title: Comparison of train-of-four ratios measured with Datex-Ohmeda's M-NMT MechanoSensor™ and M-NMT ElectroSensor™.
abstract: Neuromuscular blockade is usually monitored using train-of-four (TOF) stimulation pattern. A TOF ratio of higher than 90 % is recommended to reduce the risk of adverse effects after anaesthesia. TOF ratio 90 % is used in clinical practice with all different neuromuscular monitors. Kinemyography (KMG) is one commercialized method to obtain numerical TOF values. We compared the KMG data obtained with Datex M-NMT MechanoSensor™ module, to the EMG data collected with Datex ElectroSensor™, during clinical anaesthesia. Ipsilateral comparisons of the sensors were performed in 20 female patients during clinical procedures in propofol-remifentanil anaesthesia. After initial bolus dose of rocuronium (0.6 mg/kg), the spontaneous recovery of TOF ratio and T1 % were monitored. KMG gave higher TOF values than EMG. The difference was significant at KMG TOF values of 40 % or higher. After anaesthetic induction, but before administration of rocuronium, both TOF sensor values drifted from the TOF value of 1.0, showing either significant spontaneous fade (T1 > T4) or tendency of reverse fade (T1 < T4). KMG overestimates the recovery from neuromuscular blockade when compared with EMG. KMG and EMG cannot be used interchangeably, and TOF ratio 90 % cannot be considered as adequate level of recovery with all monitoring devices.
authors.affiliation: Department of Anaesthesiology, Medical School, University of Tampere, 33014, Tampere, Finland. salminen.jarno.o@student.uta.fi.
authors.forename: Jarno
authors.initials: J
authors.lastname: Salminen
authors.affiliation: VTT Technical Research Centre of Finland, Tampere, Finland.
authors.forename: Mark
authors.initials: M
authors.lastname: van Gils
authors.affiliation: Department of Anaesthesia, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Paloheimo
authors.affiliation: Department of Anaesthesiology, Medical School, University of Tampere, 33014, Tampere, Finland.|Department of Anaesthesia, Tampere University Hospital, Tampere, Finland.
authors.forename: Arvi
authors.initials: A
authors.lastname: Yli-Hankala
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D001696:Biomechanical Phenomena; D004558:Electric Stimulation; D004576:Electromyography / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation* / Q000706:statistics & numerical data; D019148:Neuromuscular Blockade; D055815:Young Adult
keywords: EMG; Electromyography; KMG; Kinemyography; M-NMT MechanoSensor™; Neuromuscular monitoring