ON THE INSIDE Patients know warming feels good. They may not know it can prevent heart attacks and strokes.

When you think about the benefits that come from patient warming, what comes to mind first? Increased patient satisfaction? Reducing the likelihood of surgical site infection? Faster recoveries?

All are immensely important, but what about the less-well-known and not-fully-appreciated benefits of warming, such as reducing intra-operative bleeding?

Yes, reduced anxiety is a common theme when it comes to touting the benefits of warming. Warming patients pre-operatively can be the emotional equivalent of tucking in a child at night. "It keeps patients warm, it lowers their anxiety level and it shows that we really care about them," says Mary Radke, BSN, RN, ASC manager of Dakota Surgery and Laser Center in Bismarck, N.D.

Practitioners say it's a tonic that calms the nerves. "We warm all of our patients with a warm blanket," says a facility leader. "It reduces anxiety and makes patients feel as if we're really paying attention to their needs." Exactly. When you warm patients, you are, in fact, paying attention to their needs — not only in terms of comfort, but in ways that can be easy to overlook, and that most patients would never imagine.

BEFORE, DURING AND AFTER It's best to warm patients throughout the perioperative process.

1 Warming reduces intra-operative bleeding. Studies (tinyurl.com/pdl3mz4) show that patients who aren't adequately warmed intraoperatively are likely to need significantly more units of red blood cells, plasma and platelets. That's because as core temperatures decrease, so do platelet circulation and function. One benchmark: A patient whose temperature drops 2 ?C during surgery is likely to lose twice as much blood as one who's kept warm. That's bad enough, but transfusions also increase the risks of infection, reaction and immune suppression.

2 Warming decreases the chance of a cardiac event. The literature (tinyurl.com/lu9jxyq) reinforces the point. One study found that a core temperature drop of 1.5 ?C can triple the likelihood of ventricular tachycardia, heart attack or even cardiac arrest.

Adequately warmed patients have "a decreased incidence of tachycardia and hypertension in PACU," notes Charles DeFrancesco, MD, staff anesthesiologist at Delmont Surgery Center in Greensburg, Pa. "Both are related to peripheral vasoconstriction and the body's stressor response to hypothermia."

And speaking of cardiac-related issues, a clinical director we heard from notes the "reduced incidence of arrhythmias" as another benefit. How significant might that be? A recent study (tinyurl.com/nuj9rka) suggests that patients who experience arrhythmias after non-cardiac surgery may face an increased risk of stroke somewhere down the road.

3 It's best to warm patients throughout the perioperative process. The benefits of warming typically start in pre-op and continue until the patient is ready to leave. "We warm patients from pre-op to post-op," says another clinician. "It takes more anesthesia to put cold patients to sleep, plus warm patients are happy patients."

And post-op? "Warmed patients respond better to pain medication, and wake up faster," says a director of nursing at another facility, an observation shared by Stephanie Wright, ADN, BSN, director of surgery for the perioperative area at St. Luke's Magic Valley Medical Center in Twin Falls, Idaho. "Patients seem to need fewer narcotics, they wake up faster, and there's less time spent rewarming them in PACU," says Ms. Wright.

Of course, patients who need to be rewarmed in post-op aren't just uncomfortable, they're also likely to be shivering, which creates stress, raises metabolic rates and increases cardiac demand. "Shivering can increase myocardial oxygen demand 400% above baseline," points out an anesthesia provider. "But warmed patients don't shiver when they emerge from anesthesia."

"The anesthesia gas I give, especially sevoflurane, causes shivering," says Darren Long, BA, MSN, CRNA at Avita Health System in Galion, Ohio. "Combined with a cold OR, it becomes almost unbearable for some patients in PACU. Warming provides the comfort they need."

Another practical consideration: "You don't need to repeatedly take NIBP and pulse oximetry readings because of shivering confounding the results," says Gary Lawson, MD, anesthesiologist at Adult & Children's Surgery Center of Southwest Florida in Fort Myers.

Obstacles and tips
Though the benefits of warming are numerous and undisputed, some procedures involve challenges, including abdominal procedures, procedures done in the lateral position and procedures that involve both the upper and lower body.

"For multiple procedures, we apply a sterile drape to the area completed first, then place a hot air warmer on top for the remainder of the surgery," says Carrie Frederick, MD, director of anesthesia services at Plastic Surgery Center in Portland, Maine. And as a preemptive measure, says Dr. Frederick, "IV magnesium gives the double benefit of being an NMDA receptor blockade for preventive analgesia and diminished shivering."

"Since lateral hip surgeries don't provide much surface area to warm them," says Mr. Long. "I use a fluid warmer and warm the IV solution."

How about abdominal procedures? "Use multiple warming techniques, including in-line fluid warmers and warming blankets," says Shafik Thobani, MBBS, FRCPC, a clinical assistant professor at Lions Gate Hospital in North Vancouver, Canada. "Also, keep the OR temperature higher just before induction and emergence."

Another tip for all types of procedures: "Place the warming blankets next to the patient's skin, like they're designed to be placed," says Mr. Long. "Many circulators place the warming blankets over the bath towels or blankets, which dramatically reduces the effectiveness of the warming blanket."

"Our ORs are so cold "
As several practitioners point out, ORs tend to be on the chilly side ("Our pre- and post-op areas could freeze beans," says one nurse manager). And among the many challenges are "hot-natured surgeons who want the room freezing and don't like warming devices," says a CRNA. What can you do under those circumstances? The best advice: Do anything you can, or as another anesthesia provider puts it, "Cover as much of their bodies as possible with warming devices, and do it as soon as possible."

WARMING CHALLENGES
Plan Your Warming Strategy Ahead of Time

When cases involve combinations of procedures on various exposed body parts, as well as frequent patient repositioning and changes in the orientation of the OR table, warming can be a challenge. It's a challenge I know well, since 90% of my caseload involves cosmetic surgery patients. In these cases, warming options can be limited by inaccessibility of warming equipment (fluid warmers, for example) or by interference with sterile fields, as with forced-air warming blankets.

The key in these and all challenging cases is to plan your warming strategy ahead of time. Consult with the surgeon pre-operatively regarding any changes in the position of the patient or OR table, and discuss the sequence of procedures to be performed, so that you can readily adapt warming modalities to those changes.

And speak up. For example, liposuction patients in particular can cool down rapidly following the infiltration of several liters of room-temperature tumescent solutions. Although not technically the domain of anesthesia, I insist that surgical personnel warm tumescent solutions, when possible, prior to infiltration.

Finally, if all else fails, improvise. In my practice, facelifts are a frequent procedure. During these procedures I find myself positioned at the side of the patient, often adjacent to the patient's lower extremities, far removed from the surgical site. Our particular type of fluid warmer is not easily utilized in this situation, due to the limitations of IV site and tubing length. Nevertheless, I can often improvise. We use a forced-air warming blanket on the patient's lower extremities. The IV bag and tubing are often directly adjacent to this. Instead of letting the IV tubing hang freely, I tuck the excess infusion tubing beneath the warming blanket. That helps the IV fluid lose its chill as it courses through the 12 inches of excess tubing beneath the blanket.

— Charles A. DeFrancesco, MD