindholm

Publications and source records attributed to B Lindholm.

At least 91 records · Page 5Linked to original sources
PubMed1997

Effect of increased dialysate fill volume on peritoneal fluid and solute transport.

It has recently been recommended that the peritoneal dialysate volume should in general be increased to increase the peritoneal small solute clearances. However, the net ultrafiltration volume may decrease due to higher intraperitoneal hydrostatic pressure (IPP) and higher peritoneal fluid absorption induced by higher fill volume. In the present study, we investigated the effects of increasing the fill volume on peritoneal fluid and solute transport. A four-hour dwell study with frequent dialysate and blood sampling was performed in 32 male Sprague-Dawley rats using 16 ml, 25 ml, 30 ml or 40 ml (8 rats in each group) of 3.86% glucose solution with 131I albumin as an intraperitoneal volume marker. The peritoneal transport of fluid, glucose, urea, sodium, potassium, phosphate and total protein as well as IPP with different fill volume were evaluated. The IPP and peritoneal fluid absorption rate (as estimated from the 131I albumin elimination coefficient, KE) significantly increased with increase in fill volume (P < 0.05), whereas the direct lymphatic absorption did not change with increasing fill volume. There was a strong correlation between IPP and KE. However, the net ultrafiltration volume was significantly higher in the high fill volume groups compared to the low fill volume groups, mainly due to a better maintenance of the dialysate to plasma glucose concentration gradient in the high fill volume groups. There was no significant difference in the diffusive mass transport coefficients (KBD) and sieving coefficients for any of the investigated solutes, although KBD values tended to be lower in the 16 ml group. The clearances for small solutes increased with increased fill volume, although these increases were slightly smaller than predicted from the increase in fill volume. We conclude that: (1) An increase in dialysate fill volume using 3.86% glucose solution results in higher intraperitoneal hydrostatic pressure and higher peritoneal fluid absorption, but, on the other hand, a higher net ultrafiltration; (2) The increase in net ultrafiltration with increased fill volume is mainly due to a better maintenance of glucose concentration in the dialysate, inducing an increased transcapillary ultrafiltration rate; (3) Solute clearances increase although not quite to the same extent as predicted from the increase in fill volume. Our results indicate that decreased net ultrafiltration volume associated with higher dialysate fill volume (due to higher IPP and higher peritoneal fluid absorption) could be avoided if hypertonic glucose solutions are used.

Animals↗
PubMed1997

A quantitative analysis of sodium transport and removal during peritoneal dialysis.

To quantitatively evaluate peritoneal sodium transport, the diffusive mass transport coefficient (KBD) and sieving coefficient (S), as well as the mass of sodium transported by diffusion (DM), by convection (CM) and by fluid absorption (AM) and the total sodium mass removed (RM) were calculated during a series of single dwell studies in CAPD patients. A six-hour dwell study was performed in 68 patients using 2 liter of 1.36% (N = 13), 2.27% (N = 9) or 3.86% (N = 46) glucose dialysis fluid with 131I-albumin as the intraperitoneal volume marker. The patients in whom the 3.86% glucose dialysis fluid was applied were further divided into four transport groups according to a modified peritoneal equilibration test: high (H), high-average (H-A), low-average (L-A), and low (L) transport. There was no significant difference in KBD nor in S for sodium among different solutions. However, the removed sodium mass (RM) was significantly higher in the 3.86% (70.5 +/- 31.5 mmol) and 2.27% (36.0 +/- 21.0 mmol) solutions as compared to that of the 1.36% (-1.8 +/- 26 mmol) solution mainly due to increased both CM and DM. In general, CM was twice as high as DM. AM substantially decreased sodium removal. Among the different transport groups, the KBD and S values for sodium were significantly higher in the H group as compared to the other transport groups (both P < 0.05). However, RM was significantly lower in the H group mainly due to higher AM. Using a 3.86% glucose solution, the D/P for sodium was found to be significantly different (but only after 120 min of the dwell) between all the different transport groups. In conclusion, sodium removal in CAPD is strongly related to the fluid removal. The ultrafiltration induced convective transport (CM) and peritoneal absorption of sodium (AM) were of similar magnitude and were twice as high as the diffusive transport (DM) and both play an important role in the peritoneal sodium balance. A D/P for sodium using the 3.86% glucose solution, especially at the end of the dwell, can be used to discriminate between different transport categories of patients. High transport patients have a poor fluid and sodium removal that are likely to affect their clinical outcome.

Biological Transport↗
PubMed1997

Resting membrane potential of skeletal muscle calculated from plasma and muscle electrolyte and water contents.

1. A method is described that enables the calculation of resting membrane potential from the electrolyte and water contents in blood plasma and in a sample of human muscle tissue obtained by the percutaneous needle-biopsy technique. In this calculation, the previously described equations for calculating resting membrane potential via the intra- and extra-cellular distribution of chloride were combined with the equation utilizing potassium distribution over the cell membrane. 2. The method of calculation was applied to 60 healthy subjects divided into three groups aged 19-40, 41-60 and 61-85 years. The calculated resting membrane potential in the subjects as a whole was -88.4 mV (SD 1.35; n = 60). A lower value was observed in the group aged 61-85 years (-87.7 mV, SD 1.0; n = 12) than in the group aged 19-40 years (-88.6 mV; SD 1.4; n = 32). No difference was observed between female and male subjects. 3. The RMP calculated with the present method in 60 healthy subjects was also compared with previously published values in healthy subjects, measured by the Clarke electrode method, and with values calculated from electrolyte and water distribution measured by isotope-dilution techniques. The results obtained in healthy subjects with different techniques were very similar. Data were analysed from earlier published studies in experimental animals in which resting membrane potential ranged from -91 to -65 mV. The resting membrane potential calculated from electrolytes in plasma and muscle showed a very good agreement with resting membrane potential recorded directly.

Adult↗
PubMed1997

Total, free, and protein-bound sulphur amino acids in uraemic patients.

Fasting plasma concentrations of sulphur amino acids (sAA) were measured in nine non-dialysed (ND) chronic uraemic patients on conservative treatment, 10 patients on continuous ambulatory peritoneal dialysis (CAPD), nine patients on haemodialysis (HD) treatment, and 10 healthy subjects (HS). Methionine and taurine concentrations were significantly decreased in the CAPD and HD patients and tended to be low in the ND patients. Cysteine sulphinic acid (CSA) levels were significantly higher in all patient groups. Total (t), free (f), and protein-bound (pb) homocysteine (Hcy) and cysteine (Cys) were significantly increased in all patient groups. Serine, a substrate for cystathionine synthesis from Hcy, showed significantly lower concentrations in all patient groups. The percentages of pbHcy were significantly higher in the CAPD and HD patients than in the ND patients (P < 0.0001, P = 0.002 respectively) or in the HS (P < 0.0001, P = 0.008 respectively), whereas the percentages of pbCys in CAPD and HD patients were significantly higher than in ND patients (P = 0.0006, P = 0.009 respectively) and tended to be high without reaching statistical significance compared to the HS. A single HD treatment decreased tHcy by 26%, fHcy by 39%, and pbHcy by 22%, as well as tCys by 40%, fCys by 54%, and pbCys by 27%. The tHcy concentration, although decreased by HD treatment, remained higher than in HS, whereas tCys was normalized by the dialysis session. In addition, HD treatment significantly decreased the plasma concentrations of methionine, CSA, taurine, and serine. We conclude that, except for methionine and taurine, the plasma sAA in their different forms are markedly increased in dialysed and non-dialysed uraemic patients. The percentages of pbHcy and pbCys were significantly higher in dialysed than in ND uraemic patients. HD treatment can normalize the tCys concentration, and decrease the tHcy concentration but not normalize it. The observed hyperhomocysteineaemia and low taurine levels may contribute to the high incidence of cardiovascular disease in uraemic patients.

Adult↗
PubMed1997

Dioctyl sodium sulphosuccinate increases net ultrafiltration in peritoneal dialysis.

BACKGROUND: The surface-active substance dioctyl sodium sulphosuccinate (DSS) has been reported to increase the peritoneal clearances of urea and creatinine. This study investigated the effects of DSS on the fluid and solute transport characteristics of the peritoneum. DESIGN: A 4-h single-dwell experiment session of peritoneal dialysis using 25 ml of 3.86% glucose dialysis solution with an intraperitoneal volume maker was performed in 16 male Sprague-Dawley rats. In eight rats, 0.005% (50 p.p.m.) DSS was added to the dialysis fluid. No DSS was given to the other eight rats (control group). The transport of fluid, glucose, potassium, sodium, urea, phosphate and urate were analysed. RESULTS: There was a significant increase in the intraperitoneal volume in the DSS group. At 240 min, the drain volume in DSS group (33.0 +/- 2.9 ml) was significantly higher compared to the control group (28.8 +/- 2.1 ml, P < 0.01). This increase in the drain volume was mainly due to a decrease in peritoneal fluid absorption rate in the DSS group (0.040 +/- 0.013 ml/min) as compared to the control group (0.054 +/- 0.010 ml/min, P < 0.05). There was no significant difference in the diffusive permeability and sieving coefficient for the small solutes between these two groups. However, the clearances for urea and sodium were higher in the DSS group, mainly due to the increase in the dialysate volume. CONCLUSION: Our results suggest that DSS significantly increases the net ultrafiltration of peritoneal dialysis. This effect, which was mainly due to a decrease in the fluid absorption rate, contributed to the increased clearances for urea and sodium. DSS did not alter the diffusive permeability and sieving coefficient for the small solutes.

Animals↗
PubMed1997

Hyaluronan decreases peritoneal fluid absorption in peritoneal dialysis.

Hyaluronan, exhibiting a high resistance against water flow, acts in the tissue as a barrier against rapid changes in water content. To test whether hyaluronan has any effect on the peritoneal fluid and solute transport, and, in particular, on the peritoneal fluid absorption, a 4-h dwell study with an intraperitoneal volume marker (radiolabeled human serum albumin [RISA]) was conducted in 21 male Sprague Dawley rats (three groups, seven rats in each group). Each rat was injected intraperitoneally with 25 ml of 1.36% glucose solution alone (control group), with 0.005% hyaluronan (HA1 group), or with 0.01% hyaluronan (HA2 group). Dialysate and blood samples were taken frequently for analyses of fluid and solute (urea, glucose, and protein) transport. The intraperitoneal volume was calculated from the dilution of RISA with a correction for RISA disappearance from the peritoneal cavity. This study shows that adding hyaluronan to peritoneal dialysis solution significantly (P < 0.01) increased the net peritoneal fluid removal, mainly due to a significant decrease in the peritoneal fluid absorption rate (P < 0.01). The diffusive mass transfer coefficients for glucose, urea, and protein did not differ between the three groups. The peritoneal clearance of urea increased significantly in the two hyaluronan groups compared with the control group, due to the increased net fluid removal in the hyaluronan groups. These results suggest that intraperitoneal administration of hyaluronan during a single peritoneal dialysis exchange may significantly increase the peritoneal fluid and solute removal by decreasing peritoneal fluid absorption.

Absorption↗
PubMed1997

Future clinical research with icodextrin-containing solutions.

Icodextrin-based solutions have been investigated for over ten years and are commercially available in some countries in Europe. Although many studies have been described using icodextrin, we believe that there are many interesting areas remaining for clinical research with icodextrin-based PD solutions. Included in these are the careful examination of the kinetics of icodextrin during the 14-16 hour daytime exchange in CCPD, new studies investigating fluid absorption during icodextrin exchanges, and finally, the potential use of icodextrin in an early start dialysis regime. We look forward to seeing the results from these very interesting studies.

Absorption↗
PubMed1997

Time dependence of solute removal during a single exchange.

The viability of long-term peritoneal dialysis (PD), especially once residual renal function is lost, has been challenged since recently recommended weekly targets of Kt/V of 2.1 and creatine clearance (Ccr) of 70 L/1.73 m2 may be difficult to reach. This study demonstrates the theoretical possibility of achieving these targets in PD patients even without residual renal function. A 6-hour dwell study was performed in 68 PD patients with frequent dialysate and plasma sampling using 2 L of 1.36% (n = 13), 2.27% (n = 9), or 3.86% glucose dialysate (n = 46) with 131I albumin as an intraperitoneal volume marker. Alterations in fluid balance, Kt/V, and Ccr with dwell time (t) as well as the impact of peritoneal fluid absorption on peritoneal fluid and solute removal were evaluated. Kt/V and Ccr did not follow an exponential function with t and, in fact, decreased after 4-5 hours, especially in high transporters. All patients could achieve either weekly Kt/V (especially low transporters) or Ccr target (especially high transporters) if they are treated with automated PD. Calculations showed that eliminating fluid absorption could increase mean fluid removal by 43%-179%, increase mean Kt/V by 17%-32%, and mean Ccr by 16%-30% (depending on the solution used and the patient's peritoneal transport pattern) during a 6-hour dialysis exchange. We reached the following conclusions: (1) Kt/V(urea) and Ccr are markedly time-dependent during a single exchange due to the substantial impact of peritoneal absorption and may, in fact, decline after 4 hours, especially in high transporters. (2) Extrapolating Kt/V and Ccr values from short dwell times [i.e., peritoneal equilibration test (PET) results] to long dwell times will overestimate the peritoneal clearances. (3) Enough fluid removal must be considered as an important target of adequate dialysis along with small solute clearances. (4) If fluid absorption could be eliminated, most continuous ambulatory peritoneal dialysis (CAPD) patients could achieve the recommended Kt/V and/or Ccr targets even without residual renal function.

Absorption↗
PubMed1996

Donor kidney vasculopathy: impact on outcome in kidney transplantation.

A vasculopathy score (VP score) was designed in order to evaluate donor-related arteriosclerotic changes in kidney grafts. The four histopathological parameters that are semiquantitatively graded are glomerulosclerosis, stenosis and intimal hyperplasia of artery, and arteriolar hyalinization. The score of each parameter is weighted according to relative importance, and summed into a single parameter, the VP score. In order to evaluate the predictivity of the VP score on renal graft function, we applied this method to the first biopsy taken within 1 month after cadaveric kidney transplantation in 75 consecutive patients. The VP score was correlated to the following clinical data: graft survival at 3 months, 1 year, and 2 years after transplantation, graft function as reflected by need for hemodialysis within 1 week and 1 month, and serum creatinine level at 1 week, 1 year, and 2 years after transplantation. There was a significant correlation between VP score and donor age. In a particular case, however, age per se is not a good predictor of vascular status. Secondly, there was a significant correlation between short-term (3 months) graft survival and VP score, but none between 1 or 2 years graft survival and VP score. When two groups of patients with high and low VP scores, respectively, were compared, there were significant differences between graft function at 1 week and 1 year and graft survival at 3 months. Thus, our results show that the VP score is useful to predict short-term graft survival and graft function.

Adolescent↗
PubMed1996

Enhanced scavenger receptor expression in monocyte-macrophages in dialysis patients.

The macrophage scavenger receptor (SR), which has two isoforms named type I and II, plays a leading role in the atherosclerotic process. To elucidate the mechanism of atherosclerosis in dialysis patients, SR expression was studied in monocyte-macrophages from thirteen dialysis patients and eight healthy controls. SR mRNA expression was examined in four hemodialysis patients and four controls matched for age and sex. Monocytes were allowed to differentiate into macrophages in in vitro cultures for seven days and SR type I and II mRNA expression were analyzed with the reverse transcription-polymerase chain reaction and quantitated using radiation densities of Southern blots. Only SR type I expression increased during differentiation and was accelerated by one or two days and enhanced after five days in patients, as compared to controls. To detect SR protein expression, uptake of fluorescently labeled acetylated low-density lipoprotein (Ac-LDL) was evaluated by flow cytometry. The mean fluorescence intensity of labeled cells was significantly higher in hemodialysis and continuous ambulatory peritoneal dialysis patients than in controls, although the number of SR-positive cells remained constant. In conclusion, SR expression is enhanced in macrophages from dialysis patients, probably by up-regulation of type I, which may contribute to the development of atherosclerosis in these patients.

Adult↗
PubMed1996

Influence of peritoneal dialysis solutions with glucose and amino acids on ingestive behavior in rats.

Continuous ambulatory peritoneal dialysis (CAPD) is often associated with malnutrition; reduced intake of nutrients due to anorexia is an important factor. The glucose load from glucose-based peritoneal dialysis (PD) solutions and amino acids from amino acid-based solutions may favor suppression of the appetite. To study this matter we used a new experimental model in free-moving, unstressed male Wistar rats (300 to 350 g) with feeding catheters channeled from the top of the skull to the oral cavity. When the rats recovered from surgery they were tested under standardized conditions by giving them an intraoral infusion (1 ml/min) of a solution containing 342 g/liter of the sucrose or 97 g/liter protein solutions while recording the time (volume) of ingestion. Control rats consumed 18.8 +/- 0.9 ml of the sucrose and 39.8 +/- 0.8 ml of the protein solutions. Injections of PD solutions with 13.6, 22.7, and 38.6 g/liter of glucose reduced the ingestion of sucrose by 12.4%, 23.6% and 36.1%, respectively, but did not affect the ingestion of protein. Injections of 30 ml of PD solutions containing 11, 18 and 31 g/liter of amino acids reduced the ingestion of both sucrose by 9.7%, 17.1% and 33.2% and of protein by 13.5%, 25.9% and 33.1%, respectively. We conclude that in our experimental model, the inhibition of appetite caused by peritoneal solutions containing glucose or amino acids seems to be specific for each nutritional constituent and not simply an effect of hyperosmolality or large filling volumes.

Adaptation, Physiological↗
PubMed1996

Increased plasma lipoprotein(a) in continuous ambulatory peritoneal dialysis is related to peritoneal transport of proteins and glucose.

Markedly increased plasma lipoprotein(a) [Lp(a)] levels have recently been reported in continuous ambulatory peritoneal dialysis (CAPD) patients but the genesis is obscure. Lp(a) levels in CAPD are in general higher than in hemodialysis (HD) patients, suggesting that the dialysis procedure might be of importance. In the present study, we investigated relationships between Lp(a) and parameters related to the dialysis procedure per se (dialysis dose, peritoneal glucose absorption, protein losses and protein clearances) in 32 adult CAPD patients. Uremic patients treated with HD (n = 73) as well as a group of 43 healthy subjects served as control groups. The plasma level of Lp(a) was significantly higher in the CAPD patients (median 28.2 mg/dl) than in the HD patients (median 9.2 mg/dl) and the healthy controls (median 7.0 mg/dl), whereas Lp(a) levels in the HD patients did not differ from the healthy controls. In the CAPD patients, significant correlations were found between Lp(a) and 24-hour peritoneal and total clearance for albumin (r = 0.472 and r = 0.368, p < 0.01 and p < 0.05, respectively), and between Lp(a) and 24-hour peritoneal clearance for beta(2)-microglobulin (r = 0.421; p < 0.05). Similar correlations were found between Lp(a) and 24-hour peritoneal albumin excretion, total albumin excretion and peritoneal beta(2)-microglobulin excretion. Furthermore, a significant correlation was found between Lp(a) and peritoneal glucose absorption (r = 0.352; p < 0.05). Serum cholesterol showed significant correlations with 24-hour .peritoneal albumin loss and 24-hour peritoneal beta(2)-microglobulin clearance, whereas LDL cholesterol showed a significant correlation with 24-hour peritoneal beta(2)-microglobulin clearance. In a longitudinal study of 12 CAPD patients, Lp(a) levels increased significantly between the start of CAPD and at follow-up 3-5 months later. The correlation of the markedly increased levels of Lp(a) with peritoneal albumin and beta(2)-microglobulin clearance suggests that the mechanism behind the increased Lp(a) levels may be related to the large protein losses in CAPD, perhaps via an increased synthesis rate of apolipoprotein (a) in the liver or via decreased Lp(a) catabolism in CAPD patients. Finally, the correlation between Lp(a) and peritoneal glucose absorption also indicates that the increased plasma Lp(a) levels in CAPD are related to the dialysis procedure, in particular peritoneal transport of proteins and glucose.

Adult↗
PubMed1996

Paradoxes in peritoneal transport of small solutes.

Analysis of kinetic studies of peritoneal solute transport involves the need for discrimination between three transport components: diffusion, convective transport, and peritoneal absorption. The description of convective transport in standard clinical conditions of continuous ambulatory peritoneal dialysis (CAPD), as well as in isochratic measurements, has met some problems related to the paradoxical and often anomalous values of sieving coefficient, a parameter that characterizes solute drag with the flow of ultrafiltrate. A possible explanation of some of these results is the time dependence of the transport parameters, which is in contrast to their assumed steadiness. These anomalies as well as the time dependence of the transport parameters are confined more to the standard glucose-based dialysis fluid than to some alternative dialysis fluids. Furthermore, the most striking anomalies have been found for small electrolytes as well as for osmotic agents, which are applied in high, unphysiological concentrations. These solutes may be involved in the transport between intracellular and extracellular compartments within the peritoneal membrane, which phenomena are not included in the current modeling.

Absorption↗
PubMed1996

Simple models for fluid transport during peritoneal dialysis.

Peritoneal fluid transport can be predicted using different simplified formulas. To evaluate three such models, fluid transport was studied in 38 single six hour dwell studies using standard glucose 1.36% (n = 9), 2.27% (n = 9) and 3.86% (n = 20) dialysis fluids as well as amino acid 2.70% fluid (n = 8) in 33 patients on continuous ambulatory peritoneal dialysis (CAPD). Dialysate volume and the peritoneal absorption rate were measured using radioiodinated serum albumin (RISA) as a marker. The dialysate volume over dwell time curves were examined using three mathematical models of fluid transport for solutions with a crystalloid osmotic agent: Model P based on phenomenologically derived exponential function of time (Pyle, 1981), Model OS based on linear relationship between the rate of net volume change, Qv, to the difference of osmolality in dialysate and blood, and Model G based on linear relationship between Qv and the difference of glucose concentration in dialysate and blood. All these models provided a good description of the measured dialysate volume over time curves, however the descriptions with Models OS and G for glucose 3.86% fluid were slightly but significantly less precise. The coefficients of Model OS were stable in time, but the coefficients of Model G and P dependend in general on the time period used for their estimation, especially for glucose 3.86% dialysis fluid. The evaluation of dwell studies with solutions containing amino acid 2.70% (instead of glucose) as osmotic agent, using Model OS and P, showed that the transport coefficients were stable in time and both models provided equally precise descriptions. These results suggested that all three models can be used but models P and OS can be preferred for practical applications such as predictions of fluid transport with alternative cristalloid osmotic agents. Furthermore, we found that the peritoneal barrier for fluid transport may change transiently during exchanges with the standard glucose-based dialysis fluid, whereas such changes were not observed with the amino acid-based fluid. This discrepancy may be due to a different composition of the dialysis fluids, including osmotic agent, buffer and pH.

Ascitic Fluid↗
PubMed1995

Treatment of malnourished CAPD patients with an amino acid based dialysate.

Nineteen malnourished chronic peritoneal dialysis patients who were ingesting a low protein intake underwent metabolic balance studies to test whether a dialysate that contained amino acids would improve their protein nutrition. Patients lived in the hospital for 35 days while they ate a constant diet and underwent their usual regimen of continuous ambulatory peritoneal dialysis (CAPD). The first 15 days served as a Baseline Phase. For the last 20 days, the usual dialysate was substituted with a dialysate of essentially the same composition except that it contained 1.1% essential and nonessential amino acids and no glucose. Patients received one or two dialysate exchanges with amino acids each day depending on the amount necessary to bring the individual's dietary protein plus dialysate amino acid intake to 1.1 to 1.3 g/kg body weight/day. During Baseline, patients were in neutral nitrogen balance; net protein anabolism was positive, as determined from 15N-glycine studies. After commencing intraperitoneal amino acid therapy, nitrogen balance became significantly positive, there was a significant increase in net protein anabolism, the fasting morning plasma amino acid pattern became more normal, and serum total protein and transferrin concentrations rose. Patients generally tolerated the treatment well, although some patients developed mild metabolic acidemia. These findings indicate that a dialysate containing amino acids may improve protein malnutrition in CAPD patients ingesting low protein intakes.

Acidosis↗
PubMed1995

Diffusive and convective solute transport in peritoneal dialysis with glucose as an osmotic agent.

To investigate possible effects of glucose concentration, dwell time, and peritoneal reabsorption on the combined diffusive and convective peritoneal solute transport, dialysate to plasma concentration ratios (D/P) and solute clearances were evaluated for 6-h peritoneal dwell studies with 1.36, 2.27, and 3.86% glucose solutions. The diffusive mass transport coefficient, KBD, and sieving coefficient, S, were estimated using the Babb-Randerson-Farrell model of peritoneal transport. Dialysate volumes over time and peritoneal reabsorption rates, KE, were assessed using radiolabeled iodinated serum albumin (RISA). The transport parameters were estimated with and without peritoneal reabsorption of solutes taken into account. To test the stability of the transport parameters throughout a single peritoneal dwell, KBD and S values were estimated for the initial 3-120 min, the final 120-360 min, and the entire 3-360 min dwell period for dialysis with 3.86% glucose solution. The transport parameters did not differ between the three dialysis fluids although clearances of small solutes were higher with the 3.86% solution. Values of KBD, but not S, were dependent on the correction for peritoneal reabsorption of solutes. Computer simulations showed that S could be estimated even with the 1.36% glucose solution. A significant change of the transport parameters, with increased values of KBD during the initial period of the dwell, was found for urea, potassium, sodium, and total protein during dialysis with the 3.86% solution. S values for urea and potassium were close to 1 during the initial period whereas unphysical (higher than 1) S values were found for the whole dwell period. The transient increase of KBD during the initial part of the dwell may reflect changes in the peritoneal barrier possibly induced by fresh dialysis fluid. In conclusion, the transport parameters KBD and S are not influenced by the concentration of glucose in the dialysis fluid. Moreover, the estimation of KBD but not of S is dependent on the assumed rate of peritoneal reabsorption. Finally, the current results challenge the assumption that KBD and S are constant throughout a peritoneal dialysis exchange.

Biological Transport↗