Quantifying Potential Fluid Transfused through Pressure Monitoring and Circuit Flushes in Pediatric ECMO Patients

Background: Pressure monitoring on pediatric ECMO circuits is used to aid in the evaluation of patient hemodynamics and circuit health. ELSO recommends monitoring pressures on the venous line, pre, and post oxygenator. In order to keep pressure ports patent, crystalloid can be used as a flush. The fluid transfused to the patient through these lines can be challenging to quantify accurately due to variance in clinician practice. Currently, there is no published data or practice suggestions on this topic. Methods: This study reports on experiments used to quantify passively and actively infused crystalloid using an Edwards TruWave transducer and pressurized IV bag. Frequent negative and positive pressures measured during neonatal ECMO runs were simulated in order to quantify infused volumes. Results: When the pressure transducer and associated tubing is kept patent by using a pressurized IV bag, per the instructions for use, the daily volume transfused was found to be close to a typical neonates total blood volume. Conclusions: An alternative method for pressure transducer line patency is discussed which includes the use of an automated syringe pump. This allows for more precise infusion volumes within a 24 hour period. Further study is recommended to develop and publish best practices.