Control of muscle relaxation during anesthesia: a novel approach for clinical routine.
During general anesthesia drugs are administered to provide hypnosis, ensure analgesia, and skeletal muscle relaxation. In this paper, the main components of a newly developed controller for skeletal muscle relaxation are described. Muscle relaxation is controlled by administration of neuromuscular blocking agents. The degree of relaxation is assessed by supramaximal train-of-four stimulation of the ulnar nerve and measuring the electromyogram response of the adductor pollicis muscle. For closed-loop control purposes, a physiologically based pharmacokinetic and pharmacodynamic model of the neuromuscular blocking agent mivacurium is derived. The model is used to design an observer-based state feedback controller. Contrary to similar automatic systems described in the literature this controller makes use of two different measures obtained in the train-of-four measurement to maintain the desired level of relaxation. The controller is validated in a clinical study comparing the performance of the controller to the performance of the anesthesiologist. As presented, the controller was able to maintain a preselected degree of muscle relaxation with excellent precision while minimizing drug administration. The controller performed at least equally well as the anesthesiologist.
Automatic Control Laboratory, Swiss Federal Institute of Technology (ETH), Physikstrasse 3. CH-8092 Zurich, Switzerland. kss@ieee.org
Konrad S
KS
Stadler
Peter M
PM
Schumacher
Sibylle
S
Hirter
Daniel
D
Leibundgut
Thomas W
TW
Bouillon
Adolf H
AH
Glattfelder
Alex M
AM
Zbinden
D018681:Anesthetics, General / Q000008:administration & dosage*; D003198:Computer Simulation; D004338:Drug Combinations; D004360:Drug Therapy, Computer-Assisted / Q000379:methods*; D006801:Humans; D008954:Models, Biological; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology*; D009126:Muscle Relaxation / Q000187:drug effects* / Q000502:physiology*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology; D009465:Neuromuscular Agents / Q000008:administration & dosage*
D018681:Anesthetics, General; D004338:Drug Combinations; D009465:Neuromuscular Agents