Temperature regulation is important in pediatric patients, particularly neonates, as they are prone to greater heat loss in the operating room when compared to adults. This is because of their larger surface area per kilogram, thinner skin and lower fat content. Temperature regulation is made even more difficult in the operating room because of cold air, administration of IV fluids, dry anesthetic gases, wound exposures and the direct effect of anesthetic gases on temperature regulation.
In neonates, heat generation by shivering is somewhat limited during the first three months of life. This makes nonshivering thermogenesis, which consists of metabolism of brown fat, a primary means of heat production. Temperature regulation can become difficult because this process is inhibited by the use of volatile anesthetics. Poor temperature regulation can lead to a number of adverse events, including increased oxygen consumption, which in turn can cause a metabolic acidosis. In addition, one may see delayed awakening, respiratory depression, increased pulmonary vascular resistance and cardiac irritability.
There are several mechanisms for maintaining the temperature of the pediatric patient during anesthesia but it is also important to maintain temperature during transport to and from the operating room as well. To decrease conductive temperature losses, the operating room should be warmed (80 degrees or warmer) in advance and heated air mattresses should be used. Convective heat loss can be prevented by keeping the infant in an incubator, covered in blankets. Heat lost from radiation can be minimized by using a double-shelled Isolette when transporting the patient. Evaporative heat loss can be decreased by humidifying inspired gases, using plastic wrap to prevent water loss through the skin and warming skin disinfecting solutions. The most effective way to warm pediatric patients involves the use of forced air blankets. One should also take care to keep the head covered when possible.