title: An acceleromyographic train-of-four ratio of 1.0 reliably excludes respiratory muscle weakness after major abdominal surgery: a randomized double-blind study.
abstract: OBJECTIVE
  This randomized double-blind study was designed to determine if respiratory muscle weakness - measured by maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), forced vital capacity (FVC), and forced expiratory volume in one second (FEV1) - persists even if an acceleromyographic train-of-four ratio (TOFR) of 1.0 is reached after major abdominal surgery.
  
  
  METHODS
  Twenty patients underwent respiratory function tests before induction of anesthesia. Rocuronium was given, and the tests were repeated after extubation when the TOFR reached 1.0. The patients were then randomized to receive sugammadex 1 mg·kg(-1) or placebo, and the same tests were repeated five and 20 min later. Between-group comparisons were carried out with a mixed-model analysis of variance analysis.
  
  
  RESULTS
  After anesthesia and adequate epidural analgesia, MIP and MEP decreased by 60% in both groups. In the placebo group, MIP decreased from a pre-induction value (median [range]) of 61.8 [31.3-96.1] to 19.6 [8.3-58.3] cm H2O after extubation without significant variation five and 20 min after placebo. In the sugammadex group, MIP decreased from a pre-induction value of 57.8 [13.0-96.4] to 20.5 [6.4-67.3] cm H2O after extubation. No differences were recorded after sugammadex administration (P = 0.246 between groups). In the placebo group, MEP decreased from 88.8 [65.1-120.3] before induction to 37.6 [13.4-70.6] cm H2O after extubation. In the sugammadex group, MEP decreased from 85.5 [58.6-132.7] to 30.8 [10.5-60.5] cm H2O, with no improvement five and 20 min after either placebo or sugammadex administration (P = 0.648). Similarly, the FCV and FEV1 decreased 30-40% after extubation in both study groups.
  
  
  CONCLUSIONS
  Acceleromyographic TOFR of 1.0 excludes residual neuromuscular paralysis. However, major respiratory dysfunction is observed after abdominal surgery. This trial was registered at ClinicalTrials.gov: NCT01503840.
authors.affiliation: Department of Anesthesia, Intensive Care and Palliative Care, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, Milan, 20133, Italy, federico.piccioni@istitutotumori.mi.it.
authors.forename: Federico
authors.initials: F
authors.lastname: Piccioni
authors.forename: Luigi
authors.initials: L
authors.lastname: Mariani
authors.forename: Lucia
authors.initials: L
authors.lastname: Bogno
authors.forename: Ilaria
authors.initials: I
authors.lastname: Rivetti
authors.forename: Giulia Teresa Agnese
authors.initials: GT
authors.lastname: Tramontano
authors.forename: Marco
authors.initials: M
authors.lastname: Carbonara
authors.forename: Mario
authors.initials: M
authors.lastname: Ammatuna
authors.forename: Martin
authors.initials: M
authors.lastname: Langer
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000328:Adult; D000368:Aged; D060666:Airway Extubation; D015360:Analgesia, Epidural / Q000379:methods; D000704:Analysis of Variance; D000732:Androstanols / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D009213:Myography / Q000379:methods; D019148:Neuromuscular Blockade / Q000009:adverse effects / Q000379:methods; D061886:Neuromuscular Monitoring / Q000379:methods; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage; D012129:Respiratory Function Tests; D012132:Respiratory Muscles / Q000503:physiopathology*; D000077123:Rocuronium; D000077122:Sugammadex; D014797:Vital Capacity; D047408:gamma-Cyclodextrins / Q000008:administration & dosage*
chemical_list: D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D047408:gamma-Cyclodextrins; D000077122:Sugammadex; D000077123:Rocuronium