title: Extracorporeal membrane oxygenation for pandemic influenza A(H1N1)-induced acute respiratory distress syndrome: a cohort study and propensity-matched analysis.
abstract: BACKGROUND
  Many patients with severe acute respiratory distress syndrome (ARDS) caused by influenza A(H1N1) infection receive extracorporeal membrane oxygenation (ECMO) as a rescue therapy.
  
  
  OBJECTIVE
  To analyze factors associated with death in ECMO-treated patients and the influence of ECMO on intensive care unit (ICU) mortality.
  
  
  METHODS
  Data from patients admitted for H1N1-associated ARDS to French ICUs were prospectively collected from 2009 to 2011 through the national REVA registry. We analyzed factors associated with in-ICU death in ECMO recipients, and the potential benefit of ECMO using a propensity score-matched (1:1) cohort analysis.
  
  
  RESULTS
  A total of 123 patients received ECMO. By multivariate analysis, increasing values of age, lactate, and plateau pressure under ECMO were associated with death. Of 103 patients receiving ECMO during the first week of mechanical ventilation, 52 could be matched to non-ECMO patients of comparable severity, using a one-to-one matching and using control subjects only once. Mortality did not differ between the two matched cohorts (odds ratio, 1.48; 95% confidence interval, 0.68-3.23; P = 0.32). Interestingly, the 51 ECMO patients who could not be matched were younger, had lower Pa(o(2))/Fi(o(2)) ratio, had higher plateau pressure, but also had a lower ICU mortality rate than the 52 matched ECMO patients (22% vs. 50%; P < 0.01).
  
  
  CONCLUSIONS
  Under ECMO, an ultraprotective ventilation strategy minimizing plateau pressure may be required to improve outcome. When patients with severe influenza A(H1N1)-related ARDS treated with ECMO were compared with conventionally treated patients, no difference in mortality rates existed. The unmatched, severely hypoxemic, and younger ECMO-treated patients had, however, a lower mortality.
authors.affiliation: Service de Réanimation Médicale, Groupe Hospitalier Henri Mondor, Assistance Publique-Hôpitaux de Paris, Créteil, France. taiopham@gmail.com
authors.forename: Tài
authors.initials: T
authors.lastname: Pham
authors.forename: Alain
authors.initials: A
authors.lastname: Combes
authors.forename: Hadrien
authors.initials: H
authors.lastname: Rozé
authors.forename: Sylvie
authors.initials: S
authors.lastname: Chevret
authors.forename: Alain
authors.initials: A
authors.lastname: Mercat
authors.forename: Antoine
authors.initials: A
authors.lastname: Roch
authors.forename: Bruno
authors.initials: B
authors.lastname: Mourvillier
authors.forename: Claire
authors.initials: C
authors.lastname: Ara-Somohano
authors.forename: Olivier
authors.initials: O
authors.lastname: Bastien
authors.forename: Elie
authors.initials: E
authors.lastname: Zogheib
authors.forename: Marc
authors.initials: M
authors.lastname: Clavel
authors.forename: Adrien
authors.initials: A
authors.lastname: Constan
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Marie Richard
authors.forename: Christian
authors.initials: C
authors.lastname: Brun-Buisson
authors.forename: Laurent
authors.initials: L
authors.lastname: Brochard
mesh_terms: D000328:Adult; D017677:Age Distribution; D015984:Causality; D015331:Cohort Studies; D015897:Comorbidity; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology* / Q000628:therapy*; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D016017:Odds Ratio; D058873:Pandemics / Q000706:statistics & numerical data*; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012128:Respiratory Distress Syndrome / Q000453:epidemiology* / Q000628:therapy*; D012307:Risk Factors; D012720:Severity of Illness Index; D016019:Survival Analysis; D016896:Treatment Outcome