Proven performance, modern advancements, make forced-air warming the right choice

When forced-air warming was first introduced to the surgical community in 1987, the system—known as Bair Hugger therapy—consisted of a large warming unit and just one blanket type. The technology, now known for its exceptional performance throughout the perioperative process, was initially designed to warm patients only in the post-operative environment.

Through the years, continued investments in clinical research and innovation have spurred advances in patient warming procedures and product solutions. Clinicians have shifted warming practices from the initial setting of recovery rooms, into the operating rooms and most recently, have initiated prewarming protocols to actively bank heat as an effective means of fighting off hypothermia even before it begins.

Close monitoring of customer feedback and market needs have led to a consistent track record of successful new product introductions. Today’s warming solutions incorporate advanced designs—such as patient adjustable warming gowns and new specialty blankets—to offer cost-effective, convenient and clinically effective ways to warm every surgical patient, including the most difficult-to-warm surgical populations.

Unfortunately, after more than 20 years of safe, effective use, over 110 million patients warmed, makers of competing warming modalities are positioning forced-air warming as an antiquated tool. Some have even gone so far as to claim that the country’s most prominent method of surgical warming may be contributing to surgical site infections (SSIs) by “blowing air” around the OR and trying to convince infection preventionists that this poses a risk.

Overwhelming evidence shows this is not the case. Not only does forced-air warming not present an infection risk, numerous evidence-based quality initiatives and national performance measures have specifically cited forced-air warming as a proven tool for the reduction of SSIs.

Normothermia for SSI Reduction

Perhaps the best known evidence-based quality initiative to include normothermia is the Centers for Medicare and Medicaid Services’ Surgical Care Improvement Project (SCIP), which was developed to encourage and reward widespread adoption of evidence-based guidelines under the belief that these best practices will ultimately reduce costs and improve quality of care.

Reporting for this SCIP temperature management quality measure, known as SCIP-Infection-10, became mandatory January 1, 2010. To meet the measure, facilities must use active warming methods, such as forced-air warming blankets or gowns, or achieve the target temperature of 36.0°C  within the 30 minutes immediately prior to or the 15 minutes immediately after anesthesia end time.¹

While it is far too early to judge the effect this measure will have on facilities, it will likely result in more patients being warmed and an increased investment in temperature management products. This additional focus on patient warming has resulted in some competitor companies choosing to disparage forced-air warming—the most widely used warming method, which also has been proven to be safe and effective—as they seek to expand their presence in the warming market.

Why Warming Matters

Any patient undergoing anesthesia is susceptible to unintended hypothermia during surgery, regardless of age or physical condition. One of the most significant contributors to surgical hypothermia is the physiological effects of anesthesia itself, which disrupts the body’s ability to regulate temperature. ² Inadvertent hypothermia can triple the rate of wound infection (SSIs), ³ extend recovery time and length of stay⁴ and increase mortality rates. ⁵

Normothermia maintenance has long been identified as a key method of fighting surgical site infections and studies have found forced-air warming to be the most effective method for preventing and treating unintended hypothermia.

An editorial published in a prominent anesthesia journal stated that, “Maintaining normothermia is usually easy, with hospital cost typically being less than $10; furthermore, the most commonly used warming systems are remarkably safe. There are few, if any, anesthetic interventions that have proven to so markedly improve the outcome of surgery with so little effort, risk and cost …”⁶

There is also a significant financial benefit of reducing hypothermia rates in surgical patients. Studies have demonstrated that maintaining normothermia can result in savings of $2,500 to $7,000 per patient by eliminating the costs of hypothermia-related complications, including surgical site infections. ⁷

The Technology You Trust

When it comes to clinical evidence, support for forced-air warming is overwhelming.  Forced-air warming has been studied extensively—there are more than 100 published papers documenting its clinical benefits—and the technology remains a truly cost-effective, efficient method of addressing SSI rates and improving surgical patient outcomes. It’s no wonder the technology is currently available in approximately 85 percent of U.S. hospitals.

Forced-air warming also has a long track record of helping patients worldwide avoid unintended hypothermia and its associated complications.

Of particular interest to infection preventionists are published research papers that have shown that the use of forced-air warming does not increase either the risk of wound contamination in the operating room or bacterial contamination of operating rooms. ^8,9 When tested during actual surgical conditions, research has shown that forced-air warming actually decreases the bacterial count at the surgical site. ^9,10

This was once again reiterated in a recent orthopedic surgery study using advanced air-sampling techniques. The research, published in the September 2009 issue of the Journal of Hospital Infection, found that warming with the Bair Hugger system during orthopedic surgery does not present an infection risk. ¹⁰

Another recently published piece explored the possibility of forced-air warming increasing bacterial contamination in the OR and, accordingly, the concept of withholding warming therapy until the patient is draped.

The authors conclude that, “There is no empiric support for this practice. Denying the patient access to active warming—especially during the beginning of the procedure before the application of surgical drapes when heat loss and redistribution are greatest—puts the patient at an increased risk for hypothermia, which will increase the risk of SSI.” ¹¹

The researchers go on to say, “Further, all forced-air warming units include filters that essentially eliminate bacteria in the heated air: The number of colony-forming units recovered from operating rooms is not increased by forced-air blowers.” ¹¹

Also worth noting is that, while available, most forced-air warming blankets are not designed to be sterile, nor do they enter the sterile field. When used properly and as intended, the filtered air flowing from a warming unit is gently and evenly dispersed throughout the attached warming blanket, which is isolated from the surgical site by an adhesive strip on the blanket and surgical barrier drapes.

Competitors offering conductive warming products have also recently made statements regarding forced-air warming’s performance in laminar flow conditions. While simple logic makes it clear that forced-air warming has no impact on laminar conditions, science also supports its safety. Forced-air warming blankets produce only localized, contained, short-range increases in airflow velocity that has no significant effect on operating room airflow. ^12,13

It is important to again emphasize that healthcare quality initiatives around the world, including guidelines or recommendations from the Institute for Healthcare Improvement (IHI), the UK’s National Institute for Health and Clinical Excellence (NICE), the National Health Service (NHS) Saving Lives program (UK), the 1,000 Lives Campaign in Wales and Scotland’s Patient Safety Programme note the importance of normothermia in SSI reduction efforts. Several of these organizations specifically mention forced-air warming as a key means of maintaining normothermia.

Also, professional guidelines for anesthesia and surgical staff, such as those developed by the American Society of Anesthesiologists (ASA), the Association of periOperative Registered Nurses (AORN), and the American Society of PeriAnesthesia Nurses (ASPAN) all recommend the use of forced-air warming to maintain patient normothermia.

Benefits of Single-use

Unlike invasive, reusable surgical products, the only part of a forced-air warming system that comes into direct contact with a patient is the disposable blanket. Forced-air warming blankets are typically single use, meaning they cannot transmit infection from one patient to another.

The same cannot be said for conductive warming products like electric blankets, mattresses or pads. The U.S. Centers for Disease Control and Prevention recommends disposable products for patients with known or suspected infections requiring contact precautions. 

Rely on Evidence, Experience

Before investing in any technology, facilities need to review the facts, examine a product’s track record of safety and efficacy, and study the research, or note the lack thereof. Users should also reflect on their own personal experience—no one will know more about a product’s performance than those who use it every day. The importance of clinician confidence in a product’s performance and effectiveness cannot be overlooked.

Forced-air Warming: Value in Action

Forced-air warming is the gold standard of care for managing perioperative normothermia in operating rooms throughout the world. ^14-19

And as the science of patient warming has evolved over the past 20-plus years, so has forced-air warming technology. The Bair Hugger system, for example, is specifically designed to deliver consistent, even patient warming by optimizing the airflow through the blanket’s scientifically engineered air channels and perforation pattern. This allows the Bair Hugger blankets to guide heat directly over the body’s core, where heat transfer is most effective. The perforation patterns are specifically designed to optimize heat transfer and provide consistent warming across the entire blanket.

Forced-air warming blankets are continuously in development to meet the changing needs of clinicians, and today there are product lines with 25 styles—enough to warm virtually any surgical procedure. For difficult cases like spinal or cardiac surgeries that require full patient access, Underbody blankets can be positioned beneath the patient, clinically warming from below.

Perhaps the most exciting development in forced-air warming centers on a single tool—one that can warm from pre-op through PACU, improve patient satisfaction and potentially save hospitals money by reducing the costs associated with the complications of hypothermia.

This single-use patient warming gown offers the ultimate in warming flexibility, providing hospitals with the ability to quickly, easily warm nearly every surgical patient. The gown includes a dual insert design that can prewarm patients before surgery, keeping them both comfortable and covered, and then clinically warm either the upper body or lower body in the OR with the integrated forced-air blankets.

Ultimately, it’s a practical, economic solution to warming more surgical patients. With this patient warming gown, along with specialty underbody blankets for cases with challenging patient positioning, would be all that’s needed in most facilities. Best of all, because these are forced-air warming products they allow inpatient facilities to meet the SCIP-Inf-10 normothermia measure, which includes forced-air warming as an “active warming” modality.

Patient warming products with broad clinical flexibility are more important than ever. For example, a product that can be utilized for both upper- or lower-body cases, and used before during and after surgery, offers a practical, economic solution as more patients are warmed. Likewise, not all forced-air warming products are created equal. Take the time to focus on some of the less-touted but very important features, such as drain holes in an Underbody blanket, that may not be included in a lower-cost option.

References

1. Centers for Medicaid and Medicare Services (US). Specifications Manual for National Hospital Inpatient Quality Measures – iv – Discharges 10-01-09 (4Q09) through 03-31-10 (1Q10); Section 2.4 – Surgical Care Improvement Project; p. 63-67. Available from: http://www.qualitynet.org.
2. Sessler, DI. Current Concepts: Mild Perioperative Hypothermia. New England Journal of Medicine, 336(24): 1730-1737; 1997.
3. Kurz, A. Sessler, DI. Lenhardt, R. Perioperative Normothermia to Reduce the Incidence of Surgical Wound Infection and Shorten Hospitalization. New England Journal of Medicine. 334(19): 1263-1264. 1996.
4. Sessler, DI. Consequences and treatment of perioperative hypothermia. Anesthesiology Clinics of North America. Vol. 12. Philadelphia: W.B. Saunders Company; 1994:449.
5. Tryba, M. Leban, J. et al. Does active warming of severely injured trauma patients influence perioperative morbidity? Anesthesiology. 1996; 85: A283.
6. Hannenberg, A. Sessler, DI. Improving Perioperative Temperature Management (editorial). Anesthesia & Analgesia. Nov. 2008: 107(5) 1454-1457.
7. Mahoney, CB. Odom, J. Maintaining intraoperative normothermia: A meta-analysis of outcomes with costs. AANA Journal. 67(2): 155-164. 1999.
8. Zink, RS. Iaizzo, PA. Conductive warming therapy does not increase the risk of wound contamination in the operating room. Anesthesia & Analgesia. 1993; 76:50-3.
9. Huang, JK. Shah, EF. Vinodkumar, N. Hegarty, MA. Greatorex, RA. The Bair Hugger patient warming system in prolonged vascular surgery: an infection risk? Critical Care. 2003; 7: R13–R16

10.  Moretti, B. Larocca, AM. Napoli, C et al. Active warming systems to maintain perioperative normothermia in hip replacement surgery: a therapeutic aid or a vector of infection? Journal of Hospital Infection. 2009; 73, 58-63.

11.  Thiele, H. Huffmeyer, J. Nemergut, E. The “six sigma approach” to the operating room environment and infection. Clinical Anaesthesiology. Vol. 22, Issue 3, September 2008; p. 537-552.

12.  Sharp, RJ, et al. Do warming blankets increase bacterial counts in the operating field in a laminar-flow theatre? J Bone Joint Surg Br. 2002; 84-B: 486-8.

13.  Miyazaki, H. Sato, M. Okazaki, K. Forced-air warmer did not increase the risk of contamination caused by interference of clean airflow. Anesthesiology. 2007; 107: A1594

14.  Sessler, DI. Moayeri, A. Skin-surface warming: heat flux and central temperature. Anesthesiology. 1990; 73: 218–24.

15.  Giesbrecht, GG. Ducharme, MB. McGuire, JP. Comparison of forced-air patient warming systems for perioperative use. Anesthesiology. 1994; 80:671–9.

16.  Hynson, JM. Sessler, DI. Intraoperative warming therapies: a comparison of three devices. J Clin Anesth. 1992; 4:194–9.

17.  Kurz, A. Kurz, M. Poeschl, G. Faryniak, B. Redl, G. Hackl, W. Forced-air warming maintains intraoperative normothermia better than circulating-water mattresses. Anesthesia & Analgesia.1993; 77: 89–95.

18.  Borms, SF. Englelen, SL. Himpe, DG. Suy, MR. Theunissen, WJ. Bair Hugger forced-air warming maintains normothermia more effectively than thermo-lite insulation. J Clin Anesth. 1994; 6: 303–7.

19.  Brauer, A. Pacholik, L. Perl, T. English, MJ. Weyland, W. Braun, U. Conductive heat exchange with a gel-coated circulating water mattress. Anesthesia & Analgesia. 2004; 99:1742–6.

As the innovative minds behind the concept of forced-air warming, Arizant Healthcare understands the need to warm every patient, as well as the call for healthcare providers to meet the new guidelines. We know patient warming. We created the category. It’s at the core of who we are and what we do.

Our patient temperature management devices, such as the Bair Paws Flex™ gown, Bair Hugger® blankets and the Ranger® blood and fluid warming systems, bring the value of patient warming and normothermia maintenance to patients, clinicians and facilities worldwide.