Effect of local anesthesia with lidocaine on perioperative proinflammatory cytokine levels in plasma and cerebrospinal fluid in cerebral aneurysm patients: Study protocol for a randomized clinical trial

BACKGROUND: Cerebral aneurysm surgery has significant mortality and morbidity rate. Inflammation plays a key role in the pathogenesis of intracranial aneurysms, their rupture, subarachnoid hemorrhage and neurologic complications. Proinflammatory cytokine level in blood and cerebrospinal fluid (CSF) is an indicator of inflammatory response. Cytokines contribute to secondary brain injury and can worsen the outcome of the treatment. Lidocaine is local anesthetic that can be applied in neurosurgery as regional anesthesia of the scalp and as topical anesthesia of the throat before direct laryngoscopy and endotracheal intubation. Besides analgesic, lidocaine has systemic anti-inflammatory and neuroprotective effect. Primary aim of this trial is to determine the influence of local anesthesia with lidocaine on the perioperative levels of pro-inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α in plasma and CSF in cerebral aneurysm patients. METHODS: We will conduct prospective randomized clinical trial among patients undergoing craniotomy and cerebral aneurysm clipping surgery in general anesthesia. Patients included in the trial will be randomly assigned to the lidocaine group (Group L) or to the control group (Group C). Patients in Group L, following general anesthesia induction, will receive topical anesthesia of the throat before endotracheal intubation and also regional anesthesia of the scalp before Mayfield frame placement, both done with lidocaine. Patients in Group C will have general anesthesia only without any lidocaine administration. The primary outcomes are concentrations of cytokines interleukin-1β, interleukin-6 and tumor necrosis factor-α in plasma and CSF, measured at specific timepoints perioperatively. Secondary outcome is incidence of major neurological and infectious complications, as well as treatment outcome in both groups. DISCUSSION: Results of the trial could provide insight into influence of lidocaine on local and systemic inflammatory response in cerebrovascular surgery, and might improve future anesthesia practice and treatment outcome. TRIAL IS REGISTERED AT CLINICALTRIALS.GOV: NCT03823482.