Patient warming does not prevent hypothermia
Patients actively warmed during surgery can still experience hypothermia, according to a new study published in the February issue of Anesthesiology. The research, led by Daniel Sessler at the Cleveland Clinic in Ohio, found that body temperature decreases during the first hour of surgery even when patients are actively warmed with forced air, and that patients who experience the most hypothermia are more likely to require blood transfusions.
The goal of the study was to evaluate body temperature patterns in warmed surgical patients, and determine whether even short periods of low temperature increased blood loss or prolonged hospital stays. The investigators evaluated records of intraoperative core body temperature patterns in nearly 59,000 surgical patients, all of whom were warmed with forced air, and found that 64 per cent of surgical patients became hypothermic, with core temperatures below 36°C during the first hour of anaesthesia. Nearly half of patients had a continuous core temperature less than 36°C for more than one hour, while twenty percent of patients had a continuous core temperature below 36°C for more than two hours. Core temperatures then gradually increased, and most patients had normal temperatures by the end of surgery. Patients who became most hypothermic were most likely to need blood transfusions.
An accompanying editorial commented favourably on the study’s findings. “A critical implication of this study is that current standards and practice routinely lead to intraoperative hypothermia, which is associated with a higher transfusion requirement. These results should be an impetus for changes in practice that lead to lower rates of intraoperative hypothermia,” said Harriet Hopf, from the department of anesthesiology at the University of Utah School of Medicine in Salt Lake City. “This study starts a new conversation on perioperative temperature management. Future studies should evaluate the effectiveness of interventions to reduce the degree and duration of intraoperative hypothermia and the effect of these interventions on the broad range of outcomes known to be temperature sensitive.”
Source: American Society of Anesthesiologists