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Wound malodour: dealing with a distressing issue

Una Adderley
RGN DN BSc BA
Research Nurse
Centre for Evidence Based Nursing
Department of Health Studies
University of York
District Nurse Scarborough and NE Yorks NHS Trust
E:una.adderley@virgin.net

Wound malodour is usually deeply distressing to both patients and carers. Neal's patient-centred definition that a malodorous wound is "any wound assessed as being offensive (smelly) by the patient, carer or practitioner"(1) is a useful reminder that smell is an individual experience. Malodour may be closely linked to fear of advancing disease, and the memory of malodour may cause distress even after the death of a patient.(2)
The subjective nature of odour can make assessment difficult for the clinician. Using a scoring tool (Table 1) can ensure that the clinical team share a common perception of the extent of the problem and any changes.

[[NIP05_table1_69]]
 
Malodour in wounds can be caused by necrotic tissue, infection or stale exudate, or a combination of all three.  Effective treatment can begin only when the cause has been identified.
Healthy skin can become necrotic tissue when the blood supply to the skin becomes impaired leading to tissue hypoxia. This can be due to an enlarging tumour under the skin or a "fungating tumour" that extends into the skin structure and which ruptures or occludes blood vessels. Pressure damage in immobile patients and arterial occlusion from atherosclerosis will also lead to necrosis from tissue hypoxia.  Wounds filled with debris, slough and necrotic tissue are an ideal breeding ground for anaerobic bacteria. 
Infection may be the primary cause of tissue breakdown, as well as being secondary to necrosis. Malodorous wounds usually contain at least two types of anaerobic bacteria in addition to aerobic bacteria.(4) Anaerobic pathogens destroy healthy cells by producing toxins that damage healthy tissue. Malodour occurs when the anaerobic bacteria break down proteins in dead tissue leading to tissue liquefaction and the release of volatile fatty acids with pungent odour.
Stale exudate can also be a source of malodour. Modern dressings are designed to minimise the frequency of dressing changes to promote healing. However, infection or excess exudate may necessitate more frequent dressing changes as warm moist places can easily become malodorous. Most people would choose to wash sweaty feet and change their socks fairly frequently to avoid malodour; malodorous wounds require similar attention.
When managing malodour, the primary aim should be to prevent or alleviate the underlying cause of necrosis, but in some situations, such as advancing cancer or arterial disease, this may not be possible. 
Malodorous wounds should receive gentle wound cleansing to wash away stale exudate; cleansing and dressing changes should be as frequent as necessary to minimise odour. Debridement of slough and necrotic tissue will reduce the focus for pathogenic bacteria, although some malodorous wounds will be fragile and require very gentle debridement. For example, fungating wounds are prone to bleeding, and autolytic debridement may be the only safe option.
Infection should be treated with the appropriate antibiotics and antibacterials, and bacterial swabs and tissue cultures will help identify which organisms are likely to be causing malodour. Systemic treatment such as oral metronidazole is often the treatment of choice, but oral therapy can have unpleasant side-effects and is not always effective. When a malodorous wound has an impaired blood supply, oral systemic antibiotics may not reach the wound site. Topical applications of anti-microbials such as metronidazole gel or the use of antibacterial dressings that contain cadexomer iodine, silver sulphadiazine or nanocrystalline silver may be more effective. However, unless the underlying cause can be alleviated, the problem will recur and the clinician should consider the need for long-term management. 
Infection and malodour are often accompanied by excess exudate. Effective exudate management is essential to prevent saturated dressings that quickly become stale and offensive. Where appropriate, patients can be encouraged to undertake their own dressing changes so they can change dressings when they feel the need, without being dependent on the clinician. Activated charcoal dressings absorb malodour, but as the dressing becomes saturated and the exudate "strikes through", the odour will reappear - to avoid this the dressing should be watched carefully and changed when saturation looks close. Occlusive dressings may help contain malodour, and wound drainage pouches can sometimes provide a solution for excessive exudate. Deodorisers can mask odour, but patients may find the scent of the deodoriser more overpowering than the malodour. 
Like many sensory signals, malodour alerts us to a condition requiring attention. It may not be possible to cure the condition, but effective management of malodour is important to promote quality of life and the patient's sense of wellbeing.

References

  1. Neal K. Treating fungating lesions. Nursing Times 1991;87(23):84-6.
  2. Doyle D. Domiciliary terminal care. edinburgh: Churchill Livingstone; 1987.
  3. Haughton W,Young T. Common problems in wound care: malodorous wounds. Br J Nurs 1995;4(16):959-63.
  4. Collier M.Malodour and infected wounds. A patient-centred approach. Leg Ulcer Forum 2001;14:12-4.

Resources
World Wide Wounds
An online resource for dressing materials and practical wound management information
W:www.worldwidewounds.com