Prevention of dialysis disequilibrium by use of CVVH.

OBJECTIVE: Dialysis disequilibrium occurs due to a rapid shift of osmols when hemodialysis is used in cases of extreme uremia. Continuous veno-venous hemofiltration (CVVH) with citrate anticoagulation may offer a safe method of urea reduction. DESIGN: Retrospective, clinical observation. SETTING: Tertiary pediatric intensive care unit and nephrology program. Patients. Two males, ages 10 and 12 years of age. INTERVENTION: CVVH with citrate anticoagulation. RESULTS: Three to four day reduction of BUN from 180 mg/dL to 22 mg/dL and from 279 mg/dL to 23 mg/dL. CONCLUSION: Slow and safe improvement of severe urea, hyperphosphatemia, hypocalcemia, and anemia without untoward side effects.

The effect of vascular access location and size on circuit survival in pediatric continuous renal replacement therapy: a report from the PPCRRT registry.

PURPOSE: Well-functioning vascular access is essential for the provision of adequate CRRT. However, few data exist to describe the effect of catheter size or location on CRRT performance in the pediatric population. METHODS: Data for vascular access site, size, and location, as well as type of anticoagulant used and patient demographic data were gathered from the ppCRRT registry. Kaplan-Meier curves were generated and then analyzed by log-rank test or Cox Proportional Hazards model. RESULTS: Access diameter was found to significantly affect circuit survival. None of the 5 French catheters lasted longer than 20 hours. Seven and 9 French, but not 8 French, catheters fared worse than larger diameter catheters (p=0.002). Circuits associated with internal jugular access survived longer than subclavian or femoral access associated circuits (p<0.05). Circuit survival was also found to be favorably associated with the CVVHD modality (p<0.001). CONCLUSIONS: Functional CRRT circuit survival in children is favored by larger catheter diameter, internal jugular vein insertion site and CVVHD. For patients requiring catheter diameters less than 10 French, CRRT circuit survival might be optimized if internal jugular vein insertion is feasible. Conversely, when a vascular access site other than the internal jugular vein is most prudent, consideration should be given to using the largest diameter catheter appropriate for the size of the child. The CVVHD modality was associated with longer circuit survival, but the mechanism by which this occurs is unclear.

Evaluation of the PRISMA M10 circuit in critically ill infants with acute kidney injury: A report from the Prospective Pediatric CRRT Registry Group.

Currently available extracorporeal circuits in the US often require blood priming to prevent hypotension/anemia in smaller pediatric patients. The PRISMA M10 circuit, available in other countries has not received extensive study and has not been cleared for use in the US. We performed an FDA mandated study of the M10 circuit in the US for use in critically ill pediatric patients with acute kidney injury <15 kg in size. FDA guidelines allowed for maximal blood pump flow of 20 ml/min. Fifteen pts (9 M, 6 F, mean size 5.8+/-2.8 kg, range 2.6-12.5 kg, age 4 d - 13 mo, mean creatinine =1.2+/-0.7 mg/dL) were studied at 4 ppCRRT centers. Sixty-one filters (range 1-4 circuits per pt) were used (mean circuit life 28.6+/-22.5 h, range 1 to 74.5 h, 55%>24 h). No blood leaks occurred. All circuits achieved Qb 20 ml/min. Forty-two out of 61 filters clotted and mean circuit life was lower for these filters than those changed for other reasons (23+/-17 vs. 41+/-28 h, <0.005). Circuits using larger access demonstrated significantly longer survival. We conclude that the M10 filter can serve well for CRRT in small pediatric patients. Further study is needed to determine in higher blood flow rates would decrease clotting rates and increase filter life span and ultrafiltration rates.

The Prospective Pediatric Continuous Renal Replacement Therapy (ppCRRT) Registry: design, development and data assessed.

Many issues plague the pediatric ARF outcome literature, which include data only from single center sources, a relative lack of prospective study, mixture within studies of renal replacement therapy modality without stratification and inconsistent use of methods to control for patient illness severity in outcome analysis. Since January 2001, the Prospective Pediatric CRRT (ppCRRT) Registry Group has been collecting data from multiple United States pediatric centers to obtain demographic data regarding pediatric patients who receive CRRT, assess the effect of different CRRT prescriptions on circuit function and evaluate the impact of clinical variables on patient outcome. The aim of the current paper is to describe the ppCRRT Registry design, review the decision process and rationale for the options chosen for the ppCRRT format and discuss the analysis plan and future projects envisioned for the ppCRRT Registry.

Prediction of neurobehavioral outcome 1-5 years post pediatric traumatic head injury.

OBJECTIVE: To examine the neurobehavioral status of children with traumatic head injury (THI) and to identify variables that predict outcome. DESIGN: Retrospective chart review, with follow-up 1-5 years after injury. Outcome predictor variables were identified through stepwise regression analysis. SETTING: Level one trauma center and pediatric rehabilitation program. PATIENTS: 71 Children with THI, selected from a four-year series of consecutive admissions. MEASURE: Vineland Adaptive Behavior Scales-Survey Edition. RESULTS: Significant predictors of better neurobehavioral status at follow-up included absence of a premorbid learning problem (p <.01), older age at injury (p <.01), and normal pupillary response (p <.001) and higher cerebral perfusion pressure (p <.0001) during critical care management. CONCLUSIONS: Neurobehavioral outcome after THI is influenced by premorbid psychosocial variables as well as by critical care management.

Intravenous methohexital for brief sedation of pediatric oncology outpatients: physiologic and behavioral responses.

OBJECTIVE: In this successor to a preliminary retrospective study, we sought to confirm the apparent safety and efficacy of intravenous methohexital (MHX) for brief, unconscious sedation of pediatric hematology/oncology outpatients undergoing painful, invasive procedures. METHODS: This prospective study was conducted in a children's hospital-based hematology/oncology clinic. Following published monitoring guidelines for deep pediatric sedation, MHX (1.0 mg/kg) was administered immediately before each procedure, 1% xylocaine was given locally, and additional MHX was titrated to maintain minimal response to pain during the procedure. For each patient, the procedural and physiologic response data reported below were recorded from the onset of sedation through recovery. Behavioral distress responses were measured using a standardized pediatric observational tool (Procedure Behavioral Checklist). RESULTS: Two hundred and thirty-three procedures were carried out in 76 patients ranging .1 to 19.6 years of age. The mean cumulative MHX dose/procedure was 4.6 +/- 2.9 mg/kg. The mean lengths of time from initiation of sedation until completion of the invasive procedure, attainment of patient arousability, discontinuation of monitoring, and attainment of patient alertness were 8 +/- 5, 19 +/- 8, 19 +/- 9, and 22 +/- 9 minutes, respectively. Relative to presedation values, mean arterial pressure (MAP), heart rate, and respiratory rate showed maximum mean percent changes of -16.6, +17.8, and +13.4, respectively (all clinically insignificant). Complications among procedures were transient and included hiccoughs and myoclonus (each 10%); oropharyngeal secretions (6%); and pain at the injection site, emergence phenomena, and mild stridor (each

Brief unconscious sedation for painful pediatric oncology procedures. Intravenous methohexital with appropriate monitoring is safe and effective.

PURPOSE: We report here our experience in using intravenous methohexital (MHX), an ultrashort-acting barbiturate, for brief unconscious sedation of pediatric oncology outpatients undergoing painful, invasive procedures. METHODS: Following published monitoring guidelines for deep pediatric sedation, 1.0 mg/kg MHX was administered immediately before the procedure, 1% xylocaine was given locally, and MHX was additionally titrated to maintain minimal response to pain during the procedure. Clinical data reported here were gathered retrospectively from permanent medical records. RESULTS: Data reported here represent 132 evaluable consecutive procedures in 33 patients ranging in age from 1.6 to 20.5 years. Patients underwent an average of 4 +/- 3 procedures and received a mean total MHX dose per procedure of 5.8 +/- 2.1 mg/kg. The mean length of time from start of sedation to full arousability was 30 +/- 12 min. Twenty-three (17.4%) procedures were associated with clinically insignificant decreases in diastolic blood pressure or heart rate below resting normal ranges for age. Eight (6.1%) procedures in six patients were associated with minor complications requiring no intervention, such as transient behavioral changes, transient myoclonus, and minimal stridor. Five procedures (3.8%) in five patients required simple suctioning to manage secretions. Only two procedures (1.5%) in two patients required brief bag-mask ventilation plus suctioning for suspected laryngospasm. None required intubation. No differences in clinical features or MHX doses were noted for patients with, as compared to those without, complications. All procedures were completed with a satisfactory level of sedation. CONCLUSIONS: Our experience indicates that MHX, with appropriate monitoring as described here, is a safe and effective agent for use in pediatric oncology outpatient sedation programs.

Changes in plasma fibronectin in children after elective repair of congenital heart defects.

Plasma fibronectin is an attachment protein important for maintaining capillary integrity and host defense mechanisms. Depletion of plasma fibronectin has been shown to occur in adults after septic shock, major trauma, and burns. Limited laboratory and clinical studies suggest a correlation between decreased plasma fibronectin levels and increased pulmonary capillary permeability and tissue perfusion. Mild and transient plasma fibronectin depletion has been observed in adults after cardiovascular operations. We measured plasma fibronectin by immunoturbidometric assay in 20 children (age 6 months to 12 years) undergoing repair of congenital heart defects. Plasma fibronectin levels immediately after operations and daily thereafter were compared with the preoperative values. Plasma fibronectin declined on postoperative days 1, 2, 3, 4, and 5 (p < 0.05). A nadir was reached on day 3 with a tendency toward recovery thereafter. Patients with a therapeutic intervention score of more than 35 had greater magnitude of plasma fibronectin decline than those with a score of less than 35 at 24 hours after the operation (p < 0.005). We conclude that (1) significant and prolonged plasma fibronectin depletion occurs after cardiovascular operations in children; and (2) postoperative plasma fibronectin depletion is associated with increasingly complex surgical intervention. Reduced plasma fibronectin synthesis and more extensive operations for congenital heart defects are likely reasons for children being more susceptible than adults to plasma fibronectin depletion after cardiovascular operations.

Management of hyponatremic seizures in children with hypertonic saline: a safe and effective strategy.

OBJECTIVE: To study efficacy and safety of hypertonic saline administration in the management of hyponatremic seizures. DESIGN: Retrospective, observational, cross-sectional study with factorial design. SETTING: In-patient population in a university hospital. PATIENTS: All children admitted with serum sodium concentrations less than 125 mmol/L. Sixty-nine episodes of severe hyponatremia in 60 children were reviewed. Forty-one of these children presented with seizures. INTERVENTIONS: Twenty-five of 41 seizure patients received an iv bolus of 4 to 6 mL/kg body weight of 3% saline. Twenty-eight patients were treated with a benzodiazepine and/or phenobarbital with or without the subsequent administration of hypertonic saline. MEASUREMENTS AND MAIN RESULTS: Thirteen treatment failures and ten instances of apnea occurred among the 28 patients treated with benzodiazepine/phenobarbital. Administration of hypertonic saline resulted in resolution of seizures and apnea in all cases. Those patients receiving 3% saline had a higher serum sodium increase rate from 0 to 4 hrs than the remaining patients (3.1 +/- 1.3 vs. 1.7 +/- 1.2 mmol/L.hr, p less than .01). None developed subsequent neurologic deterioration or clinical manifestations of osmotic demyelination syndrome. CONCLUSION: Treatment of hyponatremic seizures with routine anticonvulsants may be ineffective and is associated with a considerable incidence of apnea. A rapid increase in the serum sodium concentration by 3 to 5 mmol/L with the use of hypertonic saline is safe and efficacious in managing acute symptomatic hyponatremia.

Central pulmonary embolism with normal ventilation/perfusion scan-diagnosis by nuclear pulmonary artery flow studies.

Pulmonary embolism, although uncommon in children, occurs in as many as 104 per 100,000 pediatric patients. Undiagnosed and untreated pulmonary embolism has a high mortality rate; thus, a high index of clinical suspicion and reliable diagnostic modalities are necessary to ensure prompt and accurate diagnosis. We report the case of a patient with severe central pulmonary embolism with a normal ventilation-perfusion scan. The embolus was identified by a nuclear pulmonary flow study using dynamic imaging, which obviated the need for contrast pulmonary angiography. The traditional ventilation-perfusion scan may appear normal despite severe central pulmonary embolism. In this situation, early dynamic imaging is necessary to detect severe obstruction of the central pulmonary arteries. This approach may obviate the need for contrast pulmonary angiography in hemodynamically stable patients.