title: A computer-controlled, closed-loop infusion system for infusing muscle relaxants: its use during motor-evoked potential monitoring.
abstract: A microcomputer-controlled closed-loop infusion system (MCCLIS) has been developed that provides stable intraoperative levels of partial neuromuscular blockade. Complete neuromuscular blockade interferes with intraoperative motor-evoked potential (MEP) monitoring used for patients undergoing surgical procedures that place them at risk for spinal cord ischemia. Nine patients were studied during which the MCCLIS maintained stable levels of partial neuromuscular blockade and allowed transcranial magnetic motor-evoked potential (TcM-MEP) monitoring during thoracoabdominal aortic aneurysmectomy. The use of TcM-MEP for monitoring intraoperative spinal cord function was balanced against surgical considerations for muscle relaxation with 80% to 90% neuromuscular blockade fulfilling each requirement. Intraoperative adjustment of partial neuromuscular blockade to facilitate TcM-MEP monitoring was also possible with the MCCLIS. The MCCLIS should allow for further investigation into the sensitivity, specificity, and predictability of TcM-MEP monitoring for any patient at risk for intraoperative spinal cord ischemia including those undergoing thoracoabdominal aortic aneurysmectomy.
authors.affiliation: Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905.
authors.forename: L W
authors.initials: LW
authors.lastname: Stinson
authors.forename: M J
authors.initials: MJ
authors.lastname: Murray
authors.forename: K A
authors.initials: KA
authors.lastname: Jones
authors.forename: S J
authors.initials: SJ
authors.lastname: Assef
authors.forename: M J
authors.initials: MJ
authors.lastname: Burke
authors.forename: T L
authors.initials: TL
authors.lastname: Behrens
authors.forename: R L
authors.initials: RL
authors.lastname: Lennon
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000368:Aged; D000771:Anesthesia, Intravenous; D001011:Aorta / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000601:surgery*; D001279:Atracurium / Q000008:administration & dosage*; D003250:Constriction; D004576:Electromyography; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D007260:Infusion Pumps; D007866:Leg / Q000294:innervation; D008838:Microcomputers; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation; D009044:Motor Cortex / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D009466:Neuromuscular Blocking Agents / Q000008:administration & dosage*; D010525:Peripheral Nerves / Q000502:physiology; D014459:Ulnar Nerve / Q000502:physiology; D014673:Vecuronium Bromide / Q000008:administration & dosage*
chemical_list: D009466:Neuromuscular Blocking Agents; D001279:Atracurium; D014673:Vecuronium Bromide