Tubular and glomerular function in children after renal transplantation.

Glomerular and tubular function of transplanted kidneys were assessed in 46 children aged 15.7 +/- 4.6 yr, 4.2 +/- 2.8 yr after renal transplantation. There were 34 cadaveric, and 12 living-related donors. Twelve patients (26%) had acute episodes (acute tubular necrosis, rejection, or urinary tract infection) during follow-up. All patients were on triple immunosuppression. The mean serum creatinine was 1.5 +/- 0.6 mg/dL. Creatinine clearance (Ccreat) calculated from a 24-h urine collection was 48.0 +/- 19.7 mL/min/1.73 m(2), and that estimated from the Schwartz formula, 61.0 +/- 22.5 mL/min/1.73 m(2). A positive correlation was found between the calculated and estimated clearances. Mean urine concentrating ability was 487 +/- 184 mOsmol/kg, with a value lower than 400 mOsmol/kg in 35% of patients. There was a positive correlation between urine osmolality and estimated Ccreat. Metabolic acidosis (bicarbonate <22 mmol/L) was found in 41% of patients, with relatively alkaline urine and high chloride level. Fractional excretion (FE) of sodium was above 1% in 68% of patients (mean 1.66 +/- 1.06%), and FE(Mg) was above 3% (mean 10.9 +/- 5.2%) in 93% of patients. Tubular reabsorption of phosphate (TP)/glomerular filtration rate (GFR) was 3.2 +/- 0.8 mg/dL glomerular filtrate (GF). FE(K), FE(UA), and Ca/creatinine in urine were normal. There were no functional group differences between the cadaveric and living-related kidneys. Significant group differences were found in those with acute episodes and those with a normal course. Estimated Ccreat was 54 +/- 20 vs. 67 +/- 20 mL/min/1.73 m(2) in the acute episodes and the normal course groups, respectively. Also, the FE(NA), FE(UA), and FE(Mg) were higher in the acute episodes group -2.3 +/- 1.6, 10.6 +/- 4.4, and 14.8 +/- 6.5%, respectively, compared with the normal course group -1.4 +/- 0.6, 8.2 +/- 2.8, and 9.6 +/- 4.0%, respectively. There were no between-group differences in plasma bicarbonate, FE(K), TP/GFR, and urine osmolality. We believe that most, if not all tubular dysfunctions in the transplanted kidney are secondary to renal failure and interstitial damage from acute episodes and nephrotoxic drugs. These dysfunctions are similar to those in chronic renal failure, where interstitial fibrosis plays a role in kidney function deterioration.

Acute renal failure, associated with non-steroidal anti-inflammatory drugs in healthy children.

Seven patients aged 13 to 17.5 years developed acute renal failure after treatment with a variety of non-steroidal anti-inflammatory drugs (NSAID): naproxen, diclofenac, ibuprofen, dipyrone and paracetamol. Six of the patients used more than one kind of NSAID. None of the patients had previous history of renal disease or concomitant treatment with other drugs. The time interval between NSAID administration to the emergence of symptoms ranged from 1 to 4 days. The most common presenting symptoms were flank pain (4 patients), abdominal pain (3 patients) and vomiting (3 patients). All patients had normal urine output. Microscopic hematuria and proteinuria were found in 5 patients and leukocyturia in 2. Serum creatinine ranged from 1.3 to 8.3 mg% at presentation. Kidney biopsy was performed in 3 patients and showed findings consistent with mild interstitial inflammation in 1 patient, and normal renal tissue in 2. All patients were treated with intravenous fluids, 1 received corticosteroids. Renal function completely normalized in all patients within 7 to 16 days.

Prevalence of vesicoureteral reflux in neonatal urinary tract infection.

Vesicoureteral reflux (VUR) after a first episode of urinary tract infection (UTI) is apparently diagnosed much more frequently (25%-40%) in children than in neonates. The aims of the study were to determine the actual rate of VUR in neonates with UTI and to define the clinical clues to its diagnosis. The study sample included term infants with a diagnosis of UTI during their first month of life who were seen in this hospital between January 1997 and May 1999. All infants underwent complete diagnostic work-up (renal ultrasound and voiding cystourethrography [VCUG]). The medical files were reviewed for patient sex, age at UTI diagnosis, laboratory findings (including causative pathogen), and ultrasonographic findings. These parameters were correlated with the finding of VUR on VCUG. Sixty-four neonates (55 males, 9 females) with UTI were included in this study. UTI was 6 times more common in males than females, although the incidence of VUR was equal between the sexes (about 20%). The presence of VUR was associated with a significantly younger age at presentation of UTI (11.4+/-4 vs 16.9+/-6.6 days, p<0.01). VUR was diagnosed at a fourfold higher rate in neonates with Klebsiella-induced UTI compared to those with E. Coli-UTI. In 80% of those with significantly abnormal ultrasonographic findings VUR was found on VCUG. Jaundice was noted at UTI diagnosis 3 times more often in infants with VUR, and elevated creatinine level, 2.5 times more often.

Unilateral duplicated system: comparative length and function of the kidneys.

OBJECTIVE: The objective of this study was to estimate kidney length and function in patients with unilateral duplex kidney. MATERIALS AND METHODS: Thirteen patients with a unilateral duplicated system were reviewed retrospectively. The length of the kidneys was measured by ultrasound, and the relative function of the kidneys was estimated by renal scan. RESULTS: In all patients, the duplex kidney was the left one. The length of the right kidney on the renal ultrasound growth chart was from -1.5 to +0.4 standard deviations from the mean for age, and the left kidney length was from -0.5 to +4.3 standard deviations from the mean. On renal scans the kidneys with a duplicated system contributed 51 to 67% to total renal function; the contralateral ones, 33 to 49%. CONCLUSIONS: Kidneys with a duplicated system may be larger than their counterparts and they may contribute more to total renal function. When a disparity in length between the 2 kidneys is encountered, 1 of the possibilities that should be taken into account is a unilateral duplicated system.

Methaemoglobinaemia and haemolysis associated with hydrogen peroxide in a paediatric haemodialysis centre: a warning note.

BACKGROUND: Haemodialysis exposes patients to contaminants in the dialysate. The AAMI standards deal only with two disinfectants, chlorine and chloramine. We report an event of methaemoglobinaemia and haemolysis related to an unsuspected disinfection agent. METHODS: Nine children aged 3-17 years undergoing dialysis after reconstruction of our paediatric dialysis unit developed methaemoglobinaemia of 3.1-11%, with a mean reduction in haemoglobin levels of 11.9 +/- 5.9% (P < 0.001). Air bubbles were noted in the bloodlines. The water treatment system (WTS) of the dialysis unit is disinfected when necessary by adding concentrated hydrogen peroxide (HP) to the storage tank and circulating it through the re-circulation loop with draining and subsequent flushings. Total chlorine analysis of the water is performed by DPD-iodide colorimetric method. RESULTS: Dialysis water testing yielded a high chloramine concentration in the storage tank and points- of-use stations (3.08 and 2.06 p.p.m., respectively). However, this finding was not true for the tap water, and it also failed to explain the air bubbles in the dialysis tubing. The concentration of free chlorine was within the recommended range. Further investigation revealed that the WTS was disinfected by the service company during remodelling of the unit, without notification of the hospital staff. Since the DPD-iodide test is not specific, and in effect detects not only total chlorine, but all oxidants capable of oxidizing iodide, we assumed the culprit was residual HP that was inadequately flushed from the water system. CONCLUSIONS: HP used for disinfection of the WTS can pose a serious dialysis risk if not flushed out properly. Total chlorine analysis should be performed before every dialysis session, and positive results should prompt further work-up for other oxidants. The clinical staff must always be involved in decisions regarding any intervention in the dialysis water system.

Intradialytic parenteral nutrition in malnourished children treated with hemodialysis.

OBJECTIVE: To examine the feasibility and effectiveness of intradialytic parenteral nutrition (IDPN) in children on hemodialysis. DESIGN: Prospective experimental study with a single intervention group. SETTING: A pediatric hemodialysis unit. SUBJECTS: Four malnourished children on hemodialysis (3 girls and 1 boy) 4 to 18 years of age were studied during a period of 1 year. INTERVENTION: IDPN, which is composed of amino acids (8.5% solution), glucose (as 10% to 15% dextrose), and 20% fat emulsion, was administered at every dialysis session (3 times a week, during 4 hours each time) for 7 to 12 weeks. MAIN OUTCOME MEASURE: Oral caloric intake (evaluated by using a 3-day diet history), dry weight (weight after dialysis), body mass index, percent ideal body weight, total lymphocyte count, and serum levels of albumin before, immediately after cessation of IDPN, and 3 months after cessation of IDPN. RESULTS: Oral caloric intake increased markedly after IDPN administration, from 5 to 63 kcal/kg/d (mean, 33 kcal/kg/d) before IDPN administration to 35 to 177 kcal/kg/d (mean, 86 kcal/kg/d) at the time of cessation. Weight did not change during the treatment period but it did increase from 9.5 to 36.4 kg (mean, 25 kg) to 11 to 39 kg (mean, 26.7 kg) 3 months later. Percent ideal body weight increased from 73% to 88% (mean, 78.5%) to 79% to 90% (mean, 85.1%), and body mass index increased from 12.2 to 15 kg/m(2) (mean, 13.5 kg/m(2)) to 13.4 to 15.5 kg/m(2) (mean, 14.6 kg/m(2)). Total lymphocyte count increased from 538 to 2,041 cells/mm(3) (mean, 1,403 cells/mm(3)) to 724 to 2,884 cells/mm(3) (mean, 2,066 cells/mm(3)). Plasma levels of albumin increased in 1 patient but remained unchanged in others. CONCLUSION: Short-term IDPN treatment may serve as a safe and effective nutritional intervention in malnourished children on hemodialysis.