Noninvasive ventilation in postoperative critically ill patients with morbid obesity: secondary analysis of the EXTUBOBESE multicentre randomised clinical trial.

BACKGROUND

The optimal method to prevent treatment failure after tracheal extubation in postoperative critically ill patients with obesity and morbid obesity remains unknown.

METHODS

We conducted a secondary analysis of the EXTUBOBESE multicentre RCT comparing prophylactic noninvasive ventilation (NIV) and oxygen therapy (high-flow nasal oxygen [HFNO] and standard oxygen) in 585 postoperative critically ill patients with obesity (BMI ≥30 kg m-2) and morbid obesity (BMI ≥40 kg m-2). The primary outcome was treatment failure within 3 days after extubation, a composite of reintubation within 3 days (also analysed separately as secondary outcome), switch to the other study treatment, or premature study treatment discontinuation. The primary outcome analysis used a χ2 test. A Cox model was used for time without reintubation.

RESULTS

Treatment failure occurred in 39/292 patients (13.4%) in the NIV group and in 70/293 patients (23.9%) in the oxygen therapy group (absolute risk difference: -10.5; 95% confidence interval: -16.8 to -4.3). Similar results were found when analysing separately HFNO from standard oxygen in the oxygen therapy group. Reintubation rate was 8.6% (25 patients) in the NIV group and 9.9% (29 patients) in the oxygen therapy group (P=0.58). Interaction test was significant for level of obesity (P=0.045). Time without reintubation according to level of obesity significantly differed between NIV group and oxygen therapy group (P=0.02) in patients with BMI ≥40 kg m-2, but not in patients with 30≤BMI<40 kg m-2 (P=0.70).

CONCLUSIONS

Among postoperative critically ill adults with obesity undergoing tracheal extubation, our results suggest that use of noninvasive ventilation is effective to reduce treatment failure in comparison with oxygen therapy alone. These effects were more pronounced in patients with morbid obesity.

CLINICAL TRIAL REGISTRATION: NCT04014920.