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March 18, 2021
OSD Staff
Publish Date: March 18, 2021   |  Tags:   Patient Safety
eNews Briefs March 18, 2021


Avoid Misuse of Patient Warming Devices

Your Thoughts on the Benefits of Patient Warming

Maintaining Normothermia in the Perioperative Patient

How Long Should You Prewarm Patients?

APIC Looks to Grow Patient Safety Talent Pool


Avoid Misuse of Patient Warming Devices

Skin burns and even trips to the ICU can result if staff doesn't apply them correctly.

CONSTANT CHECKS CONSTANT CHECKS Staff should still closely monitor patient temperatures while warming devices are in use.

Active patient warming can help prevent hypothermia and related complications such as cardiac trouble, impaired immune function, increased risk of infection and lengthier post-op stays. But if staff don't follow proper protocols for the technology's use and application, maintaining normothermia can cause more harm than good.

One big issue for staff to understand is that warming devices aren't solely for patient comfort. They're primarily therapeutic devices that, if used improperly, can harm a patient, says Michelle Feil, MSN, RN, CPPS, WCC, clinical practice leader at Penn Medicine in Philadelphia. Ms. Feil, who analyzed 278 harmful or potentially harmful events associated with patient warming devices to author a Pennsylvania Patient Safety Authority report, recalls some common categories of distressing mishaps:

  • Thermal injuries. The most frequent incidents involved uses of warming devices that were inconsistent with manufacturer instructions for use (IFUs). One patient lied directly on top of a warming blanket during an appendectomy, resulting in skin reddening, even though the IFU specifically stated patients should never be positioned on top of the blanket, only covered by it. Another example: "free hosing," where a forced-air warming device's hose is placed underneath surgical drapes or the patient's blanket. This off-label use has resulted in serious patient burns because so much heat is concentrated in one area.
  • Overheated fluids.. Many facilities warm IV or irrigation fluid as an adjunct to patient warming. Some, however, warm IV fluids in warming cabinets designed specifically for cotton blankets, an inappropriate practice that has led to patient burns. Fluid warming devices with integrated temperature monitoring systems can ensure fluids maintain recommended temperatures.
  • Inadequate temperature monitoring. Staff members shouldn't be lulled into a false sense of security when using warming devices. They should always closely and continuously monitor patient temperatures while making sure they are using warming devices correctly. Ms. Feil recalls one incident she analyzed where a staffer set a warming blanket's temperature to 40°F instead of 40°C, which meant the patient was actually being cooled. The patient's body temperature dropped to 94.4°F and they were taken to intensive care postoperatively.
  • Equipment mishaps. Often maintenance-related, most of these issues can be avoided by following the IFUs, which describe how to clean non-disposable surfaces with specified disinfectants, when and how to change filters, how to clean a warming device's tubing between every case and more.
  • Skin tears. Ms. Feil analyzed examples of skin tearing caused by adhesive strips on warming blankets, as well as blisters on patients who were allergic to adhesives. She advises caregivers to be extra cautious when removing adhesives from patients, especially older individuals, current steroid users and those with histories of skin issues.

Ms. Feil believes hands-on training of staff who work with warming devices is crucial. "They need to know exactly how it works with real patients in real clinical situations," she says.

Your Thoughts on the Benefits of Patient Warming

Outpatient Surgery's most recent reader survey revealed many surgical facilities prioritize the prevention of hypothermia.

COMFORT AND CARE COMFORT AND CARE Administrators view patient warming as an important clinical intervention and a way to make patients feel less anxious before surgery.

Patient warming continues to be an important aspect of maintaining patient safety and comfort, according to a recent survey of Outpatient Surgery readers. Of particular note, 61% of surgical facility leaders say they warm every patient, while four of five say they employ both active warming and "passive" prewarmed blankets.

"Warming should be available to all patients and used whenever possible," says Kimberly Klinkowski, RN, MSN, director surgical services as Intermountain Healthcare in Ogden, Utah. "Warming pre-, intra- and postoperatively is a standard of care we deliver to all of our patients," agreed Roberta Schultz Tremper, DNP, administrator at Advanced Surgical Care of Boerne (Texas).

"Warming patients continues to be a critical point of care for surgical patients, as the ambient air and the procedure processes cause hypothermia without some type of assistive patient warming," says Paula Spolarich, director of perioperative services at Southwest General Health Center in Middleburg Heights, Ohio. "Judicious care with this intervention is crucial to good postoperative outcomes."

Some specialties employ warming less, or not at all. "Our surgeries last less than 30 minutes, so we do not use any warming device," says Sheo Sharma, MD, medical director at Femi-Care Surgery Center in Owings Mills, Md. Ophthalmic and ENT centers are common examples. "We are an ASC focusing on eye surgery," says Jean Beede, director of surgical services at Riverside Park Surgicenter in Jacksonville, Fla. "We use warm blankets strictly for patient comfort." Lisa Casnellie, MSN, nursing director at Center for Surgical Care in Florence, Ky., says her center doesn't warm patients either. "Many of our procedures are ear tubes and cataract surgery so they are in the OR for less than 15 minutes," she explains.

Although many researchers and clinicians stress that patient warming devices are therapeutic in nature, many providers focus on the seemingly less clinical benefit of simply making patients feel better before surgery. When we asked respondents about their rationale for warming patients, 84% said they did it to prevent hypothermia and its clinical complications, but 95% said they did to make patients comfortable and prevent shivering. "Keeping them warm is a safety benefit, but it also shows you care," says Toya Brown, BSN, RN, director of perioperative services at Metro Health OAM Surgery Center in Grand Rapids, Mich.

Maintaining Normothermia in the Perioperative Patient

Best practices emphasize active warming before, during and after surgery.

Getinge Credit: Gentherm
ASTOPAD system extends patient warming experience to include surgical prep/drape; to allow uninterrupted warming throughout Intraoperative stay.

Maintaining normothermia is critically important for patient safety, positive surgical outcomes and increasing overall patient satisfaction. Reducing the risk of unplanned perioperative hypothermia is vital for patient safety. According to authors Lynch, Dixon and Leary in "Reducing the Risk of Unplanned Perioperative Hypothermia," the causes of unplanned hypothermia in the OR include "cold room temperatures, the effects of anesthesia, cold IV and irrigation fluids, skin and wound exposure and patient risk factors."14

Keeping surgical patients warm and their core body temperature above 36ºC is not only critical to their safety, but also for their comfort. Unplanned perioperative hypothermia can lead to an increased risk of surgical site infection, prolonged duration of anesthesia and longer recovery times.

While the benefits of maintaining normothermia are clear, an estimated 30% to 40% of patients arrive hypothermic to post-anesthesia recovery.1 A meta-analysis of intra-operative hypothermia studies concluded that an average 1.5°C drop in core body temperature resulted in adverse surgical outcomes. It also resulted in an additional cost of $2,500 to $7,000 in hospitalization costs per patient11 and prolonged hospital stays by 20%.4

So, what exactly is normothermia and why is it so important to monitor during the patient's surgical journey in your facility?

Normothermia is the normal core body temperature, typically 36-38°C. In a surgical setting, a decrease in core body temperature below normothermia can dramatically increase the risk for surgical complications.1,2 Actively warming patients before, during and after the surgical procedures is no longer preventing unintended hypothermia, the most frequent preventable surgical complication.1 Even mild hypothermia, a core temperature of 34-36°C, is associated with serious surgical complications.3,4,7,13

Active warming is needed to counteract the negative effects of anesthesia on normal core body temperature.6

Patients who become hypothermic are at increased risk for a number of negative outcomes, including adverse myocardial outcomes; surgical site infections1,12,13; increased blood loss12; increased transfusion requirements2; impaired wound healing12; and prolonged recovery and hospitalization time.2

How can you lower rates of unintended hypothermia? These can be lowered when a combination of warming methods are used during surgery.4 In fact, AORN guidelines strongly support prewarming to reduce heat redistribution caused by anesthetic induction.3,5,8 Best practices for maintaining normothermia include compliance with guidelines that emphasize the importance of using some form of warming for every patient.3-5

In addition, preoperative patient assessment to identify risks for hypothermia is important. Active warming before, during and after surgery will also help lower the risk of unintended hypothermia. Monitoring patient temperature and maintenance of normothermia until the patient is stable reduces the risk factors as well.

Note: Gentherm offers a broad portfolio of patient temperature management products and is the only site-of-care provider in perioperative temperature management across all 4 modalities. Learn more at www.gentherm.com.


1. Fred C, Ford S, Wagner D, Vanbrackle L. Intraoperatively acquired pressure ulcers and perioperative normothermia: a look at relationships. AORN J. 2012;96(3):251-260.

2. Sun Z, Honar H, Sessler DI, et al. Intraoperative core temperature patterns, transfusion requirement, and hospital duration in patients warmed with forced air. Anesthesiology. 2015;122:276-285.

3. AORN Guidelines: Recommended practices for the prevention of unplanned perioperative hypothermia. AORN Journal. 2007; 85(5):972-983.

4. Hooper VD, Chard R, Clifford T, et al. ASPAN's evidence-based clinical practice guideline for the promotion of perioperative normothermia: Second edition. J Perianesth Nurs. 2010;25(6):346-365.

5. National Institute for Health and Care Excellence (NICE). Hypothermia: prevention and management in adults having surgery. https://www.nice.org.uk/guidance/cg65. Published April 2008 (2016 updates). Accessed November 2019.

6. The Association of periOperative Registered Nurses. AORN guidelines update: 4 updates for more effective hypothermia prevention. https://www.aorn.org/about-aorn/aorn-newsroom/periop-today-newsletter/2019/2019-articles/hypothermia-prevention. Published August 28, 2019. Accessed November 2019.

7. Torossian A. Thermal management during anesthesia and thermoregulation standards for the prevention of inadvertent perioperative hypothermia. Best Practice & Research Clinical Anesthesiology. 2008;22(4):659-668.

8. Horn EP, Bein B, Böhm R, Steinfath M, Sahili N, Höcker J. The effect of short time periods of pre-operative warming in the prevention of peri-operative hypothermia. Anaesthesia. 2012;67(6):612-617.

9. Lenhardt R. The effect of anesthesia on body temperature control. Front Biosci (Schol Ed). 2010; 2:1145-1154.

10. Sessler DI. Temperature monitoring and perioperative thermoregulation. Anesthesiology. 2008; 109:318-338.

11. Mahoney CB, Odom J. Maintaining intraoperative normothermia: A meta-analysis of outcomes with costs. AANA J. 1999;67(2):155-164.

12. Kay AB, Klavas DM, Hirase T, Cotton MO, Lambert BS, Incavo SJ. Preoperative warming reduces intraoperative hypothermia in total joint arthroplasty patients. J Am Acad Orthop Surg. 2019; doi: 10.5435/JAAOS-D-19-00041.

13. Sessler DI. Non-pharmacologic prevention of surgical wound infection. Anesthesiol Clin. 2007; 24(2):279-297.

14. Susan Lynch, RN, MSN, CNOR; Jacqueline Dixon, RN, BSN, MSHA, CNOR; Donna Leary, RN, CNOR, AORN Journal 92 (November 2010):553-562.

How Long Should You Prewarm Patients?

Study backs beginning warming methods just before the start of surgery.

Prewarming patients for 10 minutes is enough to prevent inadvertent perioperative hypothermia (IPH) during laparoscopic gynecologic cases, according to a team of researchers from Korea. The finding calls the standard practice of warming patients for 30 minutes before procedures into question.

The researchers, publishing the results of a randomized controlled trial in Anesthesia & Pain Medicine, sought to confirm whether a relatively brief prewarming period would benefit patients in preventing IPH. The study intended to address the findings of previous studies that showed that conventional intraoperative warming with a forced-air warming device is not enough to avoid IPH, suggesting additional methods are needed.

They randomly assigned 54 patients to two groups: one received 10 minutes of active prewarming before anesthetic induction and during surgery, while the other was warmed only intraoperatively with an active warming device. The ambient temperature of the OR was maintained between 69.8°F and 71.6°F, with all administered fluids kept at room temperature. Core body temperatures on arrival in the OR and before induction did not differ significantly between the two groups, and core body temperatures of those who had 10 minutes of prewarming did not significantly increase.

The researchers observed intraoperative hypothermia in 73% of the patients in the non-prewarming group and in just 24% of the patients in the prewarming group. Core body temperature changes were significantly different between the groups. Postoperative shivering occurred in 31% patients in the non-prewarming group and in just a single patient in the prewarming group.

Rapid drops in body temperature in the first hour after anesthesia induction are due to core-to-peripheral thermal redistribution, say the researchers. Prewarming, which warms the surface of the body before induction of anesthesia, can reduce the temperature difference between the body's core and periphery, and decreases the degree of core-to-peripheral thermal redistribution.

The duration of the prewarming used in the study goes against IPH prevention guidelines that recommend 30 minutes of prewarming. "Adopting this idea as a daily clinical practice remains a hardship, because 30 minutes is a significant amount of time in a fully scheduled operating environment," write the researchers. They sought to add to the limited research available on the 10-minute prewarming strategy, claiming to be the first study to add intraoperative active warming to prewarming to determine their combined results.

The researchers conclude, "Among patients undergoing gynecologic laparoscopic surgery, warming patients for 10 minutes preoperatively on the operating table is associated with better management of perioperative body temperature and can prevent intraoperative hypothermia." They say 10 minutes of prewarming is especially beneficial for patients undergoing shorter procedures of up to an hour in length; during longer surgeries, patients tend to be normothermic postoperatively because core temperatures start to rise after thermal redistribution is completed if patients are kept well-warmed during surgery.

One notable part of the study surrounds the site of the prewarming — on the table in the OR rather than in a pre-op bay. Acknowledging that further study is needed, the researchers hypothesize that "it is likely that the prewarming location affects the quality of warming, particularly in prewarming for a short period." A possible reason for this, they say, is that active warming cannot be maintained during transfer to the OR, leading to a loss of the thermal energy the patient had obtained.

APIC Looks to Grow Patient Safety Talent Pool

The association is teaming with universities to create infection control curriculum for college students.

Not every surgical facility employs a full-time infection control professional. In some cases, that's simply a budgetary issue, but in others it's an inability to find a qualified candidate. The Association for Professionals in Infection Control and Epidemiology (APIC) is looking to broaden the pool of infection prevention talent by creating an infection prevention and control curriculum for colleges and universities.

APIC says its IP Academic Pathway will be the first national effort to link undergraduate and graduate programs to the field of infection prevention and control, with the ultimate goal of certifying students in the field. APIC envisions bachelor's, master's and continuing education programs to prepare students for certification and careers in infection prevention and control.

"The pandemic has brought to light the tremendous need for trained infection preventionists in our nation's healthcare facilities," says APIC CEO Devin Jopp, EdD, MS. "While APIC has a robust competency model and other resources to support professionals already practicing in the field, a clear pathway into infection prevention and control careers does not currently exist for college and university students. Through IP Academic Pathway, APIC plans to create an intentional track for infection prevention certification and degree programs. This will help not only the healthcare field, but also industries like entertainment, hospitality and travel, which are increasingly hiring infection preventionists."

At present, APIC is seeking to develop the core concepts of the education pathway, which will detail competencies needed to work in infection prevention and control as outlined by the Certification Board of Infection Control and Epidemiology (CBIC). APIC is soliciting input from both the infection prevention and higher education communities, and seeks university partners willing to help design and pilot the new program.