The Journal of ExtraCorporeal Technology No 56-2 | Page 39

66 S . Robertson and K . White : J Extra Corpor Technol 2024 , 56 , 65 – 70
Figure 1 . In Vitro setup for Experiments 1 and 4 simulating volume transfused from a pressurized bag of saline , through a pressure transducer , to an empty saline bag .
Circuit flushes may be passive , active , or both . Passive flushing is allowing the volume to gradually pass into the pressure lines and ports without intervention . This is done using a pressurized bag set at a desired pressure . Active fluid flushing is the act of manually pulling the transducer flush tab or pushing volume directly into the circuit with a fluid-filled syringe for a period of time . The amount of fluid transfused passively and actively through pressure transducers is highly variable due to pressure differences in the pediatric ECMO circuit . Likewise , the fluid used during active pressure transducer flushes via the snap tab may be inconsistent amongst clinicians based on personal preference , hemodynamics , or current circuit conditions .
The purpose of this investigation is to evaluate the quantity and variability in volume measured across the flush device in pressure transducers depending on resistance . This would provide clinicians with a more accurate daily fluid balance and ultimately reduce patient fluid overload while on ECMO .
Description
In order to quantify the amount of volume transfused through pressure transducers in pediatric ECMO circuits , six experiments were performed . The first three were designed to measure passive flushing through the Edwards TruWave transducer with blue Snap-Tab ( Edwards Lifesciences Corporation , Irvine , CA , USA ) against three different pressure conditions : 0 mmHg , 150 mmHg , and �50 mmHg . The final three experiments were to quantify the amount of volume actively transfused while pulling on the Snap-Tab of the pressure transducer flushing device .
Experiment 1 ( 0 mmHg )
As illustrated in Figure 1 a 500 mL bag of 0.9 % saline ( Baxter Healthcare Corporation , Deerfield , IL , USA ) was pressurized to 300 mmHg using an Ethox 500 mL pressure infusion