Association between preoperative characteristics and risk of anaesthesia-related death in dogs in small-animal referral hospitals in Japan

Published:January 13, 2017DOI:



      To explore the major risk factors linking preoperative characteristics and anaesthesia-related death in dogs in referral hospitals in Japan.

      Study design

      Observational cohort study.


      From April 1, 2010 to March 31, 2011, 4323 dogs anaesthetized in 18 referral hospitals in Japan.


      Questionnaire forms were collated anonymously. Death occurring within 48 hours after extubation was considered as an anaesthesia-related death. Patient outcome (alive or dead) was set as the outcome variable. Preoperative general physical characteristics, complete blood cell counts, serum biochemical examinations and intraoperative complications were set as explanatory variables. The risk factors for anaesthesia-related death were evaluated using chi-square test or Fisher's exact test, followed by multivariable logistic regression analysis of the data. Significance was set at p < 0.05.


      Thirteen dogs that died from surgical error or euthanasia were excluded from statistical analysis. The total mortality rate in this study was 0.65% [28/4310 dogs; 95% confidence interval (CI), 0.41–0.89]. Furthermore, 75% (95% CI, 55.1–89.3) of anaesthesia-related deaths occurred in dogs with pre-existing diseases. Most of the deaths occurred postoperatively (23/28; 82.1%; 95% CI, 63.1–93.9). Preoperative serum glucose concentration <77 mg dL–1 (6/46; 13.0%; 95% CI, 4.9–26.3), disturbance of consciousness (6/50; 12.0%; 95% CI, 4.5–24.3), white cell count >15,200 μL–1 (16/499; 3.4%; 95% CI, 1.9–5.5) and American Society of Anesthesiologists grade III–V (19/1092; 1.7%; 95% CI, 1.1–2.7) were identified as risk factors for anaesthesia-related death. Intraoperative hypoxaemia (8/34; 23.5%; 95% CI, 10.7–41.2) and tachycardia (4/148; 2.7%; 95% CI, 0.7–6.8) were also risk factors for anaesthesia-related death.

      Conclusions and clinical relevance

      The results revealed that certain preoperative characteristics were associated with increased odds of anaesthesia-related death, specifically low serum glucose concentration and disturbances of consciousness. Greater attention to correcting preanaesthetic patient abnormalities may reduce the risk of anaesthesia-related death.


      To read this article in full you will need to make a payment


        • Alef M.
        • von Praun F.
        • Oechtering G.
        Is routine pre-anaesthetic haematological and biochemical screening justified in dogs?.
        Vet Anaesth Analg. 2008; 35: 132-140
        • Ament R.
        Origin of the ASA classification.
        Anesthesiology. 1979; 51: 179
        • Bagley R.S.
        Clinical examination of the animal with suspected neurologic disease.
        in: Fundamentals of Veterinary Clinical Neurology. Blackwell Publishing, USA2005: 57-107
        • Biboulet P.
        • Aubas P.
        • Dubourdieu J.
        • et al.
        Fatal and non fatal cardiac arrests related to anesthesia.
        Can J Anaesth. 2001; 48: 326-332
        • Bille C.
        • Auvigne V.
        • Libermann S.
        • et al.
        Risk of anaesthetic mortality in dogs and cats: an observational cohort study of 3546 cases.
        Vet Anaesth Analg. 2012; 39: 59-68
        • Bille C.
        • Auvigne V.
        • Bomassi E.
        • et al.
        An evidence-based medicine approach to small animal anaesthetic mortality in a referral practice: the influence of initiating three recommendations on subsequent anaesthetic deaths.
        Vet Anaesth Analg. 2014; 41: 249-258
        • Brodbelt D.C.
        • Hammond R.
        • Tuminaro D.
        • et al.
        Risk factors for anaesthetic-related death in referred dogs.
        Vet Rec. 2006; 158: 563-564
        • Brodbelt D.C.
        • Blissitt K.J.
        • Hammond R.A.
        • et al.
        The risk of death: the confidential enquiry into perioperative small animal fatalities.
        Vet Anaesth Analg. 2008; 35: 365-373
        • Brodbelt D.C.
        • Pfeiffer D.U.
        • Young L.E.
        • et al.
        Results of the confidential enquiry into perioperative small animal fatalities regarding risk factors for anesthetic-related death in dogs.
        J Am Vet Med Assoc. 2008; 233: 1096-1104
        • Burgoyne L.L.
        • Smeltzer M.P.
        • Pereiras L.A.
        • et al.
        How well do pediatric anesthesiologists agree when assigning ASA physical status classifications to their patients?.
        Paediatr Anaesth. 2007; 17: 956-962
        • Carr A.P.
        • Tilley L.P.
        • Miller M.S.
        Treatment of cardiac arrhythmias and conduction disturbance.
        in: Tilley L.P. Goodwin J.K. Manuals of Canine and Feline Cardiology. W. B. Saunders, USA2001: 371-405
        • Clarke K.W.
        • Hall L.W.
        A survey of anaesthesia in small animal practice: AVA/BSAVA report (1990).
        Vet Anaesth Analg. 1990; 17: 4-10
        • Dodman N.H.
        • Lamb L.A.
        Survey of small animal anesthetic practice in Vermont.
        J Am Anim Hosp Assoc. 1992; 28: 439-444
        • Dohoo I.
        • Martin W.
        • Stryhn H.
        Measures of disease frequency.
        in: Veterinary Epidemiologic Research. University of Prince Edward Island, Canada2009: 74-91
        • Dyson D.H.
        • Maxie M.G.
        • Schnurr D.
        Morbidity and mortality associated with anesthetic management in small animal veterinary practice in Ontario.
        J Am Anim Hosp Assoc. 1998; 34: 325-335
        • Eagle C.C.
        • Davis N.J.
        Report of the Anaesthetic Mortality Committee of Western Australia 1990–1995.
        Anaesth Intensive Care. 1997; 25: 51-59
        • Fossum T.W.
        Surgery of the lower respiratory system: lungs and thoracic wall.
        in: Fossum T.W. Hedlund C.S. Johnson A.L. Small Animal Surgery. 3rd edn. Mosby, USA2007: 867-895
        • Gaynor J.S.
        • Dunlop C.I.
        • Wagner A.E.
        • et al.
        Complications and mortality associated with anesthesia in dogs and cats.
        J Am Anim Hosp Assoc. 1999; 35: 13-17
        • Gil L.
        • Redondo J.I.
        Canine anaesthetic death in Spain: a multicenter prospective cohort study of 2012 cases.
        Vet Anaesth Analg. 2013; 40: e57-e67
        • Haskins S.C.
        Operating room emergencies.
        in: Slatter D. Textbook of Small Animal Surgery. 2nd edn. W. B. Saunders, USA1993: 240-259
        • Hosgood G.
        • Scholl D.T.
        Evaluation of age as a risk factor for perianesthetic morbidity and mortality in the dog.
        J Vet Emerg Crit Care. 1998; 8: 222-236
        • Joubert K.E.
        Routine veterinary anaesthetic management practices in South Africa.
        J S Afr Vet Assoc. 2000; 71: 166-172
        • Kawashima Y.
        • Seo N.
        • Morita K.
        • et al.
        Anesthesia-related mortality and morbidity in Japan.
        J Anesth. 2002; 16: 319-331
        • McDonell W.N.
        • Kerr C.L.
        Physiology, pathophysiology, and anesthetic management of patients with respiratory disease.
        in: Grimm K.A. Lamont L.A. Tranquilli W.J. Lumb and Jones' Veterinary Anesthesia and Analgesia. 5th edn. Blackwell Publishing, USA2015: 513-555
        • McMillan M.
        • Brearley J.
        Assessment of the variation in American Society of Anesthesiologists Physical Status Classification assignment in small animal anaesthesia.
        Vet Anaesth Analg. 2013; 40: 229-236
        • Muir W.W.
        • Hubbell J.A.E.
        • Bednarski R.M.
        • et al.
        Animal evaluation and preparation.
        in: Muir W.W. Hubbell J.A.E. Bednarski R.M. Handbook of Veterinary Anesthesia. 5th edn. Mosby, USA2013: 12-21
        • Newland M.C.
        • Ellis S.J.
        • Lydiatt C.A.
        • et al.
        Anesthetic-related cardiac arrest and its mortality: a report covering 72,959 anesthetics over 10 years from a US teaching hospital.
        Anesthesiology. 2002; 97: 108-115
        • Owens W.D.
        • Felts J.A.
        • Spitznagel Jr, E.L.
        ASA physical status classifications: a study of consistency of ratings.
        Anesthesiology. 1978; 49: 239-243
        • Redondo J.I.
        • Rubio M.
        • Soler G.
        • et al.
        Normal values and incidence of cardiorespiratory complications in dogs during general anaesthesia. A review of 1281 cases.
        J Vet Med A Physiol Pathol Clin Med. 2007; 54: 470-477
        • Wolters U.
        • Wolf T.
        • Stutzer H.
        • et al.
        ASA classification and perioperative variables as predictors of postoperative outcome.
        Br J Anaesth. 1996; 77: 217-222