title: Determinants of noninvasive ventilation success or failure in morbidly obese patients in acute respiratory failure.
abstract: OBJECTIVE
  Acute respiratory failure (ARF) is a common life-threatening complication in morbidly obese patients with obesity hypoventilation syndrome (OHS). We aimed to identify the determinants of noninvasive ventilation (NIV) success or failure for this indication.
  
  
  METHODS
  We prospectively included 76 consecutive patients with BMI>40 kg/m2 diagnosed with OHS and treated by NIV for ARF in a 15-bed ICU of a tertiary hospital.
  
  
  RESULTS
  NIV failed to reverse ARF in only 13 patients. Factors associated with NIV failure included pneumonia (n = 12/13, 92% vs n = 9/63, 14%; p<0.0001), high SOFA (10 vs 5; p<0.0001) and SAPS2 score (63 vs 39; p<0.0001) at admission. These patients often experienced poor outcome despite early resort to endotracheal intubation (in-hospital mortality, 92.3% vs 17.5%; p<0.001). The only factor significantly associated with successful response to NIV was idiopathic decompensation of OHS (n = 30, 48% vs n = 0, 0%; p = 0.001). In the NIV success group (n = 63), 33 patients (53%) experienced a delayed response to NIV (with persistent hypercapnic acidosis during the first 6 hours).
  
  
  CONCLUSIONS
  Multiple organ failure and pneumonia were the main factors associated with NIV failure and death in morbidly obese patients in hypoxemic ARF. On the opposite, NIV was constantly successful and could be safely pushed further in case of severe hypercapnic acute respiratory decompensation of OHS.
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Lemyze
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Pauline
authors.initials: P
authors.lastname: Taufour
authors.affiliation: Department of Biostatistics, Lille University Hospital, CHRU Lille, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Duhamel
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Johanna
authors.initials: J
authors.lastname: Temime
authors.affiliation: Respiratory Step Down Unit, Schaffner Hospital, Lens, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Nigeon
authors.affiliation: Respiratory Step Down Unit, Schaffner Hospital, Lens, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vangrunderbeeck
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Barrailler
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Gasan
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Pepy
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Thevenin
authors.affiliation: Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France.
authors.forename: Jihad
authors.initials: J
authors.lastname: Mallat
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063087:Noninvasive Ventilation; D010845:Obesity Hypoventilation Syndrome / Q000150:complications; D009767:Obesity, Morbid / Q000150:complications*; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000150:complications* / Q000628:therapy*; D017211:Treatment Failure