Effectiveness of Pre-operative Warming in Prevention of Peri-operative Shivering

Inadvertent peri-operative hypothermia (IPH) and shivering is one of the most commonly recognized problem during anesthesia which is believed to be thermoregulatory in origin. Although shivering is uncomfortable for most patients, it is unlikely that this relatively small increase in total body oxygen consumption in the average shivering patient is associated with increased peri-operative morbidity. It is common for patients to complain that their worst memory from the recovery room is the intense cold sensation and uncontrollable shivering. New guidelines recommend that patients core temperature has to be maintained at >36°C, postoperatively. Studies suggest that pre-warming the patient prior to the surgery can reduce the chances of hypothermia induced shivering during the post operative period.

Forced air warmers are the most frequently used active warming devices in the peri-operative setting. They are effective at preventing hypothermia induced shivering when used before induction of anesthesia, during anesthesia and surgery, and after emergence in the post-anesthesia care unit. Other methods such as warm fluids, opioids, blankets and warm light devices can be used but are less effective as compared to the forced air warming devices.

Currently, our hospital does not pre-warm patients but if our study shows that pre-warming reduces post-operative shivering, we will be able to make an evidence based decision to start this practice.