Outcome of inter-hospital transfer of patients on extracorporeal membrane oxygenation in Switzerland.

AIMS OF THE STUDY: An extracorporeal membrane oxygenation system (ECMO), as a bridge to either recovery, a ventricular assist device (VAD), or heart or lung transplantation, may be the only lifesaving option for critically ill patients suffering from refractory cardiac, respiratory or combined cardiopulmonary failure. As peripheral hospitals may not offer ECMO treatment, tertiary care centres provide specialised ECMO teams for on-site implantation and subsequent patient transfer on ECMO to the tertiary hospital. This study reports the results of the largest ECMO transportation programme in Switzerland and describes its feasibility and safety.
METHODS: Patients transported on ECMO by our mobile ECMO team to our tertiary centre between 1 September 2009 and 31 December, 2016 underwent retrospective analysis. Implantation was performed by our specialised ECMO team (primary transport) or by the medical staff of the referring hospital (secondary transport) with subsequent transfer to our institution. Type of ECMO, transport data, patient baseline characteristics, operative variables and postoperative outcomes including complications and mortality were collected from medical records.
RESULTS: Fifty-eight patients were included (three patients excluded: one repatriation, two with incomplete medical records). Thirty-five patients (60%) received veno-venous, 22 (38%) veno-arterial and one patient (2%) veno-venoarterial ECMO. Forty-nine (84%) patients underwent primary and nine (16%) secondary transport. Thirty-five (60%) patients were transferred by helicopter and 23 (40%) by ambulance, with median distances of 38.1 (13–225) km and 21 (3-71) km respectively. No clinical or technical complications occurred during transportation. During hospitalisation, three patients had ECMO-associated complications (two compartment syndrome of lower limb, one haemothorax after central ECMO upgrade). Median days on ECMO was 8 (<1–49) and median days in hospital was 17 (<1–122). ECMO weaning was successful in 41 patients (71%), on-transport survival was 100%, 40 patients survived to discharge (69%), and overall survival was 67% (39 patients) at a median follow-up of 58 days (<1–1441). Cumulative survival was significantly affected by cardiogenic shock vs. ARDS (p = 0.001), veno-arterial and veno-venoarterial vs. veno-venous ECMO (p = 0.001) and after secondary vs. primary transport (p <0.001). The ECMO weaning rate was significantly lower after secondary transfer (22%, two patients, both vaECMO) vs. primary transfer (80%, p = 0.002, 39 patients of which 35 (71%) had vvECMO).
CONCLUSIONS: The first results of our ECMO transportation programme show its feasibility, safety and efficacy without on-site implant or on-transport complications or mortality. The favourable early survival may justify the large effort with respect to logistics, costs and manpower. With rising awareness, referring centres may increasingly consider this lifesaving option at an early stage, which may further improve outcomes.