title: Extracorporeal membrane oxygenation for interhospital transfer of severe acute respiratory distress syndrome patients: 5-year experience.
abstract: OBJECTIVE
  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.
authors.affiliation: Experimental Medicine Department, Milano-Bicocca University, Monza, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Isgrò
authors.forename: Nicolò
authors.initials: N
authors.lastname: Patroniti
authors.forename: Michela
authors.initials: M
authors.lastname: Bombino
authors.forename: Roberto
authors.initials: R
authors.lastname: Marcolin
authors.forename: Alberto
authors.initials: A
authors.lastname: Zanella
authors.forename: Manuela
authors.initials: M
authors.lastname: Milan
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Foti
authors.forename: Antonio
authors.initials: A
authors.lastname: Pesenti
mesh_terms: D000328:Adult; D000368:Aged; D000552:Ambulances; D002675:Child, Preschool; D004867:Equipment Design; D015199:Extracorporeal Membrane Oxygenation / Q000009:adverse effects / Q000295:instrumentation; D005260:Female; D006769:Hospitals, General; D006801:Humans; D000860:Hypoxia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D007558:Italy; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010360:Patient Transfer; D015397:Program Evaluation; D012017:Referral and Consultation; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome