Effect of pre-ECMO mechanical ventilation duration on patient outcomes

Abstract

The majority of the critically ill patients who are treated with extracorporeal membrane oxygenator (ECMO), are initially supported by mechanical ventilation (MV). The pre-ECMO MV duration of more than 7 days was identified as a contraindication to start ECMO support. This study aims to assess the mortality rate in relation to duration of mechanical ventilation before ECMO initiation, as well as its impact of ECMO successful weaning in Saudi Arabia. This is a retrospective cohort study with 13 patients enrolled, who received ECMO support from 2015 to 2019 for both cardiac and non-cardiac indications. All relevant data regarding the MV and ECMO support were extracted and analysed. The whole sample showed a higher mean interval between intubation and ECMO initiation in the successfully weaned group than the group with unsuccessful weaning, with a P value > 0.05. In terms of survival, both groups showed similar MV to ECMO initiation. Total ECMO duration was 10.38 ± 6.55 and 7.60 ± 10.11 for the successful and non-successful weaning groups, respectively (P = 0.56), and was similar for survivors and non-survivors (P = 0.97). Analysis of both subgroups of venovenous ECMO and veno-arterial ECMO was non-significant, both in terms of survival and successful weaning. The pre-ECMO MV duration was significantly higher in patients who were supported by ECMO for more than one week, with a mean duration of 4.50 4.04, in comparison to 1.0 for patients with ECMO support of less than a week (P value=0.041). The impact of pre-ECMO MV duration was not significantly related to ECMO outcomes, including survival and successful weaning, in both ECMO subgroups. However, it may affect the total ECMO support duration.