title: Noninvasive ventilation in acute hypercapnic respiratory failure caused by obesity hypoventilation syndrome and chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Noninvasive ventilation (NIV) is widely used in episodes of acute hypercapnic respiratory failure (AHRF) in patients with chronic obstructive pulmonary disease (COPD). However, there is no evidence on the efficacy of NIV during similar episodes in obesity hypoventilation syndrome (OHS).
  
  
  OBJECTIVE
  To compare the efficacy of NIV in episodes of AHRF caused by OHS and COPD.
  
  
  METHODS
  We prospectively assessed 716 consecutive patients (173 with OHS and 543 with COPD) with AHRF (arterial pH < 7.35 and Pa(CO(2)) > 45 mm Hg) treated with a similar protocol of NIV. We defined successful NIV as avoidance of intubation and intensive care unit survival at least 24 hours in the ward. Hospital survivors were followed for 1 year to assess hospital readmission and survival.
  
  
  RESULTS
  Both groups had similar (mean ± SD) baseline respiratory acidosis (arterial pH, 7.22 ± 0.08; Pa(CO(2)), 86 ± 21 mm Hg). Patients with OHS were older (74 ± 11 vs. 71 ± 10 yr; P < 0.001); were more frequently female (134, 77% vs. 66, 12%; P < 0.001); had less late NIV failure (12, 7% vs. 67, 13%; P = 0.037); had lower hospital mortality (10, 6% vs. 96, 18%; P < 0.001); and had higher 1-year survival (odds ratio, 1.83; 95% confidence interval, 1.24-2.69; P = 0.002). However, survival adjusted for confounders (adjusted odds ratio, 1.41; 95% confidence interval, 0.70-2.83; P = 0.34), NIV failure (11, 6% vs. 59, 11%; P = 0.11), length of stay, and hospital readmission were similar in both groups. Among patients with COPD, obesity was associated with less late NIV failure and hospital readmission.
  
  
  CONCLUSIONS
  Patients with OHS can be treated with NIV during an episode of AHRF with similar efficacy and better outcomes than patients with COPD.
authors.affiliation: Intensive Care Unit, Hospital JM Morales Meseguer, Murcia, Spain.
authors.forename: Andres
authors.initials: A
authors.lastname: Carrillo
authors.forename: Miquel
authors.initials: M
authors.lastname: Ferrer
authors.forename: Gumersindo
authors.initials: G
authors.lastname: Gonzalez-Diaz
authors.forename: Antonia
authors.initials: A
authors.lastname: Lopez-Martinez
authors.forename: Noemi
authors.initials: N
authors.lastname: Llamas
authors.forename: Maravillas
authors.initials: M
authors.lastname: Alcazar
authors.forename: Lucia
authors.initials: L
authors.lastname: Capilla
authors.forename: Antoni
authors.initials: A
authors.lastname: Torres
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000209:etiology / Q000628:therapy; D008297:Male; D063087:Noninvasive Ventilation; D010845:Obesity Hypoventilation Syndrome / Q000628:therapy*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy*