Background: Prophylactic noninvasive ventilation (NIV) after scheduled extubation can benefit patients with chronic respiratory disorders, among which chronic obstructive pulmonary disease (COPD) is a significant example. However, it is not known whether all COPD patients benefit from prophylactic NIV.
Methods: We performed a post hoc analysis of prospectively collected data. COPD patients who successfully completed a spontaneous breathing trial were enrolled. In the prophylactic NIV group, NIV was applied immediately after extubation. In the usual care group, conventional oxygen therapy was used. Patients were followed up to 90 days post-extubation.
Results: Among patients with PaCO₂ > 45 mmHg, 128 and 40 received prophylactic NIV and usual care, respectively. Prophylactic NIV led to lower rates of re-intubation (4% vs 30% at 72 h and 11% vs 35% at 7 days, both p < 0.01) and hospital mortality (18% vs 40%, p < 0.01) than usual care. The proportion of 90-day mortality was also lower in the prophylactic NIV group (log rank test, p = 0.04). Among patients with PaCO₂ ≤ 45 mmHg, 32 and 21 received prophylactic NIV and usual care, respectively. In this cohort however, prophylactic NIV neither reduced re-intubation (6% vs 5% at 72 h, p > 0.99, and 9% vs 14% at 7 days, p = 0.67) nor hospital mortality (19% vs 24%, p = 0.74). The proportion of 90-day mortality did not differ between the two groups (log rank test, p = 0.79).
Conclusion: This exploratory study shows that prophylactic NIV benefits COPD patients with PaCO₂ > 45 mmHg, but it may not benefit those with PaCO₂ ≤ 45 mmHg. Further study with a larger sample size is required to confirm this.
Keywords: noninvasive ventilation, ventilator weaning, re-intubation