Industry Offers Suggestions for Maintaining Patient Normothermia

ICT asked members of industry to share their perspectives on key issues relating to regulating patient normothermia.

What are the key benefits of maintaining patient normothermia?

Maintaining core body temperature is critical to improving outcomes for surgical patients. Clinical research shows that even mild hypothermia leads to adverse effects including increased blood loss, delayed wound healing, potential adverse cardiac outcomes, lengthened recovery and hospital stays and increased risk of surgical site infections.(1-5)  Inadvertent hypothermia jeopardizes patient health and is costly to the facility. Actively managing the patients temperature throughout the perioperative continuum reduces risk to the patient and unnecessary cost to the facility. It is important to recognize the opportunities before, during and after surgery to maintain patient normothermia.

1. Arndt K. Inadvertent Hypothermia in the OR. AORN Journal. 70 2(1999):204-214.
2. Kurz A, Sessler DI and Lenhardt R. Perioperative Normothermia to Reduce the Incidence of Surgical Wound Infection and Shorten Hospitalization. N Eng J Med, 334 9(1996):1209-1215.
3. Schmied H, Kurz A, et al. Mild Hypothermia Increases Blood Loss and Transfusion Requirements during Total Hip Arthroplasty, The Lancet, 347 (1996):289-292.
4. Leslie K and Sessler DI. The Implications of Hypothermia for Early Tracheal Extubation Following Cardiac Surgery. J Cardiothorac Vasc Anesth, 12(1998):30-34; discussion 41-34.
5. Frank SM, Beattie C, Christopherson R, et al. Unintentional Hypothermia is Associated with Postoperative Myocardial Ischemia. Anesthesia, 78(1993):468-476.
-- Karen Moore, marketing director, Ecolab Healthcare

Normothermia maintenance can bring numerous health benefits to surgical patients, including a reduction in surgical bleeding and the need for blood products, decreased risk of postoperative myocardial infarction, reduced risk of surgical wound infection, shortened postoperative recovery and duration of hospitalization, improvement in patient comfort and a potential savings of $2,500 to $7,000 per patient.(1) SCIP-Inf-10 and other quality initiatives, including the Institute for Healthcare Improvement (IHI) and the Surgical Care Improvement Project (SCIP), and professional organizations such as the Association of periOperative Registered Nurses (AORN), the American Society of Anesthesiologists (ASA), the American Association of Nurse Anesthetists (AANA) and the American Society of PeriAnesthesia Nurses (ASPAN), all note the important role of normothermia maintenance in surgical site infection reduction.(2,3) Several of these organizations specifically mention forced-air warming as a means of maintaining normothermia.

1. Mahoney CB. Odom J. Maintaining intraoperative normothermia: A meta-analysis of outcomes with costs. AANA Journal. 67(2):155-164. 1999.
2. Hooper V, et al. American Society of PeriAnesthesia Nurses Development Panel. Evidence-Based Clinical Practice Guideline for the Promotion of Perioperative Normothermia. Journal of PeriAnesthesia Nursing. 2009; 24(5):271-287.
3. Institute for Healthcare Improvement campaign page. Available at: Accessed October 7, 2010.
-- Greta Drentlaw, senior communications specialist, 3M

The simple answer is this: all physiological functions work better at normal temperatures. It seems pretty logical, for instance, that an activated immune system, better blood flow, and higher oxygen-levels are beneficial to a healing patient. Even mild hypothermia has been associated with higher rates of SSIs, myocardial infarction, blood loss, and longer recovery times and ICU stays. Warming literally saves lives and is one of the least expensive things a hospital can do to improve surgical outcomes.
-- Scott Augustine, MD, CEO, Augustine Temperature Management

Research has shown that patient temperatures approximately 2°C below normal is associated with triple the incidence of wound infection which prolongs hospitalization by about 20 percent.(1) Thus, maintaining intraoperative normothermia may decrease patient infectious complications and potentially shorten hospitalization.(1) Looking beyond infections, maintaining normothermia positively impacts many other components of patient care including cardiac functioning, coagulation (blood clot formation), and patient comfort.(2-4)

1. Kurz A, Sessler DI, Lenhardt R. Perioperative Normothermia to Reduce the Incidence of Surgical-Wound Infection and Shorten Hospitalization. The New England Journal of Medicine, Volume 334 MAY 9, 1996 No. 19.
2. Frank SM, Fleisher LA, Breslow MJ, Higgins MS, Olson KF, Kelly S, Beattie C. Perioperative maintenance of normothermia reduces the incidence of morbid cardiac events. A randomized clinical trial. JAMA. 1997 Apr 9;277(14):1127-34.
3. Schmied H, Kurz A, Sessler DI, et al. Mild hypothermia increases blood loss and transfusion requirements during total hip arthroplasty. Lancet 1996;347:289-92.
4. Sessler, DI. Complications and Treatment of Mild Hypothermia. Anesthesiology 2001; 95:531-43.
-- Dan Fleming, chief marketing officer of vital signs devices, GE Healthcare

It is significantly less expensive to maintain normothermia than it is to treat adverse events that surround intraoperative hypothermia. There is a significant decrease in SSIs, shorter recovery and hospitalization times as well as a potential saving of $2,500 to $7,000 per patient.
-- Matthew Rotterman, director of sales, Enthermics

The key clinical benefits of maintaining normothermia in surgical patients are:
- three times the reduction in surgical site infections
- reduction in blood loss resulting in fewer transfusions
- reduced length of stay in the hospital
- reduced risk of cardiac arrest
There is another key benefit that is sometimes overlooked, and that is the benefit to patient comfort and satisfaction. This is especially important in light of the increasing weight of the HCAHPS surveys. Providing intraoperative warming for all of your surgical patients is key to creating a patient experience free from feeling cold and shivering.
-- Andy Giles, senior product manager, patient warming, Medline Industries

-Unless compensatory measures are used to maintain normothermia, unplanned perioperative hypothermia is a common occurrence in surgical patients.  Complications associated with this hypothermia include wound infections, cardiac dysfunction, coagulopathy, altered drug metabolism, delayed recovery to normothermia, and increased mortality in trauma patients. Thus, maintaining normothermia in the surgical patient can aid in preventing these complications. As reported by Carpenter and Baysinger (Obstet Gynecol Surg, 2012), the benefits of maintaining normothermia has been demonstrated in patients undergoing general surgery and include reductions in postoperative wound infection, the risk of perioperative coagulopathy, and myocardial ischemia.(1)

1. Carpenter L and Baysinger CL.  Maintaining perioperative normothermia in the patient undergoing cesarean delivery." Obstetrical and Gynecological Survey67(7): 436-446. 2012.
-- Kathleen B. Stoessel, RN, BSN, MS, senior manager, clinical education, Kimberly-Clark Health Care

Maintaining normothermia helps prevent the adverse affects of unplanned hypothermia, such as a heightened risk of infection, and slower recovery. Plus, it helps with patient comfort. Effective temperature management begins preoperatively. This is especially important in procedures with a short duration as there may not be time to re-warm intraoperatively.
-- Kelley Terrell, Encompass marketing manager, techstyles nonwovens

What should users look for when evaluating and purchasing patient warming systems?

Maintaining and monitoring core patient temperature before, during and after surgery to prevent inadvertent hypothermia should be the standard of care for every patient. When evaluating temperature management products, buyers should look for devices that improve patient outcomes, drive OR efficiency and decrease risk to the patient and the facility. Solutions should be portable, easy-to-use, and help facilities to meet clinical and quality guidelines. For instance, current protocols may require nursing staff to make multiple trips to and from a warming cabinet to retrieve warm fluids. These fluids may be too hot to use immediately without risk of burning the patient, but will then cool so quickly in the OR that they have a cooling rather than warming effect on the patient. Having a warmer that continuously warms fluid available in the O.R. provides a solution to these challenges.
-- Karen Moore, marketing director, Ecolab Healthcare

Its important to consider what technology will best position your facility to warm every surgical patient, achieve the SCIP-Inf-10 guideline goal of perioperative normothermia and improve patient satisfaction all in a cost-effective way. To decide which warming modality is the best fit, remember several key considerations, including:
- Is it proven?
- Is it safe?
- Does it improve outcomes?
- Does it increase patient satisfaction?
- Does it help lower costs?
- Is it easy to implement?
- Will staff embrace it?
- Does it effectively warm patients throughout perioperative process?
Forced-air warming has generally been found to be the most effective warming therapy,(1) but not all forced-air warming systems are the same. Keep in mind product-specific features like delivering consistent, even patient warming, ensuring optimized airflow through air channels and offering useful features like drainage holes for managing fluids. These attributes can help streamline the surgical experience for clinicians.

Reference: 1. Sessler DI. Current concepts: Mild Perioperative Hypothermia. New Eng J Med. 1997; 336:1730-1737.
-- Greta Drentlaw, senior communications specialist, 3M

Not all warming methods are equal. Users should consider the following:
1. Warming effectiveness. Conduct temperature audits, comparing PACU admission temperatures with the warming technology currently used with newer technologies.
2. Safety. Review MDRs for each product. Request that risk management and infection control read the scientific literature about infection risks, specifically independent research rather than company-funded white papers.
3. Cost. Consider all costs. Not just price-per-use, but also stocking, energy, waste disposal, etc.
4. Environmental consequences. Compare the environmental consequences of disposable products with reusable products.
5. Preferences of key staff. Although the comments of those for whom any change is threatening might be discounted, key staff members, including surgeons, should be consulted regarding issues such as noise, ambient heat and convenience.
-- Scott Augustine, MD, CEO, Augustine Temperature Management

While there are many effective patient warming systems available, intravenous fluid warming has been shown to help minimize the likelihood of hypothermia because it is efficient, immediate, and independent of the temperature variance between the bodys core and its extremities.1 When it comes to fluid warming systems, it is important to consider many factors including flow rates, total cost of ownership, speed of patient warming, ease of transportability while the patient moves from one area of the hospital to another, overall ease of use and maintenance requirements. Caregivers have increasingly recognized the importance of warming patients before, during and after surgery, and fluid warming systems that can easily move with the patient can help support this workflow.

Reference: 1. Horn EP, Schroeder F et. al. Active Warming During Cesarean Delivery. Anesth Analg 2002;94:409-14.
-- Dan Fleming, chief marketing officer of vital signs devices, GE Healthcare

It is important to evaluate how the new warming system will fit in to their current temperature management protocol. Important questions to ask include:
- What is the lifespan of the product?
- Will the new system require a disposable?
- What is the total cost of using the product?
- Will the staff be compliant and embrace the new system?
-- Matthew Rotterman, director of sales, Enthermics

The top factors in choosing a patient warming system will naturally include clinical efficacy and cost effectiveness. All commercially available warming systems provide these benefits to varying degrees, so there are several other elements users should also evaluate. High on the list is convenience of use. You are most likely to get high SCIP Inf-10 compliance and better normothermia outcomes if you use a warming method that is easily applied to all surgical cases. It is also helpful if your selected warming method requires minimal set up effort for your OR staff. The selection of a reusable patient warming system can also contribute significantly to the waste and energy reduction objectives at your facility.
-- Andy Giles, senior product manager, patient warming, Medline Industries

Ideally, a multidisciplinary committee should develop a process to guide product selection (Recommendation II from AORNs Recommended Practices for Product Selection in Perioperative Practice Settings).(1) Appropriate representation on the committee when evaluating and purchasing a patient warming system(s) may include a perioperative nurse, anesthesiologist, surgeon, clinical specialist/educator, material management/purchasing agent, and infection prevention specialist. Key considerations for the systems under review should include but not be limited to: safety, performance, quality, efficiency, ease of use, compatibility with other products, effect on quality patient care and clinical outcomes; evidence-based efficacy, financial impact analysis, cleaning/reprocessing parameters including degree of difficulty, environmental impact, availability and quality of service after purchase, amount of personnel training required, and quality of the manufacturers instructions. It is recommended that demonstration and instruction on the use of the system should be conducted before clinical evaluation and before initiating general use.

1. Association for periOperative Registered Nurses, A. (2012). Recommended Practices for Product Selection in Perioperative Practice Settings. Perioperative Standards and Recommended Practices R. Conner, AORN, Inc.
-- Kathleen B. Stoessel, RN, BSN, MS, senior manager, clinical education, Kimberly-Clark Health Care

Patient warming systems should be selected based on efficacy, ease of use, cost effectiveness and compliance potential. Evidence based practices demonstrate passive warming measures such as reflective warming, are effective for shorter duration procedures [less than one hour]. These products prevent redistribution temperature drop [RTD] using the body's endogenous heat. They are cost-effective, require no equipment, allow patient mobility for improved compliance, and are available in a variety of products to complement current protocols. Longer duration procedures [one hour or longer] typically require active warming measures.
-- Kelley Terrell, Encompass marketing manager, techstyles nonwovens


There is some debate about whether forced-air warming systems disturb protective airflow measures such as positive pressure or laminar airflow in the operating room resulting, resulting in airborne contaminants at the surgical site. What is your position on this issue?

Science and clinical evidence demonstrate there is no issue. More than 170 published studies document the clinical benefits of using forced-air warming for maintaining normothermia. Multiple studies have shown the use of forced-air warming does not increase the risk of wound contamination or bacterial contamination of the operating room.(1,2) When tested during actual surgical conditions forced-air warming was shown to decrease the bacterial count at the surgical site.(3-5) A recent study by infection preventionist Russell Olmsted and Drs. Daniel Sessler and Ruediger Kuelpmann concludes forced-air warming does not disrupt laminar flow or compromise the surgical sites protection.6 Thorough examination by multiple sources has conclusively determined there is no significant disruption of laminar airflow tied to the use of forced-air warming. Since its inception 25 years ago, forced-air has safely warmed more than 165 million patients, and it has never been conclusively linked to a surgical site infection.

1. Kurz A, Sessler DI, Lenhardt R. Perioperative normothermia to reduce the incidence of surgical-wound infection and shorten hospitalization. N Engl J Med 1996:334:1209-15.
2. Melling AC, Ali B, Scott EM, Leaper DJ. Effects of preoperative warming on the incidence of wound infection after clean surgery: a randomized controlled trial. Lancet 2001;358:876-880.
3. Barie PS. Surgical site infections: epidemiology and prevention. Surgical Infections 2002; 3:S9-S21.
4. Huang JK, Shah EF, Vinodkumar N, Hegarty MA, Greatorex RA. The Bair Hugger patient warming system in prolonged vascular surgery: an infection risk? Crit Care 2003;7:R13R16.
5. 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? J Hospital Infect 2009; 73: 5863.
6. Sessler DI, Olmsted RN, Kuelpmann R. Forced-Air Warming Does Not Worsen Air Quality in Laminar Flow Operating Rooms. Anesth Analg.113 (6): 1416-1421. 2011.
-- Greta Drentlaw, senior communications specialist, 3M

Four published studies have shown that the rising waste heat from forced-air warming, mobilizes contaminated air normally resident near the floor into the surgical site even in laminar flow ventilation operating rooms (McGovern, JBJSb; Legg, JBJSb; Dasari, Anaesthesia; Belani, A&A). Floor air is a proven reservoir of shed-skin cells and bacteria, and the rising waste heat is the mode of transmission for these infectious agents into the open surgical wound. It is well-documented that a single airborne bacterium can cause a periprosthetic joint infection (PJI) during total joint replacement surgery. The organism protects itself in a biofilm coating before proliferating.  The rising contaminated waste heat is irrelevant in soft-tissue surgeries, but when implanted foreign materials are used it can be catastrophic. McGovern and his colleagues reported results from 1,437 total joint replacement patients and found that discontinuing the use of forced-air warming resulted in a 74 percent reduction in PJI rates.
-- Scott Augustine, MD, CEO, Augustine Temperature Management

Our only position on forced air warming is that It is important to evaluate the disposable cost and medical waste that comes as a result of forced-air warming.
-- Matthew Rotterman, director of sales, Enthermics

I have reviewed the published research on this topic and have found a few compelling results. However, forced air warming comprises over 80 percent of the patient warming market today and has been used successfully for many years, so any effects from increased airborne contaminants must be minimal based on this large volume and experience of use. It is my opinion that further research should be done, especially in areas like orthopedics where the consequences of an SSI are much more dire.
-- Andy Giles, senior product manager, patient warming, Medline Industries

The healthcare facilitys selection committee should gather information about new or existing products from professional resources (third party sources) and the manufacturer. (Recommendation II from AORNs Recommended Practices for Product Selection in Perioperative Practice Settings).(1) Consult with the manufacturer/manufacture representative of the forced-air warming system(s).  The manufacturers representative should provide both clinical and technical data related to product use, safety and potential for airborne contamination. All information (pros and cons) should be weighed prior to product purchase or continuation with existing product.

1. Association for periOperative Registered Nurses, A. (2012). Recommended Practices for Product Selection in Perioperative Practice Settings. Perioperative Standards and Recommended Practices R. Conner, AORN, Inc.
-- Kathleen B. Stoessel, RN, BSN, MS, senior manager, clinical education, Kimberly-Clark Health Care

We are not involved with this specific technology. However, the majority of clinical evidence supports the safe use of forced air warming.
-- Kelley Terrell, Encompass marketing manager, techstyles nonwovens

Compiled by Jessica Barreras


Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.