Читать книгу Surgery of Exotic Animals - Группа авторов - Страница 24

Hypothermia during anesthesia is a major concern for many reasons including decreased metabolic functions and excretion of anesthetic agents. Many small exotic animals have a large body surface area/volume ratio predisposing them to developing hypothermia during anesthesia. The body temperature of a rat can drop 18 °F (10 °C) after 20 minutes of anesthesia (Harkness et al. 2010). Use an esophageal or rectal temperature probe to continuously monitor the patient's body temperature. The normal temperature for a given species may not be known; however, once the patient is anesthetized insert a temperature probe to determine its body temperature. Then monitor the temperature and how much it drops during anesthesia. Even in poikilotherms, this is very helpful and can help make decisions about the need to provide additional thermal support.

A short anesthesia and operative time accomplished by having all the necessary equipment ready and accessible will help to minimize hypothermia. It is best to use patient warming devices with temperature control such as forced warm air and warm water blankets. It can be difficult to place a warm air blanket around a small patient. These devices blow warm dry air, so pay particular attention to keeping the cornea lubricated to reduce the risk of creating corneal ulcers. This is especially important with small patients where the head is hard to visualize under the blanket. It is considered beneficial to use more than one patient warming device. For example combine a circulating warm water blanket under the patient and a forced warm air device around and over the patient where possible. For most small exotic animals set the circulating warm water blanket and forced warm air device at 104 °F (40 °C) because these patients have a high body temperature. Drape the patient as quickly as possible to help hold heat in under the drapes.

Use warm (101–103 °F; 39–40 °C) saline for abdominal and thoracic lavage. Fill the body cavity with the warm saline and do not immediately remove it. Allow it to dwell within the body for several minutes. Repeat this process until the body temperature begins to rise. Once the downward trend in body temperature reverses and the body cavity has been closed, in most cases, the temperature will continue to rise assuming other patient warming devices are in place. For most species, if the body temperature drops below 96 °F (35.5 °C) during the surgery, stop the procedure and instill warm saline into the body cavity before continuing the procedure. Repeat the process before closing.