Administration of PCSL

After Dex titration, patients were excluded if they complained of being uncomfortable or experienced side effects, such as transient hypertension, bradycardia or hypotension. Those patients who tolerated the treatment were included as candidates to continue PCSL. The Patient-controlled device (Rehn Medtech Co., Ltd., Jiangsu, China) protocols were 800 mcg Dex diluted to 200 mL (the final drug concentration was 4 mcg/mL). The device was set up to deliver a continuous infusion of 0.1 mL/h (0.4 mcg/h), a maximum dose of 30 mL/h (120 mcg/h) and a bolus of 1–3 mL (4–12 mcg), with a 10-minute lockout interval, according to the Dex titration data generated in the PACU. The loading dose was usually twenty-five percent of the sleeping doses. To request sleep, patients could press a button on a hand-held device to send a signal to the microprocessor controlling the syringe driver, which delivers a pre-determined dose of Dex via an intravenous cannula. Additionally, the PCSL device enables patients to self-administer by pressing the button whenever they wake up during the night. HR and peripheral arterial oxygen saturation (SpO₂) were monitored overnight by specially trained nurses during sleep in a sound-insulated ward. BP and respiratory rate (RR) were monitored 1 h after PCSL administration. The rescue protocol was the same as described in the rescue protocol section.