Michael K Urban1, Kara Fields2, Sean W Donegan3, Jonathan C Beathe1, David W Pinter4, Oheneba Boachie-Adjei5, Ronald G Emerson6. 1. Healthcare Research Institute, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA; Department of Anesthesia, Weill Cornell Medical College, 1305 York Ave, New York, NY 10021, USA. 2. Healthcare Research Institute, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA. 3. Orthopedics, The Foundation of Orthopedics and Complex Spine (FOCOS), 226 East 54th Street, Suite 306, New York, NY 10022, USA. 4. Department of Neurology, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA. 5. Orthopedics, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA; Orthopedics, The Foundation of Orthopedics and Complex Spine (FOCOS), 226 East 54th Street, Suite 306, New York, NY 10022, USA. 6. Healthcare Research Institute, Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA; Department of Neurology, Weill Cornell Medical College, 1305 York Ave, New York, NY 10021, USA. Electronic address: emersonr@hss.edu.
Abstract
BACKGROUND CONTEXT: Lidocaine has emerged as a useful adjuvant anesthetic agent for cases requiring intraoperative monitoring of motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SSEPs). A previous retrospective study suggested that lidocaine could be used as a component of propofol-based intravenous anesthesia without adversely affecting MEP or SSEP monitoring, but did not address the effect of the addition of lidocaine on the MEP and SSEP signals of individual patients. PURPOSE: The purpose of this study was to examine the intrapatient effects of the addition of lidocaine to balanced anesthesia on MEPs and SSEPs during multilevel posterior spinal fusion. STUDY DESIGN: This is a prospective, two-treatment, two-period crossover randomized controlled trial with a blinded primary outcome assessment. PATIENT SAMPLE: Forty patients undergoing multilevel posterior spinal fusion were studied. OUTCOME MEASURES: The primary outcome measures were MEP voltage thresholds and SSEP amplitudes. Secondary outcome measures included isoflurane concentrations and hemodynamic parameters. METHODS: Each participant received two anesthetic treatments (propofol 50 mcg/kg/h and propofol 25 mcg/kg/h+lidocaine 1 mg/kg/h) along with isoflurane, ketamine, and diazepam. In this manner, each patient served as his or her own control. The order of administration of the two treatments was determined randomly. RESULTS: There were no significant within-patient differences between MEP threshold voltages or SSEP amplitudes during the two anesthetic treatments. CONCLUSIONS:Lidocaine may be used as a component of balanced anesthesia during multilevel spinal fusions without adversely affecting the monitoring of SSEPs or MEPs in individual patients.
RCT Entities:
BACKGROUND CONTEXT: Lidocaine has emerged as a useful adjuvant anesthetic agent for cases requiring intraoperative monitoring of motor-evoked potentials (MEPs) and somatosensory-evoked potentials (SSEPs). A previous retrospective study suggested that lidocaine could be used as a component of propofol-based intravenous anesthesia without adversely affecting MEP or SSEP monitoring, but did not address the effect of the addition of lidocaine on the MEP and SSEP signals of individual patients. PURPOSE: The purpose of this study was to examine the intrapatient effects of the addition of lidocaine to balanced anesthesia on MEPs and SSEPs during multilevel posterior spinal fusion. STUDY DESIGN: This is a prospective, two-treatment, two-period crossover randomized controlled trial with a blinded primary outcome assessment. PATIENT SAMPLE: Forty patients undergoing multilevel posterior spinal fusion were studied. OUTCOME MEASURES: The primary outcome measures were MEP voltage thresholds and SSEP amplitudes. Secondary outcome measures included isoflurane concentrations and hemodynamic parameters. METHODS: Each participant received two anesthetic treatments (propofol 50 mcg/kg/h and propofol 25 mcg/kg/h+lidocaine 1 mg/kg/h) along with isoflurane, ketamine, and diazepam. In this manner, each patient served as his or her own control. The order of administration of the two treatments was determined randomly. RESULTS: There were no significant within-patient differences between MEP threshold voltages or SSEP amplitudes during the two anesthetic treatments. CONCLUSIONS:Lidocaine may be used as a component of balanced anesthesia during multilevel spinal fusions without adversely affecting the monitoring of SSEPs or MEPs in individual patients.