Urinary interleukin-18 is an acute kidney injury biomarker in critically ill children.

BACKGROUND: Urinary interleukin-18 (uIL-18) is an earlier acute kidney injury (AKI) biomarker than serum creatinine (SCr) in specific populations. In the present study, the relationship between uIL-18 and AKI was determined in a heterogeneous group of critically ill children. METHODS: We studied critically ill children to determine whether uIL-18 was an early predictor of AKI. SCr was determined daily for up to 14 days from mechanical ventilation initiation and up to four serial urine specimens were collected for the uIL-18 measurement. AKI was graded by paediatric modified risk, injury, failure, loss, end-stage kidney disease (pRIFLE) criteria. Day 0 was defined as the day of attaining pRIFLE AKI. RESULTS: One hundred thirty-seven children aged 6.5 +/- 6.4 years (53% male) were studied. The peak levels of IL-18 correlated with the severity of AKI by pRIFLE classification (P < 0.05). In non-septic AKI patients, uIL-18 rose to a level higher than control levels 2 days prior to a significant rise in SCr. Urinary IL-18 concentration from the first urine specimen was associated with AKI development within 48 h (odds ratio = 3.5, P < 0.05) independent of the paediatric risk of mortality (PRISM II) score. Urinary IL-18 concentration > or = 100 pg/ml had a specificity and negative predictive value of 81 and 83% to predict AKI development within 24 h. Urinary IL-18 > or = 200 pg/ml collected within 24 h of Day 0 had a specificity and positive predictive value of 93 and 88% respectively to predict the AKI duration > or = 48 h. Urinary IL-18 was associated with mortality (odds ratio = 1.29, P < 0.05), independent of the PRISM II score. CONCLUSIONS: Urinary IL-18 rises prior to SCr in non-septic critically ill children, predicts severity of AKI and is an independent predictor of mortality.

Urine neutrophil gelatinase-associated lipocalin is an early marker of acute kidney injury in critically ill children: a prospective cohort study.

INTRODUCTION: Serum creatinine is a late marker of acute kidney injury (AKI). Urine neutrophil gelatinase-associated lipocalin (uNGAL) is an early marker of AKI, where the timing of kidney injury is known. It is unknown whether uNGAL predicts AKI in the general critical care setting. We assessed the ability of uNGAL to predict AKI development and severity in critically ill children. METHODS: This was a prospective cohort study of critically ill children. Children aged between 1 month and 21 years who were mechanically ventilated and had a bladder catheter inserted were eligible. Patients with end-stage renal disease or who had just undergone kidney transplantation were excluded. Patients were enrolled within 24 to 48 hours of initiation of mechanical ventilation. Clinical data and serum creatinine were collected daily for up to 14 days from enrollment, and urine was collected once daily for up to 4 days for uNGAL measurement. AKI was graded using pRIFLE (pediatric modified Risk, Injury, Failure, Loss, End Stage Kidney Disease) criteria. Day 0 was defined as the day on which the AKI initially occurred, and pRIFLEmax was defined as the worst pRIFLE AKI grade recorded during the study period. The chi2 test was used to compare associations between categorical variables. Mann-Whitney and Kruskal-Wallis tests were used to compare continuous variables between groups. Diagnostic characteristics were evaluated by calculating sensitivity and specificity, and constructing receiver operating characteristic curves. RESULTS: A total of 140 patients (54% boys, mean +/- standard deviation Pediatric Risk of Mortality II score 15.0 +/- 8.0, 23% sepsis) were included. Mean and peak uNGAL concentrations increased with worsening pRIFLEmax status (P < 0.05). uNGAL concentrations rose (at least sixfold higher than in controls) in AKI, 2 days before and after a 50% or greater rise in serum creatinine, without change in control uNGAL. The parameter uNGAL was a good diagnostic marker for AKI development (area under the receiver operating characteristic curve [AUC] 0.78, 95% confidence interval [CI] 0.62 to 0.95) and persistent AKI for 48 hours or longer (AUC 0.79, 95% CI 0.61 to 0.98), but not for AKI severity, when it was recorded after a rise in serum creatinine had occurred (AUC 0.63, 95% CI 0.44 to 0.82). CONCLUSION: We found uNGAL to be a useful early AKI marker that predicted development of severe AKI in a heterogeneous group of patients with unknown timing of kidney injury.

Platelet transfusions in infants with necrotizing enterocolitis do not lower mortality but may increase morbidity.

OBJECTIVE: Necrotizing enterocolitis (NEC), a serious multisystemic inflammatory disease most commonly seen in premature neonates, is often associated with thrombocytopenia. Infants with severe forms of NEC commonly have platelet counts of less than 50,000/mm(3), occasionally less than 10,000/mm(3). Despite an absence of data to support the practice, platelet transfusions are commonly used to maintain a certain arbitrary platelet count in an effort to prevent bleeding. As platelet transfusions contain a variety of bioactive factors including pro-inflammatory cytokines, we hypothesized that a higher number and volume of platelet transfusions would not be associated with an improvement in mortality or morbidity. STUDY DESIGN: A retrospective cohort analysis was conducted of the medical records of all infants between 1997 and 2001 with Bell's Stage 2 or 3 NEC associated with platelet counts of <100,000/mm(3). The medical records were evaluated for the following variables: platelet counts, number and volume of platelet transfusions, symptoms of bleeding, and hospital course. Mortality and development of short bowel syndrome and/or cholestasis were correlated to the total number and volume (total ml and ml/kg) of platelet transfusions. Differences between the outcome groups were compared using the independent t-test, Fisher's exact test and Mann-Whitney tests. RESULTS: A total of 46 infants met the study criteria (gestational age 28+/-4 weeks and birth weight 1166+/-756 g, mean+/-SD). There were a total of 406 platelet transfusions administered to the study population. Of these, 151 (37.2%) were given in the presence of active bleeding, with 62% of these resulting in the cessation of bleeding within 24 hours. Other listed indications for platelet transfusions were hypovolemia and severe thrombocytopenia. On analysis of the entire cohort, there was no statistical improvement in either mortality or morbidity (short bowel syndrome and cholestasis) with greater number and/or volume of platelet transfusions. Furthermore, we found that infants who developed short bowel syndrome and/or cholestasis had been given a significantly higher number and volume of platelet transfusions when compared to those who did not have these adverse outcomes [median (minimum - maximum) - number of transfusions : 9 (0 to 33) vs 1.5 (0 to 20), p=0.010; volume of transfusions (ml/kg): 121.5 (0 to 476.6) vs 33.2 (0 to 224.3), p=0.013]. CONCLUSION: This retrospective analysis suggests that greater number and volume of platelet transfusions in infants with necrotizing enterocolitis are associated with greater morbidity in the form of short bowel syndrome and/or cholestasis without the benefit of lower mortality.

Severe thrombocytopenia predicts outcome in neonates with necrotizing enterocolitis.

OBJECTIVE: Necrotizing enterocolitis (NEC) is a common and serious gastrointestinal disorder that predominately affects premature infants. Few prognostic indices are available to guide physicians through the expected course of the disease. We hypothesized that the degree and timing of onset of severe thrombocytopenia (platelet count <100,000/mm(3)) would be a predictor of adverse outcome and an indication for surgical intervention in infants with NEC. STUDY DESIGN: The clinical presentation and outcome of all infants with Bell stage II or III NEC treated at Texas Children's Hospital between 1997 and 2001 were retrospectively reviewed. Patients were stratified into two groups based on the presence (Group1) or absence (Group 2) of severe thrombocytopenia (platelet count <100,000/mm(3)) within 3 days of a diagnosis of NEC. Differences between groups were compared using logistic regression to estimate adjusted odds ratios. RESULTS: A total of 91 infants met inclusion criteria (average birth weight 1288+/-135 g; average gestational age 29.0+/-3.0 weeks). Compared to infants in Group 2, infants in Group 1 were more premature (28.0+/-4.1 vs 30.0+/-4.2 weeks; p=0.02), more likely to have received postnatal steroids (42.5% vs 20.4%; p=0.02), and more likely to require laparotomy for gangrenous bowel (adjusted OR 16.33; p<0. 001). The presence of severe thrombocytopenia was also a predictor of mortality (adjusted OR 6.39; p=0.002) and NEC-related gastrointestinal complications including cholestatic liver disease and short bowel syndrome (adjusted OR 5.47; p=0.006). CONCLUSION: Severe thrombocytopenia within the first 3 days after a diagnosis of NEC suggests a higher likelihood of bowel gangrene, morbidity, and mortality. Prospective studies of infants with early and severe thrombocytopenia may help determine the optimal timing of laparotomy in infants with NEC.

Surgical technique for peritoneal dialysis catheter placement in the pediatric patient: a North American survey.

In the present study, we surveyed 425 members of the American Pediatric Surgical Association and the Canadian Association of Pediatric Surgeons to identify prevalent operative techniques used in the placement of peritoneal dialysis catheters by pediatric surgeons. Our survey assessed catheter type, skin and fascial incision orientations, deep-cuff positions, exit-site directions, and omentectomy. We received responses from 156 surgeons (36.7%) and excluded 18 of those responses. Among the assessed responses, 83 surgeons (60%) indicated that they had placed at least 1 catheter in the previous 12 months. Of the 83, 13% had placed 1 catheter, 52% had placed 2 - 5, 16% had placed 6 - 9, and 18% had placed 10+. We observed significant variability in all aspects of surgical technique. The most common catheter configuration was single-cuff (59%), curled end (60%), and non swan neck (72%). The most common surgical approach was a transverse skin incision (52%), a fascial incision through the rectus (68%), a deep cuff between the peritoneum and fascia (46%), a superior-pointing exit site (37%), and a superficial cuff distant to the exit site (53%). Routine omentectomy was reported by 59% of respondents. Only 15% reported using a laparoscopic approach on first attempt. Pediatric surgeons employ a variety of surgical techniques when placing peritoneal catheters. Some of the techniques used vary from the published recommendations. Quality can potentially be improved by wider dissemination of published surgical recommendations.

Validation of the Baylor Continence Scale in children with anorectal malformations.

BACKGROUND: Anorectal malformations (ARMs) often result in lifelong problems with defecation. There have been no studies performed to develop scoring systems in children with fecal incontinence following repair of ARM. This study was designed to develop and validate a tool (Baylor Continence Scale [BCS]) to measure social continence in children after surgical correction of ARMs. METHODS: The BCS is a 23-question survey, was administered to children who have had repair of an ARM, children with enuresis, and normal children. RESULTS: Children in the ARM group had an average BCS score of 28.0, which was statistically different from an enuresis control group (16.5) and normal controls (11.5) (P < .05). A significantly greater proportion of children in the ARM group had higher Impact on Family Scores (>30) than either the enuresis or normal control group (P < .05). CONCLUSIONS: The BCS tool should be useful in prospective studies of interventions to improve incontinence after repair of an ARM. An important secondary result of this study was to demonstrate the effect on families of caring for a child with imperforate anus, even years after the repair.