Use of the adjective 'membranous' to categorize hemodiafiltration and hemofiltration.
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Hemodiafiltration↗
Biomedical subjects
A H Tzamaloukas
Publications and source records attributed to A H Tzamaloukas.
Inadequacy of dialysis, chronic inflammation and malnutrition in Nigerian patients on chronic hemodialysis.
PURPOSE: To identify the extent of underdialysis, chronic inflammation and malnutrition and their interrelationships in Nigerian hemodialysis patients. METHODS: In a prospective study including 10 adult patients, (6 men, 4 women) on hemodialysis in North Central Nigeria, malnutrition was assessed by body mass index (BMI), serum albumin and prealbumin, and bioimpedance (BIA) pre-and post dialysis, inflammation was evaluated by C-reactive protein (CRP) and adequacy of dialysis was judged by frequency of the hemodialysis sessions and Kt/V urea. RESULTS: Post-dialysis BMI was 21.3 (19.9, 24.3) kg/m2 (< 20 kg/m2 in 4 patients), serum albumin 31.5 (24.0, 32.0) g/L (< 30.0 g/L in 5), serum pre-albumin 25.2 (15.3, 31.1) mg/dL (< 18.0 mg/dL in 4), serum CRP 4.8 (1.2, 11.5) mg/dL (> 1.0 mg/dL in 8), phase angle 4.2 (3.7, 5.1) degrees (< 3 degrees in 3) and body fat deficit was diagnosed by BIA in 4 patients. Weekly frequency of dialysis was 3 times in 2 patients, twice in 1 and 1.2 in one patient receiving dialysis only twice weekly). By combined frequency of dialysis and Kt/V urea values, no patient received an adequate dose of dialysis and, indeed, all patients had overt symptoms of uremia. Low body weight, low serological and BIA nutrition indices, and high CRP levels occurred in the same patients. Patients on dialysis for > 1 year had worse nutrition indices than those on dialysis for < 1 year. CONCLUSIONS: Underdialysis was universal, while poor nutrition and chronic malnutrition were found in the majority of the small number of patients studied. These three adverse conditions, which were interlinked, may be common in Nigerian hemodialysis patients, because their underlying socioeconomic causes are widespread.
Adult↗
Serum potassium and acid-base parameters in severe dialysis-associated hyperglycemia treated with insulin therapy.
We analyzed the changes in serum potassium concentration ([K]) and acid-base parameters in 43 episodes of dialysis-associated hyperglycemia (serum glucose level > 33.3 mmol/L), 22 of which were characterized as diabetic ketoacidosis (DKA) and the remaining 21 as nonketotic hyperglycemia (NKH). All episodes were treated with insulin therapy only. Age, gender, initial and final serum values of glucose, sodium, chloride, tonicity and osmolality did not differ between DKA and NKH. At presentation, serum values of [K] (DKA 6.2 +/- 1.3 mmol/L; NKH 5.2 +/- 1.5 mmol/L) and anion gap [AG] (DKA 27.2 +/- 6.4 mEq/L; NKH 15.4 +/- 3.5 mEq/L) were higher in DKA, whereas serum total carbon dioxide content [TCO2 ] (DKA 12.0 +/- 4.6 mmol/L; NKH 22.5 +/- 3.1 mmol/L), arterial blood pH (DKA 7.15 +/- 0.09; NKH 7.43 +/- 0.07) and arterial blood PaCO2 (DKA 26.2 +/- 12.3 mm Hg; NKH 34.5 +/- 6.7 mm Hg) were higher in NKH. At the end of insulin treatment, serum values of [K] (DKA 4.0 +/- 0.7 mmol/L, NKH 4.0 +/- 0.5 mmol/L), [AG] (DKA 16.3 +/- 5.4 mEq/L, NKH 14.9 +/- 3.0 mEq/L), [TCO2 ] (DKA 23.5 +/- 5.0 mmol/L, NKH 24.1 +/- 4.2 mmol/L), arterial blood pH (DKA 7.42 +/- 0.09, NKH 7.51 +/- 0.14) and arterial blood PaCO2 (DKA 31.8 +/- 6.7 mm Hg, NKH 34.2 +/- 8.3 mm Hg) did not differ between the two groups. Linear regression of the decrease in serum [K] value during treatment, (Delta[K]), on the presenting serum [K] concentration,([K]2 ), was: DKA, Delta[K] = 2.78 - 0.81 x [K]2 , r = -0.85, p < 0.001; NKH, Delta[K] = 2.44 - 0.71 x [K]2 , r = -0.90, p < 0.001. The slopes of the regressions were not significantly different. Stepwise logistic regression including both DKA and NKH cases identified the presenting serum [K] level and the change in serum [TCO2 ] value during treatment as the predictors of Delta[K] (R2 = 0.81). Hyperkalemia is a feature of severe hyperglycemia (DKA or NKH) occurring in patients on dialysis. Insulin administration brings about correction of DKA and return of serum [K] concentration to the normal range in the majority of the hyperglycemic episodes without the need for other measures. The initial serum [K] value and the change in serum [TCO2 ] level during treatment influence the decrease in serum [K] value during treatment of dialysis-associated hyperglycemia with insulin.
Acid-Base Equilibrium↗
Serum tonicity, extracellular volume and clinical manifestations in symptomatic dialysis-associated hyperglycemia treated only with insulin.
The absence of osmotic diuresis modifies the effects of hyperglycemia on body fluids in patients with advanced renal failure. To determine the relationship between clinical manifestations and abnormalities in tonicity and extracellular volume in such patients, we analyzed 43 episodes of severe dialysis-associated hyperglycemia (serum glucose exceeding 600 mg/dL) treated only with insulin. The main manifestations were dyspnea in 22 cases (pulmonary edema in 19), nausea and vomiting in 15, coma in 13 and seizures in 3, while 5 patients had no symptoms. Treatment with insulin resulted in a decrease in serum glucose value from 913 +/- 197 mg/dL to 170 +/- 78 mg/dL, an increase in serum sodium level from 125 +/- 5 to 136 +/- 5 mmol/L, and a fall in calculated serum tonicity value from 300 +/- 13 to 282 +/- 11 mmol/kg (all at p < 0.001). The ratio of the change in serum sodium level over change in serum glucose concentration was -1.50 +/- 0.22 mmol/L per 100 mg/dL. The percent increase in extracellular volume secondary to hyperglycemia developing from the prior euglycemic state and calculated from changes in serum sodium and chloride concentrations, was 10.9% +/- 4.6% (1.5% +/- 0.6% per 100 mg/dL increase in serum glucose level). All clinical manifestations dissipated after correction of hyperglycemia in 42 patients. One woman developed during treatment a fatal myocardial infarction. Dialysis patients with severe hyperglycemia may develop symptoms as a result of hypertonicity and extracellular expansion. Insulin alone may be sufficient treatment for these symptoms. The changes in serum tonicity and electrolytes during treatment are consistent with theoretical predictions.
Adult↗
Severe proximal myopathy in advanced renal failure. Diagnosis and management.
Myopathies encountered in uremic patients may have different pathogenetic mechanisms and treatment. Secondary hyperparathyroidism may cause uremic myopathy responding to specific treatment. This study aimed at presenting a case illustrative of the clinical features, diagnosis and management of uremic parathyroid myopathy. A 66-year old man with renal failure from membranous nephropathy developed sensory signs of uremic neuropathy and progressive painless weakness of the pelvic girdle muscles bilaterally. Motor nerve conduction velocity was normal, electromyogram was consistent with a myopathic pattern, while muscle biopsy showed a pattern of atrophy more consistent with a neuropathic pattern. Serological tests for collagen vascular diseases and hyperthyroidism were negative, while serum muscle enzymes were not elevated and serum phosphate levels were not low. Serum parathyroid hormone level was grossly elevated, while serum calcium was mildly elevated in a small fraction of the measurements, serum alkaline phosphatase showed a progressive rise and skeletal bone survey did not disclose osteopenia or signs of parathyroid bone disease. A course of calcitriol failed to improve the myopathy, which responded promptly and dramatically to parathyroidectomy. Uremic parathyroid myopathy, which has a characteristic clinical picture, must be differentiated from other neuropathic or myopathic conditions that require specific treatments. Progressive parathyroid myopathy is, by itself, an indication for parathyroidectomy, which is curative in this case.
Aged↗
Chronic hemodialysis in a Nigerian teaching hospital: practice and costs.
The incidence of end-stage renal disease (ESRD) is on the rise in developing countries. To identify issues related to renal replacement therapy in ESRD patients in the developing world, we analyzed the practice and costs of hemodialysis in Nigerian ESRD patients. Ten ESRD patients were dialyzed at the Jos University Teaching Hospital, Jos, Plateau State, Nigeria, between June 15 and July 15, 2003. In these patients, we analyzed initiation, vascular access issues, frequency, duration, adequacy and economics of chronic hemodialysis. The Nigerian patients were referred to the nephrologist for the first time only when they had developed frank uremia. No patient had a permanent vascular access at the time dialysis was initiated. Only two patients had a functioning dialysis fistula, while the other eight patients were dialyzed through temporary femoral vein catheters that were removed after each dialysis. Frequency of dialysis was three times weekly in 2 patients, twice weekly in 1 patient and once weekly or less frequently in 7 patients. The duration of a dialysis session was prescribed to be 4 hours, but sessions often lasted for as long as 10 hours because of breakdowns of the antiquated dialysis machines. The urea reduction ratio was 45.3 +/- 8.6%. In every case, the cost of dialysis was borne by the patients and their families. Comparison of the cost of dialysis, with extensive re-use of supplies, to monthly incomes of Nigerians with different professions revealed that the great majority of Nigerians cannot afford three times weekly dialysis. Underdialysis in Nigerian ESRD patients is common and caused by socioeconomic factors and technologic deficits. One step towards correction of underdialysis could be sharing of the cost of dialysis by the public.
Adult↗
Oliguric acute renal failure in mycosis fungoides with lymphomatous infiltrates in the kidneys.
OBJECTIVE: To present the clinical picture of acute renal failure in patients with mycosis fungoides (MF) and renal lymphomatous infiltrates. To analyze the pathogenesis of renal failure. METHODS: Correlation of clinical picture, urinary findings, imaging reports and autopsy findings in two patients with long-standing MF who died with renal failure. CASE SUMMARIES: Both subjects had sustained oliguria in the last 2 weeks. One patient had persistent hypotension, normal urinalysis, normal renal sonogram, and scarce interstitial lymphomatous infiltrates with preservation of renal parenchymal architecture. He was thought to have ischemic acute renal failure not directly linked to the lymphomatous infiltrates. The second patient developed hypertension one month prior to death, and had moderate proteinuria, hematuria, pyuria, grossly enlarged kidneys with hypoechoic masses, and extensive replacement of the renal parenchyma by lymphomatous infiltrates. This picture is typical of renal failure secondary to lymphomatous replacement of the kidneys. CONCLUSIONS: The development of oliguric renal failure in MF with renal lymphomatous infiltrates may have varying clinical and imaging manifestations and pathogeneses. Potentially reversible pathogenic mechanisms should be systematically investigated, particularly if the overall clinical picture is not characteristic of renal failure secondary to lymphomatous replacement of the parenchyma.
Acute Kidney Injury↗
Adequacy of peritoneal dialysis after the ADEMEX study. Back to the basics.
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Anemia↗
The relation between nutrition indices and age in patients on continuous ambulatory peritoneal dialysis receiving similar small solute clearances.
OBJECTIVE: To analyze the effect of age on nutrition indices in subjects on the same continuous ambulatory peritoneal dialysis (CAPD) schedule. METHODS: We analyzed 613 sets of clearance values and nutrition indices in 302 CAPD patients. Small solute clearances included urea clearance (Kt/Vurea) and creatinine clearance (Ccr). Nutrition indices included body mass index (BMI), serum albumin, urea and creatinine, 24-h urea nitrogen and creatinine excretion in urine plus dialysate, protein nitrogen appearance (PNA), PNA normalized by standard weight (nPNA), lean body mass (LBM) computed by creatinine kinetics, and LBM/Weight. CAPD subjects were classified in 4 age quartiles (Q): Group Q1, age 33.7 +/- 7.6 years, N = 149; group Q2, age 49.5 +/- 3.8 years, N = 158; group Q3, age 61.5 +/- 2.6 years, N = 154; and group Q4, age 72.1 +/- 5.4 years, N = 152. Group comparison was done by one-way ANOVA or chi-square. Predictors of low nutritional parameters were identified by logistic regression. Selected variables were compared by linear regression. RESULTS: Mean Kt/Vurea and Ccr were above the current adequacy standards and did not differ between the age quartiles. In contrast, older quartiles had, in general, lower nutrition indices than younger quartiles. However, the youngest quartile had the lowest BMI. By logistic regression, young age was a predictor of low BMI, while advanced age was a predictor of low creatinine and urea nitrogen excretion, low nPNA, and low LBM/Weight. The regressions of nPNA on Kt/Vurea differed between the age quartiles. By these regressions, the youngest quartile had higher nPNA values for the same Kt/Vurea than the oldest quartile in the clinically relevant range of Kt/Vurea and nPNA values. CONCLUSIONS: Nutrition indices are worse in older than in younger CAPD patients with the same small solute clearances. Nutrition of CAPD patients is adversely affected by age and requires special attention in the older age group.
Adult↗
Creatinine excretion in continuous peritoneal dialysis: a systematic error of the Cockroft-Gault formula.
We investigated the hypothesis that the rate of loss of creatinine excretion with age in peritoneal dialysis (PD) patients differs from the rate predicted from the Cockroft-Gault formula (Cr(Pred)) by analyzing creatinine excretion data obtained from clearance studies of 925 patients on continuous ambulatory PD therapy with an age range of 12 to 91 years. Measured creatinine generation (Cr(Meas)) is the sum of creatinine excretion in urine plus dialysate (Cr(Excr)) plus an estimated metabolic degradation of creatinine. The effect of age on Cr(Excr) and the differences Cr(Excr) - Cr(Pred) and Cr(Meas) - Cr(Pred) were analyzed by linear regression. In 373 women, Cr(Excr) = W(16.9360 - 0.084A), r = -0.342, P < 0.001 (where W is weight in kilograms and A is age in years). The regression slope was one half of the slope in the Cockroft-Gault formula. Cr(Excr) - Cr(Pred) = -413.91 + 4.78A, r = 0.300, P < 0.001. Cr(Meas) - Cr(Pred) = -176.36 + 4.37A, r = 0.278, P < 0.001. In 552 men, Cr(Excr) = W(21.079 - 0.108A), r = -0.338, P < 0.001. The regression slope was approximately one half of the slope in the Cockroft-Gault formula. Cr(Excr) - Cr(Pred) = -493.25 + 6.28A, r = 0.267, P < 0.001. Cr(Meas) - Cr(Pred) = -66.41 + 3.63A, r = 0.143, P = 0.001. The rate of loss of creatinine excretion with age is one half of the rate predicted by the Cockroft-Gault formula in both women and men on PD therapy. Therefore, the difference between excretion (or measured generation) of creatinine and creatinine generation predicted by the Cockroft-Gault formula is not constant, but increases with age. The Cockroft-Gault formula systematically overestimates the effect of age on creatinine excretion in PD patients and is not suitable for predicting creatinine excretion in these subjects.
Adolescent↗
Renal clearances in continuous ambulatory peritoneal dialysis: differences between diabetic and non-diabetic subjects.
We analyzed the effect of diabetes on the decline of residual renal function during the course of CAPD in a cross-sectional study including 105 diabetic subjects (41 women) who had 207 clearance studies and 125 non-diabetic subjects (50 women, 265 clearance studies). CAPD duration was 11.5+/-10.5 months in the diabetic group (DG) and 16.8+/-18.6 months in the non-diabetic group (NDG, P < 0.001). The DG had lower urine volume than the NDG (0.52+/-0.46 vs 0.61+/-0.50 L/24-h, P < 0.05), while urine-to-plasma concentration ratio was higher in the DG for creatinine (13.5+/-9.4 vs 11.5+/-11.0, P <0.05) and did not differ for urea. Weekly renal Kt/V urea (DG 0.51+/-0.57, NDG 0.53+/-0.49) and Ccr (DG 31.0+/-28.7 NDG 29.3+/-26.5 L/1.73 m2) did not differ. The slopes of the regressions of CAPD duration on renal clearances did not differ. These regressions allowed estimates of the time, from the onset of CAPD, at which renal clearances become negligible. These estimates differed for both urea clearance (DG 35.3, NDG 50.5 months) and creatinine clearance (DG 43.2, NDG 57.6 months). The slope of the regression of renal urea clearance on renal creatinine clearance was steeper in the DG, suggesting a higher renal creatinine clearance in the DG than in the NDG when renal urea clearance is the same in the two groups. Subtle differences in the rate of decline of renal function can be detected between diabetic and non-diabetic subjects on CAPD by detailed statistical analysis. These findings are supportive of the studies which have identified diabetes mellitus as a predictor of loss of residual renal function during the course of CAPD. In addition, the relationship between the renal urea and creatinine clearances differs between diabetic and nondiabetic subjects on CAPD. Therefore, the dose of CAPD required for adequate total clearances may differ between diabetic and non-diabetic subjects.
Analysis of Variance↗
Disagreement between height/weight classifications of underweight, normal weight, and obesity in peritoneal dialysis patients.
Peritoneal dialysis (PD) patients are classified as underweight, normal weight, or obese by height/weight indices including body mass index (BMI) and the body weight/desired weight (W/DW) ratio. We compared these classifications of degree of obesity in 378 women and 555 men on PD. We used these cut-off values: for underweight, BMI < or = 18.5 and W/DW < or = 0.9; for obesity, BMI > or = 30.0 and W/DW > or = 1.2. The W/DW values were calculated assuming first a small frame, then a medium frame, and finally a large frame for all subjects. Regardless of sex or skeletal frame, BMI correlated highly with W/DW (r value between 0.98 and 0.99); however, the range of BMI values corresponding by linear regression to the normal range of W/DW (0.9-1.2) was narrower than the range of "normal" BMI (18.5-30.0). Consequently, regardless of sex or skeletal frame, smaller fractions of the patient population were classified as underweight or obese by BMI standards than by W/DW standards. The degree of agreement of the classifications of subjects as underweight, normal weight, or obese by BMI and W/DW was evaluated by Cohen's kappa ratio. The kappa ratio varied between 0.47 and 0.58, indicating a reasonable--but not high--degree of agreement beyond chance. The highest kappa ratios were obtained assuming a medium skeletal frame for both women and men. Substantial discrepancies are observed in the classification of PD patients as underweight, normal weight, or obese by BMI and W/DW. Further research is needed to identify the height/weight index that has the strongest association both with clinical outcomes and with other, more precise measurements of body fat content.
Body Constitution↗
Water and small solute excretion in continuous peritoneal dialysis patients with lean body mass exceeding 90% of body weight as estimated from creatinine kinetics.
Lean body mass computed from creatinine kinetics (LBM) is an index of somatic nutrition and correlates with other nutrition indices in CAPD. However, LBM exceeding 90% of body weight (LBM/W > or = 0.9) may be an index of non-compliance, rather than nutrition. To test this hypothesis, we analyzed fluid and solute excretion in 40 CAPD patients with LBM/W > or = 0.9 (group A). The comparison group (group B) consisted of 885 CAPD patients with LBM/W < 0.9. Group A was younger (38.3+/-14.8 vs 54.7+/-14.7 yr) and had a lower percent of women (23.5% vs 41.1%) and diabetic subjects (17.5% vs 42.6%) than group B (at P < or = 0.019). Group A also had lower body mass index (22.7+/-2.7 vs 25.8+/-5.1 kg/m2, P <0.001) and serum albumin (33.0+/-6.7 vs 35.2+/-5.5 g/L, P = 0.014). Despite similar prescribed daily fill volumes (group A 8.3+/-2.4, group B 8.5+/-2.2 L/24 h) and similar D/P urea and creatinine values, group A had higher daily drain volume (11.0+/-3.6 vs 9.6+/-2.1 L/24 h, P < 0.001). Renal clearances were similar, while peritoneal and total clearances were apparently higher in group A. Creatinine excretion was higher in group A (27.4+/-5.1 vs 13.6+/-4.1 mg/kg x 24 h, P < 0.001), with a large part of the excess creatinine excretion in group A being accounted for by peritoneal excretion. The combination of an apparently high daily ultrafiltration volume (2.7 L/24 h on the average), unrealistically high creatinine excretion rate, and relatively poor nutrition (low body mass index and serum albumin) in group A is consistent with non-compliance. We suggest that the finding of LBM/W > or = 0.9 during a clearance study in CAPD should trigger an investigation for non-compliance.
Adult↗
Peritoneal dialysis in the next millennium.
The main thrust of research will be the prevention of renal disease and its progression to the end-stage state (ESRD); such efforts will reduce or even reverse the present epidemic of ESRD by the middle of the 21(st) Century. In the meantime, the number of ESRD patients will continue to increase and, unless xenotransplantation and cloning of one's own kidneys using stem cells will provide an alternative, the various modes of dialysis will continue to be the principle treatment for an increasing numbers of ESRD patients. Peritoneal dialysis (PD) has achieved success at certain salient points and, to advance further, the next generation of nephrologists will have to build on these. They include the following: PD is the treatment of choice for children; it has low rates of peritonitis; it has similar (or in some countries, better) survival rates than hemodialysis; it has lower costs; it has adequate clearances through the introduction of automated PD; and it is an effective treatment for those awaiting a kidney transplant. This report presents the authors' views concerning the areas in which PD will improve in the future. These include (1) a reduction in technique failure rates that will allow us to maintain a larger number of patients on PD for 10 years or more; (2) prevention of long-term changes of the peritoneal membrane through the use of more "friendly" solutions; (3) prevention of malnutrition; (4) the development of better peritoneal access devices; and (5) the increased use of PD as the treatment of first choice for most ESRD patients.
Humans↗
What determines how satisfactory a size indicator is as a normalizing parameter for small solute clearances in peritoneal dialysis?
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Biomarkers↗
Body mass index in patients with amputations on peritoneal dialysis: error of uncorrected estimates and proposed correction.
UNLABELLED: "Weight-height" indices including percent of ideal weight (%IW) and body mass index (BMI) are used to estimate degree of obesity in populations and are predictors of survival in dialysis patients. Amputation affects the relationship between weight and height independently of the degree of obesity. Corrections of both %IW and BMI for amputation have been published, but a National (U.S.) computer nutrition program used in the authors' institution uses only the correction for %IW. This study had two parts: (1) To test whether the weight-height cut-off values for weight deficit (%IW 90%, BMI 20 kg/m2) and obesity (%IW 120%, BMI 30 kg/m2) are compatible, we performed linear regression of BMI on %IW in peritoneal dialysis (PD) patients without amputations. In 349 men, BMI = 0.834 + 0.226 (%IW), r = 0.979. From this regression, the 95% confidence interval (CI) of BMI is 19.2-23.1 kg/m2 if %IW is 90%, and 26.1-29.9 kg/m2 if %IW is 120%. In 260 women, BMI = 2.194 + 0.184 (%IW), r = 0.974. From this regression, the 95% CI of BMI is 15.7-21.8 kg/m2 if %IW is 90%, and 21.3-27.3 kg/m2 if %IW is 120%. (2) To identify the direction and magnitude of the error of uncorrected BMI (BMIu) in dialysis patients with amputations, we analyzed weight-height indices in two groups of men by the computer nutrition program, which corrects %IW, but not BMI for amputation, and by the corrected BMI (BMIc) formula. In group A (amputation without height loss, n = 11), %IW = 110.2% +/- 16.9%, BMIu = 23.6 +/- 2.7 kg/m2, BMIc = 26.4 +/- 3.8 kg/m2 (p < 0.001, BMIc vs BMIu), and 5 of the 11 BMIu values fell below the 95% confidence band of the regression of BMI on %IW in patients without amputations. In group B (amputation with loss of height, n = 6), %IW = 92.7% +/- 19.9%, BMIu = 33.9 +/- 10.7 kg/m2, BMIc = 22.1 +/- 4.4 kg/m2 (p < 0.005, BMIc vs BMIu), and 5 of the 6 BMIu values fell above the 95% confidence band of the regression of BMI on %IW in patients without amputations. CONCLUSIONS: (1) The weight deficit cut-offs for %IW and BMI are compatible in non amputated men and women. (2) The obesity cut-offs for %IW and BMI are compatible in non amputated men, but not in non amputated women. (3) Amputation without height loss decreases BMIu, while amputation with height loss increases, in general, BMIu. (4) BMI should be corrected in PD patients with amputations.
Amputation, Surgical↗
The relation between body size and normalized small solute clearances in continuous ambulatory peritoneal dialysis.
The normalized peritoneal clearances of small solutes depend on the ratio of their concentration in dialysate and plasma (D/P) and the drain volume (Dv) corrected for some measure of body size such as body water (V) or body surface area (BSA). The clearance formulas (D/P) x (Dv/V) and (D/ P) x (Dv/BSA) can be used to examine why large individuals tend to be underdialyzed. Large people have low normalized drain volumes (Dv/V, Dv/BSA). It is not known whether size affects the D/P ratios. The purpose of this study was to examine the relationship between normalized peritoneal clearances (Kt/Vurea, CCr per 1.73 m2 BSA) and four size indicators (weight, height, V, BSA) in 301 patients on continuous ambulatory peritoneal dialysis (four daily exchanges with 2-L exchange volume) who underwent 613 clearance studies. Highly significant (P < 0.001) nonlinear relationships were found between Kt/Vurea and weight (r2 = 0.371), height (r2 = 0.289), BSA (r2 = 0.436), and V (r2 = 0.527); and between CCr and weight (r2 = 0.178), height (r2 = 0.115), BSA (r2 = 0.199), and V (r2 = 0.151). There were also significant negative correlations between the normalized drain volumes (Dv/V and Dv/BSA) and all four indicators of body size. Raw (not normalized) peritoneal clearances and drain volumes correlated positively with size. However, D/P(urea) or D/P(creatinine) did not vary with any size indicator except for a weak association between D/P(creatinine) and V (r = 0.089, P = 0.028). This association was not confirmed when V was used to stratify subjects into quartiles, and group differences for D/P(creatinine were tested by one-way ANOVA. This study shows that the exclusive cause of the low normalized peritoneal clearances in large subjects on continuous ambulatory peritoneal dialysis is a low normalized drain volume. No evidence was found to indicate that body size influences the D/P ratio of small solutes. The portion of the variance in normalized clearance explained by size varies by size indicator and solute (urea versus creatinine).
Adult↗
Interdialytic weight gain: role of salt and water intake.
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Drinking↗