Early fluid balance and mortality following extracorporeal cardiopulmonary resuscitation: a high volume, single center study

Abstract Background For patients supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO), a positive cumulative fluid balance at day three has been associated with increased mortality. However, there is limited evidence examining this association in patients requiring extracorporeal cardiopulmonary resuscitation (ECPR). The aims of this study were to (1) to describe contemporary fluid practice in patients requiring ECPR and (2) assess the relationship between early cumulative fluid balance and 28-day mortality. Methods This was a retrospective, single centre, observational study using data collected from the EXCEL registry and the hospital electronic medical record. All patients undergoing ECPR from January 2017 until December 2022 were identified using a prospectively collected database. Patients aged < 18 years old or had extra-corporeal support ceased prior to arrival to the intensive care unit were excluded. Fluid data was collected for days 1,2,3 and 7; and cumulative balances reported for day 3 and day 7. Results 104 patients were identified, of which 100 were included. The mean age was 48.9 (SD 14.1) years, 72 (72%) were male. 54 (54%) were out-of-hospital cardiac arrests. Median low flow time was 43 (IQR 39–76) minutes. 51 (51%) had died by day 28. After adjusting for location of cardiac arrest, return of spontaneous circulation and duration of ECMO, a 1 L increase in cumulative fluid balance to the end of day 3 was not independently associated with 28-day mortality (adjusted OR 1.09 [95% CI 0.97–1.22]), however by day 7 this was independently associated with an 11% increased risk of 28-day mortality (adjusted OR 1.11 [95% CI 1.001–1.23]). Conclusion A one litre increase in CFB at the end of day 3 was not associated with 28-day mortality; but a one litre increase in CFB by the end of day 7 was associated with an 11% increase in the odds of day 28 mortality. The impact of restrictive fluid management strategies in those requiring ECPR should be assessed in prospective trials.