What should surgical professionals consider when purchasing temperature management equipment in order to achieve adequate temperature in the OR for both patients and surgeons?
Patients and surgeons are both interested in the same goal – the best possible outcome.
According to several studies, patients who successfully maintain normothermia (36C – 38C) during surgery require fewer transfusions, experience less post-operative bleeding, spend less time on mechanical ventilators, require less time in intensive care and go home sooner. In fact, normothermic patients enjoy the following benefits:
- Wound infection rates reduced by 64%
- Lower myocardial infection rates reduced by 44%
- Transfusion rates reduced by 40%
- Time spent in the ICU reduced by 43%2
- Need for assisted ventilation decreased by 34%2
There are a number of important factors that should be considered when choosing the optimum patient warming solution to be used for a specific case include 1) invasiveness of the procedure, 2) procedure length 3) surface area available for warming and 4) patient predisposition to hypothermia.
If a procedure is minor and there is adequate surface area available to utilize forced air warming, then traditional interventions will likely result in the desired temperature. However, if the surgery is major, or if the procedure is expected to last longer than 2 hours, then a more sophisticated and efficient warming system should be used. Examples of such surgeries include cardiothoracic procedures, major abdominal, major plastics, trauma and some orthopedics cases. In addition, patient factors such as thin body habitus and advanced age can impact the rate of heat loss and the impact of redistribution hypothermia.
Finally, complex procedures such as on-pump coronary artery bypass grafting or similar procedures that leverage intentionally induced hypothermia, require special consideration. These procedures result in a phenomena termed, “redistribution hypothermia.” This term refers to a drop in temperature, often into the mild to moderate hypothermia range, which occurs as the patient is emerging from anesthesia and the patient’s normal thermoregulatory processes are being re-established..
In these types of complex surgeries conventional warming methods such as blankets and forced air often cannot deliver enough heat to the body to balance the losses experienced during the intra-operative period. In these cases, more effective solutions should be employed in order to avoid a shortfall and its negative consequences.
1 Kurz, A. et. al. 1996. New England Journal of Medicine 334(19); 1209-1215.
2 Wagner, VD. 2003, Aug. Impact of Perioperative Temperature Management on Patient Safety. SSM 9(4);
38-43, Forstot, RM. The Etiology and Management of Inadvertent Perioperative Hypothermia. 1995 Dec.
Journal of Clinical Anesthesiology
3 Schmied, H. et. al, 1996 Feb. Mild hypothermia increases blood loss and transfusion requirements during
total hip arthroplasty, Lancet 347(8997); 289-92. Sessler, D.1994 Sep. Consequences and Treatment of Perioperative Hypothermia, Anesthesiology Clinics of America, 12(3); 425-456.