Systematic Review and Meta-Analysis of Randomized Controlled Trials for Scalp Block in Craniotomy

Abstract

BACKGROUND: Scalp block is regional anesthetic injection along nerves innervating the cranium. Scalp blocks for craniotomy may decrease postoperative pain and opioid consumption. Benefits may extend beyond the anesthetic period. OBJECTIVE:To analyze evidence for scalp block on postoperative pain and opioid use. METHODS: This systematic review and meta-analysis, Prospective Register of Systematic Reviews registration (CRD42022308048), included Ovid Medical Literature Analysis and Retrieval System Online, Embase, and Cochrane Central Register of Controlled Trials inception through February 9, 2022. Only randomized controlled trials were included. We excluded studies not reporting either main outcome. Duplicate reviewers performed study selection, risk of bias assessment, data extraction, and evidence certainty Grading of Recommendations Assessment, Development, and Evaluation appraisal. Main outcomes were postoperative pain by visual analog scale within 72 hours and opioid consumption as morphine milligram equivalent (MME) within 48 hours. RESULTS: Screening filtered 955 studies to 23 trials containing 1532 patients. Risk of bias was overall low. Scalp block reduced postoperative pain at 2 through 72 hours, visual analog scale mean differences of 0.79 to 1.40. Opioid requirements were reduced at 24 hours by 16.52 MME and 48 hours by 15.63 MME. CONCLUSION: Scalp block reduces postoperative pain at 2 through 48 hours and may reduce pain at 72 hours. Scalp block likely reduces opioid consumption within 24 hours and may reduce opioid consumption to 48 hours. The clinical utility of these differences should be interpreted within the context of modest absolute reductions, overall care optimization, and patient populations. This is the first level 1A evidence to evaluate scalp block efficacy in craniotomy.

Regional anesthesia for head and neck neurosurgical procedures: a narrative review in adult and pediatric patients

“…Additional benefits of scalp blocks and wound/pin site infiltration showed by Akcil et al, 8 in a randomized trial of patients undergoing infratentorial craniotomy, included reduced cumulative morphine consumption and early postoperative pain scores compared with no intervention. Indeed, meta-analyses have consistently corroborated findings of superior early postoperative pain control in patients receiving scalp blocks 5,9,10 . Published studies suggest scalp blocks may be superior to scalp infiltration 11–13 …”

“…However, the overall incidence of complications directly related to scalp blocks is vanishingly low. In a recent meta-analysis of 22 randomized control trials in 1550 patients on scalp blocks in craniotomy, none of the included studies reported any adverse events attributable to scalp blocks, even though blocks were performed using anatomic landmarks and various LA concentrations, additives, and volumes 9 …”

“…Indeed, meta-analyses have consistently corroborated findings of superior early postoperative pain control in patients receiving scalp blocks. 5,9,10 Published studies suggest scalp blocks may be superior to scalp infiltration. [11][12][13] Scalp blocks for awake craniotomy Scalp blocks can serve as the base of the anesthetic plan for awake neurosurgical procedures, creating tolerable conditions critical for surgical success.…”

“…In a recent meta-analysis of 22 randomized control trials in 1550 patients on scalp blocks in craniotomy, none of the included studies reported any adverse events attributable to scalp blocks, even though blocks were performed using anatomic landmarks and various LA concentrations, additives, and volumes. 9 The cumulative volume or dose of LA used may raise concerns for LA systemic toxicity. In a prospective trial evaluating the efficacy and safety of a lidocaine-ropivacaine-epinephrine mixture for scalp blocks, 53 study participants received, on average, more than 7 mg/kg of lidocaine and more than 2 mg/kg of ropivacaine.…”