Dexmedetomidine versus clonidine as an adjuvant to local anaesthetic in brachial plexus blocks: a meta-analysis of randomised controlled trials

OBJECTIVE

This meta-analysis aimed to compare the efficacy and safety of dexmedetomidine and clonidine as an adjuvant to local anesthetics in BPBs.

METHODS

Two investigators independently searched databases to identify all RCTs comparing the efficacy and/or safety of dexmedetomidine and clonidine as an adjuvant to local anesthetics in BPBs. All outcomes were pooled using the inverse variance method with a random-effect model. An I2 test was used to assess heterogeneity. The source of heterogeneity was explored through meta-regression. The quality of the evidence was assessed using the GRADE approach.

RESULTS

Out of 123 full texts assessed, 24 studies (1448 patients) were included in the analysis. As compared to clonidine, dexmedetomidine groups showed significantly longer sensory block duration (MD = 173.31; 95% CI 138.02‒208.59; I2 = 99%; GRADE approach evidence: high); motor block duration (MD = 158.35; 95% CI 131.55‒185.16; I2 = 98%; GRADE approach evidence: high), duration of analgesia (MD = 203.92; 95% CI 169.25‒238.58; I2 = 99%; GRADE approach evidence- high), and provided higher grade quality of block (RR = 1.97; 95% CI 1.60‒2.41; I2 = 0%; GRADE approach evidence: moderate). The block positioning technique (regression coefficient: 51.45, p = 0.005) was observed as a significant predictor of the heterogeneity in the case of sensory block duration. No significant difference was observed for the risk of hypotension (RR = 2.59; 95% CI 0.63‒10.66; I2 = %).

CONCLUSION

Moderate to high-quality evidence suggests dexmedetomidine is a more efficacious adjuvant to local anesthetic in BPBs than clonidine.

Can ultrasound-guided subcostal transverse abdominis plane block be used as sole anesthetic technique?

Subcostal transverse abdominis plane (TAP) block anesthetizes area of the abdomen with cutaneous innervation of T6–T10 dermatomes. These abdominal field blocks become very advantageous when cardiac patient presents for noncardiac surgeries as sole anesthetic or as a part of multimodal anesthesia. A 58-year-male came for open surgical repair of subxiphoid incisional hernia developed post coronary artery bypass grafting (CABG). Echocardiography showed hypokinesia of left ventricle (LV) in the left anterior descending (LAD) artery territory, dilated LV, and ejection fraction of 30%, and coronary angiography after 6 months of CABG showed 70% stenosis of LAD. Surgery was successfully accomplished under ultrasound-guided bilateral subcostal TAP block except for a brief period of pain and discomfort when hernia was being reduced which required narcotic supplementation. The patient remained comfortable throughout the procedure as well as 24 h postoperatively without any analgesic supplementation. Thus, subcostal TAP block can be a safe alternative to neuraxial or general anesthesia for epigastric hernia repair in selected patients.