Search PubMed⌕ Search

Biomedical subjects

B Piraino

Publications and source records attributed to B Piraino.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Gender differences in normalized clearances in CAPD: role of body size and normalizing parameters.

OBJECTIVE: To compare raw (not normalized) and normalized urea and creatinine clearances between women and men on continuous ambulatory peritoneal dialysis (CAPD). To study whether potential gender differences are due to the normalization process. DESIGN: Retrospective analysis of clearance studies. SETTING: Dialysis units of four academic medical centers. PARTICIPANTS: The study included 302 subjects (135 women and 167 men) on CAPD with four daily exchanges and a 2-L exchange volume. INTERVENTION: Measurement of urea and creatinine clearances (261 in women, 352 in men) by standard methods. Body water (the volume of distribution, V, for both urea and creatinine) was estimated by the Watson anthropometric formulas. MAIN OUTCOME MEASURES: Comparison of raw and normalized clearances between women and men. Urea clearance was normalized by V (Kt/Vur), while creatinine clearances was normalized by both V (Kt/Vcr) and body surface area (BSA) (Ccr). RESULTS: Mean values of weekly total (peritoneal plus renal) raw clearances were higher in men (urea clearance: women 67.1 L, men 77.4 L; Ccr: women 61.7 L, men 78.3 L). Raw renal clearances were higher in men, while raw peritoneal clearances were comparable. Mean weekly total Kt/Vur was higher in women (2.19 vs 1.94 in men), mean weekly total Kt/Vcr did not differ between the genders (women 2.01, men 1.95), while mean weekly Ccr was higher in men (73.0 vs 64.7 L/1.73 m2 in women). When clearances differed, the differences were significant at p < 0.001. Men had greater height and weight, while women had greater body mass index. On the average, V in men exceeded V in women by 31%, while BSA in men exceeded BSA in women by only 12%. CONCLUSIONS: Normalization of clearances by V creates relatively higher clearance values in women, while normalization by BSA creates relatively higher clearance values in men. Thus the normalization process may create artificial differences in the normalized clearances between genders.

Body Constitution↗
PubMedDate not supplied

Normalization of clearances in peritoneal dialysis using a formula for body water derived from an end-stage renal disease population.

OBJECTIVE: To compare body water (V) estimates from the Chertow formula (Vc), which was derived in an end-stage renal disease population, to V estimates from the Watson formulas (Vw) in continuous ambulatory peritoneal dialysis (CAPD) patients. To identify CAPD patients in whom Vc is preferred to Vw for clearance studies. DESIGN: Retrospective analysis of clearance studies. SETTING: Dialysis units of four academic medical centers. PARTICIPANTS: 302 subjects on CAPD. INTERVENTION: 613 clearance studies by standard methods. MAIN OUTCOME MEASURES: Comparisons between Vc and Vw, and between urea clearance normalized by Vc [(KtVc)ur] and Vw [(Kt/Vw)ur]. RESULTS: Vc exceeded Vw by 3.5 +/- 1.6 L (p < 0.001), or 9.6% on average. This degree of overestimation of Vw is in the range of body water estimates found in CAPD subjects with severe volume overload (> 5% of body weight) in previous studies. Total (Kt/Nw)ur exceeded total (Kt/Vc)ur by 8.6%. By linear regression, Vc = -0.589 + (1.112 x Vw), r = 0.983. Vw exceeded Vc in only 12 studies. Young age, short height, low body weight, and low prevalence of diabetes characterized the studies with Vw > Vc. Total (Kt/Vw)ur was adequate (> or = 2.0 weekly) in 276 studies. Among these, 74 studies had inadequate total (Kt/Vc)ur (< 2.0 weekly). By logistic regression, the predictors of inadequate (Kt/Vc)ur, when (Kt/Vw)ur was adequate, included the presence of diabetes, great height, and long duration of CAPD. CONCLUSIONS: Vc provides estimates of body water exceeding those provided by Vw in a great majority of CAPD patients. Consequently, approximately 25% of the clearance studies that are adequate when Vw is used as the normalizing parameter may be inadequate when Vc is used. Vc may provide a more appropriate estimate of body water than Vw in CAPD patients with volume overload.

Body Water↗
PubMedDate not supplied

Prevention of peritonitis in children on peritoneal dialysis.

We reviewed methods of preventing peritonitis in children. A considerable body of evidence indicates that peritonitis rates are lowest with the use of a double-cuffed catheter, with a downward directed tunnel, placed by an experienced surgeon. Evidence in adults, but lacking in children, suggests that exit-site mupirocin will lower Staphylococcus aureus exit-site infections and thus peritonitis rates. The risk of peritonitis due to contamination can be diminished by the avoidance of spiking and by the provision of a long training period. Catheter removal and replacement for catheter-related peritonitis may be done simultaneously in certain circumstances and is useful in decreasing the risk of recurrent peritonitis. Antibiotic prophylaxis at the time of catheter insertion, for contamination, during dialysate leaks, and for invasive procedures appears to be useful in diminishing peritonitis risk.

Anti-Bacterial Agents↗
PubMedDate not supplied

Peritoneal dialysis clearance can replace residual renal function.

OBJECTIVE: There is controversy whether increasing peritoneal clearance effectively substitutes for declining residual renal function. We studied the impact of renal and peritoneal clearances on outcome, controlling for comorbidity. DESIGN: Registry database. SETTINGS: Four dialysis centers. PATIENTS: Incident peritoneal dialysis patients. METHODS: Data were collected prospectively on 90 incident patients between 1991 and 1999. At the end of their first year on peritoneal dialysis, patients were divided into groups based on the first year's clearance results: group 1 (n = 62) had weekly Kt/W greater than or equal to 2.0 and creatinine clearance (CCr/1.73 m2) greater than or equal to 60 L throughout the first year; group 2 (n = 28) fell below these targets due to loss of residual renal function and then reached targets due to prescription change. MAIN OUTCOME MEASURES: Patient and technique survival. RESULTS: Both groups were similar in baseline characteristics except age (57 years vs 49 years, p = 0.02) and initial albumin (34.4 g/L vs 37.5 g/L, p = 0.001). One-year patient survival after grouping was similar in both groups (86.3% vs 80.9%, p = 0.72). Cox proportional hazard model, controlling for comorbidity, did not show "group" to be a significant predictor of outcome (p = 0.96). One-year technique survival after grouping was similar in both groups (77.3% vs 83.2%, log rank p = 0.89). For technique failure, Cox proportional hazard model showed peritonitis (p = 0.004) to be the only significant predictor of worse outcome. CONCLUSIONS: Peritoneal dialysis patients with improved clearances due to prescription changes had survival comparable to patients who never fell below target. This suggests that loss of residual renal function may be replaced by increasing peritoneal dialysis clearance. A large multicenter trial to study this important question further is needed.

Female↗
PubMedDate not supplied

The influence of demographic factors and modality on loss of residual renal function in incident peritoneal dialysis patients.

OBJECTIVE: To determine whether gender, race, diabetes, peritoneal dialysis (PD) modality, and comorbid conditions influence loss of residual renal function (RRF). DESIGN: Retrospective study of incident PD patients, using database of prospectively collected demographic, laboratory, and clearance data. SETTING: Peritoneal Dialysis Registry of the University of Pittsburgh Medical Center. PATIENTS: The study included 184 continuous ambulatory PD and automated PD patients who had at least two 24-hour urine collections for glomerular filtration rate (GRF) between April 1991 and March 2000. 836 urine collections were analyzed. OUTCOME MEASURES: Loss of RRF was defined as the slope of the decline in GFR as measured by the average of creatinine and urea clearances in 24-hour urine collections. Stepwise forward regression was used to identify demographic and laboratory factors associated with loss of GFR. Spearman correlations were used to assess the significance of associations. RESULTS: The median rate of decline of renal function was -0.17 mL/minute/month. Gender, race, diabetes, automated PD, peritoneal equilibration test, protein equivalent of nonprotein nitrogen appearance normalized to body surface area, and serum albumin did not predict loss of RRF. Cardiac disease was the only variable affecting decline of RRF (p = 0.045). CONCLUSION: Modality of PD and patient demographic factors do not contribute to the rate at which RRF is lost in incident PD patients. Additional study of the factors contributing to the decline and maintenance of RRF is needed.

Adult↗
PubMedDate not supplied

Urea kinetics and nitrogen appearance rates in diabetic patients on peritoneal dialysis.

OBJECTIVE: We compared the relationship of protein intake (as measured by protein nitrogen appearance) and dialysis delivery in insulin-dependent diabetic (IDDM) and nondiabetic patients. DESIGN: One to two 24-hour dialysate and urine collections were obtained in 20 diabetic patients and 42 nondiabetic patients. The protein equivalent of nitrogen appearance (PNA) was calculated by the Randerson formula. KT/V was determined using V obtained by the Watson formula. PNA was normalized using three different methods to determine body weight: first, by normal or ideal body weight according to the Metropolitan Table (nPNA); second, by standard body weight according to the NHANES Table (sPNA); and third, by V/0.58 (vPNA). RESULTS: The mean PNA was not different in diabetics and nondiabetics (53 +/- 21 g/day vs 60 +/- 14 g/day), nor was weekly KT/V (2.1 +/- 0.6 vs 2.1 +/- 0.6). Mean normalized PNA was not different in IDDM versus non-DM regardless of the method. KT/V correlated with nPNA in IDDM (r = 0.54, p = 0.002 and non-DM, r = 0.31, p = 0.03), and with vPNA in IDDM (r = 0.73, p < 0.00001, and non-DM, r = 0.45, p = 0.0009). KT/V also correlated with sPNA in IDDM (r = 0.57, p = 0.001), but not in non-DM (r = 0.25, p = 0.08). The slope for normalized PNA versus KT/V was steeper for IDDM than for non-DM. CONCLUSION: KT/V and PNA are more closely correlated in IDDM patients than in non-DM patients. Thus it is extremely important that IDDM patients receive an adequate level of dialysis.

Body Weight↗
PubMedDate not supplied

Which catheter is the best buy?

Good but not perfect results can be obtained with many types of catheters. Convincing data demonstrating superiority of one catheter over another are not available. What is the comparative cost of these catheters? The straight Tenckhoff catheter remains the least expensive at $42.50 (Quinton Instrument Company). Until a large randomized trial is done demonstrating a clear superiority of another catheter, we will continue to use the straight double-cuff Tenckhoff catheter.

Bacterial Infections↗
PubMedDate not supplied

Neither size nor weight predicts survival in peritoneal dialysis patients.

OBJECTIVE: To determine if patient size or weight at the start of PD influences patient or technique survival. DESIGN: A prospective cohort study of adult PD patients. SETTING: A university and a Veterans Administration outpatient dialysis unit. PATIENTS: 343 adults patients with 660 years on PD enrolled from 1979 to 1995. MAIN OUTCOME MEASURES: Patient survival (censoring for transplant, 60 days post-transfer to hemodialysis, and end of study) and technique survival (censoring for death, transplant, or end of the study) for patients as grouped by weight (< or = 64 kg vs. > 64 kg or < or = 82.7 kg vs. > 82.7 kg) or BSA (< or = 2.0 m2 vs > 2.0 m2). RESULTS: Patient survival was 86.3% at one year, 77.0% at two years, 65.2% at three years, and 56.9% at 4 years. Technique survival was 84.9% at one year, 77.5% at two years, 63.5% at three years, and 58.3% at four years. The patient and technique survival curves were not significantly different for patients as grouped by weight or BSA. Using Cox proportional hazards model, age, diabetes, peritonitis rate, and albumin at the start of PD were independent predictors of patient survival, but BSA and weight were not. The only predictor of technique survival was the peritonitis rate. Larger patients had higher initial albumins, which may indicate better nutritional status that may offset the risk of underdialysis. CONCLUSIONS: Large patients do as well as smaller patients on PD. Size alone should not preclude patients from PD.

Adult↗
PubMedDate not supplied

Low seroconversion with hepatitis B vaccination in peritoneal dialysis patients.

OBJECTIVE: To compare seroconversion using hepatitis B vaccine between hemodialysis (HD) and peritoneal dialysis (PD) patients. DESIGN: Data on PD patients vaccinated were collected retrospectively for the period 1992 to 1995. The data on HD patients were collected prospectively from 1991 to 1994. SETTING: A university outpatient dialysis center. PARTICIPANTS: All adult patients who received all four doses of hepatitis B vaccine while on dialysis were included (47 PD and 50 HD patients). INTERVENTION: Recombinant hepatitis B vaccine (Engerix), 40 micrograms IM was administered at 0, 1, 2, and 6 months. MAIN OUTCOME MEASURE: Seroconversion was measured after completion of the vaccination series. RESULTS: 74% of the HD patients seroconverted compared to 53% of PD patients (p = 0.03). Older, heavier patients compared to all the other patients had a lower seroconversion rate in both the HD patients (55% vs. 78 %) and PD patients (38% vs. 59%) (p = 0.03). CONCLUSION: The seroconversion rate to recombinant hepatitis B vaccine is lower in patients on PD than on HD for unclear reasons. Further studies are required to determine the etiology of this difference.

Adult↗