Continuous renal replacement therapy with an automated monitor is superior to a free-flow system during extracorporeal life support.

OBJECTIVES: To determine whether integrated continuous renal replacement therapy provides more accurate fluid management than IV pump free-flow ultrafiltration in pediatric patients on extracorporeal life support. DESIGN: Retrospective study. SETTING: PICU and neonatal ICU in a tertiary academic center. PATIENTS: Infants and children less than 18 years old. INTERVENTIONS: Extracorporeal membrane oxygenation and continuous renal replacement therapy. MEASUREMENTS AND MAIN RESULTS: Clinical data collected on patients who received free-flow or integrated renal replacement therapy while on extracorporeal life support. Normalized ultrafiltration error was calculated as: (physician specified fluid loss per 24-hr period - actual fluid loss per 24-hr period) divided by patient body weight (kg). Mixed linear regression analyses were used to model longitudinal ultrafiltration error trajectories within each mode of ultrafiltration. Based on an analysis of 458 serial ultrafiltration fluid balance measurements, integrated ultrafiltration was significantly more accurate than free-flow ultrafiltration (normalized ultrafiltration error of 1.2 vs 13.1 mL; p < 0.001). After adjusting for patient factors and time, integrated ultrafiltration was associated with a significantly lower normalized ultrafiltration error (variable estimate, -24 ± 6; p < 0.001). The use of integrated ultrafiltration was associated with shorter duration of extracorporeal life support (384 vs 583 hr, p < 0.001) and renal replacement therapy (185 vs 477 hr, p < 0.001) than free-flow patients. Overall ICU and hospital length of stay and in-hospital mortality were similar between the groups. CONCLUSIONS: While free-flow ultrafiltration has the advantages of simplicity and low cost, integrated renal replacement therapy provides more accurate fluid management during extracorporeal life support. Better fluid status management with integrated renal replacement therapy may contribute to shorter duration of extracorporeal life support.

Predictors of ECMO support in infants with tachycardia-induced cardiomyopathy.

The development of tachycardia-induced cardiomyopathy (TIC) is related to the rate and duration of supraventricular tachycardia (SVT). Infants may be more susceptible to TIC because early symptoms might be unrecognized. Extracorporeal membrane oxygenation (ECMO) may improve outcome in patients with SVT and TIC; however, clinical predictors of infants who require ECMO support have not been determined. The purpose of this study was to identify predictors of the need for ECMO in infants with SVT and TIC. Sixteen infants <6 months of age who experienced resolution of TIC following control of arrhythmia were identified. Three patients (19%) required ECMO support. Comparisons were made between patients who required ECMO and those who did not. The groups were similar with respect to age at presentation, type of SVT, rate of SVT, and degree of ventricular dysfunction. However, patients requiring ECMO had increased median M-mode-derived left ventricular end diastolic dimension (LVED) z-score when compared to the medically managed patents (+2.8 vs. 0.0, P = 0.009). No patient in the medically managed group had an LVED z-score >2.3. Infants presenting with SVT and TIC with LVED z-score >2 are at increased risk for requiring ECMO support and early use of ECMO should be considered.

Comparison of wire-reinforced and non-wire-reinforced dual-lumen catheters for venovenous ECMO in neonates and infants.

Improved dual-lumen catheter design has resulted in greater efficiency of gas exchange during extracorporeal life support. However, standard venovenous (S-VV) catheters are prone to structural deformation that reduces flow capacity. Wire-reinforced dual-lumen catheters have recently been introduced to reduce the risk of structural deformation. A retrospective review was performed on 25 neonates and infants who received venovenous extracorporeal life support (ECLS) to evaluate the occurrence and nature of catheter-related complications and events related to interrupted ECLS. Comparisons were made between patients supported with wire-reinforced and non-wire-reinforced dual-lumen catheters. No significant difference in number of catheter-related complications or flow-interruption events was observed. The use of wire-reinforced catheters appeared to increase the risk of cardiac perforation whereas non-wire-reinforced catheters appeared to be more prone to early failure. Once support was established, interruptions of extracorporeal flow occurred with the same frequency during the initial 72 hours, regardless of the type of catheter used. Further improvements in dual-lumen VV catheter design may reduce the risk of failure and injury and improve efficiency of extracorporeal gas exchange.