April 29, 2021

The expense of active warming pales in comparison to the potential costs of inadvertent perioperative hypothermia events.

CREDIT: Parkland Hospital
CALM AND COZY Justin D. (J.D.) Buchert, MSN, MEd, MS, RN, places a blanket prewarmed at 130°F on a patient in pre-op.

Preventing perioperative hypothermia not only improves patient safety and satisfaction, but can also save your facility some serious dough. Parkland Hospital in Dallas tested this theory by conducting a four-week in-house study to measure whether prewarming patients helps keep them normothermic during and after surgery.

"The first thing we did was prewarm patients for 30 minutes in cotton blankets warmed to 130°F," says Justin D. (J.D.) Buchert, MSN, MEd, MS, RN, a quality specialist for surgical and trauma services at the facility. While he admits he preferred to have used active warming measures in pre-op, the facility's budget unfortunately couldn't handle the investment. "We instead opted for the warmed blankets because our hospital already owned two refrigerator-sized warming units, and they were at our disposal," he says.

During the intra-op phase, patients were actively warmed, and administered warmed IV fluids and irrigation fluids. Heated blankets were draped on patients during transport to the PACU. Staff documented patients' temperatures in pre-op, when they entered the OR and the PACU, and 30 minutes after arrival in recovery. Of the 63 patients included in the study, 20% were hypothermic in pre-op, 32% in the OR, 41% in the PACU and 7% after 30 minutes in recovery, notes Mr. Buchert. "These percentages were all well below 70%, the national average of inadvertent perioperative hypothermia in 2018," he says.

When the study was over, Parkland Hospital identified millions of dollars in potential savings. "We analyzed the previous year's patient data (2017) and compared it to the time period we measured for our study," says Mr. Buchert. "In 2017, documentation showed a staggering 70% (15,434) of the 22,049 procedures for which we had data included a hypothermic incident. These incidents cost an average of $7,000 per case, according to a literature review."

To determine potential savings, they applied that $7,000 figure to the 15,434 cases with hypothermic incidents, and added it to the savings realized by shorter lengths of stay — they determined warming would save 2.6 days of overnight stays at $875 per day — and came up with a total savings figure of $2.35 million.

To maintain normothermia in patients, break down your protocols into easy-to-implement steps.

BUNDLED UP An effective patient warming protocol starts with application of warming devices and blankets, but it doesn't end there.

Keeping your patients warm from the moment they enter the pre-op bay until after they're released from PACU is a detailed, multi-step process that can be overwhelming for busy OR staff. Surgical leaders can make maintaining normothermia a much more manageable process with the right approach, says Kathy Abbott, BSN, RN, clinical nurse specialty lead in orthopedics/spine at Phoenix Children's Hospital.

Her key to success is breaking the process down into a series of small steps:

• Start with the stretcher. The first step in the warming process is as basic and straightforward as it comes: A pre-op nurse places a body-warming blanket on the patient's stretcher.
• Position the patient accordingly. Comfortably place the patient on the stretcher with the warm blanket.
• Activate warming. Once the patient is situated on the stretcher, apply the active warming technique.
• Set the temperature. Setting the temperature warrants its own step because the process takes a little getting used to, says Ms. Abbott.
• Detach and go. Before the patient is transported to the OR, remove the warming unit and keep it in the pre-op area.
• Warm upon arrival in the OR. As soon as the patient arrives in the OR, a nurse begins active warming. "This ensures active warming continues during the induction, intubation, IV start, central line placement, urinary catheter insertion and placement-site padding," says Ms. Abbott.
• Turn down the heat. A nurse adjusts the active warming during the procedure to maintain the correct body temperature.

Ms. Abbott leaves room for variation and flexibility in her facility's warming process. For instance, patients often adjust settings on active warming devices when that option is available based on their personal comfort levels, and staff need to account for that option as well.

Patient communication, coordinated care and warming strategies all contribute to positive outcomes.

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

Adults who are scheduled for surgery in an ambulatory facility or outpatient hospital department should be given information about preventing hypothermia, according to the National Institutes of Health guidelines for perioperative care before, during and after a surgical procedure.¹ Types of temperature measurement covered by these guidelines include pulmonary artery catheter, distal esophagus, urinary bladder, zero heat-flux (deep forehead), sublingual, axilla and, new in 2016, rectal temperature.

It all starts with good communication with the adult patient and his or her family ahead of surgery to explain the importance of staying warm before surgery to lower the risk of postoperative complications. Among other important points, the updated guidelines include these recommendations for coordinated care: the patient should be advised to bring additional clothing, such as a robe, vest, warm clothing and slippers; the patient should tell staff if they feel cold at any time; the staff should pay particular attention to the comfort of patients with communication difficulties before, during and after surgery; and the staff should not use indirect estimates of core temperature in adults having surgery.

Additionally, the guidelines state that "when using any temperature recording or warming device, healthcare professionals should be trained in their use; maintain them in accordance with manufacturers' and suppliers' instructions; and comply with local infection control policies."¹

During the preoperative phase, an hour before induction of anesthesia during which the patient is prepared for surgery, each patient should be assessed for their risk of inadvertent perioperative hypothermia and potential adverse consequences before transfer to the OR. According to the NIH guidelines, "If the patient's temperature is below 36.0°C, start active warming preoperatively..." and "if the patient's temperature is 36.0°C or above, start active warming at least 30 minutes before induction of anesthesia, unless this will delay emergency surgery."¹

The surgical team is advised to "maintain active warming throughout the intraoperative phase."¹ The intraoperative phase is defined as total anesthesia time from the first anesthetic intervention through to patient transfer to the recovery area. The guidelines advise "the patient's temperature should be measured and documented before induction of anesthesia and then every 30 minutes until the end of surgery."¹

Furthermore, intravenous fluids (500 ml or more) and blood products should be warmed to 37°C using a fluid warming device, according to the NIH guidelines. To keep the patient warm throughout, a forced-air warming device can be used if anesthesia is used for more than 30 minutes or for less than 30 minutes if the adult patient is at higher risk of inadvertent perioperative hypothermia. The updated recommendation also includes using a resistive heating mattress or resistive heating blanket.

The postoperative phase, defined as the 24 hours after the patient has entered the recovery area, is also a time to pay close attention to the patient's temperature, which should be measured and documented. Importantly, "if the patient's temperature is below 36.0°C, they should be actively warmed using forced-air warming until they are discharged from the recovery room or until they are comfortably warm."¹

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. Visit Right Now Campaign | Gentherm for more information.

Avoid these patient-warming pitfalls while warding off hypothermia.

If you're not vigilant about proper patient warming procedures and precautions, your efforts could wind up doing the exact opposite of what they're intended to do: Keep patients safe and comfortable.

"Warming devices carry a real risk for patient harm," says Michelle Feil, MSN, RN, CPPS, WCC, a clinical practice leader at Penn Medicine in Philadelphia. She authored a report for the Pennsylvania Patient Safety Authority that analyzed 278 harmful or potentially harmful events associated with patient warming devices. Here are four of the most dangerous:

• Thermal injuries. These come in a variety of forms and severity, and tend to occur when providers use devices in ways that are inconsistent with the corresponding instructions for use (IFUs). One example is the extremely dangerous practice of "free hosing," where the hose of a forced-air warming device is placed underneath surgical drapes or the blanket of a patient's bed or stretcher. This off-label use has resulted in numerous cases of serious patient burns.
• Temperature monitoring mishaps. While patient warming devices are designed to maintain normothermia in patients who can't thermoregulate their body temperature due to anesthesia, both hypothermia and hyperthermia can still occur — especially when staff members don't closely monitor a patient's temperature or are using warming devices correctly. Lack of monitoring can lead to overwarming, especially during surgeries performed on pediatric patients.
• Equipment issues. Often these are maintenance-related, and can be avoided altogether by following the manufacturer's IFUs on everything from cleaning the non-disposable surface with specified disinfectants to always using the disposable coverlets that come with forced-air warming devices as single-use items.
• Skin damage. The report contained concerning examples of skin tears caused by adhesive strips on warming blankets, as well as blisters that resulted from allergies to adhesives. These can be easily avoided with some foresight. For instance, remind staff to be extra cautious when removing adhesives from certain patients, especially those older than 65, current steroid users and those with a history of previous skin issues.

Ms. Feil says these risks can be safely mitigated by providing hands-on training on the devices with staff.

Maintaining normothermia plays a key role in overall ERAS protocols.

Patient warming is an integral part of the intraoperative phase of Enhanced Recovery After Surgery (ERAS) protocols in several major Canadian healthcare institutions, according to a recent article written by seven medical professionals at the University of Winnipeg.

The techniques to maintain normothermia cited in the article, which appeared in the Canadian Medical Association Journal, focused mainly on the intraoperative phase of care, including increasing the ambient OR temperature and employing active warming devices and warmed intravenous fluids.

Proponents of ERAS strategies say the protocols result in calmer patients, better outcomes and cost savings. The research team cited a 2016 systematic review of 67 studies that found that intraoperative warming delivers a host of benefits over and above preventing hypothermia, including the reduction of surgical site infections, fewer cardiovascular complications and less blood loss.

The article also cited a randomized controlled trial that showed that pre- and post-operative warming reduced intraoperative blood loss and surgical complications as well.

The authors stress the need for close collaboration between the surgical and anesthesia teams to ensure intraoperative normothermia is maintained.