Meta-analysis: Noninvasive ventilation in acute cardiogenic pulmonary edema.
BACKGROUND
Noninvasive ventilation (NIV) is commonly used to treat patients with acute cardiogenic pulmonary edema (ACPE), but the findings of a recent large clinical trial suggest that NIV may be less effective for ACPE than previously thought.


OBJECTIVE
To provide an estimate of the effect of NIV on clinical outcomes in patients with ACPE that incorporates recent trial evidence and explore ways to interpret that evidence in the context of preceding evidence that favors NIV.


METHODS
PubMed and EMBASE from 1966 to December 2009, Cochrane Central Register of Controlled Trials and conference proceedings through December 2009, and reference lists, without language restriction.


METHODS
Randomized trials that compared continuous positive airway pressure and bilevel ventilation with standard therapy or each other.


METHODS
Two independent reviewers extracted data. Outcomes examined were mortality, intubation rate, and incidence of new myocardial infarction (MI).


RESULTS
Compared with standard therapy, continuous positive airway pressure reduced mortality (relative risk [RR], 0.64 [95% CI, 0.44 to 0.92]) and need for intubation (RR, 0.44 [CI, 0.32 to 0.60]) but not incidence of new MI (RR, 1.07 [CI, 0.84 to 1.37]). The effect was more prominent in trials in which myocardial ischemia or infarction caused ACPE in higher proportions of patients (RR, 0.92 [CI, 0.76 to 1.10] when 10% of patients had ischemia or MI vs. 0.43 [CI, 0.17 to 1.07] when 50% had ischemia or MI). Bilevel ventilation reduced the need for intubation (RR, 0.54 [CI, 0.33 to 0.86]) but did not reduce mortality or new MI. No differences were detected between continuous positive airway pressure and bilevel ventilation on any clinical outcomes for which they were directly compared.


CONCLUSIONS
The quality of the evidence base was limited. Definitions, cause, and severity of ACPE differed among the trials, as did patient characteristics and clinical settings.


CONCLUSIONS
Although a recent large trial contradicts results from previous studies, the evidence in aggregate still supports the use of NIV for patients with ACPE. Continuous positive airway pressure reduces mortality more in patients with ACPE secondary to acute myocardial ischemia or infarction.


BACKGROUND
None.
Weng
Cui-Lian
CL
Peking University People's Hospital, Peking University, China.
Zhao
Yun-Tao
YT
Liu
Qing-Hua
QH
Fu
Chang-Jun
CJ
Sun
Feng
F
Ma
Yan-Liang
YL
Chen
Yan-Wen
YW
He
Quan-Ying
QY
D045422:Continuous Positive Airway Pressure / Q000379:methods*; D017052:Hospital Mortality; D006801:Humans; D007442:Intubation, Intratracheal; D009203:Myocardial Infarction / Q000150:complications; D017202:Myocardial Ischemia / Q000150:complications*; D011654:Pulmonary Edema / Q000209:etiology* / Q000401:mortality / Q000628:therapy*; D012008:Recurrence; D012307:Risk Factors; D016896:Treatment Outcome