ECMO referrals in the UK – A descriptive analysis using refer-a-patient and Royal Brompton Hospital data (2019–2025)

Background: Adult Extracorporeal Membrane Oxygenation (ECMO) in the UK is delivered by an eight-centre network with their catchment areas based on population density. The primary method for referral to ECMO by hospitals in the UK is through an online portal – Refer-a-Patient. Methods: A retrospective, descriptive study of monthly ECMO referrals using two sources: Refer-a-Patient; (03/2020–06/2025) and Royal Brompton Hospital (RBH) ECMO commissioning data; (04/2019–06/2025). Volumes, temporal trend, seasonality using STL (Seasonal-Trend decomposition using LOESS) and geospatial flows to RBH were analysed using Python. Results: Network referrals surged during COVID-19 waves, then settled to a lower baseline with recurrent winter peaks. Excluding 2020–2021, STL showed moderate–strong seasonality (seasonality strength = 0.64; seasonal signal-to-noise ratio = 3.29) and a modest increasing trend since 2022. In RBH (n = 2,831 referrals; January 2019 - June 2025), 16.1% (n = 455) proceeded to ECMO, and 3.8% (n = 108) patients were transferred but not cannulated. Geospatially, flows were clustered locally around London, with fewer long-distance and cross-catchment. Conclusions: ECMO referrals in the UK showed seasonality, two main decision-making stages post-referral, and higher volumes of referrals to RBH from local hospitals. Cross-catchment flows were also observed.