Effect of Hot Water Bottles on Body Temperature during Magnetic Resonance Imaging in Dogs under General Anesthesia: A Retrospective Study

SIMPLE SUMMARY: In magnetic resonance imaging (MRI) examinations for dogs, general anesthesia or sedation is required for immobilization. It is difficult to prevent hypothermia induced by general anesthesia or sedation due to limitations in body temperature management methods, such as lack of force-warming equipment, including magnetic materials. A hot water bottle (HWB) is one of the few tools that can be brought into an MRI examination room, and can contribute to the prevention or attenuation of hypothermia. In this study, we aimed to retrospectively investigate the effects of HWB on body temperature during MRI examinations in dogs under general anesthesia. We obtained validated data from 100 dogs who underwent MRI under general anesthesia. The decrease in rectal temperature 15 min after intubation was significantly smaller in the group using HWB than in the group not using HWB. Our results suggested that the use of hot water bottles might be one of the methods to attenuate hypothermia in the early period but should not be expected for complete prevention of hypothermia, and it was not recommendable necessarily for body temperature management during MRI examinations in dogs under general anesthesia. ABSTRACT: Prevention of hypothermia induced by anesthesia and enhanced by low environmental temperatures is difficult in magnetic resonance imaging (MRI) examinations in dogs as forced warming devices, including magnetic materials, are not acceptable for use in the MRI room. A hot water bottle (HWB) can be carried into an MRI examination room and can contribute to the prevention or attenuation of hypothermia. Here, we retrospectively investigated the effects of HWB on body temperature during MRI examinations in dogs under general anesthesia (GA). From anesthesia records of the Veterinary Medical Teaching Hospital, Okayama University of Science, validated data of 100 dogs that underwent an MRI examination under GA were obtained and divided into the following two groups: one group received HWB, while the other did not. Decrease in rectal temperature 15 min after intubation was significantly smaller in the group using HWB than in the group without HWB. In conclusion, the use of hot water bottles might be one of the methods to attenuate hypothermia in the early period but should not be expected for complete prevention of hypothermia, and it was not recommendable necessarily for body temperature management during MRI examinations in dogs under general anesthesia.