We may be lucky enough to spend this Christmas with parents or grandparents who survived their childhood in the years prior to 1928. Remember, they survived an era before antibiotics.
At just 19 years old, my mother’s younger sister died of what is now a treatable strain of tuberculosis. She died isolated in a hospital where the only contact she could have with her family was from an upstairs window.
It’s a sad story. It’s sobering. We assume that this approach to contagious disease is confined to our past. It is not; it could well be our future.
We are in a fist fight to preserve the wonder drug of our generation and every patient that is prescribed antibiotics is a responsibility that threatens our future.
Infection or inflammation
The phase of inflammation is easily recognised by redness, swelling, pain, increased exudate and the presence of slough in the wound (Figure 1).
It is a normal process that is essential for healing where neutrophils address bacteria while macrophage activity harnesses the power of proteases that break down large redundant and residual protein-rich material into a slough that can be shed naturally.
Every wound, surgical or traumatic, will be exposed to microbes from the near environment; be that from the surgeon, the source of trauma or the patient’s own cutaneous flora. The higher the volume of bacteria, devitalised tissue and debris, the longer the inflammation process, and the formation of granulation tissue will be delayed (Table 1). Based on the physiology described above, it makes sense that healing delay is down to more than just infection (Table 2).
Healing delay is down to the bioburden that inhibits proliferation. Yes, bacteria will find this protein-rich environment a perfect opportunity to multiply to the point of causing infection, but such an outcome is avoidable with good wound bed preparation.
In human healthcare, antibiotic use is becoming increasingly taboo, specifically where wounds are being treated unless they are chosen specifically to target the strain of microbe present in the wound, and are likely to reach that microbe at a concentration that is effective.
If not, the choice could encourage proliferation of already-present resistant strains, or at ineffective concentrations, favour the development of new resistant strains. If you do use antibiotics, consider checking the points in Table 3 first. Key points:
1. It may not be possible for systemic antibiotics to reach the wound bed at an effective concentration when there is a limited blood supply to the wound bed.
2. Devitalised tissue may be exposed to sub-optimal concentrations of antibiotic, and breeding bacteria will be more susceptible to developing resistance. 3. Local contamination does not warrant a systemic approach when local debridement and decontamination is an option.
Reducing bioburden without antibiotics
Skin prep
- Skin prep of clipped area using chlorhexidine ‘scrubs’ should be at preparations of 4% (neat) using moist gauze as resistance encouraged by use at suboptimal concentrations now exists.
- Ensure all antimicrobial skin preparations are used at the correct concentrations for the purpose.
Wound lavage
- Gross decontamination can be achieved with copious lavage using plain tap water.
- Wound lavage using saline, Hartmanns, lactated ringers at a minimum of 100ml per 1cm wounds.
Debridement – surgical or mechanical
- Surgically debride to healthy margins. If in doubt, tissue can remain and the wound managed open using advanced dressings. Non-viable tissue will declare itself over the next few days for soft tissue and as much as 10 days for tendon and bone.
- Mechanical removal through use of wet to dry dressings or debridement pads (Debrisoft).
The increasing threat of antimicrobial resistance is a ‘One Health’ priority, and rightly so. It is impacting the political agenda on a global scale and threatens every one of us
Autolytic debridement – to encourage softening of dead and devitalised tissue
- Hydrogels (e.g. Intrasite) will soften necrotic tissue by donating moisture to the wound. A semi permeable film or foam dressing will be required to maintain humidity so that the moisture level is maintained during one to two days’ wear. Slough and necrotic tissue will soften and be easier to remove manually.
Topical antimicrobial dressings
- Medical-grade manuka honey aids debridement due to a high sugar concentration (around 84% ideally) while offering a broad spectrum antimicrobial effect. Its success is attributed to the combination of a low pH (3.4), and the antimicrobial effect of its natural enzymes and unique manuka derived plant phytochemcal profile.
- Silver (and many other heavy metals) can be combined with wound-friendly materials to deliver positive, antimicrobial ions at the wound bed. Dissociation of these ions in solutions enables them to bind to negatively charged microbes in the local environment and disrupt their ability to function. However, silver may no longer be immune to resistance. Reports of some species of Pseudomonas being immune to the effects of silver raises some serious concerns. Pseudomonas species being some of the most destructive in terms of wound breakdown, the thought of selection in favour of this microbe could be disastrous.
- Polyhexamethylene biguanide (known as PHMB) is a broad spectrum, wound-friendly antimicrobial that has been combined with many materials to suit the needs of the wound.
- Dialkylcarbamoyl chloride (DACC for short) is a fatty acid coating that enables irreversible binding of microbes to the fibres of the dressing so that microbial load is actively reduced and removed with the dressing; the concept of irreversible binding being one that could reduce the impact of exotoxins released by microbes that are broken down by natural macrophage activity (Cutimed Sorbact).
Conclusion
The increasing threat of antimicrobial resistance is a ‘One Health’ priority, and rightly so. It is impacting the political agenda on a global scale and threatens every one of us. With the threat of untreatable pandemic disease on our near horizon, we need to do everything possible to avoid unnecessary antibiotic use.
When it comes to wound management, we could be guilty of assuming infection is more prevalent than it actually is. Good wound bed preparation, debridement and the latest wound care products can help us reduce the need for antibiotic use. If a wound ‘looks’ infected, we should ask ourselves if it really is infection, and if so, if the initial management was up to scratch. Could we have done something at an earlier stage that would have avoided what must have been an ideal environment for microbial proliferation?
Whatever we decide, the fact is we are on a collision course with resistance. Reducing the need for antibiotics for wounds today could really be all that stands between us and a last goodbye through a pane of glass.
