Andrew Kingsley

I'm a nurse, trained in Bristol in the early 80s, worked through general surgery, intensive care, coronary care. Got into infection control first and then became very interested in wounds really throughout my career, seeing some of the early more modern dressings such as the alginates and the hydrocolloids really take off and become the sort of field of play that we currently know. Got into wound care in the mid-90s and combine that with infection control, which leads on to my particular interest in wound infection. The idea of the infection continuum is to gather signs together in order to build up a picture so that you can determine where you are. And so we have wounds that are not infected but are colonized with bacteria. All open wounds will have bacteria in them, that is normal, and so we shouldn't worry about that. It's a question of balance. If If the balance is in favor of the patient and all of their immune system is working well and the wound is visibly healing and visibly getting smaller and doing importantly what you expect, debriding, granulating and closing, then all will be well. That wound is described as colonized, you don't need to intervene, you use very standard dressings and standard methodologies and all will be well. As we move up the continuum towards infection or overt infection, we have a stage where the wound becomes delayed and stuck. The whole wound stops healing. That is something where the bacterial burden may well be out of control in relation to the host's immune system. So that balance has been tipped now, rather than in favor of the host, but in favor of the bacteria. So a lot of bacteria, a lot of different species of bacteria with all the possible interactions that they might have in the wound and in the different parts of the wound with all the different potential environmental conditions that exist there. So in that wound, the key feature of a critically colonized wound is one that is stopped in its healing progress despite all other good and sensible therapy. We often get a variety of signs and symptoms to go with that, namely the wound is often wet, it may be smelly, it will have a lot of slough and fibrin in the wound and is generally unpleasant and unfair for the patient. So that is sometimes where we can intervene with a topical antimicrobial in order to make a difference and put the balance back in favour of the host and tip the wound back towards healing. If we're then taking the next stage up, it becomes from that rather covert infection setting to something much more obvious, a local infection. And a local infection is something where we see a local cellulitis around the wound, perhaps a flare in a particular corner of the wound, or perhaps a ring of redness. That is often painful to pressure, it's new redness, but of course it is the sign of inflammation so you have to determine if this is new or if it's just redness associated with an initial injury. But for a lot of chronic wounds, you will see that this begins to develop where previously it wasn't like that. So new redness, pain, swelling, heat around a wound is a sign of local infection and it's much more obvious than those in the critical colonisation state where the base of the wound is really showing a problem, but the surrounding skin isn't. So local infection, very much in local in character, and then finally, you've got the state where you've gone much beyond the local borders of the wound and we have a spreading infection, so typically a cellulitis of the leg around a leg ulcer, and it's creeping away, moving away from the wound, and is clearly much more acutely focused, exquisitely painful, often with temperature as well, raised white count, raised C-reactive protein and other obvious markers. And that requires urgent attention with antibiotics and other supportive therapies. So all of the ragbag of signs and symptoms for all of these states on the wound infection continuum, they overlap. So whilst you might have some key features, you have some similar features that present in all of those states. Telling the difference between one state and another, which will lead you on to a particular course of action, very important. So to develop a checklist really is to put the signs and symptoms based on the colonized, critically colonized, local and spreading infection groups. Give those signs and symptoms and allow people to identify on a checklist, tick things off so that they can build up the picture in front of them, show the evidence, make it much more obvious about how you've come to a decision. Show your workings, really, so that you can see and help you to make that decision, to feel confident in the action that you're going to take, whether that's intervening with topical antimicrobial, whether it's referring to somebody else for further treatment, whether it's getting an antibiotic prescription as well. There will be probably multiple things that you're doing, but a checklist, build up that evidence, take a confident course of action. The wound swab is an adjunct to ensuring that the antibiotic therapy that you have chosen for a patient is correct, so it's a check mechanism, really. It can be useful in a few certain circumstances in order to determine in advance what is there if you get into trouble, and it's certainly useful to identify MRSA in routine screening processes, but in most circumstances with open wounds, you would only take a swab if you were in a local infection or a spreading infection setting. You don't need to do that in a critically colonized wound. You should be able to do local treatment, local antisepsis, and see improvement. If, however, you don't see improvement in two to four weeks' time with that sensible therapy, then taking a swab at that point and then reviewing your therapy is very sensible. So it's not a first-line measure to determine diagnosis of infection. That's done clinically, but it's a good secondary method, but it's also used very predominantly for checking that the antibiotics given are correct, and in particular, to ensure that you don't have an antibiotic-resistant organism, such as MRSA in the wound for which you would otherwise have to change your antibiotic therapy. But bearing in mind, antibiotic therapy only for local infection or spreading infection. I think over the time that I've been in wound care and my nursing career over the last 30 years, it's we've moved away from debridement because we worried about damaging the surface of the wound and quite rightly so, because we had a tendency to do more damage than good. However, when we stopped doing debridement, we ended up preventing harm, yes, but also losing some of the better aspects that came with that. So I think it's now time to look at re-investigating our ability to debride and how we can get debridement done gently and regularly because we do need to remove the environment in which the larger numbers of bacteria live. That'll bring the number down and help to reduce the possibilities of critical colonization. And critical colonization also, and the new biofilm area, it may help in that area as well. If we can remove the environment in which those things occur, then we should see more healing. So, debridement very crucial to healing and to making sure that the balance is in the favor of the patient and not in the favor of the chronicity. We should be able to, with the right therapy, start to see progress within two weeks and almost certainly within four. My personal view is that if you don't see improvement within four weeks with an appropriate set of therapies, you then make a referral. for all chronic wounds, you should see visible and obvious difference within that time period. And if it's stuck and static, that's the time to make a referral. And I think that's when we're gonna use our primary, secondary, and potentially professorial or tertiary-led centers where they are in the country to the very best use. But in the first instance, if you're a primary caring nurse or doctor, pass on to a secondary person, whether that's a tissue viability nurse or perhaps a specialist dermatology clinic or others, but somebody in a secondary position to take another look if it's not improving at four weeks. So if we have a spreading infection, so this is a large cellulitis, then you need antibiotics and you need them systemically. And dependent upon the extent of that, then you'll probably need intravenous antibiotics for a short period, and then followed up with oral antibiotics. A typical IV to oral switch is usually 48 hours of IV antibiotics in a hospital, followed by perhaps five to seven days worth of oral antibiotics to make sure the signs and symptoms, all of that redness goes down and that your normal markers like temperature and raised white count go down. In a local infection, so we've now got our wound with a local flare of redness or a circular ring of redness around that wound, then for me, that state, taking a swab is very valuable in that sense because you want to be able to check the antibiotic prescription that's being given and giving then an oral antibiotic titrated to symptoms, which I mean is that you give it for the duration that it takes to get the redness and cellulitis gone. So that is not necessarily a course. It might be five days, it might be eight days, but it takes as long as it takes to get that redness down. But it's likely to be around the five day mark that we'll take if you're dosed correctly for that. So a local infection, you'll have an antibiotic, but as an adjunct, you can use a topical antiseptic dressing as well. there's no reason why not to deal with local symptoms. In a critically colonized wound, then you've really got the need to do debridement and also to do topical antisepsis, and that will work well. You don't have to use, in my opinion, oral antibiotics in that setting. You can actually get away with and do very well with a lot of the topical antimicrobial dressings that we have. And in a colonized wound, you just use standard dressings in the main. However, we are exploring now those wounds which are at greater risk of infection and trying to identify in advance those that we ought to do our utmost, perhaps with a topical antimicrobial to prevent infection. But these are those at particular greater risk where the outcome would be much more severe for the patient, where perhaps bone is exposed, perhaps where tendon is exposed. So very specific circumstances and not just anybody at risk.