title: The role of non-invasive positive pressure ventilation in post-extubation respiratory failure: An evaluation using meta-analytic techniques.
abstract: BACKGROUND
  The use of non-invasive positive pressure ventilation (NIPPV) in post-extubation respiratory failure is not well-established. Meta-analytic techniques were used to assess the effects of prophylactic application of NIPPV (prior to the development of respiratory failure) and therapeutic application of NIPPV (subsequent to the development of respiratory failure).
  
  
  METHODS
  Randomized controlled trials (RCTs) from 1966 to May 2010 were identified using electronic databases. RCTs, which reported the use of NIPPV in post-extubation respiratory failure with defined assessable endpoints: reintubation, mortality and length of stay, were included.
  
  
  RESULTS
  Reintubation was the primary outcome, mortality and lengths of stay were the secondary outcomes. Risk ratios (RR) were calculated for discrete outcomes and weighted mean differences (WMD) for continuous measures. There were 13 trials with 1420 patients; 9 prophylactic with 861 patients and 4 therapeutic with 559 patients. In the prophylactic group, NIPPV was associated with lower rates of reintubation: RR 0.53 (95% confidence interval [CI], 0.28-0.98), P = 0.04. In the therapeutic group, NIPPV showed a null effect on reintubation: RR 0.79 (95% CI, 0.50-1.25), P = 0.31. The analysis on the secondary outcomes suggested significant reduction of hospital mortality with prophylactic application of NIPPV: RR 0.62 (95% CI 0.4-0.97), P = 0.03, with no effect on the other outcomes. Therapeutic application of NIPPV reduced intensive care unit length of stay: WMD -1.17 (95% CI -2.82 to -0.33), P = 0.006, but no effect on the other secondary outcomes.
  
  
  CONCLUSIONS
  The results of this review suggested prophylactic NIPPV was beneficial with respect to reintubation and the therapeutic use of NIPPV showed a null effect.
authors.affiliation: Intensive Care Unit, St. John's Medical College and Hospital, Bangalore, Karnataka, India.
authors.forename: Bhuvana
authors.initials: B
authors.lastname: Krishna
authors.forename: Sriram
authors.initials: S
authors.lastname: Sampath
authors.forename: John L
authors.initials: JL
authors.lastname: Moran
keywords: Bi-level positive airway pressure ventilation; continuous positive airway pressure ventilation; non-invasive ventilation; post-extubation; reintubation; respiratory failure