Discussion
V-V ECMO blood flow, blood flow-dependent increase, ARDS, thermo-indicator loss, EVLWI
ARDS
In 20 mechanically ventilated patients with severe ARDS undergoing V-V ECMO support, we evaluated the impact of 3 ECBF rates (6, 4, and 2 l/min) on ITBVI and EVLWI derived by TPTD. We found that (1) the measurements of ITBVI and EVLWI with TPTD are affected by ECBF mainly due to a blood flow-dependent increase in MTt and DSt; (2) ITBVI is less influenced by V-V ECMO blood flow than EVLWI.To our knowledge, this is the first study prospectively investigating ITBVI and EVLWI under clinical conditions in a selected group of patients with severe ARDS receiving V-V ECMO support. TPTD is easily performed at the bedside, it has a high inter- and intra-observer reliability, and it does not need extensive training and formal education [In case of thermo-indicator loss into the extracorporeal circuit and delayed dispersion into the patient’s circulation, V-V ECMO resembles an intracardiac left-to-right shunt. Significant anatomic intracardiac left-to-right shunt influences TPTD curves [Our results differ from those reported by Haller et al., who found increased CO measured by dye dilution TPTD at a higher ECBF [