Comparison between epidural postoperative analgesia with Bupivacaine with 50mg Magnesium sulphate and of Bupivacaine with 50mg Tramadol for patients undergoing lower limb surgeries

Abstract

Background

The comparative efficacy of epidural bupivacaine with Magnesium sulphate and bupivacaine combined with Tramadol in providing postoperative analgesia remains controversial.This study aims to assess the efficacy of epidural postoperative analgesia using a combination of 0.125%of Bupivacaine with 50mg MgSO4, compared to 0.125%of Bupivacaine with 50mg tramadol in patients undergoing surgeries for the lower limbs.

Method

60 patients classified as ASA grade I and II were randomly divided into two groups, Group I and Group II, each containing 30 patients. Group I received a total of 9 ml of 0.125% bupivacaine (8 ml) combined with 50mg tramadol (1 ml), while Group II was given 9 ml of 0.125% bupivacaine (8 ml) with 50mg MgSO4 (1 ml). The analgesic effectiveness was evaluated by the onset of analgesia, duration of analgesia, quality of analgesia, and the time taken to administer the first rescue analgesic.

Results

The onset of analgesia in Group I was recorded as 6.67±0.80 minutes, while Group II had an onset time of 7.67±0.80 minutes (p=0.001). The duration of analgesia for Group I was 5.16±0.72 hours, compared to 4.51±0.62 hours in Group II (p=0.001). The time until the first rescue analgesia was 5.260±0.716 hours for Group I, whereas Group II required 4.617±0.622 hours (p=0.001). Over a 24-hour period, Group I needed an average of 3.47±0.51 rescue doses, while Group II required 3.97±0.49 doses. The quality of analgesia was evaluated in both groups, showing no statistically significant differences. Adverse effects included nausea and vomiting in 4 patients and pruritus in 1 patient in Group I, while Group II experienced hypotension in 4 patients and bradycardia in 2 patients. Mean systolic and diastolic blood pressures were comparable across both groups, with significant differences only at 5, 10, and 15 minutes. The mean heart rates at 5, 10, and 15 minutes were 94.67±4.15, 89.73±3.85, and 85.40±4.40 in Group I, and 97.00±4.09, 92.20±3.46, and 87.53±3.27 in Group II, indicating statistical significance. The mean post-operative VAS scores recorded upto 24hrs. The mean VAS score was 0.40±0.498 and 0.47±0.507 at 2hrs, 2.87±0.730 and 2.93±0.691 at 4 hrs, 1.60±0.621 and 1.87±0.730 at 6hrs, 2.60±0.621 and 2.87±0.507 at 8hrs, 1.87±0.629 and 2.07±0.691 at 12hrs, 2.60±0.621 and 2.67±0.479 at 24hrs respectively.

Conclusion

Tramadol proved to be more effective than magnesium when combined with bupivacaine, as it led to a faster onset of pain relief, prolonged the duration of analgesia, and decreased the requirement for extra rescue epidural top-up doses within a 24-hour timeframe.