The effects of intra-operative low-dose dexmedetomidine infusion on postoperative pain in patients undergoing septorhinoplasty

Abstract

Study objective: To determine the effects of intra-operative low-dose dexmedetomidine infusion on postoperative morphine consumption, pain, sedation and patient satisfaction in patients undergoing septorhinoplasty. Method: Fifty adult patients were randomised to receive either dexmedetomidine (a loading dose of 1 μg kg−1 for the first ten minutes and a maintenance dose of 0.2 μg kg−1 h−1 afterwards, Group D) or 0.9% saline in the same manner (Group C) after induction of anaesthesia. At the end of the operation, the infusions were discontinued. After extubation, patient controlled analgesia was started intravenously. Results: Patients in Group D consumed 47% less morphine than patients in Group C during the first 24 h and had a lower cumulative morphine consumption at all times after starting patient controlled analgesia (7.08 mg vs. 8.56 mg at 2 h (p < 0.05), 10.84 mg vs. 14.0 mg at 4 h (p < 0.05), 13.56 mg vs. 18.28 mg at 6 h (p < 0.05) and 17.96 mg vs. 33.72 mg at 24 h (p < 0.05), respectively in Group D and Group C). Visual analogue scale scores for pain were higher at all times in Group C than in Group D (p < 0.05). Sedation scores were higher in Group D than in Group C at 30 min after starting patient controlled analgesia (p < 0.05). Patient satisfaction scores were higher at all times in Group D than in Group C (p < 0.05). Conclusions: Intra-operative low-dose dexmedetomidine infusion during septorhinoplasty decreases postoperative morphine consumption, provides effective postoperative pain relief and achieves better patient satisfaction without increased adverse effects.