title: Prevention of laryngospasm with rocuronium in cats: a dose-finding study.
abstract: OBJECTIVE
  To identify the dose of rocuronium that will prevent a laryngeal response to water spraying of the glottis in anesthetized cats.
  
  
  METHODS
  Randomized crossover study.
  
  
  METHODS
  Eight healthy, adult, short-haired cats, aged 1-4 years, weighing 3.2-6.0 kg.
  
  
  METHODS
  Each cat was anesthetized four times and administered one of four doses of rocuronium (0.1, 0.2, 0.3 and 0.6 mg kg(-1) ) in random order. The larynx was observed with a video-endoscope inserted through a laryngeal mask airway. Video-clips of the laryngeal response to a sterile water spray (0.2 mL) were obtained at baseline (without rocuronium) and at maximal effect of each treatment. Glottal closure score (0-2), duration of glottal closure, and number of adductive arytenoid movements were obtained from video-clips of laryngeal responses (reproduced in slow motion) at baseline and after treatment. Two observers blinded to treatment allocation scored the vigor of the laryngeal response on a visual analog scale (VAS). The duration of apnea (up to 5 minutes) was recorded for each treatment.
  
  
  RESULTS
  Compared with baseline, rocuronium 0.3 mg kg(-1) and 0.6 mg kg(-1) significantly decreased all glottal scores obtained from the videos (all p < 0.03). Both observers gave lower VAS scores after 0.3 mg kg(-1) (both p = 0.015). Apnea lasting ≥ 5 minutes occurred in none, one, three and seven of eight cats administered doses of rocuronium 0.1, 0.2, 0.3 and 0.6 mg kg(-1) , respectively.
  
  
  CONCLUSIONS
  Rocuronium 0.3 mg kg(-1) and 0.6 mg kg(-1) consistently decreased the completeness and duration of the laryngeal response to water spray, and reduced the number of arytenoid adductive movements in response to that stimulus. However, a laryngeal response was never completely prevented. Rocuronium 0.3 mg kg(-1) may be useful for facilitating tracheal intubation. Positive pressure ventilation must be available for cats administered rocuronium.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
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: Daniel M
authors.initials: DM
authors.lastname: Sakai
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Portela
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: Lucia
authors.initials: L
authors.lastname: Borlle
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
mesh_terms: D000732:Androstanols / Q000627:therapeutic use*; D000818:Animals; D001049:Apnea / Q000139:chemically induced; D002371:Cat Diseases / Q000517:prevention & control*; D002415:Cats; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D005931:Glottis; D007826:Laryngismus / Q000517:prevention & control / Q000662:veterinary*; D008297:Male; D003473:Neuromuscular Nondepolarizing Agents / Q000627:therapeutic use*; D010812:Physical Stimulation; D000077123:Rocuronium
chemical_list: D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium
keywords: acceleromyography; intubation; laryngospasm; neuromuscular block