Hemodynamically significant cardiac arrhythmias during general anesthesia for spine surgery: A case series and literature review

BACKGROUND CONTEXT: Hemodynamically significant bradycardia and cardiac arrest (CA) are rare under general anesthesia (GA) for spine surgery. Although patient risks are well defined, emerging data implicate surgical, anesthetic and neurologic factors which should be considered in the immediate management and decision to continue or terminate surgery. PURPOSE: To characterize causes and contributors to significant arrhythmias during spine surgery. We also provide an updated literature review to inform spine care teams and aid in the management of intraoperative bradycardia and CA. STUDY DESIGN: Case series and literature review PATIENT SAMPLE: Six patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia OUTCOME MEASURES: Our primary outcome was to identify potential risk factors of interest for significant arrhythmia during spine surgery. METHODS: Medical records of patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia during spine surgery were identified from a departmental Quality Assurance Database. We evaluated the presence/absence of patient, surgical, anesthetic and neurologic risk factors and estimated the most likely etiology of the event, immediate and subsequent management, whether surgery was postponed or continued and outcomes. RESULTS: We found a temporal relationship of bradyarrhythmia and CA after somatosensory evoked potential (SSEP) stimulation in 4/6 cases and pharmacy/polypharmacy in 2/6. Surgery was completed in 4/6 patients, and terminated in 2/6 (subsequently completed in both). We found no adverse outcomes in any patients. Our literature review predominately identified case reports for guidance to support decision making. New literaure suggests peripheral nerve blocks and opioid-sparing anesthetic agents should also be considered. CONCLUSIONS: Significant bradycardia and CA during spine surgery does not always require termination of the surgical procedure. Decision making should be undertaken in each case individually, with an updated awareness of potential causes. The study also suggests the need for large prospective studies to adequately assess incidence, risk factors and outcomes.