Takaharu Itami1, Hiroko Aida2, Makoto Asakawa3, Yoko Fujii4, Tomoya Iizuka5, Ayako Imai6, Toshie Iseri7, Tomohito Ishizuka8, Kei Kakishima9, Masatoshi Kamata5, Takako Miyabe-Nishiwaki10, Shotaro Nagahama11, Kiyokazu Naganobu12, Ryohei Nishimura5, Shozo Okano13, Tadashi Sano14, Kazuto Yamashita14, Yoshiki Yamaya15, Masashi Yanagawa16. 1. Veterinary Teaching Hospital, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan. Electronic address: titami@vetmed.hokudai.ac.jp. 2. Japan Racing Association, Equine Research Institute, Shimotsuke-shi, Tochigi, Japan. 3. College of Veterinary Medicine, Cornell University, Ithaca, NY, USA. 4. Azabu University, School of Veterinary Medicine, Sagamihara-shi, Kanagawa, Japan. 5. The University of Tokyo, Veterinary Medical Center, Bunkyo-ku, Tokyo, Japan. 6. Japanese Society of Veterinary Anesthesia and Surgery, Bunkyo-ku, Tokyo, Japan. 7. Yamaguchi University, Joint Faculty of Veterinary Medicine, Yamaguchi-shi, Yamaguchi, Japan. 8. Veterinary Teaching Hospital, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan. 9. Animal Emergency Center, Kawaguchi-shi, Saitama, Japan. 10. Primate Research Institute, Kyoto University, Inuyama-shi, Aichi, Japan. 11. Japanese Association of Animal Anesthetists, Setagaya-ku, Tokyo, Japan. 12. University of Miyazaki, Faculty of Agriculture, Miyazaki-shi, Miyazaki, Japan. 13. Kitasato University, School of Veterinary Medicine, Towada-shi, Aomori, Japan. 14. Rakuno Gakuen University School of Veterinary Medicine, Ebetsu-shi, Hokkaido, Japan. 15. Department of Veterinary Medicine, Nihon University, Fujisawa-shi, Kanagawa, Japan. 16. Obihiro University of Agriculture and Veterinary Medicine, Obihiro-shi, Hokkaido, Japan.
Abstract
OBJECTIVE: 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. ANIMALS: From April 1, 2010 to March 31, 2011, 4323 dogs anaesthetized in 18 referral hospitals in Japan. METHODS: 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. RESULTS: 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.
OBJECTIVE: 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. ANIMALS: From April 1, 2010 to March 31, 2011, 4323 dogs anaesthetized in 18 referral hospitals in Japan. METHODS: 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. RESULTS: 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.