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 μg/kg remifentanil.