Fig. 4
From: Early nasal high-flow versus Venturi mask oxygen therapy after lung resection: a randomized trial
Kaplan–Meier plots of the cumulative incidence of postoperative hypercapnia in the two study groups. The inter-group difference remained significant after adjustment for age, history of clinically documented pulmonary infections in the month preceding surgery, and preoperative PaCO2, with a hazard ratio for HFNC of 0.33 [0.14–0.74] (p = 0.007). Please note that this analysis was not prespecified and should be considered exploratory in nature.