Regional Scalp Blockade for Painless Removal ofIntracranial Pressure Bolts: Technical Note and Patient-Reported Outcomes

Abstract

Elective insertion of intracranial pressure (ICP) monitoring bolts is useful for the diagnosis and treatment of disorders of cerebrospinal fluid dynamics. Patients typically report severe discomfort on bolt removal, which negatively impacts overall patient satisfaction of ICP monitoring. We assessed the efficacy and safety of using supratrochlear and supraorbital nerve block-a commonly used form of scalp anesthesia-alongside oral analgesia before bolt removal. We compared the efficacy and safety of regional scalp block anesthesia alongside oral analgesia versus oral analgesia alone in a cohort of 85 patients undergoing removal of diagnostic ICP bolts between June 2017 and April 2019 using retrospective patient questionnaires, as well as electronic admission documentation. We found that scalp block alongside oral analgesia improved bolt removal experience (4/5 vs. 3/5 on a 1-5 point Likert scale) and that a majority (70.6%) of patients would have preferred local anesthetic before removal in the oral analgesia-only group. Only 2 patients experienced mild and localized side effects: mild bruising and temporary facial and eyelid swelling following regional scalp block. We conclude that regional supraorbital and supratrochlear nerve block is a simple, safe, and effective adjunct to minimizing discomfort during bolt removal and improving overall patient satisfaction of ICP monitoring.