title: Effectiveness and predictors of success of noninvasive ventilation during H1N1 pandemics: a multicenter study.
abstract: BACKGROUND
  The use of non-invasive ventilation (NIV) in acute hypoxemic respiratory failure (AHRF) due to H1N1 virus infection is controversial. In this multicenter study we aimed to assess the efficacy of NIV in avoiding endotracheal intubation (ETI) and to identify predictors of success or failure.
  
  
  METHODS
  In this prospective multicenter study, 98 patients with new pulmonary infiltrate(s) sustained by H1N1 virus and a PaO(2)/FiO2<300 were eligible for study; 38/98 required immediate ETI, while the others received NIV as a first line therapy; 13/60 patients failed NIV and were intubated after 5.8+5.5 hours from enrolment. The remaining 47/60 patients were successfully ventilated with NIV.
  
  
  RESULTS
  Hospital mortality was significantly higher in those patients who failed NIV vs. those who succeeded (53.8% vs. 2.1%; OR=0.52, P<0.001). ETI was associated with higher number of infectious complications, mainly sepsis and septic shock. The OR of having one of these events in the NIV failure group vs. NIV success was 16.7, P<0.001. According to logistic regression model, a SAPS II>29 and a PaO(2)/FIO(2)≤127 at admission and PaO2/FIO(2)≤149 after 1 hr of NIV were independently associated with the need for ETI.
  
  
  CONCLUSIONS
  The early application of NIV, with the aim to avoid invasive ventilation, during the H1N1 pandemics was associated with an overall success rate of 47/98 (48%). Patients presenting at admission with an high SAPS II score and a low PaO(2)/FiO(2) ratio and/or unable to promptly correct gas exchange are at high risk of intubation and mortality.
authors.affiliation: Respiratory Diseases Unit, Hospital of Sestri Levante, Sestri Levante, Genoa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Nicolini
authors.forename: E
authors.initials: E
authors.lastname: Tonveronachi
authors.forename: P
authors.initials: P
authors.lastname: Navalesi
authors.forename: M
authors.initials: M
authors.lastname: Antonelli
authors.forename: I
authors.initials: I
authors.lastname: Valentini
authors.forename: R M
authors.initials: RM
authors.lastname: Melotti
authors.forename: A
authors.initials: A
authors.lastname: Pigna
authors.forename: A
authors.initials: A
authors.lastname: Carrassi
authors.forename: P
authors.initials: P
authors.lastname: Righini
authors.forename: M
authors.initials: M
authors.lastname: Ferrari Bravo
authors.forename: P
authors.initials: P
authors.lastname: Pelosi
authors.forename: F
authors.initials: F
authors.lastname: Nicoli
authors.forename: R
authors.initials: R
authors.lastname: Cosentini
authors.forename: R
authors.initials: R
authors.lastname: Vaschetto
authors.forename: S
authors.initials: S
authors.lastname: Faenza
authors.forename: S
authors.initials: S
authors.lastname: Nava
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005544:Forecasting; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology / Q000401:mortality / Q000628:therapy*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D063087:Noninvasive Ventilation / Q000379:methods*; D058873:Pandemics; D012131:Respiratory Insufficiency / Q000209:etiology / Q000628:therapy; D016896:Treatment Outcome