title: Under sevoflurane anaesthesia, a reduced dose of neostigmine can antagonize a shallow neuromuscular block: A double-blind, randomised study.
abstract: BACKGROUND
  It has been demonstrated that small doses of neostigmine (10-30μg.kg(-1)) effectively antagonize atracurium blocks at a train-of-four (TOF) ratio of 0.4 under propofol anaesthesia. The results might not be valid with halogenated agents, which potentiate neuromuscular blockades. The goal of this study was to determine the dose of neostigmine required to antagonize a block corresponding to a TOF ratio of 0.4, a level at which fade is not visually detected.
  
  
  METHODS
  Sixty patients were included and anaesthesia was induced with propofol, remifentanil and cisatracurium, and maintained with sevoflurane and remifentanil. Patients were randomized to receive neostigmine at 40, 20, 10μg.kg(-1) or placebo with atropine (20, 10, 5 or 0μg.kg(-1), respectively) as soon as the TOF ratio reached 0.4. Elapsed times to 0.9 and 1.0 TOF ratios were measured.
  
  
  RESULTS
  The median times elapsed from 0.4 to 0.9 and 1.0 TOF ratios in the placebo group were 19 (10.5-36) min and 26 (20-50) min, respectively, and significantly shorter (I=0.002) with any dose of neostigmine than without. Times for complete recovery after 40 and 20μg.kg(-1) neostigmine were similar [5.5 (4-11) min and 7.8 (3.5-11) min, respectively] but significantly shorter than after 10μg.kg(-1) neostigmine [17min (7-55); I=0.001].
  
  
  CONCLUSIONS
  Under sevoflurane anaesthesia, in absence of tactile or visual TOF fade, which corresponds to a TOF ratio≥0.4, 20μg.kg(-1) neostigmine is as effective as 40μg.kg(-1) in antagonizing shallow cisatracurium block.
authors.affiliation: Département d'anesthésie, centre hospitalier départemental de La Roche-sur-Yon, Les Oudairies, 85000 La Roche-sur-Yon, France.
authors.forename: Alice
authors.initials: A
authors.lastname: Preault
authors.affiliation: Clinique Jules-Verne, 2, route de Paris, 44300 Nantes, France. Electronic address: florent.capron@mla.fr.
authors.forename: Florent
authors.initials: F
authors.lastname: Capron
authors.affiliation: Unité de recherche clinique, centre hospitalier départemental de la Roche-sur-Yon, Les Oudairies, 85000 La Roche-sur-Yon, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Chantereau
authors.affiliation: Département d'anesthésie, hôpital Maisonneuve Rosemont, Montréal, Québec H1T, 2M4, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Donati
authors.affiliation: Unité de recherche clinique, centre hospitalier départemental de la Roche-sur-Yon, Les Oudairies, 85000 La Roche-sur-Yon, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Dimet
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D001279:Atracurium / Q000031:analogs & derivatives; D001285:Atropine / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers; D008875:Middle Aged; D009388:Neostigmine / Q000008:administration & dosage / Q000494:pharmacology*; D019148:Neuromuscular Blockade; D003473:Neuromuscular Nondepolarizing Agents; D010880:Piperidines; D015742:Propofol; D000077208:Remifentanil; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D002800:Cholinesterase Inhibitors; D008738:Methyl Ethers; D003473:Neuromuscular Nondepolarizing Agents; D010880:Piperidines; D001279:Atracurium; D000077149:Sevoflurane; D009388:Neostigmine; D001285:Atropine; D000077208:Remifentanil; C101584:cisatracurium; D015742:Propofol
keywords: Anaesthesia; Muscle relaxants