Comparison of 3 methods for preventing perianesthetic hypothermia in callimicos (Callimico goeldii)

Perianesthetic hypothermia is one of the most common complications in veterinary anesthesia, especially in small patients with a large body surface area to mass ratio. During anesthesia, body heat can be lost through 4 mechanisms - radiation, convection, conduction, and evaporation - but anesthetists frequently address only one mechanism at a time. Here we sought to evaluate 3 methods of preventing perianesthetic hypothermia in callimicos (Callimico goeldii). In our experience, these small NHP routinely become hypothermic under even brief inhalant anesthesia. To address multiple routes of heat loss, animals received 1 of 3 treatments: 1) placement of a reflective blanket over the patient to limit radiative heat loss to the surrounding environment; 2) placement of a reflective blanket and use of a heated anesthetic circuit, which warmed the inspired air to 104 °F (40 °C), and 3) placement under the patient of a forced-air warming blanket set at 109.4 °F (43 °C). Sources of radiative heat loss were assessed by using infrared thermography. Each animal was anesthetized with isoflurane and maintained in sternal recumbency in a temperature-controlled room (65 °F; 18.3 °C); esophageal core body temperature was monitored every 5 min for a total of 30 min. The rate of heat loss did not differ between the use of a reflective blanket with or without a heated anesthetic circuit. Animals provided the forced-air warming blanket experienced a slight increase in average body temperature. According to these findings, an underbody warm-air blanket provided the best protection against hypothermia for callimicos in sternal recumbency.