title: Predicting mortality risk in patients undergoing venovenous ECMO for ARDS due to influenza A (H1N1) pneumonia: the ECMOnet score.
abstract: OBJECTIVE
  The decision to start venovenous extracorporeal membrane oxygenation (VV ECMO) is commonly based on the severity of respiratory failure, with little consideration of the extrapulmonary organ function. The aim of the study was to identify predictors of mortality and to develop a score allowing a better stratification of patients at the time of VV ECMO initiation.
  
  
  METHODS
  This was a prospective multicenter cohort study on 60 patients with influenza A (H1N1)-associated respiratory distress syndrome participating in the Italian ECMOnet data set in the 2009 pandemic. Criteria for ECMO institution were standardized according to national guidelines.
  
  
  RESULTS
  The survival rate in patients treated with ECMO was 68 %. Significant predictors of death before ECMO institution by multivariate analysis were hospital length of stay before ECMO institution (OR = 1.52, 95 % CI 1.12-2.07, p = 0.008); bilirubin (OR = 2.32, 95 % CI 1.52-3.52, p < 0.001), creatinine (OR = 7.38, 95 % CI 1.43-38.11, p = 0.02) and hematocrit values (OR = 0.82, 95 % CI 0.72-0.94, p = 0.006); and mean arterial pressure (OR = 0.92, 95 % CI 0.88-0.97, p < 0.001). The ECMOnet score was developed based on these variables, with a score of 4.5 being the most appropriate cutoff for mortality risk prediction. The high accuracy of the ECMOnet score was further confirmed by ROC analysis (c = 0.857, 95 % CI 0.754-0.959, p < 0.001) and by an independent external validation analysis (c = 0.694, 95 % CI 0.562-0.826, p = 0.004).
  
  
  CONCLUSIONS
  Mortality risk for patients receiving VV ECMO is correlated to the extrapulmonary organ function at the time of ECMO initiation. The ECMOnet score is a tool for the evaluation of the appropriateness and timing of VV ECMO in acute lung failure.
authors.affiliation: Department of Cardiac Anesthesia and Intensive Care, Vita-Salute San Raffaele University, Via Olgettina 60, Milan 20132, Italy. pappalardo.federico@hsr.it
authors.forename: Federico
authors.initials: F
authors.lastname: Pappalardo
authors.forename: Marina
authors.initials: M
authors.lastname: Pieri
authors.forename: Teresa
authors.initials: T
authors.lastname: Greco
authors.forename: Nicolò
authors.initials: N
authors.lastname: Patroniti
authors.forename: Antonio
authors.initials: A
authors.lastname: Pesenti
authors.forename: Antonio
authors.initials: A
authors.lastname: Arcadipane
authors.forename: V Marco
authors.initials: VM
authors.lastname: Ranieri
authors.forename: Luciano
authors.initials: L
authors.lastname: Gattinoni
authors.forename: Giovanni
authors.initials: G
authors.lastname: Landoni
authors.forename: Bernhard
authors.initials: B
authors.lastname: Holzgraefe
authors.forename: Gernot
authors.initials: G
authors.lastname: Beutel
authors.forename: Alberto
authors.initials: A
authors.lastname: Zangrillo
mesh_terms: D000328:Adult; D015331:Cohort Studies; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications / Q000401:mortality* / Q000628:therapy*; D008297:Male; D011446:Prospective Studies; D012128:Respiratory Distress Syndrome / Q000401:mortality* / Q000628:therapy* / Q000821:virology; D018570:Risk Assessment; D015996:Survival Rate; D014680:Veins