title: Assessment of neuromuscular transmission by the evoked acceleration response. An evaluation of the accuracy of the acceleration transducer in comparison with a force displacement transducer.
abstract: This paper presents preliminary observations on an acceleration-responsive transducer designed to monitor neuromuscular transmission. Simultaneously evoked acceleration and tension responses of the adductor pollicis muscles were studied. Registrations were obtained during recovery from atracurium-induced block in 29 individuals in neurolept II anaesthesia (Group I) and in 4 ICU patients (Group II) sedated with pentobarbital or midazolam. Regression analysis of 1567 train-of-four (TOF) registrations, in regard to TOF-ratio (T4/T1) and first twitch ratio (T1/T0), demonstrated regression coefficients (b) and correlation coefficients (r) in the range 0.91-1.06 and 0.89-0.98, respectively. During 1 Hz single twitch stimulation and post-tetanic count stimulation, b and r were in the range 0.85-1.03 and 0.77-0.90, respectively. Following administration of edrophonium (n = 6, Group I) a deviation of T1/T0 regression values was observed in four individuals, i.e. 0.48 (b) and 0.56 (r). This investigation proved a good level of accuracy of the acceleration transducer compared to the force displacement transducer during spontaneous and neostigmine-induced recovery from atracurium block. The acceleration transducer-based system does not require a rigid suspension and seems to have a good monitoring potential in clinical assessment of neuromuscular transmission.
authors.affiliation: Department of Anaesthesia, Esbjerg Central Hospital, Denmark.
authors.forename: M U
authors.initials: MU
authors.lastname: Werner
authors.forename: H
authors.initials: H
authors.lastname: Kirkegaard Nielsen
authors.forename: O
authors.initials: O
authors.lastname: May
authors.forename: M
authors.initials: M
authors.lastname: Djernes
mesh_terms: D000328:Adult; D000368:Aged; D000762:Anesthesia Recovery Period; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009469:Neuromuscular Junction / Q000502:physiology*; D009435:Synaptic Transmission; D014159:Transducers