Effect of preinduction low-dose ketamine bolus on intra operative and immediate postoperative analgesia requirement in day care surgery: A randomized controlled trial

Background: Availability of narcotics is an issue in developing countries, and low-dose ketamine offers an alternative to these drugs.Objective: The objective of this study is to evaluate the effect of a preemptive dose of low-dose ketamine on intra operative and the immediate postoperative analgesic requirements.Design: Randomized double-blind control trial.SETTINGS: This study has been performed in the operating rooms and postanesthesia care unit at Aga Khan University Hospital, Karachi, Pakistan.MATERIALS AND Methods: Totally, 60 adult American Society of Anesthesiologists I and II patients undergoing day care surgery were randomly allocated into two groups, Group A (ketamine group) and Group B (saline group).INTERVENTION: All patients underwent general anesthesia. Propofol 2 mg/kg was used as an induction agent; laryngeal mask airway (size 3 for females and 4 for males) was inserted. Following induction patients in Group A received ketamine 0.3 mg/kg and Group B saline bolus in a blinded manner. All patients were administered injection fentanyl 1 mug/kg as an analgesic and anesthesia was maintained with oxygen 40%, nitrous oxide 60% and isoflorane 1-2 minimum alveolar concentration. Patients breathed spontaneously on Lack circuit. Postoperatively rescue analgesia was provided with intravenous morphine 0.1 mg/kg when patient complained of pain.MAIN OUTCOME MEASURES: We observed analgesic effects of low-dose ketamine intra operatively and narcotic requirements in immediate postoperative period for day care surgeries.Results: There was no significant difference in demographic data in between groups. Saline group required more rescue analgesia (morphine) postoperatively (P \u3c 0.001). No significant psychotomimetic symptoms were noted in either group.CONCLUSION: Low-dose ketamine 0.3 mg/kg provided adequate co-analgesia with fentanyl 1 mug/kg and was effective in a reduction of morphine requirement in the postoperative phase with minimal adverse effects