Trans-nasal sphenopalatine ganglion block for post-dural puncture headache management: a meta-analysis of randomized trials

Abstract Objective: To evaluate the efficacy and safety of trans-nasal Sphenopalatine Ganglion (SPG) block over other treatments for Post-Dural Puncture Headache (PDPH) management. Methods: A systematic literature search was conducted on databases for Randomized Controlled Trials (RCTs) comparing trans-nasal SPG blockade for the management of PDPH over other treatment modalities. All outcomes were pooled using the Mantel-Haenszel method and random effect model. Analyses of all outcomes were performed as a subgroup based on the type of control interventions (conservative, intranasal lignocaine puffs, sham, and Greater Occipital Nerve [GON] block). The quality of evidence was assessed using the GRADE approach. Results: After screening 1748 relevant articles, 9 RCTs comparing SPG block with other interventions (6 conservative treatments, 1 sham, 1 GON and 1 intranasal lidocaine puff) were included in this meta-analysis. SPG block demonstrated superiority over conservative treatment in pain reduction at 30 min, 1 h, 2 h, 4 h after interventions and treatment failures with "very low" to "moderate" quality of evidence. The SPG block failed to demonstrate superiority over conservative treatment in pain reduction beyond 6 h, need for rescue treatment, and adverse events. SPG block demonstrated superiority over intranasal lignocaine puff in pain reduction at 30 min, 1 h, 6 h, and 24 h after interventions. SPG block did not show superiority or equivalence in all efficacy and safety outcomes as compared to sham and GON block. Conclusion: Very Low to moderate quality evidence suggests the superiority of SPG block over conservative treatment and lignocaine puff for short-term pain relief from PDPH. PROSPERO Registration: CRD42021291707.

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

Abstract 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.