Science Digest: What are the effects of wrapping the peripheral limbs of small dogs to prevent hypothermia during anaesthesia?

14 October 2024

Intraoperative hypothermia following general anaesthesia is a common complication in veterinary medicine, and dogs with a lower body mass are more susceptible. Previous research has shown that 83.6% of dogs that do not receive active thermal support during anaesthesia experience post-anaesthesia hypothermia1.

Whilst there is evidence to demonstrate the benefits of patients wearing socks, using blankets or a warm water circulation mattress in maintaining body temperature, the effect on smaller dogs, that are more prone to heat loss, is unknown.

New research published in Veterinary Anaesthesia and Analgesia by Ayano Kudo and other researchers has investigated the effects of wrapping the peripheral limbs of small dogs with table leg covers on rectal temperature during anaesthesia2.

A total of 60 client-owned dogs with a body mass < 15 kg and anaesthetised for soft tissue surgery were included, and randomly assigned to either receive routine thermal support only (the control group) or have their peripheral limbs wrapped in addition to routine thermal support (the limb-wrapping group).

Propofol or alfaxalone were used to induce anaesthesia, and it was maintained using isoflurane in oxygen. Endotracheal intubation and a rebreathing circuit were used on all dogs. For dogs in the control group, routine thermal support was provided by placing a warm air blanket at a 42 °C temperature under the dogs and covering them with a cotton or polyester towel. For dogs in the limb-wrapping group, their peripheral limbs were wrapped up until the mid-metacarpal/metatarsal region with polyester table leg covers after anaesthesia induction, in addition to the same routine thermal support provided to the control group. Rectal temperature was measured before anaesthesia induction, and immediately after intubation and application of the anaesthesia monitoring equipment, until to the end of the surgery.

The findings showed significant differences in rectal temperature between dogs with and without limb-wrapping. Rectal temperature didn’t differ between the two treatment groups at the time of intubation, but it was significantly higher in the limb-wrapping group (36.7 ± 1.0 °C) compared to the control group (35.9 ± 0.8 °C) at the end of surgery. Rectal temperature at both 15 minutes and 30 minutes after incision was significantly higher in the limb-wrapping group compared to the control group. The incidence of hypothermia (<37.0 °C) was significantly lower in the limb-wrapping group compared to the control group. No other factors such as age, body condition score, anaesthesia or surgery duration, influenced rectal temperature.

Take home message

Wrapping peripheral limbs of small dogs with table leg covers slowed the reduction in intraoperative rectal temperature during anaesthesia, resulting in significantly higher rectal temperature at the end of surgery. Limb-wrapping is inexpensive and easy to perform, making it a practical option for minimising hypothermia during anaesthesia in small dogs undergoing soft tissue surgery.

References

1Redondo JI, Suesta P, Serra I et al. (2012) Retrospective study of the prevalence of postanaesthetic hypothermia in dogs. Vet Record. 171 (15), 374-374

2Kudo A, Oboso R, Oshita R et al. (2024) Peripheral warming for prevention of hypothermia in small dogs during soft-tissue surgery: a randomized controlled trial. Veterinary Anaesthesia and Analgesia. https://doi.org/10.1016/j.vaa.2024.08.011