Noninvasive ventilation on reintubation in patients with obesity and hypoxemic respiratory failure following abdominal surgery A post-hoc analysis of a Randomized Clinical Trial

Abstract

Purpose Although noninvasive ventilation (NIV) may reduce reintubation in patients with acute hypoxemic respiratory failure following abdominal surgery, this strategy has not been specifically assessed in patients with obesity. Methods We conducted a post-hoc analysis of a multicenter randomized controlled trial comparing NIV delivered via facial mask (inspiratory pressure support level, 5-15cmH2O; positive end-expiratory pressure, 5-10cmH2O; fraction of inspired oxygen titrated to Spo2 ≥ 94%) to standard oxygen-therapy (up to 15 L/min to SpO2 ≥ 94%) among patients with obesity and acute hypoxemic respiratory failure within seven days after abdominal surgery. The primary outcome was reintubation within seven days. Secondary outcomes were invasive ventilation–free days at day 30, Intensive Care Unit (ICU)-acquired pneumonia and 30-day survival. Results Among 293 patients with hypoxemic respiratory failure following abdominal surgery, 76 (26%) patients had obesity and were included in the intention-to-treat analysis. Reintubation rate was significantly lower with NIV (13/42, 31%) than with standard oxygen-therapy (19/34, 56%) within seven days (absolute difference: -25%, 95%Confidence Interval(CI) -49% to -1%, p = 0.03). NIV was associated with significantly more invasive ventilation–free days compared with standard oxygen-therapy (27.1 ± 8.6 vs 22.7 ± 11.1 days; p = 0.02), while fewer patients developed ICU-acquired pneumonia (1/42, 2% vs 6/34, 18%; absolute difference, − 16%; 95%CI, − 31% to − 1%; p = 0.04). The 30-day survival was 98% in the NIV group (41/42) versus 85% in the standard oxygen-therapy (absolute difference, 13%; 95%CI, − 3–28%; p = 0.08). Conclusions Among patients with obesity and hypoxemic respiratory failure following abdominal surgery, use of NIV compared with standard oxygen-therapy reduced the risk of reintubation within seven days. Trial Registration clinicaltrials.gov Identifier: NCT01971892