title: Recovery from rocuronium-induced neuromuscular block was longer in the larynx than in the pelvic limb of anesthetized dogs.
abstract: OBJECTIVE
  To determine if neuromuscular monitoring at the pelvic limb accurately reflects neuromuscular function in the larynx after administration of rocuronium in anesthetized dogs.
  
  
  METHODS
  Prospective experimental study.
  
  
  METHODS
  Six healthy Beagle dogs.
  
  
  METHODS
  Anesthesia was maintained in dogs with isoflurane and a continuous infusion of dexmedetomidine. Rocuronium (0.6 mg kg-1) was administered intravenously to induce neuromuscular block. Train-of-four (TOF) impulses were applied to the left recurrent laryngeal nerve (RLn) and the peroneal nerve (Pn). The evoked TOF ratio (TOFR; T4:T1) was measured with electromyography (EMG) simultaneously at the larynx and at the pelvic limb. Spontaneous recoveries of T1 to 25% (T125%) and 75% (T175%) of twitch height, and to TOFR of 0.70 and 0.90 (TOFR0.90) at each EMG site were compared.
  
  
  RESULTS
  Data from five dogs were analyzed. Times to T125%were similar at the pelvic limb and larynx when measured by EMG; time to T175%was slower at the larynx by 6±4 minutes (p=0.012). The larynx had a slower recovery to TOFR0.70(41±13 minutes) and TOFR0.90(45±13 minutes) than did the pelvic limb [29±8 minutes (p=0.011) and 33±9 minutes (p=0.003), respectively]. When the pelvic limb EMG returned to TOFR0.70and TOFR0.90, the larynx EMG TOFR0.70and TOFR0.90values were 0.32±0.12 (p=0.001) and 0.38±0.13 (p=0.001), respectively.
  
  
  CONCLUSIONS
  After administration of rocuronium, neuromuscular function assessed by EMG recovered approximately 36% slower at the larynx than at the pelvic limb. The results in these dogs suggest that quantitative neuromuscular monitoring instrumented at a pelvic limb may be unable to exclude residual block at the larynx in anesthetized dogs.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sakai
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA. Electronic address: mm459@cornell.edu.
authors.forename: Manuel
authors.initials: M
authors.lastname: Martin-Flores
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Marta
authors.initials: M
authors.lastname: Romano
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Chia T
authors.initials: CT
authors.lastname: Tseng
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Luis
authors.initials: L
authors.lastname: Campoy
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Robin D
authors.initials: RD
authors.lastname: Gleed
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Cheetham
mesh_terms: D000732:Androstanols; D000818:Animals; D004285:Dogs; D007830:Larynx / Q000187:drug effects* / Q000502:physiology; D019148:Neuromuscular Blockade / Q000379:methods / Q000662:veterinary*; D003473:Neuromuscular Nondepolarizing Agents; D010388:Pelvis / Q000294:innervation; D011446:Prospective Studies; D000077123:Rocuronium; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology
chemical_list: D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium
keywords: airway obstruction; aspiration; complication; monitoring; residual paralysis