The relations between the level of Mu-opioid receptor (μORs) and postoperative analgesic use in patients undergoing septoplasty: A prospective randomized controlled trial.

Abstract

Background In this study, the μ-Opioid receptor activity was examined before the septoplasty. We assessed preoperative μ-Opioid receptor activity association with postoperative pain level and second analgesic requirement in patients undergoing septoplasty. Methods In our prospective study, 120 adult patients underwent septoplasty from June 2015 to January 2019 were randomly divided into preop 2 groups. The first group (n=60) was patients given tramadol (1-2 mgr/kg) for postop analgesia, and the second group (control group) (n=60) was initially performed only fentanyl (1 µg/ kg-i.v.) in the induction. The μ-Opioid receptors activities were investigated in preoperative blood samples and compared post-op pain level and requiring time for second analgesic agent. The visual analogue score(VAS) was used to evaluate the postoperative pain degree (0 no pain,10 worst pain). Patients' post op VAS scores were evaluated upon arrival to recovery room, and at 1st, 3rd, 7th, 10th, and 24 th hours in postoperative period. Results Demographic data and perioperative variables was similar in both study group (p<0.05). There was no significant difference between the receptor levels in both two groups and the mean receptor level was 200.94 pg/ml. While the highest receptor level was 489.92 pg/ ml, the lowest receptor level was 94.56 pg/ml. In patients who used tradomal, as the levels of μ-Opioid receptors increased, VAS scores of patients and second analgesic use decreased in post-operative period. Vas scores were lower in the tramadol group compared to the control group. Patients in Tramadol group needed second pain killer later than patients in the Control group. Conclusions In this study, we revealed that postoperative pain level and second analgesic requirement decreased as μ-Opioid receptor levels increased in tramadol group.