THERMAL THROUGHPUT Pre-warming gives you a head start on keeping patients normothermic throughout the surgical process.

Several years ago, we noticed that patients' temperatures dipped when we brought them into the OR, then evened out once we'd finished positioning, prepping and draping. We wondered: Would pre-warming make a significant difference in helping maintain normothermia throughout the perioperative process? Turns out, it did. Let's look at the essential elements of the warming plan we came up with in order to reduce patient discomfort and limit surgical complication risks (see "Warming's Link to Patient Safety" on page 16).

1. Tailor approaches
Pre-warming increases the core temperature to prevent hypothermia later on in surgery, eliminating the need to play catch-up in order to regain normothermia along the way. Establish 2 methods for pre-warming patients, determined by how long a patient is expected to spend in the OR. For every patient who arrives in pre-op for a procedure that will take less than an hour — colonoscopies, minor cosmetic surgeries or other short, quick cases — use 2 warmed cloth blankets to keep them comfortable. The cases aren't long and the patients aren't generally exposed to cold OR fluids, so there isn't an extreme risk of heat loss.

This approach doesn't require much in the way of purchasing decisions, just a warming cabinet. Capacity is the key factor in choosing one: You'll want to have a sufficient supply of warm blankets. Metal doors are sturdy, but you can see through glass doors to know when it's time to refill. A cabinet that can warm both blankets and IV fluid simultaneously is an efficient use of equipment space.

For patients who will be in surgery for an hour or more, undergoing total joint or spine surgeries, for example, a more active pre-warming approach will help keep core temperatures up. Put an electrically warmed blanket (made from a conductive polymer fabric) or forced-air gown over the patient and leave it on them, surgical access permitting, throughout their perioperative stay.

RESEARCH RECAP

Warming's Link To Patient Safety

• Clinical research has drawn a link between hypothermia and how its adverse effect on tissue viability increases the risk of surgical site infections. A study (tinyurl.com/9nmmv3n) published in the September 2012 issue of AORN Journal, however, notes that maintaining perioperative normothermia may also be an important step in preventing intraoperatively acquired pressure ulcers, previously seen as a function of a procedure's length and the patient's positioning. In a retrospective study, researchers found that patients who were at higher risk of suffering skin breakdowns during surgery were those who were critically ill, had low Braden Scale skin assessment scores, were thin, and were male, and whose core temperatures dropped at least 1 ?F (1.8 ?C).
• It's a double-whammy: general and neuraxial anesthesia will decrease a surgical patient's core temperature, and if they're undergoing open surgery, exposure to cold and dry room air will also result in heat loss, even with standard warming efforts. For a clinical trial (tinyurl.com/963a6s7) reported in the Aug. 10, 2012, issue of the journal Anesthesia & Analgesia, researchers observed 83 patients undergoing open colon surgery. Some were treated with forced-air warming, warmed fluids and head and limb insulation; the others also had their wounds insufflated with CO2 warmed to 37 ?C and humidified to 100% relative humidity. They found that warmed insufflation helped keep wound and core temperatures up.
• Researchers conducted a small study to determine what effect active patient warming has on total knee arthroplasty patients' temperatures and pain responses. Of 30 patients observed, half were given a traditional gown and a warmed cloth blanket, and half were given a patient-controllable forced-air warming gown. While the 2 groups' post-op pain scores weren't radically different, the patients who got forced-air gowns showed warmer temperatures, required fewer opioids and reported greater satisfaction with their post-op experiences. The findings (tinyurl.com/8cpwdqh) were reported in the May 2012 issue of the American Journal of Nursing.

— David Bernard

2. Make warming routine
The core temperatures of actively warmed patients don't vary much from the normothermic norm throughout the surgical process, which is what you ideally want. When it comes to actively warming patients, you've got a number of products to choose from. We looked at forced-air warming units and their proprietary gowns designed for easy access to multiple areas during surgery, which are certainly a popular choice among surgical professionals. Then we trialed an electric blanket at our CRNA's recommendation. During the trials, we surveyed our patients for input on how well the products worked. Why not? They were the ones who felt the effects.

For us, the electric blanket seemed like a big hit. Its operating unit ran silently; it had a small footprint, mounted on an IV pole instead of taking up floor space, which makes a difference in pre-op bays as well as in the OR; and it consumed little energy. Plus, it's reusable — you can clean it between uses with an antibacterial wipe — and doesn't depend on a disposable component, which is economically and environmentally appealing.

WARMING TREND The core temperatures of actively warmed patients hover around the normothermic norm.

Don't just warm patients with these devices; also warm the stretchers they're getting onto. The nurses who set up pre-op bays should lay the warming blankets on top of bedsheets, where they act as big heating pads. After patients change into their gowns, they climb onto stretchers and beneath the sheets, which have already been warmed for them. If patients are arriving hours before their surgeries, and if the schedule is running late, this is vastly preferable to starting them out on cold stretchers.

One thing to keep in mind, though, is to educate your staff on the proper care and handling of these devices in order to extend their useable lives. The wires inside electric blankets will see a lot more expensive wear and tear a lot sooner if, for instance, they're balled up and left on the floor instead of folded neatly after cleaning and hung on the IV pole rack by the power unit.

3. Educate patients
Some patients, of course, tend to be naturally warm and may complain of being overheated by your active pre-warming efforts. They'll keep kicking the blankets off or pushing them to the side. Explain to them the importance of pre-op warming and that you've rarely, if ever, had a patient emerge from the OR who's hypothermic. This doesn't mean, however, that you shouldn't put warming to use in the PACU. If patients say they feel cool in recovery, keep your warming method of choice applied and active.

Everyone benefits
What's the best way to maintain normothermia, while also ensuring thermal comfort for our physicians and staff? Make patient warming part of your safety culture, so everyone's onboard with your efforts. Emphasize that maintaining normothermia makes you compliant with quality of care recommendations and might influence whether you get paid. In more ways than one, active pre-warming is a big factor in providing the best possible care.