Fig. 2. Kaplan-Meier survival analysis for time to successful extubation. Patients treated with dexmedetomidine were more likely to be extubated earlier, Cox regression model (Hazard ratio 1.27, 95% CI 1.01–1.60, P = 0.040). Separation of Kaplan-Meier curves occurred after 18 h. For patients intubated for longer than 12 h (Hazard ratio 1.35, 95% CI 1.00–1.82, P = 0.047). D = dexmedetomidine; M = morphine.