Noninvasive Positive-Pressure Ventilation for Community-Acquired Pneumonia
abstract & commentary
Source: Confalonieri M, et al. Acute respiratory failure in patients with severe community-acquired pneumonia: A prospective randomized evaluation of noninvasive ventilation. Am J Respir Crit Care Med 1999; 160:1585-1591.
This multicenter, prospective, randomized trial compared standard treatment plus noninvasive positive pressure ventilation (NPPV) delivered through a face mask to standard treatment alone in patients with severe community-acquired pneumonia and acute respiratory failure. Exclusion criteria were: severe hemodynamic instability, requirement for emergent cardiopulmonary resuscitation, home mechanical ventilation or long-term oxygen supplementation, concomitant severe disease with a low expectation of life, inability to expectorate, or contraindications to the use of the mask.
There were 56 consecutive patients (28 in each arm) enrolled, and the two groups were similar at study entry. The need for endotracheal intubation was 21% in the NPPV groups and 50% in the standard treatment group (P = 0.03). The mean duration of intensive care unit stay was significantly lower in the NPPV group (1.8 days vs 6.0 days, P = 0.04). The two groups had a similar intensity of nursing care workload, time interval from study entry to endotracheal intubation, duration of hospitalization, and hospital mortality. Among patients with chronic obstructive pulmonary disease (COPD), those randomized to NPPV had a lower intensity of nursing care workload (P = 0.04) and improved two-month survival (88.9% vs 37.5%; P = 0.05).
Comment by Stephanie B. Abbuhl, MD, FACEP
This study is important because it is the first randomized, controlled trial to evaluate NPPV in patients with acute respiratory failure caused by community-acquired pneumonia. The authors convincingly showed that NPPV was associated with a significant reduction in the rate of endotracheal intubation and duration of ICU stay. A post-hoc analysis was done (with significant limitations) that suggested a survival advantage at two months in patients with COPD.
Most of the evidence to date has suggested that the benefits of NPPV may be seen primarily in patients with a COPD exacerbation. A meta-analysis of controlled trails with NPPV concluded that in patients with COPD, there is strong evidence that NPPV decreases the need for intubation, decreases mortality, and shortens ICU stay.1 Other potential advantages of NPPV include avoiding the complications of intubation such as ventilation-associated pneumonia and sinusitis, preserving airway defense mechanisms, improving patient comfort, preserving speech and swallowing, and improving clearance of respiratory secretions. The data are more limited in patients with acute respiratory failure not related to COPD. Patients with cardiogenic pulmonary edema appear to benefit from CPAP for certain outcomes, but further studies are needed to clarify the effects of NPPV on hemodynamics and infarction rates in these patients. A multicenter randomized trial in asthma patients is currently under way.
It is encouraging that we may be able to expand our use of NPPV to include carefully selected pneumonia patients. Even though the actual number of ED patients that fit these criteria may be quite small, this study provides us with additional rationale to consider using NPPV in patients (especially with COPD) who have a reasonable chance of needing intubation in the next few hours.
1. Keenan SP, et al. Effect of noninvasive positive pressure ventilation on mortality in patients admitted with acute respiratory failure: A meta-analysis. Crit Care Med 1997;27:1685-1692.
21. All of the following are true about noninvasive positive pressure ventilation (NPPV) except:
a. Several studies have shown that NPPV decreases the need for intubation in many chronic obstructive pulmonary disease (COPD) patients.
b. NPPV has been shown to decrease mortality in COPD patients in some studies.
c. In patients with acute respiratory failure and severe community-acquired pneumonia, NPPV has been shown to significantly decrease the need for intubation when compared to a control group.
d. In the randomized, controlled trial of NPPV in patients with respiratory failure and community-acquired pneumonia, there was no difference in the length of ICU stay in the two groups.