Utilisation and outcomes of a mobile (ambulance and air transport) venovenous extracorporeal membrane oxygenation (VV-ECMO) program in Poland during the COVID-19 pandemic – a retrospective, two-centres, case-series study

Introduction:
Many patients required mechanical ventilation support due to severe COVID-19 pneumonia. A significant proportion of mechanically ventilated patients also required venovenous extracorporeal membrane oxygenation (VV-ECMO) due to refractory hypoxemia. A high demand for VV-ECMO support during the pandemic was challenging due to many factors, including limited resources and lack of established transfer protocols. This study aims to present the organisation and outcomes of a mobile VV-ECMO program in two high-volume centres in Poland during the COVID-19 pandemic.

Material and methods:
This retrospective, two-centre case series study, which lasted 36 months, was conducted between March 10, 2020, and January 31, 2023. The data of all patients transferred using venovenous extracorporeal membrane oxygenation (VV-ECMO) were analysed, including five women in the perinatal period with severe respiratory failure attri­buted to the COVID-19 virus. The analysis encompassed baseline patient demographics, Sequential Organ Failure Assessment (SOFA) scores, admission laboratory parameters, ECMO therapy, duration of mechanical ventilation, and patient survival to ICU discharge.

Results:
We assessed 86 patients who met the ELSO inclusion criteria and were transported during VV-ECMO support. Mortality in the analysed group was high (80.3%). Despite high mortality, VV-ECMO appeared to be a safe procedure in COVID-19 patients with severe ARDS. No complications were noted in more than half of the analysed procedures. Despite the above, many severe complications were observed, including stroke or cerebral haemorrhage (9.8%) and limb or gut ischemia (1.6%). The most common problems co-existing with VV-ECMO treatment were bleeding complications (34.4%).

Conclusions:
The ICU mortality rate among patients requiring VV-ECMO for COVID-19 in high-volume ECMO centres was high but not associated with the type of transportation.