Fellow Washington University in St. Louis Saint Louis, Missouri, United States
Abstract:
Introduction: While Extracorporeal membrane oxygenation (ECMO) outcomes have improved, fluid overload in these patients continues to be associated with increased mortality, length of intensive care unit stay, worsened oxygenation, and increased duration of mechanical ventilation. Fluid balance on ECMO is complicated by fluid shifts leading to higher total body water, increased extracellular fluid, and increased body weight. Traditionally documented net fluid balance only accounts for easily measurable intake (enteral or parenteral) and output (urine, stools and other quantifiable drainage); in vitro studies have attempted to quantify oxygenator related insensible losses. In this study we aimed to measure insensible losses in vivo in pediatric ECMO.
Methods: We approached all pediatric ECMO patients from January 2022 to August 2022 in the PICU and CICU; 10 patients were enrolled. Water content of the oxygenator inflow sweep gas and exhaust gas were calculated by measuring the ambient temperature and relative humidity at frequent intervals and various levels of sweep. Other demographics, lab values, weights, and fluid balance were obtained from the medical chart.
Results and
Conclusion: Median age was 6.04 years (IQR 13.42 years). Three (30%) were female. Seven (70%) were on veno-arterial ECMO and mean sweep was 3.84 L/min (SD 2.01 L/min). ECMO set temperature mean was 36.9 degrees C (SD 0.32 degrees). Using 2563 data points, the calculated water loss per L/min of sweep was 76.8 ml/day. This pilot study confirms previously known significant insensible losses, however future studies are needed to delineate if more accurate measurement impacts patient management and thus outcomes.
