Elsevier

Annals of Emergency Medicine

Volume 48, Issue 3, September 2006, Pages 260-269.e4
Annals of Emergency Medicine

Cardiology/original research
The Use of Noninvasive Ventilation in Emergency Department Patients With Acute Cardiogenic Pulmonary Edema: A Systematic Review

https://doi.org/10.1016/j.annemergmed.2006.01.038Get rights and content

Study objective

Acute cardiogenic pulmonary edema is a common cause of respiratory distress in emergency department (ED) patients. Noninvasive ventilation by noninvasive positive pressure ventilation or continuous positive airway pressure has been studied as a treatment strategy. We critically evaluate the evidence for the use of noninvasive ventilation on rates of hospital mortality and endotracheal intubation.

Methods

We searched the databases of MEDLINE, EMBASE, and the Cochrane Library from 1980 to 2005. Additional sources included key journals, bibliographies of selected articles, and expert contact. We included studies that incorporated a randomized design; patients older than 18 years and with acute cardiogenic pulmonary edema; diagnosis and treatment initiated in the ED; noninvasive ventilation in addition to standard medical therapy compared to standard medical therapy alone, or noninvasive positive pressure ventilation compared to continuous positive airway pressure (both in addition to standard medical therapy); and data on hospital mortality or intubation. A random-effects model was used to obtain the summary risk ratios (RRs) and 95% confidence intervals (CIs) for hospital mortality and intubation.

Results

A pooled analysis of 494 patients suggested that noninvasive ventilation in addition to standard medical therapy significantly reduced hospital mortality compared to standard medical therapy alone (RR 0.61; [95% CI 0.41, 0.91]). Similarly, a meta-analysis of 436 patients suggested that noninvasive ventilation was associated with a significant decrease in intubation rates (RR 0.43; [95% CI 0.21, 0.87]).

Conclusion

Our results suggest that noninvasive ventilation with standard medical therapy is advantageous over standard medical therapy alone in ED patients with acute cardiogenic pulmonary edema. Future studies, powered appropriately for mortality and intubation rates, are necessary to confirm these findings.

Introduction

Acute cardiogenic pulmonary edema is a common cause of respiratory distress in patients presenting to the emergency department (ED). Patients with less severe symptoms of acute heart failure may respond to conventional treatment with oxygen, diuretics, and vasodilators. However, a subset of patients with respiratory compromise will require endotracheal intubation and mechanical ventilation. Unfortunately, this therapy has been associated with significant morbidity, such as nosocomial pulmonary infection, increased need for sedation (and thus longer duration of ventilation), and upper airway complications of endotracheal tube placement.1 As a result, there has been considerable interest in developing less invasive alternatives that can decrease the need for intubation.

Two noninvasive ventilation strategies have been studied in the treatment of acute cardiogenic pulmonary edema. Continuous positive airway pressure is a modality that maintains a constant positive pressure during inspiration and expiration and has been shown to have several benefits. Continuous positive airway pressure decreases the work of breathing2 and left ventricular afterload while maintaining cardiac index.3 Noninvasive positive pressure ventilation (or bilevel positive airway pressure [BiPAP]), which provides inspiratory pressure support coupled with positive end-expiratory pressure, theoretically provides the same benefits of continuous positive airway pressure, as well as inspiratory assistance to further decrease the work of breathing.4 Both treatment modalities are delivered through a tight-fitting facial or nasal mask.

Several small randomized clinical trials in patients with acute cardiogenic pulmonary edema have demonstrated a reduced need for intubation and mechanical ventilation with continuous positive airway pressure. These studies lacked sufficient power to detect a decrease in mortality.5, 6, 7 A systematic review and meta-analysis performed in 1998 suggested an absolute risk difference of 26% in the need for intubation with continuous positive airway pressure compared to standard care alone and a trend toward decreased hospital mortality.8 Of the 3 trials included, one included patients that were not clearly identified and treated in the ED.7

At the time of the Pang et al8 review, only 1 trial of noninvasive positive pressure ventilation in acute cardiogenic pulmonary edema had been published. That study demonstrated greater respiratory and hemodynamic improvement in the noninvasive positive pressure ventilation group compared with continuous positive airway pressure, but both continuous positive airway pressure and noninvasive positive pressure ventilation had similar rates of intubation and hospital mortality.4 However, there was an increased incidence of myocardial infarction reported in the noninvasive positive pressure ventilation group.

Since 1998, there have been a number of additional small randomized trials comparing noninvasive ventilation in addition to standard medical therapy versus standard medical therapy alone, or noninvasive positive pressure ventilation was compared to continuous positive airway pressure (both in addition to standard medical therapy) in an attempt to clarify the role of noninvasive ventilation in cardiogenic pulmonary edema.9, 10, 11, 12, 13, 14, 15, 16, 17, 18 Two of these trials suggested a decreased rate of intubation with noninvasive ventilation compared with standard medical therapy,9, 11 and one suggested a decreased rate of hospital mortality in the noninvasive ventilation group when compared with standard medical therapy.11 The remainder of the studies suggests that noninvasive ventilation had no effect on rates of hospital mortality or intubation. To date, there have been no systematic reviews that have focused solely on the use of noninvasive ventilation in ED patients with acute cardiogenic pulmonary edema.

The purpose of this systematic review was to critically evaluate the body of evidence on noninvasive ventilation in patients who had acute cardiogenic pulmonary edema and presented to the ED. Four interventions were assessed: (1) noninvasive ventilation (continuous positive airway pressure or noninvasive positive pressure ventilation) compared with standard medical therapy alone; (2) a comparison of continuous positive airway pressure and noninvasive positive pressure ventilation; (3) continuous positive airway pressure compared with standard medical therapy alone; and (4) noninvasive positive pressure ventilation compared with standard medical therapy alone. The primary and secondary outcome measurements (metameters) were hospital mortality and the rate of intubation, respectively.

Section snippets

Study Design

In reporting the results of this systematic review, the authors have followed the recommended guidelines from the Quality of Reporting of Meta-Analysis (QUORUM) Statement.19

A comprehensive literature search of MEDLINE, EMBASE, and the Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Clinical Trials Register) from January 1980 to July 2005 was performed. The key words used were “congestive heart failure,” “heart failure,” “pulmonary edema,”

Characteristics of Study Subjects

The initial search strategy identified 22,658 possible publications relevant to this meta-analysis (Figure 1). After applying the initial exclusion criteria to this search, a total of 442 trials were reviewed in more detail for inclusion. The majority of these studies (n=415) were excluded because they did not involve the management of acute cardiogenic pulmonary edema (n=112), involved patients with respiratory failure caused by multiple conditions (n=111), did not involve a randomization

Limitations

This analysis was based on aggregate data from all the individual studies. In this meta-analysis, the similarity of inclusion criteria and intervention protocols between studies suggests comparable patient populations and was supported by the lack of significant heterogeneity. Although baseline characteristics were similar between treatment groups, the inability to adjust statistically for differences in other factors beyond treatment group assignment could have influenced the hospital

Discussion

To our knowledge, this is the first meta-analysis of noninvasive ventilation in ED patients with acute cardiogenic pulmonary edema. The results of this meta-analysis suggest that a strategy of noninvasive ventilation plus standard medical therapy significantly reduces hospital mortality and need for endotracheal intubation when compared with standard medical therapy alone. From this analysis, it can be estimated that early application of noninvasive ventilation in the ED can decrease the

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      The effectiveness of continuous positive airway pressure (CPAP) in reducing endotracheal intubation and mortality in acute respiratory failure (ARF) due to cardiogenic pulmonary edema is well established (Bellone et al., 2005; Collins et al., 2006; Di Marco et al., 2008; Weng et al., 2010; Vital et al., 2013; Rochwerg et al., 2017).

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    Supervising editor: Brian H. Rowe, MD, MSc

    Author contributions: SC, LM, HW, MB, DS conceived the study and performed the overall literature search and data abstraction. SC and LM performed data analysis. SC, LM, HW, MB, DS, AS contributed to the writing of the manuscript. SC takes responsibility for the paper as a whole.

    Funding and support: The authors report this study did not receive any outside funding or support.

    Reprints not available from the authors.

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