Heart failure: acute pulmonary edema: CPAP reduces the need for endotracheal intubation

Clinical bottom line (level 1a)

  1. Patients with severe cardiogenic pulmonary edema who receive continuous positive airway pressure (CPAP) ventilation in addition to standard medical therapy compared with standard medical therapy alone are less likely to require intubation (NNT = 4 at unknown) .
  2. Noninvasive positive pressure ventilation (NPPV) is not clearly as effective or safe as CPAP.
  3. There is no clear effect on mortality.
Pang et al: Chest 1998; 114 (4): 1185-1192
Expires October 2003

The study

Systematic review of all randomised controlled trials of
  • Patients: acute pulmonary edema
  • Intervention: continuous positive airway pressure (CPAP) or noninvasive positive pressure ventilation (NPPV) and standard medical therapy compared with standard medical therapy
  • Outcome: hospital survival, need for endotracheal intubation


    • Articles found in English using Medline, 1983 to 1997 (search terms: pulmonary edema (therapy), respiratory insufficiency (therapy) and positive pressure ventilation ) and searching bibliographies of selected articles and reviews. Supplements of respiratory journals were handsearched from 1985 to 1997 to identify abstracts.

    Selection criteria: see above
    Appraisal criteria: based on randomisation concealment, objective criteria for study population, objective criteria for endotracheal intubation, description of potential confounders, complete follow-up, mention of co intervention standardisation and intention-to-treat analysis
    Articles excluded if:
    • not done in humans


    3 randomised controlled trial found comparing CPAP and standard medical therapy. 7 case series reports found comparing NPPV and standard medical therapy. 1 randomised controlled trial found comparing CPAP and NPPV.
    Studies were not found to be heterogeneous.

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    death unknown 16
    (17.8%)    		 9
    (10.1%)    		 43%
    (-22% to 73%)    		 6.6%
    (-3% to 16%)    		 15
    (NNT = 6 to infinity;
    NNH = 30 to infinity)
    endotracheal intubation unknown 37
    (41.1%)    		 14
    (15.7%)    		 62%
    (34% to 78%)    		 26%
    (13% to 38%)    		 4
    (3 to 8)

    • In the case series for NPPV mortality ranged from 0% to 22% and intubation from 0% to 44%. NPPV is not a substitute for endotracheal intubation, it is one more tool to improve a deteriorating patient before she/he meets intubation criteria.
    • The study comparing CPAP and NPPV was too small to show any difference between the two groups.

    Citation

    1. Pang D, Keenan SP, Cook DJ, et al: the effect of positive pressure airway support on mortality and the need for intubation in cardiogenic pulmonary edema: a systematic review. Chest 1998; 114 (4): 1185-1192
    Contributor: Chris Ball and Clare Wotton, October 1999
    Reviewer: Luis Ruiz Del Fresno

    Clinical Question.
    Patient cardiogenic pulmonary oedema
    Intervention or Exposure continuous positive airway pressure (CPAP) ventilation, non-invasive positive pressure ventilation (NPPV)
    Outcome death, endotracheal intubation