Benefit with preventive noninvasive ventilation in subgroups of patients at high-risk for reintubation: a post hoc analysis.

Background: High-flow nasal cannula (HFNC) was shown to be non-inferior to noninvasive ventilation (NIV) for preventing reintubation in a general population of high-risk patients. However, some subgroups of high-risk patients might benefit more from NIV. We aimed to determine whether the presence of many risk factors or overweight (body mass index (BMI) ≥ 25 kg/m) patients could have different response to any preventive therapy, NIV or HFNC in terms of reduced reintubation rate.

Methods: Not pre-specified post hoc analysis of a multicentre, randomized, controlled, non-inferiority trial comparing NFNC and NIV to prevent reintubation in patients at risk for reintubation. The original study included patients with at least 1 risk factor for reintubation.

Results: Among 604 included in the original study, 148 had a BMI ≥ 25 kg/m. When adjusting for potential covariates, patients with ≥ 4 risk factors (208 patients) presented a higher risk for reintubation (OR 3.4 [95%CI 2.16-5.35]). Patients with ≥ 4 risk factors presented lower reintubation rates when treated with preventive NIV (23.9% vs 45.7%; P = 0.001). The multivariate analysis of overweight patients, adjusted for covariates, did not present a higher risk for reintubation (OR 1.37 [95%CI 0.82-2.29]). However, those overweight patients presented an increased risk for reintubation when treated with preventive HFNC (OR 2.47 [95%CI 1.18-5.15]).

Conclusions: Patients with ≥ 4 risk factors for reintubation may benefit more from preventive NIV. Based on this result, HFNC may not be the optimal preventive therapy in overweight patients. Specific trials are needed to confirm these results.