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Clinical Policy Bulletin:
Noncontact Normothermic/Nonthermal Wound Therapy
Number: 0372


Aetna considers Warm-Up® Active Wound Therapy, also known as noncontact normothermic wound therapy (NNWT), experimental and investigational because there is insufficient evidence in the peer-reviewed medical literature that Warm-Up® Active Wound Therapy/NNWT is effective for the treatment of wounds.

Aetna considers noncontact, nonthermal, low-frequency ultrasound therapy experimental and investigational for the treatment of wounds because its effectiveness has not been established.


Warm-Up® Active Wound Therapy (Augustine Medical, Inc., Eden Prairie, MN), also known as noncontact normothermic wound therapy (NNWT) uses a non-contact radiant-heat bandage to treat chronic venous ulcers when conventional wound-healing therapy has failed.  The device consists of a noncontact, domed wound cover into which a flexible infrared heating card is inserted.  A battery pack powers the device and warms the wound to a pre-determined temperature.  The inside of the wound cover contains a foam ring, which acts as a wick to drain away exudate.

In a Decision Memorandum, the Center for Medicare and Medicaid Services (CMS) reviewed the evidence of the effectiveness of noncontact normothermic wound therapy.  The CMS concluded that “the medical literature does not support a finding that NNWT heals any wound type better than conventional treatment.”  CMS concluded, therefore, that there is insufficient evidence in the peer-reviewed medical literature to consider this device as reasonable and necessary for the treatment of wounds.

An assessment of treatments for chronic pressure ulcers by the Ontario Ministry of Health and Long-Term Care (2009) concluded that "thermal dressings such as noncontact normothermic dressings or radiant heat dressings were associated with greater improvement in stage III and IV pressure ulcers; however, this did not translate into more wound closure. There is no evidence at present to conclude that thermal dressings will result in more complete healing in stage III or IV pressure ulcers."

Several recent studies have evaluated the effectiveness of NNWT for the treatment of chronic wounds.  However, there are drawbacks from these studies -- small sample sizes and lack of long-term follow-up.  McCulloch and Knight (2002) examined the effect of a noncontact, radiant warming device in the treatment of neuropathic foot wounds secondary to diabetes.  Patients (n = 36) were assigned to management with off-loading and warming (treatment) or off-loading therapy only (control) for a period of 8 weeks or until healing.  Wounds of subjects in the treatment group healed at a rate of 0.019 +/- 0.019 cm2/day compared with that of 0.008 +/- 0.009 cm2/day in the control group (p = 0.049).  The difference between treatment and control groups barely reached statistical significance.

The authors of a small (13 patients) preliminary study on Warm-Up® Active Wound Therapy concluded that Warm-Up® Active Wound Therapy is a safe treatment modality for chronic venous stasis ulcers; however, further investigation using a larger prospective study is needed to demonstrate effectiveness

Kloth and associates (2002) studied the effect of NNWT versus standard wound care on patients (n = 40) with 43 stage III and IV pressure ulcers.  A sterile noncontact wound dressing was applied to 21 wounds for 24 hours per day, 7 days per week.  Each day after the wound was irrigated and the noncontact dressing was changed, a heating element in the dressing was activated for 3 1-hour periods for 12 weeks or until wound closure.  Twenty-two control wounds were treated with standard, moisture-retentive dressings 24 hours per day, 7 days per week for 12 weeks or until wound closure.  The healing rate for the treatment group was significantly greater than that for the control group (0.52 cm2 per week and 0.23 cm2 per week, respectively; p < 0.02).  However, the difference in the incidence of closure among wounds that completed the entire 12-week protocol between treatment and control groups were not significant (11 of 14 or 78.5 % for the treatment group and 8 of 16 or 50 % for the control group).

In a pilot study, Karr (2003) studied the use of NNWT in the treatment of wounds associated with osteomyelitis.  This study consisted of 2 arms: (i) the control arm (11 patients with 11 ulcers) received standard wound care, and (ii) the treatment arm (5 patients with 6 ulcers) received NNWT.  Standard wound care resulted in complete ulcer healing at an average of 127 days, while NNWT resulted in complete ulcer healing at an average of 59 days, or 54 % faster than in the control arm.  However, the mean wound healing times between the 2 groups were not significantly different (p < 0.33).  Moreover, the median wound healing time for the 2 groups were quite similar (70 days for the control group and 68 days for the treatment group).  The authors concluded that a larger prospective study that evaluates NNWT for ulcers associated with osteomyelitis is warranted.

In a prospective, randomized, controlled study, Alvarez and colleagues (2003) compared diabetic foot ulcer healing in patients being treated with either NNWT applied for 1 hour 3 times daily until healing or 12 weeks, or standard care (saline-moistened gauze applied once-daily).  Surgical debridement and adequate foot off-loading was provided to both groups.  Evaluations were performed weekly and consisted of acetate tracings, wound assessment, and serial photography.  A total of 20 patients completed the study and both treatment groups were distributed evenly (n = 10).  Ulcers treated with NNWT had a greater mean percent wound closure than control-treated ulcers at each evaluation point (weeks 1 to 12).  After 12 weeks, 70 % of the wounds treated with NNWT were healed compared with 40 % for the control group.  However, the differences were not significant (p < 0.069).  The authors concluded that further study in a greater patient population is needed to assess the effectiveness of NNWT in treating neuropathic foot ulcers.

In a randomized controlled study, Thomas et al (2005) examined the effectiveness of radiant heat bandage on the healing of stage 3 or stage 4 pressure ulcers.  A total of 41 subjects with a stage 3 or stage 4 truncal pressure ulcer greater than 1.0 cm2 were recruited from outpatient clinics, long-term care nursing homes, and a rehabilitation center.  The experimental group was randomized to a radiant-heat dressing device and the control group was randomized to a hydrocolloid dressing, with or without a calcium alginate filler.  Subjects were followed until healed or for 12 weeks.  Eight subjects (57 %) in the experimental group had complete healing of their pressure ulcer compared with 7 subjects (44 %) with complete healing in the control group (p = 0.46).  The authors noted that although a 13 % difference in healing rate between the 2 arms of the study was found, this difference was not statistically significant.

In a single center randomized study with 49 patients, Alvarez et al (2006) reported that NNWT improves the healing of diabetic neuropathic foot ulcers.  Moreover, these researchers stated that further study in a greater patient population is needed to fully assess the effectiveness of this device and to provide additional information on whether local warmth can reduce the incidence of infection.

Serena et al (2009) examined if noncontact, nonthermal, low-frequency ultrasound (LFU) therapy is effective in controlling wound bacterial colony counts in a series of 4 related experiments.  First, ultrasound penetration in both wounded and intact skin was assessed in-vitro.  Compared to sham, noncontact ultrasound penetrated farther into both wounded (3.0 to 3.5 mm versus 0.35 to 0.50 mm) and intact (2.0 to 2.5 mm versus 0.05 to 0.07 mm, respectively) pig skin.  Second, using an in-vitro model to stain and count live/dead bacteria, 0 % of sham-treated and 33 % of Pseudomonas aeruginosa, 40 % of Escherichia coli and 27 % of Enterococcus faecalis were dead after 1 ultrasound application.  Minimal effects on methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus were observed.  Third, using an in-vivo model, after 1 week, while differences between different bacterial species were observed, overall bacterial quantity decreased with ultrasound treatment (from 7.2 +/- 0.79 to 6.7 +/- 0.91 colony forming units [CFU] per gram of tissue [CFU/g]) and silver anti-microbial dressings (from 7.2 +/- 0.79 to 5.7 +/- 0.6 CFU/g) but increased to 8.6 +/- 0.15 CFU/g for sham and 8.6 +/- 0.06 CFU/g for water-moistened gauze.  Fourth, 11 patients (average age of 60 years) with pressure ulcers containing bacterial counts greater than 10(5) CFU/g of tissue received 2 weeks of noncontact ultrasound therapy.  The quantities of 7 bacterial organisms were reduced substantially from baseline to 2 weeks post-treatment.  None of the wounds exhibited signs of a clinical infection during the treatment period and no adverse events were observed.  Taken together, these 4 studies indicated that noncontact ultrasound can be used to reduce bacterial quantity.  The authors concluded that controlled clinical studies are needed to determine the effectiveness of this treatment and to further elucidate its effects on various Gram-negative and Gram-positive bacteria.

In an in-vitro study, Conner-Kerr and colleagues (2010) examined the effects of LFU delivered at 35 kHz on bacterial viability, cell wall structure, and colony characteristics, including antibiotic resistance on vegetative forms of MRSA.  They concluded that studies to elucidate the observed effects of LFU on MRSA and evaluate its effect in-vivo are needed.  Furthermore, in a Cochrane review on therapeutic ultrasound for venous leg ulcers, Cullum et al (2010) concluded that the studies evaluating ultrasound for venous leg ulcers are small, poor-quality and heterogeneous.  There is no reliable evidence that ultrasound hastens healing of venous ulcers.  There is a small amount of weak evidence of increased healing with ultrasound, but this requires confirmation in larger, high-quality randomized controlled trials.  There is no evidence of a benefit associated with LFU.

Voigt and colleagues (2011) examined if LFU used as an adjunctive therapy improves the outcomes of complete healing and reduction of size of chronic lower limb wounds.  PubMed, Cochrane/CENTRAL, technical assessment, relevant wound-related journals, and clinical guidelines were searched along with contacting manufacturers and authors of relevant randomized controlled trials (RCTs) were completed.  Searches focused on the use of LFU in RCTs.  Data were collected via a data collection form and was adjudicated independently via coauthors.  Meta-analyses and heterogeneity checks were performed using Mantel-Haenszel and inverse variance (fixed and random effects) statistical methods on studies with similar outcomes (complete healing and percent wound area reduction) over similar time periods.  Single study results were reported via the statistical methods used in the study; 8 RCTs were identified.  Results demonstrated that early healing (at less than or equal to 5 months) in patients with venous stasis and diabetic foot ulcers was favorably influenced by both high- and low-intensity ultrasound delivered at a low frequency -- either via contact or noncontact techniques.  However, the authors noted that the quality of the data may be suspect, especially for low-frequency, low-intensity noncontact ultrasound because of significant biases.

Madhok et al (2013) stated that debridement is a crucial component of wound management.  Traditionally, several types of wound debridement techniques have been used in clinical practice such as autolytic, enzymatic, bio-debridement, mechanical, conservative sharp and surgical.  Various factors determine the method of choice for debridement for a particular wound such as suitability to the patient, the type of wound, its anatomical location and the extent of debridement required.  Recently developed products are beginning to challenge traditional techniques that are currently used in wound bed preparation.  These investigators reviewed the current evidence behind the use of these newer techniques in clinical practice.  They noted that there is some evidence to suggest that LFU therapy may improve healing rates in patients with venous ulcers and diabetic foot ulcers.

CPT Codes / HCPCS Codes / ICD-9 Codes
CPT codes not covered for indications listed in the CPB:
HCPCS codes not covered for indications listed in the CPB:
A6000 Non-contact wound warming wound cover for use with the non-contact wound warming device and warming card
E0231 Non-contact wound warming device (temperature control unit, AC adaptor and power cord) for use with warming card and wound cover
E0232 Warming card for use with the non-contact wound warming device and non-contact wound warming cover
ICD-9 codes not covered for indications listed in the CPB (not all-inclusive):
250.60 - 250.63 Diabetes with neurological manifestations
250.70 - 250.73 Diabetes with peripheral circulatory disorders
250.80 - 250.83 Diabetes with other specified manifestations
440.23 Atherosclerosis of the extremities with ulceration
440.24 Atherosclerosis of the extremities with gangrene
443.9 Peripheral vascular disease, unspecified
454.0 Varicose veins of lower extremities with ulcer
682.0 - 682.9 Other cellulitis and abscess
685.0 Pilonidal cyst with abscess
685.1 Pilonidal cyst without mention of abscess
707.00 - 707.9 Chronic ulcer of skin
870.0 - 897.9 Open wound
998.31 - 998.32 Disruption of operation wound
998.59 Other postoperative infection
998.83 Non-healing surgical wound

The above policy is based on the following references:
  1. Robinson C, Santilli SM. Warm-up active wound therapy: A novel approach to the management of chronic venous stasis ulcers. J Vasc Nurs. 1998;16(2):38-42.
  2. Santilli SM, Valusek PA, Robinson C. Use of a noncontact radiant heat bandage for the treatment of chronic venous stasis ulcers. Adv Wound Care. 1999;12(2):89-93.
  3. Whitney JD, Salvadalena G, Higa L, et al. Treatment of pressure ulcers with noncontact normothermic wound therapy: Healing and warming effects. J Wound Ostomy Continence Nurs. 2001;28(5):244-252.
  4. Canadian Coordinating Office for Health Technology Assessment (CCOHTA). Warm-up therapy. Emerging Device List. No. 8. Ottawa, ON: CCOHTA; July 2001. Available at: Accessed June 14, 2004.
  5. Center for Medicare and Medicaid Services (CMS). Warm-Up Wound Therapy® a/k/a Noncontact Normothermic Wound Therapy. Updated (02/13/02) (#CAG-00114N). Baltimore, MD: CMS; 2002. Available at: Accessed March 8, 2002.
  6. Center for Medicare and Medicaid Services (CMS). Coverage Issues Manual Section 60-25, Noncontact Normothermic Wound Therapy (NNWT). Baltimore, MD: CMS; 2002.
  7. McCulloch J, Knight CA. Noncontact normothermic wound therapy and offloading in the treatment of neuropathic foot ulcers in patients with diabetes. Ostomy Wound Manage. 2002;48(3):38-44.
  8. Macario A, Dexter F. Is noncontact normothermic wound therapy cost effective for the treatment of stages 3 and 4 pressure ulcer? Wounds. 2002;14(3):93-106.
  9. Kloth LC, Berman JE, Nett M, et al. A randomized controlled clinical trial to evaluate the effects of noncontact normothermic wound therapy on chronic full-thickness pressure ulcers. Adv Skin Wound Care. 2002;15(6):270-276.
  10. Karr JC. External thermoregulation of wounds associated with lower-extremity osteomyelitis. A pilot study. J Am Podiatr Med Assoc. 2003;93(1):18-22.
  11. Alvarez OM, Rogers RS, Booker JG, Patel M. Effect of noncontact normothermic wound therapy on the healing of neuropathic (diabetic) foot ulcers: An interim analysis of 20 patients. J Foot Ankle Surg. 2003;42(1):30-35.
  12. Thomas DR, Diebold MR, Eggemeyer LM. A controlled, randomized, comparative study of a radiant heat bandage on the healing of stage 3-4 pressure ulcers: A pilot study. J Am Med Dir Assoc. 2005;6(1):46-49.
  13. Alvarez O, Patel M, Rogers R, Booker J. Effect of non-contact normothermic wound therapy on the healing of diabetic neuropathic foot ulcers. J Tissue Viability. 2006;16(1):8-11.
  14. Serena T, Lee SK, Lam K, et al. The impact of noncontact, nonthermal, low-frequency ultrasound on bacterial counts in experimental and chronic wounds. Ostomy Wound Manage. 2009;55(1):22-30.
  15. Ontario Ministry of Health and Long-Term Care. Management of chronic pressure ulcers. An evidence-based analysis. Ontario Health Technology Assessment Series. Toronto, ON: Ontario Ministry of Health and Long-Term Care; 2009;9(3).
  16. Conner-Kerr T, Alston G, Stovall A, et al. The effects of low-frequency ultrasound (35 kHz) on methicillin-resistant staphylococcus aureus (MRSA) in vitro. Ostomy Wound Manage. 2010;56(5):32-42.
  17. Cullum NA, Al-Kurdi D, Bell-Syer SE. Therapeutic ultrasound for venous leg ulcers. Cochrane Database Syst Rev. 2010;(6):CD001180.
  18. Voigt J, Wendelken M, Driver V, Alvarez OM. Low-frequency ultrasound (20-40 kHz) as an adjunctive therapy for chronic wound healing: A systematic review of the literature and meta-analysis of eight randomized controlled trials. Int J Low Extrem Wounds. 2011;10(4):190-199.
  19. Madhok BM, Vowden K, Vowden P. New techniques for wound debridement. Int Wound J. 2013 Feb 19. [Epub ahead of print]

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Copyright Aetna Inc. All rights reserved. Clinical Policy Bulletins are developed by Aetna to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. This Clinical Policy Bulletin contains only a partial, general description of plan or program benefits and does not constitute a contract. Aetna does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Aetna or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. This Clinical Policy Bulletin may be updated and therefore is subject to change.
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