Bringing renewed interest in patient temperature management protocols, numerous organizations are drawing attention to surgical site infections (SSIs) – just one of the costly complications associated with hypothermic surgical patients.

Leading the pack for a number of patient safety initiatives is the Institute for Healthcare Improvement (IHI) with its "100,000 Lives Campaign" which is recruiting hospitals nationwide in an effort to save lives through the implementation of protocols known to improve patient care. One of the six targeted interventions is to "Prevent Surgical Site Infections" and one of the four ways to achieve that is to maintain post-operative normothermia.

Arizant Healthcare (Eden Prairie, MN) recently launched its own "Prevent Hypothermia" campaign targeting a reduction in SSIs. Citing statistics that say that of the 27 million people undergoing surgery in the U.S. annually, 14 million will suffer from unintended hypothermia and nearly 750,000 will acquire an SSI, Arizant is attempting to educate healthcare providers on simple, cost-effective ways to prevent SSIs, of which 40 to 60 percent are avoidable. The "Prevent Hypothermia"campaign, available at www.PreventHypothermia.org, includes an educational kit featuring a variety of warming measurement and tracking tools, implementation tips and an educational presentation.

Clinical evidence cited by the IHI and others includes a study that evaluated patients undergoing colorectal surgery and proved that there was nearly three times greater chance of an infection with hypothermic patients: an 8 percent infection rate in normothermic patients versus a 19 percent infection rate in hypothermic patients.1 Normothermia is defined as 36 to 38 degrees Celsius; even one degree less than 36 degrees C constitutes a hypothermic patient. And that one degree can make all the difference in patient outcomes and costs.

In a recent study that looked specifically at difficult-to-manage Off-Pump Cardiac Artery Bypass (OPCAB) patients, researchers found that patients who were just 1 degree C below normothermia upon entering the ICU had nearly twice the chest tube drainage output; required two additional units of blood; almost five hours longer to extubation; a little more than half a day longer in the intensive care; and stayed almost a full day longer in the hospital.2

In order to reduce the incidence of such complications, an effective temperature management protocol will involve the use of several different warming products and techniques tailored to meet the unique needs of specific groups of patients. Available options include forced air or convective warming systems; circulating-water conductive systems; fluid warmers and temperature monitoring products.

 The most common systems used to maintain normothermia in surgical patients are forced air warming systems, in which warm air is piped through a blanket placed over or under the surgical patient. It’s cost-efficient and it’s been proven clinically effective time and time again.

"More than 100 scientific papers have been written about the benefits of forced-air warming and maintaining normothermia. In fact, two clinical organizations, including the American Society of PeriAnesthesia Nursing and the American Society of Anesthesiologists, already have forced-air warming guidelines in place," said Troy Bergstrom, senior public relations specialist, Arizant Healthcare.

Complex cases call for
high-tech systems

Indeed forced air warming is effective for the majority of surgeries. However, important to note: "It’s definitely not one size fits all in managing patient temperatures," emphasized Tim Dye, general manager, medical device business, Kimberly-Clark Health Care (Roswell, GA). "I think we will see the market continuing to evolve towards differentiation in the products and greater understanding that [facilities] need to have different applications for different patient populations."

In particular, complex, lengthy and invasive procedures that require access to a large body surface area – such as cardiac surgery, thoracic surgery, organ transplantation, total hip replacement, even robotic surgery – carry a greater risk of hypothermia. These types of procedures are not particularly suited for the more traditional forced air warming products.
                                      Enthermics fluid warmer
Case in point is the above mentioned study on OPCAB patients led by Y. Joseph Woo, M.D., assistant professor of surgery, director of the minimally program for the University of Pennsylvania.2 The study compared the facility’s standard warming practices for OPCAB surgeries, which included the use of a forced air warming system, to the Kimberly-Clark Patient Warming System, a conductive warming system that uses circulating water and unique warming pads with an adhesive hydro-gel layer for optimal heat transfer. The researchers found that the Kimberly-Clark Patient Warming System was able to maintain a 1 degree C higher temperature than standard practice, an average of 36.5 degrees C versus 35.6 degrees C for those warmed by standard practice.

"That one degree temperature difference resulted in a number of significant patient outcomes," said Judson Boothe, senior product manager, temperature management business, Kimberly-Clark Health Care.

Key to the success of Kimberly-Clark’s system is that it’s able to keep a patient warm with very little surface area coverage. Water is an inherently more efficient heat conductor than air and the hydrogel pads provide an excellent interface with the patient’s skin for maximum heat transfer. Kimberly-Clark was recently awarded a group purchasing contract with Premier for its Patient Warming System under the group’s Technology Breakthroughs Clause.

"It’s the high end of treatment methodologies for warming patients and it’s specifically applicable for those complex surgeries where forced air cannot deliver on the objective of maintaining a patient above 36 degrees C as they leave surgery," said Boothe of the Kimberly-Clark Patient Warming System. "It’s been proven in the most complex surgeries that exist." An important safety feature, the K-C Patient Warming System operates under negative pressure, so that when nicked, water is suctioned back into the system, rather than spilling out onto the floor.

To help educate clinicians on temperature management techniques for complex surgery patients, Kimberly-Clark is in its second year of partnership with the Anesthesia Patient Safety Foundation (APSF). "One of our objectives as we partnered with them was to see what kind of an impact we and they could have on the education of the anesthesia community; that actually there is a way to treat more complex surgical patients now that did not exist three or four years ago," said Boothe.

In addition, the company hosted a Kimberly-Clark Knowledge Network Symposium this November: "Thermal Regulation: Implications for the Complex Surgical Patient." The symposium featured four speakers – two cardiac surgeons (including Woo),– a trauma surgeon and an anesthesiologist who talked specifically about the struggles and solutions to treat complex surgical patients from a thermal standpoint.

"If [facilities] look at their procedure basis, they’ll find that they’re doing a pretty good job on maybe 70 percent of their cases, but there’s a large number of those real complex cases that are relatively untreatable without an advanced system like ours," said Boothe. "You just really can’t do it with the more inefficient systems without enough coverage area."

Compounding the problem, "the surgeries tend to be longer, the patients tend to be sicker, they have higher rate of complications to begin with. They already consume a great deal of the healthcare resources," said Boothe.

Facilities often don’t recognize that a problem exists, contends Boothe. Or they may not know that there is a way to maintain normothermia on these types of patients. "They have spent a great deal of time in the past – ten and 15 years ago in some cases – addressing what they thought was a problem and thinking they had solved it by implementing things like forced air warming and other treatments, but had gotten to the point where they’d done all they could and not been able to treat a percentage of the population," he said.

Laura Grisanti, RN, CN, OR, perioperative and temperature management advisor, Gaymar Industries (Orchard Park, NY) agreed that conventional methods are not always best for certain surgeries. "I think they have to be a little bit more creative in how they’re warming their patients, especially with robotics," she said. "There are not a whole lot of places where you can put a warming blanket to cover the patient. I think they’re not able to warm those patients as effectively as they could with some of the existing products or even to try to tell a manufacturer what type of product they need to warm those types of patients."

Grisanti explains that Gaymar’s Medi-Therm water-based unit combined with RaprRound blankets could potentially be used to maintain normothermia during robotic surgery by wrapping both legs.

Cincinnati Sub-Zero (Cincinnati, OH) also has water therapy conductive warming systems including the Blanketrol II that provides both heating and cooling, and the Norm-O-Temp, a compact, heat-only solution. Blanket options include the Maxi-Therm Lite single-use blankets with a soft, non-woven surface, as well as a reusable Plasti-Pad version. Designed specifically for OPCAB patients and applicable for a variety of complex surgical situations, the CSZ Head Wrap allows total patient access by cooling/heating the major blood supply to and from the brain.

Forced air solutions

When selecting forced air solutions, consider safety features such as secure hose connections, heat-sensing alarms, tear- and flame-resistance; the blanket’s likeliness to billow and obstruct the surgical site; as well as blanket configuration and fabric options. Some companies offer a more standardized line of blankets designed to adapt to more surgeries with less stocking options. Others offer a broad range of blanket options each uniquely tailored to specific surgeries and other applications.

Arizant’s Bair Hugger series includes 24 models of blankets – including a new XL Upper Body Blanket designed for obese and bariatric patients – that are attached to the Bair Hugger warming unit.

Providing a unique pre- to post-operative warming option, Arizant’s Bair Paws Gown, originally designed as a comfort warming patient gown, now provides both comfort and clinical warming through a dual-chamber design. The gown can be connected to a conventional Bair Paws warming unit for comfort warming pre- and post-op and also connects to the Bair Hugger warming units in the O.R. to offer clinical warming capabilities during extremity procedures.

"The Bair Paws gown stays with the patient throughout the perioperative process, so it may be used during brief surgical procedures that might not receive warming with a traditional blanket. It is an excellent option for extremity procedures that might not otherwise benefit from warming," said Bergstrom.

Smiths Medical (Carlsbad, CA) offers its EQUATOR convective warming system along with a full line of SnuggleWarm blankets that feature a hose-end temperature control that automatically adjusts to deliver the chosen temperature no matter how cold the environment. The Equator features a strong blanket-to-hose connection with an angled hose-end and an added ridge to prevent the hose from pulling away from the blanket. The SnuggleWarm blankets are made of a high-quality, comfortable fabric that’s resistant to punctures and tears – and they’re designed to conform to the patient’s body and not billow. The blankets are self-extinguishing in the event of a fire.

The Thermacare Patient Warming System from Gaymar is lightweight and portable and can be used with Gaymar’s lower, upper, torso, pediatric and full body quilts (for use in PACU) that are made of a spun bounded nonwoven material.

Cincinnati Sub-Zero’s WarmAir FilteredFlo System uses a low volume air pumping method and filters the air that’s delivered to the blanket through a 0.2 micron HEPA filter. The lightweight compact warming system is used with FilteredFlo blankets in a variety of configurations that transfer warm air in a uniform manner across the heating surface. CSZ’s Warming Tube connects to the WarmAir system and inflates around the patient allowing full-body access for use in the O.R., PACU and radiology.

The WarmTouch convective warming system from Nellcor (Pleasonton, CA) includes a warming unit and CareDrape blankets that are made from a durable but soft Kimberly-Clark material that helps to reduce floating. If torn, the blankets continue to inflate and warm the patient. Nellcor’s CareQuilt is a full body/multi access warming blanket for use in PACU.

Fluid warming

An important component of any perioperative temperature management protocol is fluid warming and there are a number of ways to warm both blood and fluids for injection or irrigation.

Smiths Medical offers several fluid warmers designed for specific applications and best patient outcomes: the HOTLINE fluid warmer is designed for use in routine surgery, while the Level 1 H1200 Fast Flow fluid warmer provides infusion at up to a liter a minute at normothermic temperature for major surgery and trauma.

The systems operate on counter-current technology, or a circulating solution system, that, at lower flow rates allows for much warmer fluids, and at high flow rates affords a much faster and warmer fluid. The Hotline warmer is also equipped with triple lumen tubing that prevents "patient line cool-down" by warming through the tube. An air detector clamp is available for the Smiths rapid infusion systems that detects the presence of air in the line, alerts users with audible and visual alarms, and then clamps the line closed to prevent the air from reaching the patient. The Smiths fluid warmers include a one-year maintenance protocol that helps to reduce costs as well as provides a microbe-free environment since the system is continually cleansed.

Laurie Schechter, director of marketing, Smiths Medical, notes that facilities should warm crystalloids as well as blood, because even though the crystalloids are stored at room temperature, the higher volume needed for infusion will affect patient temperatures.

Another method of fluid warming involves the use of warming cabinets designed specifically for injection fluids, such as those offered by Enthermics Medical (Menomonee Falls, WI). The company offers solutions for warming blankets, injection fluids, and irrigation fluids all in separate cabinets and at different temperatures.

"You cannot warm injection fluids in irrigation cabinets and you cannot warm them in blanket warming cabinets. They must be warmed to proper temperature with a proper accuracy in a properly approved chamber," explained Mark Suszkowski, vice president, sales and marketing, Enthermics Medical.

While fluids warmed in a cabinet will not provide continuous injection at a constant temperature, Suszkowski contends that the initial injection of fluids into the patient is the most critical. Plus, the cabinets provide a readily available solution that doesn’t need to be set up during surgery or authorized by a physician, and doesn’t incur a cost for the patient. "If you have a lot of people and you have to make these decisions, our product would always be available."

Enthermics also makes warming cabinets for blankets. While not a clinical, active warming method, the blankets provide an extra layer of immediate comfort for patients thats shouldn’t be discounted, said Suszkowski. "It’s often the only positive thing that the patient remembers," he said. He describes cotton blankets as complementary to other methods of warming. "Nothing you do would ever replace the blankets. You’re always going to have blankets and it’s a lot better to have them warm. It’s a psychological boost while the patient is conscious and it’s part of the comfort and care offered by the hospital and the staff." The Enthermics cabinets are built to last for around 25 years, have insulated glass, are available with wheels and in counter-top models, are stackable, and use no fans in the heating process for added durability.

Another common method for fluid warming is the use of dry heat technology in which cartridges or warming plates are used.

Gaymar’s Medi-Temp III blood and fluid warmer maintains temperatures between 38 degrees C and 43 degrees C at flow rates of up to 500 ml/min. A digital display of fluid temperature allows for easy monitoring, and includes a bubble trap with manual air vent.

Arizant’s Ranger Blood/Fluid Warming System uses SmartHeat technology to provide heat only when it’s needed. Highly conductive warming plates maximize heat transfer and the system responds to sudden changes in flow.

Temperature monitoring

Several guidelines point to the need to monitor the temperature of patients at key points throughout surgery. Ideally, temperature monitoring, when combined with the right temperature management techniques, will help ensure that patients never reach hypothermic conditions, and at a minimum, will alert surgical staff that aggressive warming measures need to be initiated.

"Temperature should be monitored in all cases where patients undergo general anesthesia. It’s a simple step that’s often overlooked," said Kimberly-Clark’s Boothe. "And then it’s pretty straight forward, if their temperature falls below 36 degrees C, there’s overwhelming data that says they should be warmed back to 36. And they need to take whatever measures they have to, to treat everyone to that standard."

"Clearly the first step in managing temperature is to monitor," agreed Schechter. She explained that Smiths offers a full line of disposable temperature probes that can be used with any monitor on the market.

Nellcor also offers a series of temperature management products including the Mon-a-Therm temperature monitors, probes and sensors for a variety of applications.

Attaining best outcomes

The first step in achieving the goal of maintaining all patients at normothermia is to evaluate current warming methods and caseloads then enact a temperature management protocol specific to your facility.

While guidelines from professional organizations can certainly provide a basis from which to start, Boothe noted that there are no specific mandates. "The guidelines from the organizations do discuss some of the modalities of how you can attain normothermia, but they don’t specifically tell you how. And that’s where some of the challenge in the clinical world lies."

"What we’ve seen to work best is for institutions to consider a procedure-based standard of care," continued Boothe. "They look at certain procedures and identify what works for those procedures and then they can make that their standard care delivery for that particular type of case. From a facility’s standpoint, it allows them to control what type and cost of care they’re delivering as long as they’re meeting their objective. There seems to be too much variability if you take it on a per patient basis."

To help facilities tailor their temperature management protocols, Smiths Medical offers its Heat TQM program designed to help hospitals evaluate current methods and make improvements that lead to better outcomes. "TQM is an excellent example of a partnership between industry and clinicians," said Schechter. "It was the brainstorm of somebody on our sales force who, in working with a clinician interested in reducing the incidence of unplanned hypothermia, came up with this program. We took that idea and expanded it into a turnkey program for use in other hospitals that they can present to JCAHO as well as a demonstration of continuous process improvement within the hospital." In one case, said Schechter, the incidence of hypothermia was reduced from 32 percent to 3 percent, though reductions of around 20 percent are not uncommon.

Gaymar also offers Temperature Effectiveness Analyses that track patients from pre-op to PACU to help suggest improvement measures for perioperative temperature management.

Moving forward, facilities may find that increased reporting requirements will ultimately drive improvements in protocols.

"CMS Medicare guidelines are moving towards reporting on the measures in quality improvement areas. One of those measures is maintenance of normothermia in certain subsets of patients," said Boothe. "They’ve specifically identified CABG [Coronary Artery Bypass Graft] patients, total hip/knee, and a couple of other target areas as needing improvement and within that they’ve identified normothermia, and have actually created tracking mechanisms where they have to report the percentage of patients at or above normothermia at the end of the case."

Clearly many facilities are still lacking in their temperature management techniques and increased attention to the subject will bring great rewards.