The active prewarming of patients has proven invaluable in the fight against inadvertent perioperative hypothermia (IPH), a serious but preventable complication that can delay wound healing and increase risk of surgical site infections. Patients who suffer IPH might also require more aggressive post-op pain management, remain in recovery longer and be at higher risk of needing a blood transfusion. The clinical benefits of maintaining normothermia clearly go well beyond patient comfort, although the satisfying effects of active warming measures can't be ignored.

Two years ago, we conducted a study to test the benefits of actively prewarming orthopedic and colorectal patients. We wanted to find out if prewarming would:

• reduce episodes of IPH and lower SSI risks and the need for blood transfusions; and
• increase patients' thermal comfort and reduce their anxiety throughout the perioperative experience.

The trial involved applying forced-air warming for 30 minutes to about 500 patients in pre-op. We discovered prewarming resulted in numerous benefits:

• SSIs and blood transfusions decreased in spinal and total joint patients.
• The rate of IPH-related blood transfusions declined from 6% to 4.6%.
• Patients reported an 8% increase in thermal comfort and a decrease in anxiety.
• We realized significant cost savings on the laundering of cotton blankets, which we previously used much more frequently to warm patients.
• 58% our staff showed improvement in their understanding of interventions for maintaining normothermia and its impact on successful surgical outcomes.

We were inspired to launch this nurse-driven study by AORN's and ASPAN's recent evidence-based guidelines that suggest perioperative nurses develop strategies within the plan of care to reduce IPH. Part of our trial included providing education on the benefits of active warming in relation to maintaining normothermia. Our pre-op staff required education because applying forced-air warming involved a completely different process than wrapping patients with the warmed cotton blankets they used previously.

We also provided a lot of education on exactly what normothermia is, along with the risk factors hypothermic patients face. Using online surveys pre- and post-intervention, we noted significant improvement in staff knowledge of the causes of IPH and the most effective interventions for maintaining normothermia. A lot of our staff didn't even know prewarming made a difference.

Our pre-op staff used to cover patients in three, four or even five cotton blankets. In the OR, before draping occurred, staff covered patients with more blankets. Then in recovery, patients received even more blankets. Now, we place a single warmed blanket on top of the forced-air warming gown, mainly for privacy purposes in the hallways. The forced-air warming gowns are single-use, so we don't need to clean or wash them like we did the mountains of cotton blankets we'd pile onto patients before.

Throwing a forced-air warming gown in the trash after every patient use isn't great for the environment, but the accompanying benefits likely are a net positive both for our hospital and the planet. Overall, we saw almost a 30% decrease in linen costs with our vendor when we implemented forced-air warming because the vendor is using less water and detergent.

We selected the style of gown we use because it can be put on patients in pre-op and remain in place as staff connect and disconnect it to forced-air warming units in the OR and PACU. Working with a warming option that can travel with the patient is an efficient way to maintain normothermia. It should be noted there are other effective ways to actively warm patients, including under- and over-body conductive fiber mattresses and table pads.

Warm welcomes

You know the feeling you get when you wrap up in a towel that has come right out of the dryer? That's the feeling warming gowns provide. The patient can control the temperature setting themselves on the models we use, something we call self-regulated warming. Patients appreciate the sense of control and comfort. They feel it's an extra level of care and concern that's been provided for them during their stay.

We found that patients who are warmed in pre-op feel less anxious, and because they're more comfortable, they're easier to anesthetize. They wake up after surgery easier, too. There's no doubt prewarming leads to a better overall patient experience.

Our study supports the effectiveness of prewarming patients to avoid IPH and its related complications. Within our organization, word has spread about how this relatively simple intervention has produced significant changes in how we can care for our patients more effectively. We've also showed the importance of maintaining normothermia and how relatively simple it is to address. We believe healthcare systems should adopt new evidence and support execution of AORN's and ASPAN's evidence-based guidelines on prewarming to offer safe and comfortable care across the perioperative experience. OSM