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

Abstract

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 (n¼1150; 95%) had venovenous ECMO alone. The survival rate at ECMO ICU discharge was 74% (n¼887). Survivors had a lower median age (43 yr [32e52]), compared with non-survivors (49 y [39e60]). Increased severity of hypoxaemia at time of decision-to-cannulate was associated with a lower probability of survival: survivors had a median SaO 2 of 90% (84e93%; median PaO 2 /FiO 2 , 9.4 kPa [7.7e12.6]), compared with non-survivors (SaO 2 88% [80e92%]; PaO 2 /FiO 2 ratio: 8.5 kPa [7.1e11.5]). Patients requiring ECMO because of asthma were more likely to survive (95% survival rate (95% CI, 91e99%), compared with a survival of 71% (95% CI, 69e74%) 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: NCT 03979222.

Re: Insight into ECMO, mortality and ARDS: a nationwide analysis of 45,647 ECMO runs (Friedrichson et al., Critical Care, January 2021)

“…We would suggest that the underlying pathophysiology may be more important than simply meeting definition criteria of ARDS. In our study, patients with certain underlying pathologies, such as asthma, were more likely to survive [2].…”

“…Data and especially the clinical setting published by Warren et al are indeed completely contrary to the situation in Germany [5]. In addition to the lower number of centres in England compared to Germany, there is also a significantly lower ECMO incidence rate of approx.…”

“…The authors note that by 2018, there were 231 centres in Germany providing veno-venous ECMO support (VV-ECMO), with a median case volume of 4 patients per year; 70% of centres reported 10 or fewer cases annually. In the United Kingdom, since 2011, ECMO for respiratory failure has been provided by six centres in a hub-and-spoke network [2], similar to that the authors propose. We estimate from the data provided that in 2018, Germany had one VV-ECMO centre per 358,000 head of population; in the UK this figure was one per 11 million [3].…”

“…We estimate from the data provided that in 2018, Germany had one VV-ECMO centre per 358,000 head of population; in the UK this figure was one per 11 million [3]. Our recent analysis of the first six years of this service demonstrated a median annual case volume of 37.5 patients per centre and overall ICU mortality of 26% [2].…”

“…Author details 1 Division of Anaesthesia, University of Cambridge, Cambridge, UK. 2 Department of Asthma, Allergy and Lung Biology, King's College London, London, UK. 3 Guy's & St Thomas' Hospital, London, UK.…”