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Purpose: The purposes of this study were to analyze changes in the frequency of different categories of surgical procedures after initiation of chronic hemodialysis (HD) and to identify the types of procedures associated with in-hospital postoperative mortality., Methods: This was a retrospective analysis of surgical procedures performed in an incident HD population of 392 patients followed in the dialysis unit of one hospital over 15 years. Among these patients, 384 were men and 258 had diabetes mellitus. At the start of HD, age of the patients was 66.3 ± 11.2 years and Charlson index 5.35 ± 2.41. Rates of procedures per patient year (n/[pt-yr]), reported as mean (95% Confidence Interval [CI]), were compared by nonparametric methods., Results: In the whole HD population, the overall rate of procedures increased in the HD period (pre-HD 0.125 [95% CI 0.101-0.149] n/[pt-yr]; HD 0.928 [95% CI 0.795-1.061] n/[pt-yr]; p<0.001). The increase, noted in patients with and without diabetes, reflected increases in the rates for both vascular access and non-vascular access procedures from the pre-HD to the HD period. Amputations and surgery for hip fractures accounted for the increase in the rates of procedures related to non-vascular access. Procedures associated with mortality in the HD period included amputations, hip repair and abdominal surgery for septic conditions., Conclusions: Rates of surgical procedures for vascular access, amputations, and hip fractures ?increased after the start of HD. Amputations and hip fractures, both potentially preventable, are associated with mortality in HD patients.

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.

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.

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.

The purpose of this study was to determine if Kt/V urea in continuous ambulatory peritoneal dialysis (CAPD) could be estimated by a multivariate model based upon simple clinical observations. The study included 439 clearance studies in 301 CAPD patients followed in 8 dialysis centers. Weekly urea clearance, 24 h urine volume and 24 h drain volume were normalized to body water by the formulae of Watson (Kt/V, UV/V and DV/V respectively). Adequate dialysis was defined as Kt/V > or = 2.0 weekly. Subjects at 2 units were used to derive the models, while others were used for model validation. Stepwise multiple linear regression was performed on the derivation set (DS) to identify the clinical variables that correlated with Kt/V. The model was then used to estimate Kt/V for the validation set (VS). In the DS, 110 clearance studies were performed in subjects with residual renal function. Multiple linear regression showed that weekly Kt/V was defined by the expression: Kt/V=1.48 + 24.1 (UV/V) + 2.92(DV/V) - 0.049 (serum creatinine) (r=0.750, p<0.001). In 204 VS studies, the correlation between estimated and measured Kt/V was 0.633. There were marked differences in the proportion of adequately dialyzed patients when Kt/V estimated from the formula shown was <2.0, between 2.0 and 2.3, and >2.3 weekly (7.9%, 54.7% and 79.7%, respectively; p2.3 weekly (8.1%, 68.8%, and 100%, respectively; p<0.001). The risk of low Kt/V can be estimated by multivariate linear models requiring only simple clinical measurements.

The expression (Estimated-Predicted)/Predicted creatinine generation ¿(E-P)/P¿ has been proposed as an index of compliance in continuous peritoneal dialysis (CPD). We attempted to define an (E-P)/P value that can be used as a cut-off for non-compliance and to characterize the relation of (E-P)/P to serum albumin. In 324 clearance studies, (E-P)/P had a normal distribution with a mean of +0.094 and an SD of 0.357. In these studies, there was a weak correlation between (E-P)/P and serum albumin (r = 0.12, P < 0.05), but (E-P)/P was not a predictor of serum albumin by logistic regression. In 34 CPD patients, who had an increase in the dose of CPD resulting in an increase in measured creatinine clearance from 43.8 +/- 14.0 to 66.1 +/- 17.6 L/1.73 m2 weekly (P < 0.001), (E-P)/P increased correspondingly from +0.018 +/- 0.284 to +0.153 +/- 0.369 (P = 0.018), although all subjects should be in a steady state of creatinine excretion in the second study. The rise in (E-P)/P was statistically significant in the subgroup of 17 subjects who had a decrease in serum albumin, but not in the subgroup of 14 subjects who had an increase in serum albumin from the first to the second clearance study. The (E-P)/P cut-off for a definitive diagnosis of CPD non-compliance may be around +0.400 or +0.500. The findings of this study suggest that non-compliance, as indicated by (E-P)/P, has an adverse effect on serum albumin and that non-compliance increases after a prescribed increase in the dose of CPD.

The association between azotemic index dialyzer clearances and hematocrit was investigated in a 63-year-old dialysis-dependent man with acquired renal cysts. During 43 months of hemodialysis, hematocrit rose from 27.3 to 65.0 vol%, as a consequence of high serum erythropoietin levels. Concomitantly, dry weight also increased from 116.8 to 140.8 kg. Both hematocrit and dry weight correlated with: (a) urea reduction ratio, (b) creatinine reduction ratio (CRR), and (c) KT/V urea. All correlations were negative. Stepwise regression showed that only hematocrit was an independent correlate of the CRR (CRR = 0.662 - 007* Hct, R2 = 0.770); whereas, both hematocrit (Hct) and weight (W) were independent correlates of KT/V urea (KT/V = 2.070 - 0.005*Hct - 0.009*W,R2 = 0.721). In addition to creatinine clearance, urea clearance through the dialyzer is reduced by a rising hematocrit. The effect of hematocrit on urea clearance is relatively small. Therefore, it requires large changes in hematocrit in order to be detected.

Adequacy of continuous ambulatory peritoneal dialysis (CAPD) and its variants is assessed by clinical outcomes, biochemical parameters and clearance parameters. Clinical outcomes lack specificity and probably sensitivity. Nevertheless, they constitute the "gold standard" to which any other method assessing dialysis adequacy must be compared. Biochemical parameters are both non-sensitive and non-specific and cannot be used to assess dialysis adequacy. Clearance of small molecular weight azotemic substances (urea, creatinine) presents considerable computational problems and interpretative difficulties. In preliminary studies, clearance studies have been able to differentiate between peritoneal dialysis patients having symptoms of inadequate dialysis and those clinically adequately dialyzed. Among population outcomes (morbidity, maintenance of peritoneal dialysis for long periods, hospitalization rate, mortality), only mortality seems to be associated with low clearances in retrospective studies. Prospective multicenter studies comparing clearance values to clinical outcomes are needed to evaluate clearance studies as methods of assessing peritoneal dialysis adequacy.

Eight diabetic men with poor glycemic control, probably worsened by severe congestive heart failure and gastroparesis, were sequentially dialyzed by CAPD and hemodialysis. Mean blood glucose concentration, blood glycosylated hemoglobin, and insulin dose were higher during CAPD than during hemodialysis. Among blood glucose determinations, however, the frequency of hypoglycemia (glucose less than 3.3 mmol/L) was higher during hemodialysis (13.2 +/- 8.9%) than during CAPD (2.8 +/- 2.1% p = 0.012), whereas the frequencies of hyperglycemia (glucose greater than 11.1 mmol/L) and euglycemia (glucose between 3.5 and 11.1 mmol/l) did not differ between the two dialysis modalities. Furthermore, hypoglycemia was severe during hemodialysis and was associated with two deaths. There were no deaths linked to abnormalities in blood glucose concentration during CAPD. When hypoglycemia is frequent in diabetics with poor glycemic control, CAPD is preferable to hemodialysis.