- Personal Health Information & Self-Help
Negative pressure wound therapy for wounds that are difficult to heal
A very basic description of how negative pressure therapy works.
I have been working with negative pressure wound therapy for eight years and have held many courses around Europe on the different types of techniques used when treating different types of wounds.
Negative pressure wound therapy is used to both clean wounds and encourage granulation of hard to heal wounds. There are no wounds too small or too large, too difficult or too simple to treat.
I have experienced a lot over the past eight years and have witnessed chronic wounds on patients which they have had for over two years actually heal and close. This does, however, take time and patience but the wounds are treated and healed.
I have witnessed patients being admitted to hospital for amputations of limbs due to diabetic ulcers that have become infected being cleansed and treated successfully. Again this takes patience and time. Unfortunately not all patients are so lucky but i can honestly say that i have experienced far more successes than failures amongst the several hundreds of wounds i have been involved with.
What is negative pressure wound therapy?
First of all i will say that i am going to try to explain this to you as simply as possible. I will not use difficult medical terminology as i feel that it is important for people not working in the medical profession to understand this method of treatment.
This is a topical negative pressure which treats wounds locally. That is that the treatment is only applied to the area where the bandage or dressing is inserted.
By applying a drain into the dressing you are able to suck out wound debris and fluid from the wound bed allowing the wound to receive more nutrients and oxygen from the surrounding blood vessels at the base and edges of the wound. The wound fluid, bacteria, pus etc is sucked through the drain and tubing into a canister found on the suction machine. This fluid etc is then removed from the machine and emptied as infected material.
The gauze dressing in the wound cavity is covered by a transparent plaster which only breathes in one direction. When the wound therapy machine is switched on it causes a negative pressure/ vacuum under the dressing allowing the inflammation fluid to be drawn off and away from the woundbed continously.
I like to call this procedure the human bodies vacuum cleaner as it litteraly sucks out the grime dirt and stuff that keeps bacteria happy and wounds from growing or healing.
When the unwanted grime is removed and there is no more fluid to empty out the granulation begins. Granulation is that nice red beefy appearance which you see growing inside of the wound. Anything yellow, black or slimey is not healthy and should be removed before treatment is continued.
The wound grows from the bottom up and from the edges inwards towards the middle. Always inspect for fistulas and pockets deep within the wound on each wound dresing change as these need to be treated before allowing the wound to close completely.
Also when changing dressings use your sense of smell this tells you a lot about a wound. Smelly wounds are usually infected wounds but do not confuse the smell of the dirty bandage full of grime, wait until the wound has been cleansed and then observe.
It is obvious that a bandage which has been in the wound for several days without direct oxygen will smell unpleasant.
Should the wound be really infected at the start of treatment then i would always suggest to shift the dressing at least once a day for the first three days before going over to shifting every third day.
It is possible to achieve complete closure of a wound but in some cases the doctor will bring the granulation to a point where the wound has been filled and then they will order a skin transplant to finish the procedure quickly. This saves both time and the scar tissue area is reduced.
In this case the skin graft is also fixed into place with three further days of treatment with the vacuum machine.( Specific technique needed )
There are very many different machines found on the market today and as long as a negative pressure can be applied they all work just as well.
The main thing is that the technique chosen for the type of wound is correct.
Depending on the type of wound and dressing used you can be treated for several hours each day, intermittently or continously for several days at a time before the dressing is either changed or removed.
If this hub is of interest i would be more than happy to provide more pictures and techniques with even more descriptive details.