Humidification and Loss of Body Heat During Anaesthesia: Ii: Effects in Surgical Patients

Abstract

Changes in temperature and body heat were measured in 30 patients. Despite the warming of most fluids given intravenously, all the patients ventilated with dry anaesthetic gases became cooler, with an average heat loss of 12.4 kilocalories per hour. In a group to whom the gases were delivered saturated at body temperature, the average hourly loss was 1.5 kilocalories. This difference is in agreement with the effects calculated from respiratory heat exchange, and indicates that heated humidification can help to limit or prevent the development of hypothermia in anaesthetized adults.

Prevention of intraoperative hypothermia during abdominal surgery

“…A core temperature as low as 32°C has been reported (18). Net heat losses have been claimed to amount to 50-100 kJ per hour (2, 3, 9, 1 1 , 15,19,20). The greatest fall in core temperature occurs after induction of anaesthesia and during the first hour ( 1 6, 17).…”

Mean Skin Temperature During Anaesthesia: An Assessment of Formulae in the Supine Surgical Patient

“…Yet, unless the temperature of the peripheral tissues is assessed, a decrease in deep body temperature associated with anaesthesia might reflect only a redistribution of body heat, and not actual loss (House and Vale, 1972). This necessitates an estimate of mean skin temperature during anaesthesia to be used when heat gain and loss are being studied (Lunn, 1969;Dyde and Lunn, 1970;Vale and Lunn, 1969;Shanks, 1974). It becomes important to find the minimum number of sites which can provide a reliable estimate of the true mean, and to assess the error which might occur when measuring at a conveniently smaller number of sites.…”

Infection control hazards associated with the use of forced-air warming in operating theatres

“…19e21 These losses of body heat are compounded by heat loss from wound lavage, intravenous infusion and respiratory heat exchange. 22,23 Preventing inadvertent perioperative hypothermia decreases the duration of surgery, reduces morbidity and mortality, incidence of postoperative pressure ulcers, length of stay in intensive care and total hospital stay. 1,24e26 It has also been associated with a reduced requirement for mechanical ventilation, and blood transfusion.…”