Wound cleansing & debridement of chronic and / or secondary healing wounds.

Some principles of wound cleansing

Knowing whether or not to cleanse a wound, which solution to use, sterile saline or tap water, is absolutely vital for basic wound care.

If you cannot see the whole of the wound; if there is undermining and you cannot see the base of the wound; if the patient is immuno-compromised, or if you are simply unsure, use a sterile solution! You cannot go wrong with that decision.

It is most important that you do not allow tap water / shower water to fill a wound cavity where it may be absorbed into deeper tissue or other structures that are normally sterile e.g. bone, tendon, the blood stream, joint prostheses.

Objectives of debridement

•  Perfusion of injured tissue is crucial for healing to progress

•  Removal of necrotic (devitalized) tissue is essential

•  Wounds will not heal until necrotic tissue has been removed

•  Necrotic tissue is a focus for bacterial proliferation

•  Necrotic tissue often hides a ‘bag of pus’

Choices for debridement

•  Surgical physical / excising

•  Autolytic naturally + moist wound environment

•  Mechanical high pressure irrigation

•  Chemical caustic agents e.g. hypochlorites (do not use!!)

•  Bio-surgical sterile maggots
I am only going to focus on the first two, surgical and autolytic, as these are the commonest methods I have used, and seen used, over the past 10 years or so. I will explain my preference for each.

Surgical debridement

This is by far and away the quickest method of removing dead tissue and depending on the amount and extent of necrotic tissue my first choice is to have the patient referred to a surgeon for surgical debridement (in one session). If this is followed with negative pressure wound therapy, where appropriate, healing can be rapid and uncomplicated.

Figure 1 Thick black necrotic cap with pus, under pressure, ‘bubbling’ and oozing from the edges of the pressure ulcer.

I have debrided (with a scalpel) numerous sacral pressure ulcers over the years in nursing home residents. I no longer do this because I have found it is quicker, better for the patient and cheaper, to have them referred to a surgeon for debridement. They do a far better job than I could ever do!

Figure 2 Scarring over the sacrum following surgical debridement and negative pressure wound therapy of a sacral pressure ulcer (patient lying on right side). This photograph shows a healed sacral pressure ulcer. I first saw it as a full thickness ulcer, with a black necrotic cap just like that depicted in Figure 1.

The patient was eventually referred to a surgeon, full debridement was carried out in just one session and negative pressure wound therapy used. Within two months the pressure ulcer had healed.

Autolysis

Autolysis is the term used for the body’s way of getting rid of dead tissue naturally.

The process of autolysis can be enhanced by providing a moist wound environment with various dressings and gels. It is however, very time-consuming and exposes the patient to many weeks and often months of painful dressings and potential infection.

While ever there is any wound, any break in skin integrity, the patient is at risk of (cross-infection) contamination with e.g Methicillin-resistant Staphylococcus aureus. (MRSA) amongst other nasty bugs which may result in a severe and potentially fatal infection.

MRSA IS VIRULENT. WHY IS IT IMPORTANT? [1] [2]

•  Restricted range of effective antibiotics

•  Spread of multi – drug resistance

•  Widespread vancomycin usage

•  Detection implies the failure of simple infection control measures

Figure 3 Following excision of a black necrotic cap this foul-smelling pressure ulcer was found to be filled with adherent soft black necrotic tissue. It took weeks to remove using gels and regular sharp debridement.

Figure 4 Removal of dead tissue from this sacral pressure ulcer took weeks and revealed deep areas of undermining as more and more dead tissue was removed.

Both patients depicted in Figure’s 3 and 4 were MRSA positive.

Only sterile normal saline was used to cleanse this sacral pressure ulcer (Figure 4) because initially the depth and extent of tissue loss was not known. When most of the necrotic tissue was removed there was a vast area of undermining and exposed bone. Months of antibiotic therapy was required to treat the infected bone (MRSA osteomyelitis).

A variety of dressings was used at the various stages of healing. Alginates and foams were used to absorb exudates. Hydrocolloids were used when there was no sign, nor symptom, of infection.

When there was no undermining and the wound was shallow (Figure 5) cleansing under the shower was appropriate and faster.

Figure 5 Several months later the sacral pressure ulcer depicted in Figure 4 was almost healed. At this stage a hydrocolloid dressing was being used but this frequently became contaminated with faeces so required changing more often than would otherwise have been necessary.

KEY DETAILS for showering patients with shallow sacral pressure ulcers •  Shampoo hair and wash body •  Wrap hair and upper body in towels to keep warm •  Remove dressing from sacrum •  Shower wound area and ensure peri-wound skin is clean •  Pat dry skin surrounding wound •  Re-apply wound dressing (no need for a dressing pack)

There are too many variables that may influence the outcome of foot complications in diabetic patients or those with peripheral arterial disease.

The anatomy of the foot, including the various arteries and veins is complex and the presence, or absence, of pedal pulses is not a definitive indicator of a good blood supply to the foot.

There are many healthcare professionals reading this who are perfectly qualified to deal with necrotic ulcers on feet. However I have grave concerns about nurses (& I am one!) debriding feet [and other parts of the body with a scalpel or scissors]. Unless a nurse is very well-trained, knowledgeable in the complex anatomy of the foot and competent in the assessment of feet with pressure ulcers I cannot approve, nor will I endorse, any attempt at debridement, sharp or autolytic.

Most nurses who have attended the wound care courses I have taught over the past 15 years cannot answer the questions on the anatomy of the skin. They simply do not know ‘the anatomy of the skin,’ never mind the anatomy of a foot, yet they want to cut into it with a scalpel!

Figure 6 necrotic right heel pressure ulcer — refer to surgeon

REFERENCES

1. Barakate MS. Harris JP. West RH. Vickery AM. Sharp CA. Macleod C. Benn RA. A prospective survey of current methicillin-resistant Staphylococcus aureus control measures. Australian and New Zealand Journal of Surgery. 69(10):712-6, 1999 Oct.

2. Barakate MS. Yang YX. Foo SH. Vickery AM. Sharp CA. Fowler LD. Harris JP. West RH. Macleod C. Benn RA. An epidemiological survey of methicillin-resistant Staphylococcus aureus in a tertiary referral hospital. Journal of Hospital Infection. 44(1):19-26, 2000 Jan.