Evaluation of a Disposable Vascular Pressure Device for Pre- and Postmembrane Pressure Monitoring During Venovenous Extracorporeal Membrane Oxygenation.

Abstract

Membrane pressure monitoring during extracorporeal membrane oxygenation (ECMO) is integral to monitoring circuit health. We compared a disposable vascular pressure device (DVPD) to the transducer pressure bag arterial line (TPBAL) monitoring system to determine whether the DVPD can reliably and accurately monitor membrane pressures during venovenous extracorporeal membrane oxygenation (VV ECMO). We analyzed existing quality assurance data collected at a single center as part of routine circuit performance monitoring and process improvement on a convenience sample of four VV ECMO circuits. We placed and zeroed a DVPD in line with the pre- and postmembrane TPBAL setups in coordination with a standard transducer setup. We recorded DVPD and TPBAL pressure measurements every 4 hours for 2.5 days on the four separate VV ECMO circuits. We compared the standard and DVPD pressures using Bland-Altman plots and methods that accounted for repeated measures in the same subject. We recorded 58 pre/postmembrane pressures. Mean membrane pressure values were similar in the DVPD (pre: 208 mmHg [SD, 50.8]; post: 175 mmHg [46.3]) compared to the standard TPBAL setup (pre: 205 mmHg [52.0]; post: 177 mmHg [46.3]). Using Bland-Altman methods, premembrane pressures were found to be 2.2 mmHg higher (95% confidence interval [CI]: -5.3 to 9.7) in the standard TPBAL setup compared to DVPD and 1.8 mmHg higher (95% CI: -5.3 to 8.9) than the postmembrane pressures. The DVPD provided an accurate measurement of circuit pressure as compared to the TPBAL setup. Across the range of pre- and postmembrane pressures, both methods reliably agreed. Future trials should investigate DVPD accuracy in different environments such as prehospital field cannulation or critical care transport of ECMO patients.