Warming can improve patient outcomes

Since the publication of the NICE guideline for maintaining perioperative normothermia in 2008, practice has changed and a great deal more evidence is available. It is to be hoped that fewer than the 40% of patients who are said to suffer perioperative hypothermia,1 experience it nowadays, with better information, education and more devices available to mitigate the effects. 

It is not just unpleasant for patients to be cold intra and post operatively, being hypothermic reduces their ability to heal optimally and there are numerous other poor outcomes. These include increased likelihood of surgical site infections, increased blood loss intraoperatively, reduced ability to metabolise post operative pain control medications, longer hospital stays and potentially delayed wound healing. 

Hypothermia is defined as a core body temperature of below 36˚C and can be classified as: mild hypothermia (34-36˚C); moderate hypothermia (30-34˚C); and severe hypothermia (less than 30˚C). Symptoms of perioperative hypothermia can be reduced by active warming. The two most common causes of perioperative hypothermia are exposure to the cold environment of the operating theatre and anaesthetic induced impairment of thermoregulatory control; known as redistribution hypothermia where core warmth is redistributed to the periphery, where it may be lost.