Background: The factors affecting the thermal status in neonates and infants undergoing general anesthesia are not yet investigated in detail. We evaluated the factors leading to intraoperative hypothermia in 60 neonates and infants.
Methods: The initial body temperatures and the core temperatures at the 10th, 30th, 60th and 90th minute of anesthesia, as well as at the end of the operation were recorded. The patients were divided into the groups according to the age, type of surgery (minor vs major), operating room (OR) temperatures (low '<23 degrees C' vs high '>23 degrees C') and the initial core temperature of the patients.
Results: In 31 neonates and 29 infants, the mean core temperatures decreased 10 min after anesthesia induction. In all neonates and in infants with 'low OR temperature' (<23 degrees C), these decreases continued to the end of the surgery. Except infants undergoing minor surgery, in all patients, the core temperatures at the end of surgery were lower than the baseline temperature. The greatest decrease in core temperatures occurred in neonates undergoing major surgery and with low OR temperature. In low OR temperature, the decrease of core temperature is higher in patients with major surgery. In patients undergoing minor surgery, the decrease of core temperature is more in neonates than infants. Major surgery increased the chance of decrease of the core temperature by 2.66 times and operating room temperature less than 23 degrees C by 1.96 times.
Conclusion: The type of surgery and the OR temperature are the main factors for decrease of the core temperature in neonates and infants. In neonates, the core temperatures are less stable, regardless of OR temperature and type of surgery. In high OR temperature, infants can stabilize their core temperature better than neonates.