Prevalence and Neurological Outcomes of Comatose Patients With Extracorporeal Membrane Oxygenation

Abstract

Objectives: To investigate prevalence, risk factors, and in-hospital outcomes of comatose extracorporeal membrane oxygenation (ECMO) patients.

Design: Retrospective observational.

Setting: Tertiary academic hospital.

Participants: Adults received venoarterial (VA) or venovenous (VV) ECMO support between November 2017 and April 022.

Interventions: None.

Measurements and main results: We defined 24-hour off sedation as no sedative infusion (except dexmedetomidine) or paralytics administration over a continuous 24-hour period while on ECMO. Off-sedation coma (coma_off) was defined as a Glasgow Coma Scale score of ≤8 after achieving 24-hour off sedation. On-sedation coma (coma_on) was defined as a Glasgow Coma Scale score of ≤8 during the entire ECMO course without off sedation for 24 hours. Neurological outcomes were assessed at discharge using the modified Rankin scale (good, 0-3; poor, 4-6). We included 230 patients (VA-ECMO 143, 65% male); 24-hour off sedation was achieved in 32.2% VA-ECMO and 26.4% VV-ECMO patients. Among all patients off sedation for 24 hours (n = 69), 56.5% VA-ECMO and 52.2% VV-ECMO patients experienced coma_off. Among those unable to be sedation free for 24 hours (n = 161), 50.5% VA-ECMO and 17.2% VV-ECMO had coma_on. Coma_off was associated with poor outcomes (p < 0.05) in VA-ECMO and VV-ECMO groups, whereas coma_on only impacted the VA-ECMO group outcomes. In a multivariable analysis, requirement of renal replacement therapy was an independent risk factor for coma_off after adjusting for ECMO configuration, after adjusting for ECMO configuration, acute brain injury, pre-ECMO partial pressure of oxygen in arterial blood, partial pressure of carbon dioxide in arterial blood, pH, and bicarbonate level (worst value within 24 hours before cannulation).

Conclusions: Coma_off was common and associated with poor outcomes at discharge. Requirement of renal replacement therapy was an independent risk factor.

Keywords: acute brain injury; coma; extracorporeal membrane oxygenation; modified Rankin scale; neurological outcomes; sedation.