title: The risk of passive regurgitation during general anaesthesia in a population of referred dogs in the UK.
abstract: OBJECTIVE
  To evaluate the risk of passive regurgitation during anaesthesia, and to identify major factors associated with this in dogs attending the Queen Mother Hospital for Animals (QMHA), the Royal Veterinary College.
  
  
  METHODS
  A case-control study nested within the cohort of dogs undergoing anaesthesia with inhalation agents.
  
  
  METHODS
  All dogs undergoing general anaesthesia at the referral hospital between October 2006 and September 2008 (4271 cases).
  
  
  METHODS
  All dogs anaesthetized at the QMHA during the study period were included. Regurgitating cases were defined as dogs for which reflux material was observed at the external nares or in the mouth, either during anaesthesia or before return to normal consciousness immediately after general anaesthesia. The risk of regurgitation was estimated and risk factors for regurgitation were evaluated with multivariable logistic regression (p < 0.05).
  
  
  RESULTS
  The overall risk of regurgitation was 0.96% (41 cases out of 4271 anaesthetics, 95% confidence interval [95% CI] 0.67-1.25%). Exclusion of animals where pre-existing disease was considered a contributing factor to regurgitation (n = 14) resulted in a risk of passive regurgitation of 0.63% (27 cases of 4257 anaesthetics, 95% CI 0.40-0.87%). In the multivariable logistic regression model, procedure and patient weight were significantly associated with regurgitation. Dogs undergoing orthopaedic surgery were 26.7 times more likely to regurgitate compared to dogs undergoing only diagnostic procedures. Dogs weighing more than 40 kg were approximately five times more likely to regurgitate than those weighing <20 kg.
  
  
  CONCLUSIONS
  This study highlights the rare but important occurrence of perioperative regurgitation and identifies that dogs undergoing orthopaedic procedures, and those weighing more than 40 kg, are particularly at risk. Further work is required to evaluate the reasons for these observations.
authors.affiliation: Department of Veterinary Clinical Sciences, Royal Veterinary College, North Mymms, UK.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Lamata
authors.forename: Verity
authors.initials: V
authors.lastname: Loughton
authors.forename: Monie
authors.initials: M
authors.lastname: Jones
authors.forename: Hatim
authors.initials: H
authors.lastname: Alibhai
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Armitage-Chan
authors.forename: Karen
authors.initials: K
authors.lastname: Walsh
authors.forename: David
authors.initials: D
authors.lastname: Brodbelt
mesh_terms: D000768:Anesthesia, General / Q000009:adverse effects / Q000662:veterinary*; D000769:Anesthesia, Inhalation / Q000009:adverse effects / Q000662:veterinary; D000818:Animals; D016022:Case-Control Studies; D004283:Dog Diseases / Q000453:epidemiology / Q000209:etiology*; D004285:Dogs; D007431:Intraoperative Complications / Q000453:epidemiology / Q000662:veterinary*; D016015:Logistic Models; D015999:Multivariate Analysis; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology; D014839:Vomiting / Q000453:epidemiology / Q000209:etiology / Q000662:veterinary*