Objective:To evaluate the sensitivity of anthropometry and bioelectrical impedance analysis (BIA) in detecting alterations in body composition of children treated with peritoneal dialysis (PD), and to determine the prevalence of malnutrition in this population, in short- and long-term PD duration, using anthropometric and BIA-derived indices.Patients: Eighteen children treated with automated PD (11 males, 7 females; mean age 8.7 +/- 4.7 years). Design: Eighteen patients were studied using anthropometry and BIA at the start (t0) and after 6 months (t1) of PD, 15 of these patients at 12 months (t2), and 8 at 24 months (t3) of PD. Midarm muscle circumference (MAMC), arm muscle area (AMA), and arm fat area (AFA) were calculated from anthropometric measures according to Frisancho (FrisanchoAR. New norms of upper limb fat and muscle areas for assessment of nutritional status. Am J Clin Nutr 1981; 34:2540-5.). The bioelectrical measures of resistance (R) and reactance (Xc) were obtained directly from the impedance signal; phase angle (PA) and distance (D) were calculated using mathematical formulas. Nutritional status was assessed by anthropometric measurements and BIA-derived indices, expressed as standard deviation scores (SDS), and by a score system based on BIA and anthropometric parameters. The percentage of children with values of anthropometric and BIA-derived indices below the 3rd percentile or between the 3rd and 25th percentiles, and the percentage of children with scores of 7 - 12 and 4 - 6 were calculated in order to detect patients with severe or moderate derangement of nutritional status.Results:The mean SDS values of Xc, PA, and D significantly improved (p = 0.05, p = 0.001, p = 0.02) during the first 6 months of PD and remained almost stable during the following months. The SDS values of the anthropometric indices were less compromised than those of the BIA-derived indices, particularly at the start of dialysis. By 6 months, the percentages of children with values of BIA and anthropometric indices below the 3rd percentile had decreased. The percentages of patients with moderate and severe derangement of BIA and anthropometric indices remained substantially unchanged after 12 months. However, at 24 months, the percentage of patients with moderate derangement of BIA indices increased. All these findings were confirmed by the nutritional score system.Conclusion: BIA is more sensitive than anthropometry in detecting alterations in body composition of children on PD. The prevalence of malnutrition, high at the commencement of PD, decreases during the first year of treatment but not over the long term.

To develop models to estimate nitrogen (N) losses of children on chronic peritoneal dialysis (CPD) from easily measurable indexes and laboratory tests, we measured the N content and all nitrogenous compounds in dialysate (D), urine (U), and feces over 3 days in 19 pediatric patients on CPD. Total measured N losses (TNm) were 5.56±2.26 g/day (69.9±11.1% in dialysate, 16.3±10.6% in urine, and 13.6±4.6% in feces). Correlation coefficients between measured dialysate and urinary N losses and the single nitrogenous compounds indicated values of over 0.9 only for urea in dialysate and urine; fecal N losses correlated well with body surface area (BSA). Taking into account these correlations, we developed a univariate additive model and three multivariate models to predict total estimated N losses (TNe). The best prediction of TNm was obtained with model 3, which considered not only urea output in dialysate and urine but also dialysate protein loss and BSA: TNe (g/day)=0.03+1.138 UN urea+0.99 DN urea+1.18 BSA+0.965 DN protein. A confirmatory analysis performed on a second group of 23 pediatric patients on CPD, using all four models, showed a higher percentage of studies with a relative difference between TNm and TNe less than 10% for model 3 than for the other models. Thus, N losses of pediatric patients on CPD can be estimated from measured urea and protein losses in dialysate and urea loss in urine, together with BSA.

Renal-transplanted children may present stunted growth, negative nitrogen balance (Nb), and alterations in body composition. Recombinant human growth hormone (rhGH) is a potent anabolic agent which improves nutritional status and Nb. In renal-transplanted children, rhGH increases growth velocity but its effect on nutritional status has not been reported. We evaluated the effect of 6 months of rhGH treatment on Nb, urea nitrogen appearance (UNA), anthropometric indexes, and growth velocity in 14 pediatric patients with a renal transplant. Nb improved significantly (P = 0.02) and was accompanied by a decrease of UNA. A significant improvement was observed also in mid-arm muscle circumference (P = 0.002), arm muscle are (P = 0.001), and arm fat are (P = 0.017). Growth velocity increased in prepubertal patients (P = 0.003). Creatinine clearance and the number of rejection episodes were not affected by rhGH treatment. In conclusion, short-term administration of rhGH improves Nb and UNA as well as the main indexes of body composition.

Dietary protein restriction, progressive loss of renal adaptive capacity, and uremic toxicity may contribute to the development of malnutrition and water retention in severe chronic renal failure (CRF). Malnutrition is also common in children treated with chronic peritoneal dialysis (CPD). It is not clear how the start of CPD influences body composition of children with CRF. We used a bioimpedance analysis device (BIA 101S Akern) to measure resistance and reactance in 7 children, with residual creatinine clearance of about 5 mL/min/1.73 m2 at the start of CPD (t0) and repeated the test 6 months later (t1). Distance (D), which is considered a reliable index of hydration and nutrition, was obtained from resistance (R) and reactance (Xc) by calculating phase angle (PA). BIA values of our patients were compared with those of healthy children of the same statural age from a series of 551 controls. There was an overall improvement of Xc, PA, and D after 6 months of CPD. In some cases D did not normalize, which indicates that some children with CRF on a restricted protein diet may present changes of body composition that are only partially reversed by short-term CPD. The present indications for the start of CPD should probably be reassessed, at least in some cases, to prevent malnutrition.

Objective To propose a simplified equilibration test specific for tidal peritoneal dialysis (TPD) that will overcome the inconveniences of the measurement of TPD peritoneal solute clearances through whole dialysate collection. This will enable the prediction of peritoneal creatinine and urea clearances, the suitability of patients for TPD, and routine assessment of TPD delivery. Design In a prospective study, patients had a standardized TPD run, and dialysate-to-plasma (DIP) ratios for creatinine and urea were calculated at various TPD and peritoneal equilibration test (PET) time points and on total TPD dialysate. Solute clearances were estimated and measured, and correlation coefficients were obtained among all these variables. Setting Dialysis unit of a pediatric nephrology department and patients’ homes. Patients Eleven pediatric patients with end-stage renal disease in stable clinical conditions treated with TPD. Interventions Dialysate and blood sample collections. Main Outcome Measures DIP ratios for creatinine and urea at the fifth and seventh TPD exchanges, at 15–,30–,60, and 120-minute PETtimes, and on total TPD dialysate and TPD peritoneal creatinine and urea clearances. Results Correlation coefficients between PET -derived and total TPD dialysate-derived DIP ratios, and those between PET -derived and measured creatinine and urea clearances were more significant at the 120-minute PET time point compared with the other PET time points. Best correlations were obtained at the fifth and seventh TPD exchanges. DIP ratios for creatinine and urea of the fifth and seventh TPD exchanges correlated significantly with the DIP ratios calculated from total TPD dialysate. A significant correlation was also found between peritoneal creatinine and urea clearances on total dialysate volume (measured clearances) and those derived from the dialysate collection of the fifth and seventh TPD exchanges (estimated clearances) -that based on the seventh exchange being slightly more significant. Moreover, the estimated clearances derived from the seventh exchange were within 10% of the measured value in 90.9% of patients both for creatinine and urea. Conclusion The significant correlation between measured and estimated peritoneal creatinine and urea clearances and the low percentage of underestimates of measured clearances obtained using the seventh TPD exchange-derived indices confirm the accuracy of the DIP ratios for creatinine and urea derived from any exchange after the fifth (preferably the seventh) of a standardized TPD run in estimating peritoneal creatinine and urea clearances. This method could represent a simple and accurate means for prescribing TPD and routinely assessing TPD delivery.

Prediction of suitability of patients for tidal peritoneal dialysis (TPD) treatment based on the peritoneal equilibration test (PET) may be hypothetically subject to errors, due to the difference between the long equilibration times of the PET and the short dwell times currently utilized during TPD. Eleven patients, mean age 12.4 +/- 3.3 years, mean body weight 34.2 +/- 15kg, had both a standardized TPD run (initial fill volume 40 mL/kg, tidal volume 50%, dwell time 10 min, treatment time 8 h) and a PET performed. D/P ratios for creatinine and urea were calculated at the 5th and 7th TPD exchanges (approximating equilibration time of the TPD run), at the time points of the PET and on the total TPD dialysate volume. D/P ratios for creatinine and urea of the 5th and, even more, the 7th TPD exchange, and D/P ratios obtained from total TPD dialysate were significantly correlated overall (r = 0.96, p < 0.0001 for 5th D/P creatinine and urea; r = 0.98, p < 0.0001 for 7th D/P creatinine and urea). Correlation coefficients between PET-derived and total TPD dialysate-derived D/P ratios were generally poor or only modest. Thus, it is possible to predict TPD clearance, and consequently the suitability of patients for TPD, knowing the D/P ratios for creatinine and urea at the 7th TPD exchange of a standardized TPD run. Our data could represent a new reliable test for TPD prescription.

The Italian Registry of Pediatric Chronic Peritoneal Dialysis (CPD) carried out a special study on patient hospitalization during the years 1989-1992. Ninety-two children (mean age 8.4 +/- 4.7 years) entered the study, for a total of 1406 CPD-months. The contribution of the different causes of hospitalization for a total of 4683 hospital days was: CPD training 31%; routine controls 14%; CPD-related complications 35%; clinical complications 14%; other causes 6%. The rate of patient hospitalization that resulted was 3.33 days/CPD-month; it was higher in the first year (4.32 days/CPD-month) than in the second year (1.64 days/CPD-month) or in the third year (2.25 days/CPD-month). This difference was mainly due to the need for the training at the start of the CPD treatment. The evaluation of the hospitalization rate in different age groups showed a statistically significant difference (p < 0.05) between the group 0-2 years (5.47 days/CPD-month) and the group 3-15 years (2.78 days/CPD-month). Complications were the cause of 150 admissions to the hospital (1:9.6 CPD-months). Ninety-eight admissions were due to CPD-related complications: peritonitis (33%), problems with the catheter (19%), abdominal hernias (4%), and others (9%). Among clinical complications (52 admissions), the main cause of hospitalization was hypertension (15%), followed by infections (4%), and malnutrition (3%).

During the period 1986-1991, the Italian Registry of Pediatric Chronic Peritoneal Dialysis collected data from 140 patients younger than 15 years at the start of chronic peritoneal dialysis (CPD). In this study we review the Registry's complications and patient hospitalization data. A total of 395 complications directly related to CPD were registered during 2722 dialysis-months. There were 176 episodes of peritonitis (44.5%), 161 catheter-related complications (40.7%) (103 exit-site infections, 17 leakages, 15 obstructions, 15 cuff extrusions, 5 hemoperitoneum, and 6 other complications), and 58 technique-related complications (14.8%) (39 abdominal hernias, 10 hydroceles, 5 with abdominal pain, 4 hydrothorax complications). The patient hospitalization rate during the period 1989-1991 was evaluated; the analysis referred to 106 patients who underwent treatment for a total of 1520.5 dialysis-months. Patients starting CPD in the year and patients already on CAPD spent 5.8 and 2.1 days per patient-month in the hospital, respectively; the difference was not statistically significant. The evaluation of complications (both technical and systemic) causing patient hospitalization showed that peritonitis was responsible for 43.2% of patient admissions and 36.3% of days hospitalized, catheter-related complications for 22% and 19.8%, technique-related complications for 8.3% and 5.1%, and other clinical complications for 26.5% and 38.8%, respectively.

The peritoneal equilibration test (PET) is routinely performed in adults treated with chronic peritoneal dialysis to assess the peritoneal transport rate and to optimize treatment prescription. Only a few and not well-standardized studies on the PET have been reported in children. Twenty-six PETs were performed In 16 children, mean age 10.9±4.9 years, mean body weight (BW) 26.8±11.9 kg, treated with nightly intermittent peritoneal dialysis (NIPD). The PET was performed according to Twardowski. Forty mL/kg BW of 2.27% glucose solution were Infused at a rate of 10 mL/kg BW every 2 minutes. In the simplified test, dialysate samples were taken at dwell times 0, 2 and 4 hours for glucose and creatinine. A blood sample was taken after a 2-hour dwell time for the same parameters. The standard PET (8 patients) consisted of dialysate samples at 0, 15, 30, 60, 120, and 240 minutes and blood samples at 0 and 240 minutes. Mean DIP ratio for corrected creatinine and DIDo ratio for glucose at 2 hours were 51.6±11.6 and 50.4±9, respectively; at 4 hours 69.6± 12 and 34.4±9.8, respectively. There was good correlation between DIP creatinine and DIDo glucose at 4 hours (p<0.0001). Patients were classified as high (3 cases), high-average (5), low-average (6), and low (2) transporters. A statistically significant difference was found between the curves obtained by the simplified PET and those of the standard PET In the first hour (r=0.66; p<0.05). In conclusion, the PET, modified for use in children, gave reliable and reproducible results. Mean values of DIP creatinine for children were higher and DIDo glucose lower than those of adults as reported by Twardowskl. A consistent percentage of children had, nevertheless, a low-average or low transport rate. Standard PET is required in case of automated peritoneal dialysis prescription.

During the period 1986-1990, 119 patients were enrolled in the Italian Registry of Pediatric CPD. CAPD was largely predominant in the first 3 years, while CCPD accounted for 48% of dialysis months in the period 1989-1990. The connect-disconnect system was a Y set for all patients during the whole observation period. The incidence of peritonitis decreased from 1 episode: 10.9 patient-months in 1986 to 1:19.8 in 1988, and then passed to 1:16.2 in 1990. A comparison of the incidence of peritonitis between CAPD and CCPD, referring to the 1989-1990 period, showed no significant difference. The percentage of positive peritoneal fluid cultures changed from 48% in 1986 to 73% in 1990. Gram-positive bacteria, primarily Staphylococcus aureus and Staphylococcus epidermidis, accounted for most of the isolated organisms. Candida albicans was cultured in 3 cases both in 1986 and 1987. Exit site infection was the predominant (82%) complication, followed by leakage and catheter cuff extrusion. The hospitalization rate for peritonitis resulted persistently high (61% of episodes) and the mean duration was 12.7 days. Of the 8 patients who were switched to hemodialysis, 4 had recurrent peritonitis and 1 Candida albicans peritonitis.