The comparison of preemptive effects of propofol, remifentanil and ketamine on post-operative pain scores and analgesic requirements in elective lower abdominal surgery under general anesthesia: A randomized, double-blinded study

Background: In this randomized, double-blinded study, we investigated the preemptive effects of propofol, remifentanil or ketamine on post-operative pain scores and analgesic requirements in elective lower abdominal surgeries under general anesthesia during the first 24 h of post-operative period. Materials and Methods: Seventy five patients, American Society of Anesthesiologists physical status I or II candidate for elective lower abdominal surgery under general anesthesia were randomized to three groups (25 each). According to their allocated group, patients received either propofol 0.25 mg/kg, remifentanil 0.25 mic/kg or ketamine 0.3 mg/kg as preemptive analgesia immediately after the induction of general anesthesia. Post-operative pain scores with a numerical rating scale (visual analogue scale 0-10) were assessed and analgesic requirements and side-effects were compared through analysis using the SPSS version 18 in the post-operative period; post-anesthesia care unit 2, 6, 12 and 24 h. Results: Patients' demographics were similar in all groups. The pain scores were significantly lower in remifentanil group immediately after recovery and also at 2 and 6 h post-operatively, but it reversed at 12 and 24 h after recovery comparing with propofol and ketamine. However, the mean of administered morphine in the first 24 h was significantly lower in propofol group (18.97 +/- 6.6) comparing with remifentanil group (21.96 +/- 6.55) and ketamine group (24.26 +/- 5.84) (P value, 0.01). Conclusion: Prophylactic preemptive single dose of intravenous (IV) 0.25 mg/kg propofol significantly decreased post-operative analgesia requirements comparing with IV 0.3 mg/kg ketamine or 0.25 mu g/kg remifentanil.