title: Early and late parameters describing the offset of neuromuscular blockade are highly intercorrelated.
abstract: BACKGROUND
  Neuromuscular blocking agents have always shown wide inter-individual variability when it comes to their duration of action. This prevents clinicians from anticipating the evolution of the neuromuscular block for any given patient. With this study, we aimed to assess the nature of the relationships existing between different time course parameters used to describe paralysis onset and offset.
  
  
  METHODS
  Sixty American Society of Anesthesiologists (ASA) score III-IV anaesthetised patients were randomised to receive a single equipotent dose (2ED95) of either rocuronium, mivacurium or atracurium. We used acceleromyography to monitor neuromuscular transmission. We described the relationships between the time-interval measurements of: onset, the first response (T1) reappearance, T1 25% of control, train-of-four ratio 0.25 and 0.75. Pearson correlation coefficients were calculated.
  
  
  RESULTS
  We found no significant relationships between onset and any of the four parameters used to describe the offset. On the other hand, we showed strong and highly significant linear relationships between all the parameters describing the offset for each of the muscle relaxants studied (correlation coefficients ranging from 0.850 to 0.992).
  
  
  CONCLUSIONS
  We evidenced strong linear correlations between the four offset time course parameters of spontaneous recovery after a single neuromuscular blocking agents (NMBAs) bolus. Such relationships open up new clinical perspectives concerning quantitative neuromuscular transmission monitoring: the scope of individual valuable anticipation of the patient's recovery.
authors.affiliation: Department of Anaesthesiology, University of Louvain, CHU Mont-Godinne, Yvoir, Belgium. phil.dubois@uclouvain.be
authors.forename: P E
authors.initials: PE
authors.lastname: Dubois
authors.forename: M
authors.initials: M
authors.lastname: Gourdin
authors.forename: J
authors.initials: J
authors.lastname: Jamart
authors.forename: S M
authors.initials: SM
authors.lastname: Broka
authors.forename: P
authors.initials: P
authors.lastname: Eucher
authors.forename: A
authors.initials: A
authors.lastname: D'Hollander
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000732:Androstanols; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General; D001279:Atracurium; D002138:Calibration; D001026:Coronary Artery Bypass; D004576:Electromyography; D005260:Female; D006801:Humans; D007546:Isoquinolines; D007674:Kidney Diseases / Q000150:complications; D008107:Liver Diseases / Q000150:complications; D008297:Male; D008875:Middle Aged; D000077590:Mivacurium; D016343:Monitoring, Intraoperative; D019148:Neuromuscular Blockade / Q000592:standards*; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000732:Androstanols; D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D000077590:Mivacurium; D000077123:Rocuronium