There’s no question that maintaining optimal patient body temperature throughout a surgical procedure plays a vital role in overall patient care and positive outcomes. Studies have shown that even mild intra-operative hypothermia may lead to numerous complications that extend far beyond patient discomfort, including increased risk for surgical wound infection and intra-operative blood loss, protein wasting, cardiac-related incidents and longer healing times and lengths of stay. The associated cost of treating hypothermia is also staggering, with studies placing the figure between $2,500 and $7,000 per patient.

While the risk for patient hypothermia is inherent in virtually every OR thanks to cool ambient temperature in the surgical suite, administration of fluids and use of anesthesia which compromises the body’s ability to regulate body temperature, the good news is that a plethora of products are now available to help ensure thermoregulation – not just during the procedure, but before and after.

"Patient warming products have been around for many years, but those that are offered today have come a long way as more has been discovered about temperature regulation," says Dan Koewler, product manager for Cincinnati Sub-Zero, Cincinnati, OH. "The industry is moving forward and meeting the [healthcare sector’s] needs by offering technology that is more effective, user-friendly and safer than products of the past."

Gone are the days where ORs in this country are limited to cotton blankets, heated humidified air and circulating water mattresses. Today’s surgical staff can now choose from innovative forced air systems, wrap-around warming pads, fluid warming systems and cabinets – and even space-saving, lightweight and adornable products that can move with the patient throughout the entire surgical process. Another benefit, sources told Healthcare Purchasing News, is that such cutting-edge warming technology doesn’t have to burn a hole in hospital budgets.

"Not only must these products be clinically effective, they also have to be cost-effective. If they’re not, they won’t be used," said Brian Stelley, acute care marketing manager, Gaymar Industries, Orchard Park, NY.

Convective warming

Statistics show the most common method of managing core body temperature in the surgical patient is via forced air or convective warming. At least two-thirds of U.S. acute care hospitals and a growing number of surgery centers and outpatient facilities employ this technology. Forced air or convective warming is also viewed as one of the most effective methods for decreasing the risk of adverse outcomes and limiting costs incurred by patients, providers and third-party payers. In fact, an article published in the American Association of Nurse Anesthetists Journal referred to 20 different studies that found forced air warming was the best way to maintain normothermia.

While the forced air or convective warming method itself is not new, manufacturers have certainly worked at meeting evolving surgical demands and keeping the products up-to-date. Cincinnati Sub-Zero has expanded its offerings by adding more procedure-specific products that it feels are sterile, disposable, less cumbersome and do not interfere with the procedure. For open heart surgery, for example, Koewler said the FilterFlo warming blanket — used in conjunction with the company’s convective warming system — can be placed just below the naval, while still warming effectively and efficiently. Cincinnati Sub-Zero currently offers six different blankets and will be adding eight more to its product line.

Arizant Healthcare Inc., Eden Prairie, MN, offers a next generation warming unit in its Bair Hugger temperature management lineup. The latest model offers enhanced features over its predecessor, including hose-end temperature sensing and microprocessor control for accurate air temperature delivery, increased airflow, three temperature sensors, and a built-in hour meter for monitoring usage for preventive maintenance. The product line also includes a broad range of blanket models for use throughout the perioperative period, including models with cut-outs that expose the surgical site.

John Carroll, product manager for the Bair Hugger line, said the low price point is making it easier to implement the technology in surgeries across the board, regardless of their duration.

"For short cases, many may not take the time to put the warming unit in place prior to surgery because they may believe that patients will develop hypothermia during shorter procedures. That’s where the big misunderstanding lies because it’s in the first hour that body heat drops the most."

"As technology has evolved, prices have dropped and the [units] have become smaller, more lightweight and easier operate," Carroll continued, adding that convective warming blankets that once were priced nearly $20 each can now be purchased for about half that
figure.

Suppliers are also responding to customer demand for space-saving equipment to keep surgical environments more streamlined, efficient and clutter-free. Pleasanton,CA-based Nellcor, a division of Tyco, manufacturers a convective warming system that is nearly half the size and one-third the weight of earlier models. The WarmTouch system also has advanced safety and operational features that weren’t found on models of the past, including an automatic temperature stepdown and shutdown, a high air flow rate, fast warm-up with the system reaching 38°C in 30 seconds. The unit works in conjunction with CareDrape blankets, which come in numerous sizes and styles, including a sterile blanket for use during cardiac procedures.

Gaymar manufactures Thermacare, a portable warm air blower unit, and various sizes of "non-lofting" quilts that are perforated to allow direct access to the patient. And because the quilts are compatible with other warm air blowers, facilities can net more savings, Stelley noted.

Hospitals have other options as well, including less obtrusive, mobile radiant warming systems that use infrared energy to warm the patient. The SunTouch warmer made by New Zealand’s Fisher & Paykel Healthcare (Laguna Hills, CA), for example, can be placed over the patient to heat face, hands, feet, legs or torso, eliminating the need for direct contact. Radiant infrared heating can warm the blood by passing through the skin’s dermal layer to the sub-dermal vasculature and arteriovenous anastomoses (shunts linking the arteries and veins).

The SunTouch warmer use feedback from a skin temperature sensor to control heat delivered to the patient and features high- and low-temperature alarms for added control and accuracy. The company cites potential cost savings as another benefit. Because the warmer never touches the patient and can be used repeatedly, hospitals can reduce the need for single-use disposables and blanket inventories.

Liquid heat

Water-based warming technology, another thermoregulation staple, has also become more sophisticated. Kimberly-Clark Professional, Roswell, GA, the big disposable
products manufacturer, entered the patient temperature control market this summer when it acquired the patient warming system business of Louisville, CO-based Medivance Inc.

"In listening to customer needs and goals, we decided this was an important area that we wanted to [address]," said Mike Mattos, general manager for Kimberly-Clark’s infection control and patient warming businesses. Although the system appears to be a departure from the products K-C has historically offered, Mattos said the equipment’s disposable components are a logical extension to the company’s disposable line.

The patient warming system, which requires coverage of less than 20 percent of the patient’s body and provides maximum access to surgical sites, circulates temperature-controlled water through disposable gel pads that are applied directly to the patients’ body. The unit is available with both a self-regulating automatic mode and a manual mode, and features an easy-to-use control panel and sophisticated control algorithm.

"The system has a patented no leak, negative-pressure design that allows fluid to run between the foam and film layer. With the negative pressure, if the pad is cut, fluid will flow back into the system and not contaminate the operating room," Mattos explained.

Gaymar is also a player in the water-based warming segment. Its MediTherm III system features a central control unit with a manual mode for controlling blanket temperature and an automatic mode for patient temperature control.

Once the ideal temperature has been reached, the water flows through leak-proof connectors and into a double-sided disposable blanket that features a random flow design for continuous flow and even temperature distribution. The MediTherm III system is also compatible with the company’s new Rapr·Round blanket, which conforms to the patient and can cover up to 72 percent of the skin surface.

Some products may even simplify patient transferring. With Cincinnati Sub-Zero’s warming pads, patients can be placed on top, eliminating the need for blankets that can slip off the patient or potentially hinder patient transfers. The same can be said for the Cool/Heat warming pads and patient positioners from Pedigo Products Inc., Vancouver, WA. The product line, developed for use before, during and after surgery, offers precise temperature control, minimal set-up time between patients and a pressure reduction, fluid-resistant pad.

While external warming technology is undoubtedly effective, it isn’t the only means of boosting patient temperature. Introducing warmed fluids intravenously is another popular approach, and technological advancements are making the practice even more widespread. In addition to offering alternatives to water bath-based systems that can be a potential source for gram-negative bacteria in the OR, there’s even the trend toward so-called "intelligent" systems that react to changes in flow rates and include a range of built-in safety features.

Arizant’s Ranger Blood and Fluid Warming System uses conductive warming plates to warm fluid at flow rates up to 30 liters per hour. The system employs SmartTechnology to automatically and instantly respond to flow rate changes. It is also equipped with various safety features, such as audible and visible alarms that sound if temperature exceeds or falls below the set point, as well as a secondary, back-up alarm system.

Using dry heat warming technology, the Medi-Temp III blood and fluid warmer from Gaymar eliminates concerns about filling and spilling water, and the risk for contamination. The IV-mounted system was designed to handle a broad range of flow rates and features an adjustable temperature set point from 38°C to 43°C that allows the clinician to select the temperature best suited for the type of procedure or patient.

Raising comfort

Surgical staffers who have made numerous trips to the warming cabinet to grab yet another cotton blanket understand that comfort is another core factor in patient warming. But with patients using an average of nine cotton blankets during the perioperative period, OR personnel also know just how inefficient – and costly – it can be to keep a patient comfortable.

Despite their longstanding presence in the OR, studies show that cotton blankets aren’t exactly the most cost-efficient way to maintain patient comfort, particularly given blankets’ rapid heat loss. The price of an average 1.75-lb. bath blanket can range from $4 to $5 each and cost more than $1 to launder. Add to that the time nurses spend replacing the blankets and the associated storage expenses and it becomes clear why manufacturers have been searching for alternatives.

Enter Bair Paws Patient Adjustable Warming System, a new product by Arizant designed to comfort patients, replace traditional blankets and gowns, and alleviate some of the burden on nursing staff. The patient-controlled system consists of a portable forced air warming unit that attaches to a perforated gown. When a hose is attached to the gown, warm air circulates through the holes.

"Cotton blankets are great at first, but heat dissipates quickly and nurses have to keep going and getting another one," said Julie Wick-Powell, senior product manager for Arizant Bair Paws line. "Bair Paws eliminates those issues. With this system, patients get their own gown and can control the temperature with a hand-held controller. It is also portable, allowing patients to take the system with them throughout pre-op, surgery and into recovery."

That’s not to say the cotton blanket has fallen by the wayside. In fact, few can argue that, despite their drawbacks, they remain an OR staple. And warming cabinet manufacturers are turning out new technology to better meet the surgical sector’s needs.

Not unlike other warming equipment, today’s cabinets are becoming more sophisticated with various configurations, more streamlined construction, digital controls and even separate chambers to allow different temperatures. Blickman Health Industries, Lodi, NJ, features single- and double-door cabinets, and independent temperature control for dual compartment units. Cari-All Healthcare, Battle Creek, MI, also offers a wide selection of warming cabinets designed with digitally-controlled heating chambers, rapid warm time and a 90°-160°F range.

When Menomonee Falls, WI-based Enthermics entered the market in 1995, company executives saw a need for products that could pull double-duty. It responded by offering cabinets with various interchangeable chambers to accommodate injection fluids, irrigation fluids and blankets – at temperatures most appropriate for each product. The injection mode, for example, offers a temperature range of 90°-110°F, while the irrigation mode ranges from 90°-150°F. Working under the premise that blankets should be warmer, Enthermics features a blanket warming mode that ranges from 90°-200°F.

According to Mark Suszkowski, vice president of sales and marketing for Enthermics, chambers can be mixed and matched to suit individual OR needs and can also be stacked to save valuable space. Further, he explained that using Enthermics’ views its fluid warmer as a more cost-effective alternative to inline catheter warming systems.

"We don’t want to replace catheter warming systems, but we believe that [using] convenient, easy to reach fluids that don’t have
to be charged to the patient are a good
alternative."

Cooling trends

Just as warming a patient can offer both therapeutic and comfort benefits, the same can be said for cooling. In fact, a study by the Montreal Heart Institute revealed that cooling body temperature by a few degrees is not only safe and effective, but may benefit heart attack and stroke patients. Mild hypothermia is believed to offer organ protection, including heart muscle, after blood flow has been interrupted.

In light of such findings, manufacturers of temperature management systems are making great strides in the realm of patient cooling. For its Arctic Sun Model 2000, Medivance uses a temperature control unit to cool water before sending it into energy transfer pads that are placed directly on the patient. Gaymar’s Rapr·Round blanket can also be used to keep patients cool, as can Pedigo’s Cool/Heat pads.

Cincinnati Sub-Zero offers localized water-based cooling systems for treatment of sports injuries and migraines, as well as a cardiovascular heating/cooling system that delivers temperature-controlled water to a blood heat exchanger.

"By cooling the brain, damage can be minimized and by cooling the body down quickly in post-cardiac arrest patients, it’s been shown to offer protection from a lack of oxygen and against [reopening of the artery]," said Koewler, adding that cooling systems are also beneficial in the event of high fevers that may occur during or after the procedure.

Like warming, cooling may also help increase patient comfort. Although Bair Paws offers no therapeutic cooling benefits, the product allows patients to select ambient air to keep them comfortably cool.