ECMO referral in severe viral ARDS — FFICM MCQ

Correct answer: A — Discuss early with a severe respiratory failure or ECMO centre

The correct answer is A, discuss early with a severe respiratory failure or ECMO centre. This patient meets recognised NHS referral criteria for severe potentially reversible respiratory failure, with a PaO2/FiO2 ratio of 7.1 kPa (below the 6.7 kPa threshold sustained for the referral trigger) despite optimised lung-protective ventilation, neuromuscular blockade and proning. He is young, has no major comorbidity, a normal lactate and a plateau pressure at the upper safe limit, making him an ideal candidate whose disease is likely reversible. Survival benefit from ECMO is time-dependent and falls sharply the longer conventional high-pressure, high-FiO2 ventilation continues, so referral should occur as soon as criteria are met rather than after further deterioration. Why the other options are wrong: C. Increase tidal volume to achieve PaO2 above 10 kPa: this abandons lung-protective ventilation and raises plateau pressure above safe limits, increasing ventilator-induced lung injury without addressing the underlying oxygenation failure. E. Delay referral until ventilation has failed for 7 days: waiting this long allows accumulation of ventilator-induced lung injury and multiorgan dysfunction, and outcomes from ECMO worsen substantially with delayed referral. B. Start routine high-dose corticosteroids solely to avoid ECMO: steroids are not indicated purely to circumvent ECMO referral and do not correct refractory hypoxaemia meeting extracorporeal support criteria; their use should follow specific evidence-based indications, not as an avoidance strategy. D. Commence bicarbonate infusion to improve oxygen delivery: bicarbonate does not improve oxygenation or gas exchange in ARDS and has no role in managing refractory hypoxaemia here. Key point: A PaO2/FiO2 ratio below the NHS ECMO referral threshold in a young patient with reversible disease and optimised conventional therapy mandates early discussion with a specialist centre, since delay erodes survival benefit.

Reference: NHS England and NHS Improvement, Extra-Corporeal Membrane Oxygenation (ECMO) Speciality Guide (Adult): referral criteria for potentially reversible severe respiratory failure include PaO2/FiO2 <6.7 kPa for >=3 hours or <10 kPa for >=6 hours despite optimised conventional management; https://warwick.ac.uk/fac/sci/med/research/ctu/trials/recovery-rs/news/speciality-guide-extra-corporeal-membrane-oxygenation-ecmo-adult.pdf