A new blog needs a new mini logo. That is why we have “W” with two arrows. It stands for: closing the gap from both sides. Which means we are trying to improve wound care both practical and theroretical.
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Maand: May 2015
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Reverse evidence
Since 1962 we all know that wounds without a scab heal 40% faster compared to wounds with a scab. This has been tested on two pigs (Winter, Nature 1962) and seven inmates (Hinman, Nature1963). This means, since 1962, we all are convinced that a for instance diabetic wound on an 83-year-old will heal up to 40% faster, only if you apply a moist environment.
Reversibly you may also try to answer the question how much slower wounds would heal if you would use of moist gauze, which have to be changed up to 3 times a day. Almost 50 years after Winter some people have tried to answer this question (Ubbink DT et al, Arch Surg 2008). What appears was that moist wound healing was not better but actually worse than a conventional gauze treatment. But there was one remark, these findings apply only for wounds with an acute etiology (and in a hospital setting).
Ehh well yess…. what type of wounds were investigated in the Winter and Hinman papers?
But fair is fair, one study should not make a difference, scientific principles dictate a finding should be repeated several times in order to be accepted.
This is why we have organisations which examine the evidence. One of those organisation is the Cochrane foundation which has as purpose to help medical professionals in their decisions. The method they use is to ruthlessly examine all research papers against the highest standards. <http://www.cochrane.org/about-us>. And nothing is easier than to go to their website and read what they have to tell about wound care.
If I cite them randomly: negative pressure therapy, there is not enough evidence. (And it is not only Cochraine but also for instance Vig S et al, J. of Tissue Viability 2011), Alginate; there is no evidence that alginate is better than any other addressing, foams; conclusion is the same, no evidence. The only exception appears to be hydrogel were the conclusion is that hydrogel is have some evidence to be more effective compared to other dressings. Silver dressings, no evidence etc. After a quick glance I counted 105 studies with almost 10,000 patients which actually met the Cochrane criteria.
Cochrane provides one, real unnerving outcome, no one is able to prove or repeat the 40% faster promise from the original articles more than 50 years. Apparently it is not possible to design a study or do a study which is meeting current scientific criteria and show a 40% faster healing.
So we start reducing our expectations. Perhaps we are asking too much my looking for a 40% faster healing, so let’s settle for 20%, 10% or even 5%. That appears fair to me.
But even that is not possible, the most positive statement in these studies is “there is some proof”, which is quite different from 5% faster healing. Apparently it is not possible for any current wound care dressing to prove in a well-designed study it actually makes sense to use.
Now what, it appears we have a problem.
We are not able to prove how much a wound benefits from using a moist dressing. The next step would be to reverse the question, does it actually work? The answer to this question is very easy to answer, because there are plenty studies, meeting the highest scientific standards providing the answer, the Cochrane collection from above. The significant answer meeting the highest standards is: a moist environment does not lead to faster wound healing.
And this finally leads us to the heart of the problem. We have a Mexican standoff between 2 pigs, seven inmates and 285 clinical patients. I don’t believe that the Winter and Hinman articles were wrong. It doesn’t take rocket science to understand why a scab might be hindering wound healing progress. But I also don’t believe that the Cochrane findings have to be dismissed because they don’t fit our view on today’s wound care. It does mean we have a gap in our knowledge. The gap can be summarised as we are not able to explain why Cochrane and Winter are both right.
Interesting is that all stakeholders in wound care should be aware of this gap since there have been no repeating studies which proof the moist paradigm in different circumstances.
For some reason we have chosen to ignore this issue for the last 50 years which sadly also lead to 50 years of “less useful” research which papers invariably end with the conclusion “more research is needed”.
To me it appears we have some work to do.
To paraphrase: if not me, who… if not now, when.
Wether a wound heals or not is usually described as a balance, can the body handle what is going on in the wound? Logically we focus on what is going on on the “wound”-side of the balance. Nevertheless it is a balance and we may make good use of a word to summarize what is going on on the “bodily”-side of the balance. Why not use the word “vigor” ? Vigor originates from the Latin; vigere ‘be lively’. Generally it is used to describe the “force and strenght to live”. The amount of “Vigor” then has to outbalance the amount of “complexity” on the other side. Vigor is a favourable term because it is has a more holistic feel to it. Your vigor increases after a good night sleep but also with an antibiotic treatment. It also provides insight in why a wound might stall in its development (both ways).
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Let’s bring wound care to the 21st century
Wound care in the 21st century is quite different compared to the current treatment. Even though most wounds heal by themselves, the wound healing process offers a window on the metabolism of the aging human. With the knowledge gained we also might find new treatment opportunites. It will not be an easy road but we will have to take it nevertheless.
Please do not hesitate to contact us if you disagree or agree, discussion makes life better. harmjsmit@gmail.com
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Biofilm is a natural dressing for wounds.
The biofilm may be, next to the scab, the other natural dressing. The difference is the biofilm has to be changed like any other dressing.
Animal life and thus humans have evolved in the presence of microbes. This means there always have been bacteria, yeasts and fungi (microbes) in wounds.
It makes no sense for a microbe in a wound to cause an infection. If you kill your host you also destroy your home. As a microbe it makes a lot more sense to create a situation in which the wound stays open and you and your host live long and (or not) happy.
This open wound situation would be an equilibrium between the microbe on the one end and the human body on the other. If you are a healthy person this will not be a problem. There is a reason we say “time heals all wounds”. Only if you are weakened by age or illness the balance can tip in the “advantage” of the microbe.
The biofilm is part of this game. In the beginning of times the first live was only primitive bacteria, They lived in the sea. They invented the biofilm which glued them to the rock and protected them against the waves and hostile chemicals.
If you as a microbe, want the wound to stay open you have first of all to protect yourself against the host immune system. This means you need a shelter. If not , here you can see what will happen. Apart from keeping it open you also have to protect the host and the wound against trauma and also against other pathogens which might me not so interested in the well-being of the host. During the human development the biofilm has been produced by microbes for this purpose; create and protect a living environment. It is pretty strong and made of sugars, proteins and is glued to the environment using eDNA.
The biofilm is a dynamic shelter or layer which is replaced regularly, animals lick their wounds and you brush your teeth. Apparently replacing it regularly is part of the equilibrium, just like any other bandage. Nature is used to this removal and within hours after removal, the microbe has started on a new biofilm. If this process or balance is disturbed an infection may occur. (in that case nature invented the maggot as a last resource to prevent infection) So the microbe-wound balance is a dynamic process which involves removal and rebuilding the biofilm. It can be disturbed by aggressive pathogens or by weakened hosts (patients).
All in all I think the biofilm has two functions in the game between the human and the microbe.
- protect the microbe.
- protect the host.
All this is nice to know but what are the implications for today’s wound care?
Giving the average condition of our patients it is advisable to deal with biofilms.
The best way to remove a biofilm is to debride the wound. That is a good idea anyway because by debridement you remove also other sources of infection and cell death. As you will understand from above, debriding means cutting, brushing, rinsing and all kinds of other forms of mechanical cleaning.
All in all the biofilm can be seen as a natural bandage. And just like any other bandage you have to change it regularly, check for signs of infection and do not leave it in the body (and certainly not on prostheses.
Treating wounds is a delicate game. Looking at it as a biologist makes a lot of fun and hopefully will help us learn how to hack the wound healing process. If you have a question, just contact me via LinkedIn.
If you think the idea is worth spreading, liking it will help.
Debriding is a medical intervention which only skilled medical professionals are allowed to do. A non-healing wound has to be seen by a specialised doctor or nurse.