Intraoperative use of low-dose dexmedetomidine for the prevention of emergence agitation following general anaesthesia in elderly patients: a randomized controlled trial

To clarify the effect of an intraoperative low-dose dexmedetomidine infusion on emergence agitation following general anaesthesia in elderly patients.Eighty elderly patients (> 64-years-old) following elective general anaesthesia for radical cancer surgeries were randomly allocated into two groups (n = 40 each): the dexmedetomidine group (Group D) and the normal saline group (Group C). Anaesthesia was maintained with continuous intravenous infusion of dexmedetomidine at - 0.2 µg kg-1 h-1 in Group D, and an equal volume of normal saline (0.5 ml kg-1 h-1) was given in Group C. All patients were observed for 30 min in the post-anaesthesia care unit (PACU), AFPS and NRS were recorded every 2 min, and the total doses of nalbuphine and fentanyl were calculated in the PACU. MAP and HR were recorded at the time of 10 min (T1), 20 min (T2), 30 min (T3) after dexmedetomidine or saline pumping, and before extubation (T4), immediately after extubation (T5), and 5 min after extubation (T6). We also documented some durations, including anaesthesia duration (D1), surgery duration (D2), duration from the end of surgery to extubation (D3), and emergence agitation duration (D4).The MAP in Group C was significantly higher than that in Group D (P < 0.05), and there were no significant changes between the two groups in HR and MAP within each time point and D1, D2, D3, and D4. The incidence of agitation, NRS score and total dose of nalbuphine and fentanyl were all lower in Group D than in Group C (P < 0.05).An intraoperative low-dose dexmedetomidine continuous infusion can reduce emergence agitation following general anaesthesia in elderly patients (> 64-years-old), remain stable in terms of haemodynamics, and not lead to delays in anaesthesia recovery time and extubation time.