Research

A comparison of continuous and bi-level positive airway pressure non-invasive ventilation in patients with acute cardiogenic pulmonary oedema: a meta-analysis

Kwok M Ho^1,2 and Karen Wong¹

¹Department of Intensive Care, Royal Perth Hospital, Perth, Western Australia, Australia

²School of Population Health and Medicine and Pharmacology, University of Western Australia, Crawley, Perth, Western Australia, Australia

author email corresponding author email

Critical Care 2006, 10:R49doi:10.1186/cc4861

Published:	27 March 2006

Abstract

Introduction

We conducted the present study to investigate the potential beneficial and adverse effects of continuous positive airway pressure (CPAP) compared with bi-level positive airway pressure (BiPAP) noninvasive ventilation in patients with cardiogenic pulmonary oedema.

Method

We included randomized controlled studies comparing CPAP and BiPAP treatment in patients with cardiogenic pulmonary oedema from the Cochrane Controlled Trials Register (2005 issue 3), and EMBASE and MEDLINE databases (1966 to 1 December 2005), without language restriction. Two reviewers reviewed the quality of the studies and independently performed data extraction.

Results

Seven randomized controlled studies, including a total of 290 patients with cardiogenic pulmonary oedema, were considered. The hospital mortality (relative risk [RR] 0.76, 95% confidence interval [CI] 0.32–1.78; P = 0.52; I² = 0%) and risk for requiring invasive ventilation (RR 0.80, 95% CI 0.33–1.94; P = 0.62; I² = 0%) were not significantly different between patients treated with CPAP and those treated with BiPAP. Stratifying studies that used either fixed or titrated pressure during BiPAP treatment and studies involving patients with or without hypercapnia did not change the results. The duration of noninvasive ventilation required until the pulmonary oedema resolved (weighted mean difference [WMD] in hours = 3.65, 95% CI -12.12 to +19.43; P = 0.65, I² = 0%) and length of hospital stay (WMD in days = -0.04, 95% CI -2.57 to +2.48; P = 0.97, I² = 0%) were also not significantly different between the two groups. Based on the limited data available, there was an insignificant trend toward an increase in new onset acute myocardial infarction in patients treated with BiPAP (RR 2.10, 95% CI 0.91–4.84; P = 0.08; I² = 25.3%).

Conclusion

BiPAP does not offer any significant clinical benefits over CPAP in patients with acute cardiogenic pulmonary oedema. Until a large randomized controlled trial shows significant clinical benefit and cost-effectiveness of BiPAP versus CPAP in patients with acute cardiogenic pulmonary oedema, the choice of modality will depend mainly on the equipment available.