Prophylactic administration of diphenhydramine/paracetamol reduced emergence agitation and postoperative pain following maxillofacial surgeries: a randomized controlled trial.

Background Emergence agitation after maxillofacial surgeries is an anxious and problematic complication for the surgeon and anesthesiologist that may lead to self-extubation, haemorrhage, and surgical destruction. In this study, we investigated the effects of preemptive administration of diphenhydramine on emergence agitation and quality of recovery after maxillofacial surgery in adult patients. Methods Eighty-five patients undergoing maxillofacial surgery were randomized into two groups. The diphenhydramine group (Group D, n = 40) received diphenhydramine premedication 0.5 mg/kg before anesthesia induction, while the control group (Group C, n = 40) received volume-matched normal saline as a placebo. Before incision, all patients receive 0.1 mg/kg morphine sulfate slowly intravenously within 5 min. Continuous infusion of remifentanil 0.2 μg/kg/h and inhalation of isoflurane was maintained during the anesthesia period. Paracetamol 1 g was infused 15 min before extubation. We evaluated the incidence of agitation during the extubation period after general anesthesia, hemodynamic parameters, and recovery characteristics during the postoperative period. Results During extubation time, the incidence of emergence agitation was lower in Group D than in Group C (16% vs. 49%, P = 0.041). The time from isoflurane discontinuation to extubation (7.7 min in Group D vs. 6.8 min in Group C, P = 0.082) was not different. Grade of cough during emergence, the severity of pain, analgesic requirements, and hemodynamic changes were lower in group D compared with Group C. Conclusions Preemptive administration of diphenhydramine provided smooth emergence from anesthesia. It also improved the quality of recovery after maxillofacial surgery. Trial registration number This study was registered at http://irct.ir (registration number IRCT20130304012695N3).