Outcomes of the NHS England National Extracorporeal Membrane Oxygenation Service for adults with respiratory failure: a multicentre observational cohort study

Background: Extracorporeal membrane oxygenation (ECMO) is increasingly used to support adults with severe respiratory failure refractory to conventional measures. In 2011, NHS England commissioned a national service to provide ECMO to adults with refractory acute respiratory failure. Our aims were to characterise the patients admitted to the service, report their outcomes, and highlight characteristics potentially associated with survival.

Methods: An observational cohort study was conducted of all patients treated by the NHS England commissioned ECMO service between December 1, 2011 and December 31, 2017. Analysis was conducted according to a prespecified protocol (NCT: 03979222). Data are presented as median [inter-quartile range, IQR].

Results: A total of 1205 patients were supported with ECMO during the study period; the majority (n=1150; 95%) had veno-venous ECMO alone. The survival rate at ECMO ICU discharge was 74% (n=887). Survivors had a lower median age (43 yr [32-52]), compared with non-survivors (49 y [39-60]). Increased severity of hypoxaemia at time of decision-to-cannulate was associated with a lower probability of survival: survivors had a median Sao₂ of 90% (84-93%; median Pao₂/Fio₂, 9.4 kPa [7.7-12.6]), compared with non-survivors (Sao₂ 88% [80-92%]; Pao₂/Fio₂ ratio: 8.5 kPa [7.1-11.5]). Patients requiring ECMO because of asthma were more likely to survive (95% survival rate (95% CI, 91-99%), compared with a survival of 71% (95% CI, 69-74%) in patients with respiratory failure attributable to other diagnoses.

Conclusion: A national ECMO service can achieve good short-term outcomes for patients with undifferentiated respiratory failure refractory to conventional management.

Clinical trial registration: NCT03979222.