Abstract
STUDY OBJECTIVE: Anesthesiologists at our hospital commonly administer spinal anesthesia for routine lumbar spine surgeries. Anecdotal impressions suggested that patients received fewer anesthesia-administered intravenous medications, including vasopressors, during spinal versus general anesthesia. We hypothesized that data review would confirm these impressions. The objective was to test this hypothesis by comparing specific elements of spinal versus general anesthesia for 1-2 level open lumbar spine procedures. DESIGN: Retrospective single institutional study. SETTING: Academic medical center, operating rooms. PATIENTS: Consecutive patients (144 spinal and 619 general anesthesia) identified by automatic structured query of our electronic anesthesia record undergoing lumbar decompression, foraminotomy or microdiscectomy by one surgeon under general or spinal anesthesia. INTERVENTIONS: Spinal or general anesthesia. MEASUREMENTS: Numbers of medications administered during the case. MAIN RESULTS: Anesthesiologists administered in the operating room a total of 10 ± 2 intravenous medications for general anesthetics and 5 ± 2 medications for spinal anesthetics (-5, 95% CI -5 to -4, p<0.001, univariate analysis). Multivariable analysis supported this finding (spinal versus general anesthesia: -4, 95% CI -5 to -4, p<0.001). Spinal anesthesia patients were less likely to receive ephedrine, or phenylephrine (by bolus or by infusion) (all p<0.001, Chi-squared test). Spinal anesthesia patients were also less likely to receive labetolol or esmolol (both p = 0.002, Fishers' Exact test). No neurologic injuries were attributed to, or masked by, spinal anesthesia. Three spinal anesthetics failed. CONCLUSIONS: For routine lumbar surgery in our cohort, spinal compared to general anesthesia was associated with significantly fewer drugs administered during a case and less frequent use of vasoactive agents. Safety implications include greater hemodynamic stability with spinal anesthesia along with reduced risks for medication error and transmission of pathogens associated with medication administration.