Incidence of Inadvertent Intraoperative Hypothermia and Its Risk Factors in Patients Undergoing General Anesthesia in Beijing: A Prospective Regional Survey

Abstract

Background/ObjectiveInadvertent intraoperative hypothermia (core temperature <360 C) is a recognized risk in surgery and has adverse consequences. However, no data about this complication in China are available. Our study aimed to determine the incidence of inadvertent intraoperative hypothermia and its associated risk factors in a sample of Chinese patients.MethodsWe conducted a regional cross-sectional survey in Beijing from August through December, 2013. Eight hundred thirty patients who underwent various operations under general anesthesia were randomly selected from 24 hospitals through a multistage probability sampling. Multivariate logistic regression analyses were applied to explore the risk factors of developing hypothermia.ResultsThe overall incidence of intraoperative hypothermia was high, 39.9%. All patients were warmed passively with surgical sheets or cotton blankets, whereas only 10.7% of patients received active warming with space heaters or electric blankets. Pre-warmed intravenous fluid were administered to 16.9% of patients, and 34.6% of patients had irrigation of wounds with pre-warmed fluid. Active warming (OR = 0.46, 95% CI 0.26–0.81), overweight or obesity (OR = 0.39, 95% CI 0.28–0.56), high baseline core temperature before anesthesia (OR = 0.08, 95% CI 0.04–0.13), and high ambient temperature (OR = 0.89, 95% CI 0.79–0.98) were significant protective factors for hypothermia. In contrast, major-plus operations (OR = 2.00, 95% CI 1.32–3.04), duration of anesthesia (1–2 h) (OR = 3.23, 95% CI 2.19–4.78) and >2 h (OR = 3.44, 95% CI 1.90–6.22,), and intravenous un-warmed fluid (OR = 2.45, 95% CI 1.45–4.12) significantly increased the risk of hypothermia.ConclusionsThe incidence of inadvertent intraoperative hypothermia in Beijing is high, and the rate of active warming of patients during operation is low. Concern for the development of intraoperative hypothermia should be especially high in patients undergoing major operations, requiring long periods of anesthesia, and receiving un-warmed intravenous fluids.

Predictive factors of maternal hypothermia during Cesarean delivery: a prospective cohort study

“…These results are in agreement with those previously reported in surgical patients, for whom baseline temperature prior to anesthesia and temperature at the start of the operation were among the most important factors associated with intraoperative hypothermia. 23,24 Hence, reducing the normal core-toperipheral tissue temperature gradient by warming such patients before induction of anesthesia (active prewarming) would be particularly important in this setting to minimize the consequent redistribution hypothermia. Thus, several studies reported that starting active prewarming with warmed intravenous fluid and / or forced-air warming at least 15 min prior to induction of anesthesia and surgical incision was effective for preventing hypothermia.…”

“…Yi et al previously reported that an infusion of more than one litre of unwarmed fluid tripled the risk of intraoperative hypothermia during surgical procedures performed under general anesthesia. 23 During CD, intravenous fluid coloading is advocated at the time of spinal anesthesia, in combination with infusion of vasopressors, to prevent maternal hypotension. 28 Hence, women may receive 1-3 L of crystalloid fluids intraoperatively and, consequently, may be significantly cooled.…”

“…These results are not surprising since oxytocin acts on uterine contractions and thermoregulation 30 while increased body mass index is associated with a reduced incidence of hypothermia in surgical patients. 23,31 In fact, redistribution hypothermia (reduction in maternal temperature during the first hour of anesthesia) may be inversely proportional to the percentage of body fat. 32 Core hypothermia during CD performed under spinal, epidural, or general anesthesia is mainly related to core-toperipheral redistribution of body heat.…”

Effectiveness of infusion warmer use to prevent hypothermia and shivering after general anesthesia

“…Shivering is an unpleasant condition which usually occur as a complication after both general and regional anaesthesia in patient underwent either elective or emergency surgery. 1,2, 3 Post-surgical shivering may cause several unwanted complications such as physiological stress, increased oxygen demand by 2-3 times, increased metabolism, increased intracranial and intraocular pressure, elevating carbondioxide production, cathecolamine release, and increased post surgical pain. 4,5, 6 Temperature control at recovery room can be done by using dry blanket to reduce heat evaporation, and the use of warm saline solution.…”

Tympanic and Temporal Thermometry in Hypothermia Assessment for Adult in Intraoperative Abdominal Surgery

“…4 The concern with the development of intraoperative hypothermia exists especially in patients undergoing major surgery, which require long periods of anesthesia. 5 Complications of hypothermia in the intraoperative period that are highlighted by the literature include: coagulopathy and increased need for blood transfusion, morbid coronary events such as heart attack, tachycardia and hypertension, surgical site infection, thermal discomfort, tremors, decreased drug metabolism, and prolonged recovery. Due to the serious consequences associated with hypothermia, the standard of care is to monitor the body temperature during the anesthesia, and maintain a stable temperature.…”