The efficacy and safety of ankle blocks for foot and ankle surgery: A systematic review with meta-analysis and trial sequential analysis.

BACKGROUND: Peripheral nerve blocks may be essential elements in a multimodal pain management regime following foot and ankle surgery. We assessed the effects of ankle blocks compared with no intervention/sham block or a sciatic nerve block in patients undergoing surgery of the foot or ankle. METHODS: We searched CENTRAL, Medline, and Embase for randomised clinical trials comparing ankle block with no intervention/sham block or a sciatic nerve block for patients undergoing surgery of the foot or ankle. Our primary outcomes were duration of analgesia and cumulative 24-hour opioid consumption. We followed the recommendations of the Cochrane Handbook, and performed meta-analysis, Trial Sequential Analysis (TSA), and assessed the risk of bias and certainty of the evidence using the GRADE approach. RESULTS: We included five trials (362 participants) comparing ankle block with no intervention/sham block and three trials (247 participants) comparing ankle block with a sciatic nerve block. Ankle block may increase the duration of analgesia when compared with no intervention/sham block (MD 431 min; 96.7% CI 208 to 654), but the evidence was very uncertain. Duration was decreased when compared with a sciatic nerve block (MD -410 min; 96.7% CI -462 to -358). The ankle block duration was probably important in both comparisons. The effects on cumulative 24-hour opioid consumption were very uncertain in both comparisons. CONCLUSIONS: Ankle block may increase the duration of analgesia when compared with no intervention/sham block, but the evidence was very uncertain, and decrease the duration of analgesia when compared with a sciatic nerve block. The ankle block duration was probably clinically important in both comparisons. The effects on cumulative 24-hour opioid consumption were very uncertain.

Combined Dexamethasone and Dexmedetomidine as Adjuncts to Popliteal and Saphenous Nerve Blocks in Patients Undergoing Surgery of the Foot or Ankle: A Randomized, Blinded, Placebo-controlled Clinical Trial.

BACKGROUND: Both dexamethasone and dexmedetomidine increase the duration of analgesia of peripheral nerve blocks. The authors hypothesized that combined intravenous dexamethasone and intravenous dexmedetomidine would result in a greater duration of analgesia when compared with intravenous dexamethasone alone and placebo. METHODS: The authors randomly allocated participants undergoing surgery of the foot or ankle under general anesthesia and with a combined popliteal (sciatic) and saphenous nerve block to a combination of 12 mg dexamethasone and 1 µg/kg dexmedetomidine, 12 mg dexamethasone, or placebo (saline). The primary outcome was the duration of analgesia measured as the time from block performance until the first sensation of pain in the surgical area as reported by the participant. The authors predefined a 33% difference in the duration of analgesia as clinically relevant. RESULTS: A total of 120 participants from two centers were randomized and 119 analyzed for the primary outcome. The median [interquartile range] duration of analgesia was 1,572 min [1,259 to 1,715] with combined dexamethasone and dexmedetomidine, 1,400 min [1,133 to 1,750] with dexamethasone alone, and 870 min [748 to 1,138] with placebo. Compared with placebo, the duration was greater with combined dexamethasone and dexmedetomidine (difference, 564 min; 98.33% CI, 301 to 794; P < 0.001) and with dexamethasone (difference, 489 min; 98.33% CI, 265 to 706; P < 0.001). The prolongations exceeded the authors' predefined clinically relevant difference. The duration was similar when combined dexamethasone and dexmedetomidine was compared with dexamethasone alone (difference, 61 min; 98.33% CI, -222 to 331; P = 0.614). CONCLUSIONS: Dexamethasone with or without dexmedetomidine increased the duration of analgesia in patients undergoing surgery of the foot or ankle with a popliteal (sciatic) and saphenous nerve block. Combined dexamethasone and dexmedetomidine did not increase the duration of analgesia when compared with dexamethasone.