Fig. 3From: High flow nasal therapy versus noninvasive ventilation as initial ventilatory strategy in COPD exacerbation: a multicenter non-inferiority randomized trialAbsolute difference between HFNT and NIV treatment in mean PaCO2 reduction after 2 h (and 1-sided 95% confidence interval), according to conducted analyses: per-protocol on patients who completed the treatment originally allocated after 2 h (PP 2 h) and intention-to-treat (ITT). The black box indicates the mean PaCO2 reduction after 2 h, full lines indicate 95% confidence interval and dashed line the pre-planned non-inferiority margin of 10 mmHgBack to article page