Indirect comparison between two non-invasive weaning strategies in intubated patients with COPD

Background: Non-invasive weaning may be ideally suitable for intubated patients with COPD. Either spontaneous breathing trial (SBT) failure after meeting simple weaning criteria or pulmonary infection control window (PIC window) is adopted as switching timing for non-invasive weaning. This study aimed to explore the optimal timing of sequential non-invasive ventilation to reduce mortality and intubation-associated complications. Methods: A comprehensive literature search was performed to identify randomized controlled trials (RCTs) comparing non-invasive weaning at the two switching points with conventional invasive weaning in intubated patients with COPD. The primary outcome was mortality. Secondary outcomes included ventilator associated pneumonia (VAP) and duration of endotracheal mechanical ventilation (ETMV). Using conventional invasive weaning as a bridge, we indirectly compared the two non-invasive weaning strategies by Bucher approach. Results: We identified 7 RCTs enrolling 357 intubated patients with COPD. Indirect comparison showed that no significant difference was observed on mortality (RR 1.11, 95%CI 0.40 to 3.07, P=0.8479) and VAP (RR 0.58, 95%CI 0.16 to 2.06, P=0.3952). Compared with non-invasive weaning at PIC window, non-invasive weaning at SBT failure after meeting simple weaning criteria was associated with increased duration of ETMV (SMD 1.51, 95%CI 0.48 to 2.54, P=0.0039). Conclusions: Current evidence indicated that non-invasive weaning using PIC window as switching timing might decrease duration of ETMV though had no effect on mortality and VAP. The optimal timing for non-invasive weaning in intubated patients with COPD remains to be further elucidated.