Kaur P, et al. - This study compared the effectiveness as well as of side effect profile of clonidine with that of magnesium sulfate (MgSO₄) when used as an adjunct to lignocaine in intravenous regional anesthesia (IVRA) for postoperative analgesia. As an adjunct to lignocaine in IVRA, MgSO₄ versus clonidine provided better postoperative analgesia with fewer side effects.

Methods

• This prospective double-blind randomized controlled study was conducted in a tertiary care institute and included forty adult patients.
• Researchers assigned patients into 2 groups; Group 1 (n = 20) received 3 mg/kg of 2% lignocaine + 50% MgSO₄ 1.5 g diluted with normal saline to 40 ml, while Group 2 (n = 20) received 3 mg/kg of 2% lignocaine + clonidine 150 μg diluted with normal saline to 40 ml.
• They compared pain score, time to first rescue analgesic (TTFA), total number of rescue analgesics required, and the side effects of the two drugs for 24 h postoperatively.

Results

• Findings demonstrated that the mean TTFA was significantly longer in Group 1 (193.9 ± 38.4 min) than in Group 2 (169.5 ± 33.3 min); P <0.05.
• Researchers found that the mean number of rescue analgesics required was 1.6 ± 0.7 in Group 1 as compared to 2.1 ± 0.8 in Group 2 (P < 0.05).
• They also noted more serious side effects such as hypotension and bradycardia with clonidine, although all patients experienced transient pain during intravenous injection of MgSO₄.