Warmed IV fluids. Forced-air warming devices. Booties and hats in the OR. No single intervention can prevent perioperative hypothermia on its own. The secret to making sure your patients stay warm is to combine measures to maintain body temperature from the time patients enter your facility through discharge. This offers the greatest likelihood of minimizing body temperature change and maximizing comfort in surgical patients. Here are 4 relatively simple strategies to prevent hypothermia.

1. Warmer rooms
Even short, non-invasive surgery is associated with unintentional hypothermia. A simple solution is to increase the OR temperature. Since 1970, studies have shown that patients who enter ORs with the temperature set to 70 ?F have a significantly reduced risk of hypothermia. While setting the room to 70 ?F may seem warm initially, after the "golden hour" (the first hour in the operating room) you can lower the ambient temperature for the surgical team's comfort. Body temperature drops 1 to 3 degrees during the first hour in the OR. How-ever, after the first hour, body temperature usually stabilizes.

It's important that everyone on the surgical team understands the significance of the patient arriving in an OR with an ambient temperature of 70 ?F and takes the necessary steps to keep the patient warm during the first hour. Unfortunately, that's not always the case. A survey published in the March 2009 issue of ORNurse found that 74% of operating room nurses who responded were unaware of the specific ambient temperature's influence on unintentional hypothermia.

2. Pre-warming
Preventing unintentional hypothermia should be a team effort, beginning in the pre-operative area. Taking patients to surgery when they're already warm (normothermic) helps minimize the loss of body heat while they're in the operating room. Using active warming devices as well as passive warming measures, including cotton blankets and layering, helps maintain body temperature. Research shows that placing a forced-air warming blanket on patients before they're brought into the operating room minimizes the incidence of unintentional hypothermia.

Pre-operative warming decreases heat redistribution. In a classic study, Camus and colleagues found that core body temperature decreased at a rate of 0.6 ?C per hour in pre-warmed patients, but decreased 1.1 ?C per hour in patients who were not pre-warmed. Since this early investigation, published in the Journal of Clinical Anesthesia in 1995, other studies have supported the use of pre-operative warming to avert the problems associated with unintentional hypothermia.

Forced-air blankets seem to work better than cotton blankets. Research shows that patients maintain body temperature to a greater degree when forced-air warming blankets are used pre-operatively, as compared to cotton blankets. In addition to minimizing hypothermia in surgery patients, pre-warming may facilitate IV placement and improve overall patient comfort and satisfaction.

3. Intraoperative warming
During surgery, using warmed IV fluids, blood warmers and warmed irrigants can help to minimize heat loss. Warming irrigating solutions before instilling them into open body cavities promotes blood flow and oxygen delivery to tissues. Storing IV fluids in a warming cabinet can also help you maintain normothermia in your patients.

Minimizing body exposure, layering blankets and using circulating water mattresses and garments can also be used to promote normal thermal balance. Head wraps and warmed humidified anesthetic gases can also contribute to overall maintenance of body temperature. For pediatric patients, radiant heat lamps will aid in averting unintentional hypothermia.

4. Post-op assessment
Measuring the patient's body temperature upon arrival in the PACU lets the nursing staff determine whether the patient is hypothermic. For normothermic patients, blankets help maintain body temperature following surgery and anesthesia. For patients who are hypothermic, forced-air warming offers the best measure to promote a return to normal body temperature and overall patient comfort. As in the OR, warmed IV fluids and warmed, humidified oxygen aid in promoting normal body temperature in the PACU. For hypothermic patients who arrive in the PACU with a core body temperature under 36 ?C (96.8 ?F), American Society of PeriAnesthesia Nurses guidelines recommend measuring the body temperature every 15 minutes. Frequent measurement will help you determine what to do next to maintain normal body temperature.

Not a matter of "set it and forget it"
Keeping patients warm should be a primary concern during their stay in your facility. Unintentional hypothermia can cause physiological changes that affect all body systems and can cause extended anesthesia care, myocardial infarction, coagulopathy and poor wound healing. In fact, wound infection is 3 times higher in hypothermic patients with a core body temperature less than 36 ?C.

The Surgical Care Improvement Project's safety reporting measures emphasize hypothermia's link to post-operative infection. Measure 10 for infection control (SCIP-Inf-10) calls for reporting patient temperature and documenting whether it dropped below 36 ?C from 30 minutes before the anesthesia end time until 15 minutes after the anesthesia end time. This measure applies to patients of all ages who receive general or regional anesthesia for 1 hour or more.