October 13, 2021

While almost universally lauded for patient comfort, the majority also appreciate the clinical and operational benefits of warming.

CREDIT: Rylee Chalmers
WARMING FOR ALL Anxious pediatric patients can benefit from the cozy, calming feeling provided by active warming systems.

Given the undeniable evidence that consistently applied patient warming protocols can stave off hypothermia and related complications — such as cardiac issues, increased infection rates and lengthier stays in recovery — while bolstering patient satisfaction, most surgical facility leaders have made maintaining normothermia a top priority.

Illustrating this trend, an impressive 63.3% of facilities said they "always" warm surgical patients, according to an Outpatient Surgery Magazine survey of more than 400 facility leaders. However, facilities diverge on the methods they employ.

According to the survey, the two top methods facilities use are forced-air warming systems (83.2%) or a warmed cotton blanket (81.4%). Other warming methods included a spinal underbody blanket, thermal mattress or bed pad (6.61%), a radiant warming device (3%) and a conductive polymer fabric that warms the patient from above and below simultaneously (1.5%). Another 6.3% cited "other," with write-in answers including warm compresses, hot packs and a Mylar blanket.

While the clinical benefits obviously play a crucial role, the survey found the most popular reason for keeping people warm throughout their perioperative journey centered on the patient experience. An eye-opening 92.4% said they used warming to "make patients comfortable/prevent shivering." This makes sense when you consider the crucial role patient satisfaction plays in outpatient surgery, a field where cold patients can easily become unsatisfied patients. As Pamela Borello, BS, RN, CNOR, CSSM, a nurse at the Michigan Cosmetic Surgery Center in West Bloomfield, puts it, "I've always felt that when patients are warm, they're happier and feel better taken care of."

That's not to imply that these facilities don't appreciate the clinical benefits of warming as well. Nearly 80% said they warm patients to "prevent hypothermia and its clinical complications" and more than half said they warm patients to prevent surgical site infections and reduce recovery/PACU times.

High-tech and low-tech options can ensure IV and irrigation fluid aren't too hot or cool.

CREDIT: Pamela Bevelhymer
CONSISTENT AND RELIABLE Fluid warming cabinets with integrated temperature monitoring systems can ensure that IV and irrigation fluids are always the correct temperature.

When combined with other active patient warming methods, the warming of IV or irrigation fluid has shown to be an effective practice in preventing hypothermia. If your providers employ this tactic, however, they must avoid a critical mistake: warming the fluids in cabinets designed specifically for cotton blankets. The high temperatures in those cabinets have led to burns of patients.

In addition to ensuring fluid isn’t too hot, though, surgical facilities also need to make sure it’s warm enough. "With fluid, the risk is that it's too hot or too cold," says Paul Austin, CRNA, PhD, a professor of nurse anesthesia at Texas Wesleyan University in Fort Worth. "You don't want to burn the patient, but on the other hand, you want the warmed fluid to be as efficacious as possible." Dr. Austin advises facilities to use a fluid warming device with an integrated temperature monitoring system, which ensures the fluid is warmed to the recommended temperature.

If your facility doesn’t possess such technology, a low-tech way to track when to remove solutions from the warming cabinet exists. "Go to an office supply store and purchase a price-marker label gun," says Brent Klev, MBA, BSN, RN, director of nursing at University of Utah Health in Salt Lake City.

"Store the label gun, along with its instructions on how to set the date, by the warmer." As a staff member places bottles in the cabinet, they simply take the gun, quickly set the expiration date, and print and stick the bright, easy-to-read labels on each bottle. "This cheap trick ensures that all bottles are clearly marked with the date when you need to remove them from the warmer," says Mr. Klev.

The importance of improving patient outcomes with proactive temperature management to help avoid unintended hypothermia. 

CREDIT: 3M
Author Amanda Motter, RN, CNOR, is a registered nurse with operating room and preoperative experience in various specialties in pediatrics and adults. Amanda has worked as a specialty service leader and in OR leadership. In her current role at 3M in the Healthcare Business Group, she works with the perioperative and patient warming product portfolios on new product development and provides education, training, and support to global clinicians. She has spoken around the country on patient safety and infection control practices. She is a member of AORN and APIC.

CREDIT: 3M
3M^™ Bair Hugger^™ Patient Warming System.

Maintaining normothermia, which is defined as core body temperature 36°C-37.5°C before, during and after surgery is critical.^1,2 Keeping patients normothermic in all practice settings is critically important to help lower the risk of negative surgical outcomes associated with unintended hypothermia.

In fact, clinical practice guidelines, along with recommendations from the WHO and the CDC, recognize the critical nature of temperature management in ultimately helping to improve patient outcomes. Yet, perioperative hypothermia still remains a common, surgical complication that can lead to several adverse and sometimes deadly consequences.

The difference between a positive patient outcome and a complicated recovery can be simply a matter of degrees. Numerous studies have demonstrated that even mild hypothermia can result in significant complications, including increased rate of wound infection,^3,4 increased mortality rates,⁵ coagulopathy,^5-7 prolonged and altered drug effect,⁸ myocardial ischemia and cardiac disturbance,^9,10 shivering and thermal discomfort,^3,1-14 and delayed emergence from anesthesia.¹⁴

The major cause of intraoperative hypothermia is not heat loss to the environment or cold operating room temperature, but instead a phenomenon commonly referred to as redistribution temperature drop (RTD). RTD is caused by the action of anesthetic medications on the body's ability to properly thermoregulate. Under anesthesia, the ability of the hypothalamus to regulate temperature is diminished as the anesthetic agents reduce metabolism and depress the thermoregulatory response, triggering vasodilation – or an opening of the shunts used to retain warmer blood in the core.

Anesthetic-induced vasodilation allows heat in the warm core tissue to mix with cooler peripheral tissue, which warms the periphery at the expense of the core temperature.12,16 When warmer blood in the core mixes freely with cooler blood in the periphery, this causes a dramatic drop in core body temperature — up to 1.6°C within the first hour of surgery.¹⁵ This means that a patient who has a normal pre-induction core temperature of 36.2°C may be hypothermic approximately 7.5 minutes following induction.

Inadvertent perioperative hypothermia remains a common complication of surgery, however, a proactive approach to temperature management can help prevent it. The best solution is to institute such a proactive perioperative temperature management system to help maintain normothermia across the continuum of care.

Proactive temperature management

Proactive temperature management has three distinct goals: 1) increase preoperative mean body temperature (pre-op); 2) maintenance or restoration of intraoperative core body temperature (OR); and 3) post-operative thermal comfort and normothermia (PACU). For both ambulatory and hospital settings, Enhanced Recovery After Surgery (ERAS) protocols, which have been developed by the ERAS^® Society, can help your staff drive collaboration, reduce postoperative complications, and ultimately improve patient outcomes. In fact, data suggest that these ERAS pathways not only improve clinical outcomes and quality of care, but also come with significant cost savings.¹⁷

One convective warming example of the implementation of an ERAS-Compliant Perioperative Normothermia Protocol includes the following:¹⁸

• All surgical patients, especially infants and children, should have their core temperature monitored continuously during the entire perioperative period.
• Prior to surgery, all adult patients scheduled for neuraxial, general or combined anesthesia should be prewarmed with a convective air warming device on its high temperature setting for at least 10 minutes.
• The amount of time between the end of prewarming and induction of anesthesia should be as brief as possible, but ideally fewer than 10 minutes.¹⁹ If more than 1L of intravenous fluid will be administered during the procedure, a fluid warmer should be used.
• During surgery, all patients with anticipated anesthesia durations 30 minutes or longer should receive intraoperative warming that can cover the largest possible amount of skin surface. The warming unit should be operated on the lowest temperature and blower settings that help maintain the core temperature within the normothermic range. Infants and children should be warmed unless contraindicated.
• After surgery, all patients should be warmed until they are thermally comfortable and have a core temperature within the normal range.

Warming and monitoring throughout the patient journey

To be successful, facilities should supply clinicians with the temperature management solutions they need to warm and monitor patients in any type of procedure, under any type of anesthesia, in any setting — throughout the perioperative journey. When selecting a partner to support your temperature management efforts, it is important to consider that partner's ability to meet your facility's unique needs. Ultimately, the chosen solution should provide broad clinical flexibility and proven efficacy. Ask about the system's history, its track record of safety and efficacy, and review the available research. Take the input of a product's end user into account — no one knows more about a system's performance than those who use it every day. The importance of clinician confidence in a product cannot be overlooked.

Note: 3M is committed to helping advance quality of care, improve product utilization, optimize workflow, and strengthen patient satisfaction. Through the 3M^™ Peak^™ Clinical Outcomes Program, we will partner with you to provide insights that will help you achieve better outcomes for your patients.

Note: Please click here for more information. (https://www.3m.com/3M/en_US/medical-us/ambulatory-care/?utm_term=hcbg-msd-ooh-en_us-eng-asc:_ssi_risk_reduction-ona-adv-osm-learn-na-oct21-na)

Multiple measuring techniques can lead to unreliable information about patients' core temperatures.

Most surgical leaders now understand that warming patients throughout the entire perioperative process is a critical aspect of maintaining normothermia. However, one component of warming that often doesn't get the attention it deserves is consistent monitoring of the patient's core temperature. Without it, providers could be getting unreliable patient readings and even allowing cases of hypothermia to go undetected.

One facility that has taken notice of this deficiency is WellSpan York (Pa.) Hospital, which recently identified inconsistent temperature measurement practices throughout each phase of its surgical care. For example, it discovered that different forms of temperature measurements — such as oral, rectal, temporal-artery, esophageal and pulmonary artery temperatures — were being used on the same patients. Because each of these measurement techniques have different levels of reliability, WellSpan York found inconsistency in identifying and ultimately treating hyperthermia.

WellSpan York essentially pushed "reset" and worked to develop a consistent technique for temperature measurement. After a trial and approval process, WellSpan York embraced a non-invasive core temperature monitoring (NCTM) system and implemented it throughout all phases of surgical care. After implementing the NCTM system, WellSpan provided initial and ongoing education to all nurses and anesthesia providers in the perioperative and perianesthesia settings, installed new equipment that allowed temperature data to go directly to the health system's EMR, and conducted audits related to compliance of use, post-op length of stay and rate of hypothermia.

Following these changes, WellSpan's data showed a greater volume of hypothermia among patients, which suggested cases were previously undetected because of less reliable and inconsistently used temperature measuring techniques. This finding led to numerous positive changes at the facility, including improved awareness about hypothermia and more active warming measures deployed in the PACU before discharge. These improvements are crucial because, as the study authors put it, "Early identification and intervention for hypothermia is imperative for improved surgical patient outcomes."

Reflective blankets are a cheaper and potentially more effective alternative to cotton blankets.

Active warming is the gold standard for keeping patients comfortable while keeping hypothermia at bay. If an active warming system isn't in your budget, other options exist to make patients warmer, more comfortable and ultimately more satisfied with the care they received. One alternative is to use reflective warming blankets.

Staff at Houston Physicians' Hospital rely on reflective blankets during the pre- and postoperative phases of care. The blanket is placed on the patient in the preoperative area, and then stored under the stretcher once the patient is moved to the OR. When the procedure is complete, the recovery team simply places the blanket back on the patient during their time in the PACU.

By trapping radiated body heat that would otherwise disperse into the environment, reflective blankets are more effective than plain cotton blankets, says Karen Acosta, MSN, RN, CNOR, Houston Physicians' director of surgical services. They also help to improve patient comfort and satisfaction, she says.

Ironically, Ms. Acosta and her staff hit on the idea to use reflective blankets because of a pandemic-based linen shortage. The facility learned it was spending $15 per patient on linen costs, and could cut that number in half by switching to reflective blankets. It was a rare supply issue that actually led to a beneficial solution. "We reduced linen waste and gained the potential to improve patient outcomes," says Ms. Acosta. "It was a win for our patients and for the facility."

While active warming throughout the entire perioperative process is the preferred approach, any type of warming you can offer your patients is better than no warming at all.