Comparison of preemptive paracetamol, paracetamol-diclofenac & paracetamol-tramadol combination on postoperative pain after elective abdominal surgery under general anesthesia, Ethiopia: A randomized control trial study, 2018

Background: In the practice of postoperative pain management, pain is still poorly managed in low resource setting where the practice of epidural and opioid free analgesia is impractical. There has been a recent trend of combining different drugs and concept of preemptive analgesia but the therapeutic superiority remains understudied for postoperative pain management. The aim of this study is to assess postoperative analgesic effect of preemptive Paracetamol, Paracetamol-diclofenac and Paracetamol-tramadol combination in patients undergoing laparotomy surgery. Methods: Three-arm, randomized control trial study conducted on 63 patients undergone laparotomy surgery; group-P (paracetamol 1 g), group-PD (1 g + diclofenac 75 mg) and group-PT (paracetamol 1 g + tramadol 100 mg). The Numerical Rating Scale (NRS) pain rating system was used for this study. The primary endpoint of the study was total amount of analgesia consumption. Post-operative analgesic therapy [intravenous tramadol, 50 mg] were provided when patients complain of pain (request medication) or a numeric rating scale ≥4 was recorded. Secondary endpoint of the study were the time of first analgesic request and the intensity of the pain during 24 h post-op follow up period. Parametric data were analyzed using (ANOVA) and nonparametric data analyzed by Kuruska-Wallis H rank test. Chi-square test used for categorical variable. Statistical significance were sated at p value < 0.05 with a power of 80%. Results: The mean total tramadol consumption was significant higher in paracetamol group 250 ± 79.06 mg compared to paracetamol-diclofenac (173.81 ± 87.49 mg p = 0. 008) and paracetamol-tramadol (154.76 ± 70.54 mg p = 0. 001) group. Time to first analgesic request was significantly shorter within paracetamol group (87.62 ± 20.95 min) compared to paracetamol-diclofenac (103.01 ± 23.53 min p = 0.029) and paracetamol-tramadol (144.05 ± 14.72 min p < 0.001) group. There was statistically significant difference at 4th, 6th and 8th hour showing lower median pain score in paracetamol-tramadol group compared to paracetamol group. Conclusion: Preemptive combination of paracetamol-tramadol and paracetamol-diclofenac reduce total tramadol consumption and prolongs time to first analgesic request compared to paracetamol alone in patients undergoing laparotomy surgery. Trial registration: The study was retrospectively registered on 07 July 2019 at Pan African Clinical Trial Registry with the identification number of PACTR201908890749145. It was accepted on 14 August 2019.