Fig. 4. Aggregate additional open label sedation and analgesia. Hourly (mean ± SD) mg of additional morphine ( A ) and propofol ( B and C ). By using unpaired t test, the mean ± SD of total dose of propofol given by infusion was significantly less in the dexmedetomidine group ( P < 0.001). The mean ± SD of total mg of propofol boluses and additional morphine were comparable ( P = 0.084 and P = 0.476, respectively).