In Summary, for those who received the ventilatory support:

Benefits in NNT

  • 87% saw no benefit
  • 8.5% were saved from death
  • 13% were saved from intubation
  • 1 in 13 were helped (life saved)
  • 1 in 8 were helped (prevented intubation)

Harms in NNT

  • 0% were harmed by myocardial infarction
  • None were harmed (myocardial infarction)

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Source: Vital FMR, Saconato H, Ladeira MT, et al. Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary edema. Cochrane Database of Systematic Reviews 2008, Issue 3. Art. No.: CD005351. DOI: 10.1002/14651858.CD005351.pub2.

Efficacy Endpoints: Mortality, Intubation

Harm Endpoints: Acute Myocardial Infarction, "Adverse Events"

Narrative: Noninvasive positive pressure ventilation (NIPPV) has been theorized to offer the advantages of respiratory assistance and improved gas exchange without the disadvantages associated with sedation, paralysis, and endotracheal intubation. This Cochrane Review includes 21 trials (n = 1071) in both the ICU and emergency department settings. Some compared bilevel positive airway pressure (BIPAP) devices, or continuous devices (CPAP) to standard therapy, while other studies compared the two devices to each other. There was no advantage to one form over the other. Exclusion criteria were consistent across studies, and typically included immediate need for intubation, altered sensorium, or hypotension. Pharmacologic treatments varied however, with some subjects receiving nonstandard therapies such as morphine, dopamine, digoxin, or diazepam. There was a range in the settings for each method. With BIPAP inspiratory pressures ranged from 9 to 17 (cm H2O) and expiratory from 4 to 11. During CPAP positive end-expiratory pressures levels ranged between 7.5 and 11.

In aggregate, clinically important and statistically significant benefits were demonstrated.

Caveats: Unfortunately, only 8 of 21 trials reported adverse events associated with NIPPV use. Surprisingly, increases in complications such as pulmonary aspiration, pneumothorax, asphyxia, and claustrophobia were not detected. Some less dangerous but still relevant adverse events were associated with NIPPV use, specifically skin damage (5%), gastric distention (6%) and mask discomfort (3%).

Author: Ashley Shreves, MD

Published/Updated: August 22, 2010

  1. The Title Bar

    The title bar is color-coded with our overall recommendation.

    • Green: Benefits outweigh risks.
    • Yellow: Unclear risk/benefit profile.
    • Red: Benefits do not outweigh risks.
    • Black: Obvious harms, no clear benefits.
  2. Tip content...