June 1, 2023

You don’t need to reinvent the wheel when fighting perioperative hypothermia.

LAYERING WARMTH No matter if you use active or passive warming methods, keeping patients happily cozy while also safe from inadvertent hypothermia is the goal.

Want a surefire way to tarnish a superior surgical outcome from the patient’s perspective? Leave them with a lasting memory of the teeth-chattering, bone-chilling cold they experienced at your surgery center.

Fortunately, it’s relatively simple to keep patients happily warm that won’t add much time to your staff’s already demanding schedule. Here are three prime considerations to keep in mind:

Don’t skimp on prewarming. Most facilities warm patients intraoperatively and in the PACU, but many overlook the crucial moments when patients are anxiously waiting for their surgery in pre-op — which happens to be a time many patients remember and complain about after the fact. Warming during this phase of care is not only important for inadvertent hypothermia prevention, but also a proven way to bolster patient satisfaction.

Up the ante when needed. Artesia (N.M.) General Hospital prewarms all total joint patients preoperatively, with most receiving warmed blankets. For some patients, however, active warming measures are administered as well. “First we cover patients with warmed blankets, and if they’re obviously still cold after that, we use active warming,” says the facility’s perioperative services director, Randall Rentschler, RN, BA, CNOR, CSSM, TNS. In such cases, Artesia generally uses the 10-minute active warming timeframe supported by the current literature.

Set it for success. In many ORs, it can be an uphill battle to convince surgeons to turn up the thermostat. A conflict-free way to find a middle ground while better maintaining patient normothermia is to adjust the ambient temperatures in your preop bays. For example, Advanced CardioVascular Solutions, a heart and vascular center in Oklahoma City, strives to keep its pre-op bays a little warmer than its ORs, at between 72 and 75 degrees.

As with many aspects of the perioperative environment, a few small steps can make a major difference in order to keep patients comfortable, safe and — ultimately — satisfied.

Core temperatures should be monitored and maintained from pre-op all the way through PACU.

Pamela Bevelhymer
HOW WARM? Warming the surgical patient is a wise practice, but if patient temperatures aren’t also monitored consistently and accurately, the intervention won’t be as useful or safe.

Responding to a patient’s perioperative hypothermia is one thing. Maintaining a patient’s normothermia is another. Although both revolve around keeping the patient appropriately warm, the much less emergent task of maintaining patient warmth sometimes gets short shrift.

“While preventing surgical related hypothermia is an ongoing struggle for the perioperative team, maintaining normothermia is a novel concept,” says Heather D. Kooiker, MSN, RN, CNL, CNOR, CRNFA, perioperative professor of nursing at Davenport University in Grand Rapids, Mich., and president of the Association of periOperative Registered Nurses’ (AORN’s) West Michigan chapter. With that in mind, Ms. Kookier presented a poster, “Normothermia: The New Norm,” at the 2023 AORN Global Surgical Conference and Expo in San Antonio.

Ms. Kookier provided not only the latest evidence-based research on safe warming techniques, but described how that research can be translated into practice to ensure patients maintain a safe, normothermic state. The scope of the issue is large: One study she cites found that intraoperative hypothermia was observed in 72.5% of patients. While she vouches for the effectiveness of both passive and active warming, she says high-quality evidence supports the use of active warming methods to prevent unplanned hypothermia.

Ms. Kookier says patients should always be assessed for both extrinsic and intrinsic risk factors that may contribute to inadvertent hypothermia. Extrinsic factors are modifiable risks such as the time and duration of both the procedure and planned anesthesia, patient positioning, use of a pneumatic tourniquet or an intermittent pneumatic compression, and warming equipment constraints such as skin surface area contact and access to the surgical site. Patient-specific intrinsic risk factors include age, sex, low body surface area or weight, congestive heart failure, cardiac vessel disease, previous cardiac surgery, hypotension, history of organ transplantation and a variety of other pre-existing conditions.

She also notes the method of temperature monitoring is important, as surface temperature management may not reflect the patient’s true temperature as well as core temperature management can.

Hypothermic risk management, she says, should take place in all three perioperative phases:

• Preoperatively, providers should record baseline temperature, prewarm the patient for up to 30 minutes, use warmed IV fluids and communicate any identified hypothermia risk to the OR nurse.
• Intraoperatively, the patient should be immediately warmed upon table transfer using warming technology that is evenly distributed and covers the most available surface area. The patient’s temperature should be monitored throughout the procedure. Warm irrigation fluids should be used, and the ambient temperature should be between 68 and 72 °F. All temperature management techniques and patient risk should then be communicated to the post-op nurse.
• Postoperatively, when a large cohort of patients shiver after receiving general or regional anesthesia, providers should measure core temperature and employ active warming technology until the patient reaches normothermia.

“A consistent normothermic state ensures that the patient doesn't suffer the poor outcomes attributed to hypothermia,” concludes Ms. Kookier.

Maintaining patient normothermia pre-, intra- and post-operatively is a critical element to help reduce the risk of surgical site infections and other complications.

3M^®
Perioperative temperature management is key for patient safety.

The healthcare professionals who work in the ambulatory setting have a top goal of keeping patients who enter their doors – for any type of surgery – feeling safe and in good hands. Creating a warming and temperature monitoring protocol is one of the key actions that can lead to increased patient satisfaction and help improve patient safety.

Patients undergoing even short surgical procedures can have inadvertent changes in body temperature that can cause hypothermia as explained in a recent article in Outpatient Surgery Magazine.¹ In the fast-paced ambulatory environment, the systems and steps for active warming and temperature monitoring are critical to keep patients comfortable during their outpatient stay.

The importance of having a plan in place to actively warm all patients and monitor them in pre-op, during surgery and post-op is underscored by the Association of Perioperative Nursing (AORN) in its guidelines. In addition, AORN’s “Prevention of Perioperative Hypothermia (PPH) Tool Kit” (Prevention of Perioperative Hypothermia Tool Kit | AORN), is open access and includes “Ten Steps of Planning Implementation of Prevention of Perioperative Hypothermia” as well as a variety of useful resources and evidence-based practices to promote positive outcomes for surgical patients.

Perioperative hypothermia increases the risk of negative patient outcomes. Maintaining normothermia in patients is a critical element during the entire surgical journey from pre-op, during surgery and in the post-op phase – and this takes buy-in from the entire OR team and is a collaborative effort.

A patient’s core temperature can drop in as few as 30 minutes from the administration of anesthesia. Therefore, it is imperative for the ambulatory surgical team to pay close attention to warming protocols that help to prevent the dangers of surgical site infections and other complications such as metabolic acidosis, cardiovascular effects, increased respiratory distress and surgical bleeding.¹

Unintended hypothermia is commonly considered to occur when a patient’s core body temperature dips below 36°C (96.8° F).² Surgical patients are at an increased risk of hypothermia related to anesthesia for two primary reasons – as explained in AORN’s Guideline for Prevention of Hypothermia. Anesthesia medications impair the body’s voluntary responses (such as moving to a warmer space) and autonomic responses (vasoconstriction and shivering).²

General anesthesia also decreases metabolic heat production by about 15% to 30% and causes a phenomenon known as redistribution temperature drop (RTD). RTD occurs as peripheral vasodilation allows warmer core blood to mix with the colder peripheral blood. As the cooled blood circulates back to the heart the core temperature drops as the body can no longer maintain the temperature gradient between its core and periphery.

This intraoperative temperature drop has been found to potentially create a cascade of negative and even deadly effects, as noted by AORN. In recovery, unplanned hypothermia has been found to increase the risk of wound infections and can also contribute to an increase in poor wound healing and postoperative pain.¹

As patients of all ages and comorbidities enter the outpatient space, clearly the attention to proactive and regulated warming will have a huge impact in patient safety, positive outcomes and patient satisfaction.

References:

1. Stanton, Carina, “Great Reasons to Actively Warm Patients,” Outpatient Surgery Magazine, February 2023

2. Guideline for the Prevention of Hypothermia in Guidelines for Perioperative Practice. Denver, CO: AORN, Inc; 2023

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