title: Noninvasive ventilation for acute hypercapnic respiratory failure: intubation rate in an experienced unit.
abstract: BACKGROUND
  Failure of noninvasive ventilation (NIV) is common in patients with COPD admitted to the ICU for acute hypercapnic respiratory failure (AHRF). We aimed to assess the rate of NIV failure and to identify early predictors of intubation under NIV in patients admitted for AHRF of all origins in an experienced unit.
  
  
  METHODS
  This was an observational cohort study using data prospectively collected over a 3-year period after the implementation of a nurse-driven NIV protocol in a 24-bed medical ICU of a French university hospital.
  
  
  RESULTS
  Among 242 subjects receiving NIV for AHRF (P(aCO2) > 45 mm Hg), 67 had cardiogenic pulmonary edema (CPE), 146 had acute-on-chronic respiratory failure (AOCRF) (including 99 subjects with COPD and 47 with other chronic respiratory diseases), and 29 had non-AOCRF (mostly pneumonia). Overall, the rates of intubation and ICU mortality were respectively 15% and 5%. The intubation rates were 4% in CPE, 15% in AOCRF, and 38% in non-AOCRF (P < .001). After adjustment, non-AOCRF was independently associated with NIV failure, as well as acidosis (pH < 7.30) and severe hypoxemia (P(aO2)/F(IO2) ≤ 200 mm Hg) after 1 hour of NIV initiation, whereas altered consciousness on admission and ventilatory settings had no influence on outcome.
  
  
  CONCLUSIONS
  With a nurse-driven NIV protocol, the intubation rate was reduced to 15% in patients receiving NIV for AHRF, with a mortality rate of only 5%. Whereas the risk of NIV failure is associated with hypoxemia and acidosis after initiation of NIV, it is also markedly influenced by the presence or absence of an underlying chronic respiratory disease.
authors.affiliation: Réanimation Médicale, Hôpitaux Universitaires Henri Mondor, Assistance Publique Hôpitaux de Paris, Créteil, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Contou
authors.forename: Chiara
authors.initials: C
authors.lastname: Fragnoli
authors.forename: Ana
authors.initials: A
authors.lastname: Córdoba-Izquierdo
authors.forename: Florence
authors.initials: F
authors.lastname: Boissier
authors.forename: Christian
authors.initials: C
authors.lastname: Brun-Buisson
authors.forename: Arnaud W
authors.initials: AW
authors.lastname: Thille
mesh_terms: D000142:Acidosis, Respiratory / Q000209:etiology; D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D006935:Hypercapnia / Q000209:etiology; D000860:Hypoxia / Q000209:etiology; D007442:Intubation, Intratracheal / Q000379:methods / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods / Q000706:statistics & numerical data; D063087:Noninvasive Ventilation / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D017063:Outcome Assessment, Health Care; D057184:Practice Patterns, Nurses'; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications*; D012124:Respiratory Care Units / Q000706:statistics & numerical data; D012131:Respiratory Insufficiency / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D018570:Risk Assessment; D012307:Risk Factors; D017211:Treatment Failure
keywords: COPD; acute respiratory failure; acute-on-chronic respiratory failure; cardiogenic pulmonary edema; endotracheal intubation; hypercapnic coma; noninvasive ventilation