Hypothermia on arrival in the intensive care unit after surgery

Minimising perioperative hypothermia is a priority for anaesthetists. However, there are few studies of postoperative hypothermia in intensive care units. We tested the hypotheses that many patients arrive in the ICU with hypothermia and that patients are warmer after cardiac surgery than after non-cardiac surgery.

We undertook a prospective audit of the temperature of all patients who arrived in the ICU from the operating suite of a university-affiliated tertiary referral hospital between July and August 2006. Temperature was measured with infrared tympanic membrane thermometers. We compared arrival temperatures and proportion of patients with hypothermia (defined as temperature < 36.0 degrees C) after cardiac versus non-cardiac surgery.

171 consecutive surgical patients were assessed. Their median temperature on arrival in the ICU was 36.0 degrees C (95% CI, 35.4-36.5 degrees C). Almost half (48%; 95% CI, 41%- 55%) had hypothermia. Patients who underwent cardiac surgery (n = 49) had worse ASA physical status and spent twice as long in the operating room as those who underwent non-cardiac surgery (n = 122), but a smaller proportion were hypothermic (31% [95% CI, 18%-44%] v 55% [95% CI, 47%-64%]). The difference (24%; 95% CI, 8%-41%) was significant (P = 0.004).

Hypothermia is common among postoperative patients admitted to our ICU. We suggest that ICU staff should routinely expect to actively warm postoperative patients, particularly after non-cardiac surgery, and should have sufficient resources to do so.