Extracorporeal Membrane Oxygenation for Interhospital Transfer of Severe Acute Respiratory Distress Syndrome Patients: A 5-year Experience

Abstract

PURPOSE: Transfer of severely hypoxic patients is a high-risk procedure. Extracorporeal membrane oxygenation (ECMO) allows safe transport of these patients to tertiary care institutions. Our ECMO transportation program was instituted in 2004; here we report results after 5 years of activity. METHODS: This is a clinical observational study. Criteria for ECMO center activation were: potentially reversibile respiratory failure, PaO₂ <50 mmHg with FiO₂ >0.6 for >12 hours, PEEP >5 cmH₂0, Lung Injury Score (LIS) ≥3 or respiratory acidosis with pH <7.2, no intracranial bleeding, and no absolute contraindication to anticoagulation. If eligible, a skilled crew applied ECMO at the referral hospital. Transportation was performed with a specially equipped ambulance. RESULTS: Sixteen patients were possible candidates for ECMO transfer. Two patients were excluded while 14 (mean±SD, age 35.4±18.6, SOFA 8.4±3.7, Oxygenation Index 43.7±13.4) were transported to our institution (distance covered 102±114 km, global duration of transport 589±186 minutes). Two patients improved after iNO-trial and were transferred and subsequently managed without ECMO. The remaining 12 patients were transferred on veno-venous ECMO with extracorporeal blood flow 2.7±1 L·min⁻¹, gas flow 3.8±1.8 L·min⁻¹, and FiO₂ 1. Data were recorded 30 minutes before and 60 minutes after initiation of ECMO. ECMO improved PCO₂ (75±23 vs. 53±9 mmHg, p<0.01) thus improving pH (7.28±0.13 vs. 7.39±0.05, p<0.01) and allowing a reduction in respiratory rate (35±14 vs. 10±4 breaths/min, p<0.01), minute ventilation (10.1±3.8 vs. 3.7±1.7 L·min⁻¹, p<0.01), and mean airway pressure (26±6.5 vs. 22±5 cmH₂O, p<0.01). No major clinical or technical complications were observed. CONCLUSIONS: ECMO effectively enabled high-risk ground transfer of severely hypoxic patients.