Noninvasive positive pressure ventilation as a weaning strategy for intubated adults with respiratory failure
Abstract
Background
Noninvasive positive pressure ventilation (NPPV) provides ventilatory support without the need for an invasive airway approach. Interest has emerged in using NPPV to facilitate earlier removal of an endotracheal tube and decrease complications associated with prolonged intubation.
Objectives
To summarize the evidence comparing NPPV and invasive positive pressure ventilation (IPPV) weaning on clinical outcomes in intubated adults with respiratory failure.
Search methods
We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2008), MEDLINE (January 1966 to April 2008), EMBASE (January 1980 to April 2008), proceedings from four conferences, and personal files; and contacted authors to identify randomized controlled trials comparing NPPV and IPPV weaning.
Selection criteria
Randomized and quasi‐randomized studies comparing early extubation with immediate application of NPPV to IPPV weaning in intubated adults with respiratory failure.
Data collection and analysis
Two review authors independently assessed trial quality and abstracted data according to prespecified criteria. Sensitivity and subgroup analyses were planned to assess the impact of (i) excluding quasi‐randomized trials, and (ii) the etiology of respiratory failure on selected outcomes.
Main results
We identified 12 trials of moderate to good quality that involved 530 participants with predominantly chronic obstructive pulmonary disease (COPD). Compared to the IPPV strategy, NPPV significantly decreased mortality (relative risk (RR) 0.55, 95% confidence Interval (CI) 0.38 to 0.79), ventilator associated pneumonia (RR 0.29, 95% CI 0.19 to 0.45), length of stay in an intensive care unit (weighted mean difference (WMD) ‐6.27 days, 95% CI ‐8.77 to ‐3.78) and hospital (WMD ‐7.19 days, 95% CI ‐10.80 to ‐3.58), total duration of ventilation (WVD) ‐5.64 days (95% CI ‐9.50 to ‐1.77) and duration of endotracheal mechanical ventilation (WMD ‐ 7.81 days, 95% CI ‐11.31 to ‐4.31). Noninvasive weaning had no effect on weaning failures or the duration of ventilation related to weaning. Excluding a single quasi‐randomized trial maintained the significant reduction in mortality and ventilator associated pneumonia. Subgroup analyses suggested that the benefits on mortality and weaning failures were nonsignificantly greater in trials enrolling exclusively COPD patients versus mixed populations.
Authors' conclusions
Summary estimates from 12 small studies of moderate to good quality that included predominantly COPD patients demonstrated a consistent, positive effect on mortality and ventilator associated pneumonia. The net clinical benefits associated with noninvasive weaning remain to be fully elucidated.
PICOs
Plain language summary
Use of noninvasive ventilation (a mask with pressurized air) holds promise as a method to help adults who have been on ventilators because of respiratory failure to breathe for themselves
Patients with acute respiratory failure frequently require endotracheal intubation and mechanical ventilation (invasive positive pressure ventilation) to sustain life. Complications of mechanical ventilation include respiratory muscle weakness, upper airway pathology, ventilator associated pneumonia and associated deaths and sinusitis. For these reasons it is important to minimize the duration of mechanical ventilation. Noninvasive positive pressure ventilation is achieved with an oronasal, nasal or total face mask connected to a ventilator and does not require an indwelling artificial airway.
Results from 12 randomized controlled trials demonstrated that for 530 selected patients (predominantly with chronic obstructive pulmonary disease) who had respiratory failure and were starting to breathe spontaneously, showed that noninvasive ventilation could decrease deaths, pneumonia, length of stay in the intensive care and hospital and the duration of ventilator support. Noninvasive weaning demonstrated no effect on weaning failures and the duration of mechanical ventilation related to weaning. Insufficient data were available to assess adverse events or the impact of noninvasive weaning on quality of life. Further trials are required to determine the overall clinical benefits, risks and consequences associated with the use of noninvasive weaning.
