Evaluation of analgesic effect of two different doses of fentanyl in combination with bupivacaine for surgical site infiltration in cases of modified radical mastoidectomy: A double blind randomized study.

Background: Limited evidence supports the efficacy of peripheral route fentanyl and local anesthetic combination for postoperative analgesia. Our study was therefore designed to demonstrate the analgesic efficacy of two different doses of fentanyl in combination with bupivacaine for surgical site infiltration in patients undergoing modified radical mastoidectomy (MRM).

Materials And Methods: 60 patients undergoing MRM under general anesthesia were randomly allocated into two groups, first group receiving 0.5% bupivacaine at a dose of 2 mg/kg body weight with 50 μg fentanyl and second group receiving bupivacaine 0.5% at a dose of 2 mg/kg body weight with 100 μg fentanyl as infiltration of operative field in and around the incision site, after the incision and just before completion of surgery. In postoperative period pain, nausea-vomiting and sedation was recorded at 0 hr, 2, 4, 6, 12 and 24 hrs.

Results: Both the combinations of bupivacaine and fentanyl (Group I and Group II) were effective for postoperative analgesia. In both the groups the Visual Analogue Scale (VAS) score was less than 3 at each time interval. None of the patients required rescue analgesia. The comparison of VAS scores at different intervals showed that group II had lower VAS scores at all time points.

Conclusions: Fentanyl and bupivacaine combinations in doses of 50 and 100 μg along with 0.5% bupivacaine at a fixed dose of 2 mg/kg body weight are effective in the management of postoperative pain. Patients who received 100 μg fentanyl (Group II) had lower VAS scores as compared to the patients who received 50 μg fentanyl (Group I) with similar side effects.