title: Antagonism of cisatracurium and rocuronium block at a tactile train-of-four count of 2: should quantitative assessment of neuromuscular function be mandatory?
abstract: With a train-of-four (TOF) ratio >0.70 as the standard of acceptable recovery, postoperative residual paralysis is a frequent occurrence in postanesthesia care units (PACUs). However, detailed information regarding prior anesthetic management is rarely provided. We examined the incidence of postoperative weakness after the administration of cisatracurium and rocuronium when using a rigid protocol for muscle relaxant and subsequent neostigmine administration. Under desflurane, N(2)O, and opioid anesthesia, tracheal intubation was accomplished after either cisatracurium 0.15 mg/kg or rocuronium 0.60 mg/kg. The response of the thumb to ulnar nerve stimulation was estimated by palpation. Additional increments of muscle relaxant were given as needed to maintain the TOF count at 1 or 2. At the conclusion of surgery, at a TOF count of 2, neostigmine 0.05 mg/kg plus glycopyrrolate 10 micro g/kg was administered. The mechanical TOF response was then measured with a force transducer starting 5 min postreversal. Patients were observed until a TOF ratio of 0.90 was achieved. There were no significant differences in the recovery profiles of cisatracurium versus rocuronium. TOF ratios at 10 min postreversal were 0.72 +/- 0.10 and 0.76 +/- 0.11, respectively. At 15 min postreversal, only one subject in each group had a TOF ratio of <0.70. No patient in either group arrived in the PACU with a TOF ratio <0.70. Our results suggest that if cisatracurium or rocuronium is administered by using the TOF count as a guide, critical episodes of postoperative weakness in the PACU should be an infrequent occurrence.
  
  
  CONCLUSIONS
  After the administration of cisatracurium or rocuronium, train-of-four (TOF) ratios <0.70 should rarely be observed in the postanesthesia care unit if neostigmine-assisted antagonism of residual block is delayed until the tactile TOF count at the thumb is 2 or more.
authors.affiliation: Department of Anesthesiology, New York Medical College, Valhalla, New York.
authors.forename: Aaron F
authors.initials: AF
authors.lastname: Kopman
authors.forename: Lee M
authors.initials: LM
authors.lastname: Zank
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ng
authors.forename: George G
authors.initials: GG
authors.lastname: Neuman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000732:Androstanols / Q000037:antagonists & inhibitors*; D000762:Anesthesia Recovery Period; D001279:Atracurium / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors*; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D004558:Electric Stimulation; D005260:Female; D006024:Glycopyrrolate / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000627:therapeutic use; D018908:Muscle Weakness / Q000139:chemically induced* / Q000503:physiopathology; D009388:Neostigmine / Q000627:therapeutic use; D003473:Neuromuscular Nondepolarizing Agents / Q000009:adverse effects*; D009474:Neurons / Q000187:drug effects*; D010147:Pain Measurement; D011183:Postoperative Complications / Q000517:prevention & control*; D000077123:Rocuronium; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D000732:Androstanols; D002800:Cholinesterase Inhibitors; D018727:Muscarinic Antagonists; D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D009388:Neostigmine; C101584:cisatracurium; D006024:Glycopyrrolate; D000077123:Rocuronium