NPWT Using Common Household/Medical Materials

Orthopods working in developing countries usually don't have supplies of commercial topical negative pressure dressings, pumps, and accessories lying around. But a clever and resourceful one can still apply NPWT on his patients using common, indigenous, and dirt-cheap materials.

What follows is a cursory discussion of how common household or medical materials (the one you can easily find lying around the hospital) can be utilized to apply the principles of NPWT. Each major component will be discussed further in the following posts.

The working set-up of NPWT is fundamentally simple. With the suction pump providing a vacuum, topical negative pressure is applied over the wound via tubings and foam under an airtight seal. The reservoir acts as a water trap for whatever fluids (i.e., exudates) that have been suctioned off the wound.

MATERIALS NEEDED:

I. Suction Pump (In this case, an ingeniously converted aquarium pump has been proven to do the job quite well)

II. Tubings & Reservoir

1. Oxygen cannula (used or new); Alternatively, aquarium aerator hoses may be used

2. 3/16" Copper tubing, 2" long, 1 piece

3. Empty Dopamine or IV bottle

4. IV tubings (macroset) - preferred because they come in sterile packages

III. Dressings

1. Open cell foam (1" thick upholstery foam, sterilized by steam autoclave)

2. Cling wrap
3. Scalpel blade or scissors, preferably sterile

4. Sterile gloves

5. Medical plaster/tape

THE RESERVOIR

Empty Dopamine or IV bottles are very useful as reservoirs. They can be easily found in the wards, and will cost nothing. Since their previous contents are sterile, they require very minimal cleaning & preparation.

Gently bend your 2" long copper tubing, then stick it onto the rubber stopper of the bottle. The bend will help make connecting the tubes to the reservoir easier. If you want to plunge the macroset's drip chamber directly (as illustrated later), you don't need to put the second copper tubing.

Now that the reservoir assembly is done, you can even sterilize this reservoir set-up using steam autoclave.

CONNECTING THE RESERVOIR TO THE PUMP

Get the oxygen cannula and cut off both ends. Stick one end to the suction pump, and the other end to the reservoir. Basically you can use whatever tubing that comes in handy, as long as it fits.

CONNECTING THE RESERVOIR TO THE NPWT DRESSING

We prefer using the IV tubings (macroset) because they come in sterile packages, and they're easy to acquire in the hospital wards. Carefully take out the drip chamber device (the end that you stick into the IV bag), and drive it into the reservoir's rubber stopper. Make sure that the rate controlling clamp is fully open.

THE FOAM DRESSING

Upholstery foam can be easily acquired from upholstery shops; just look for the foam scraps they sell at bargain prices. These are usually leftovers, but are new, clean foam. A foam thickness of 1" or 1.5" works well. It's best to cut up the foam into small rectangles around 2" wide and 3" long, then wrap them individually for autoclaving. This way, you need not waste large chunks of foam; you just need to open the number you need, basing on the wound area.

Sometimes it is also wise to slit the foam in the middle (to accommodate the suction tubings) BEFORE you sterilize them. This makes the job easier when you're applying the dressings later.

When it's time to apply the foam over the wound, select the appropriate number and sizes of foam to cover the wound (ONLY). It is advised not to go over the wound margins.

Cut off the end of the IV tubing (the end that attaches to the IV needle/cannula) and embed it into the foam. Measure the length of the tubing that is embedded into the foam and cut multiple holes along the length of the tubing THAT WILL BE EMBEDDED IN THE FOAM ONLY.

After placing the appropriate size & number for foam squares over the wound, apply several layers of clingwrap over the foam & tubing. 5-7 layers will do. Seal the ends to assure an airtight seal, paying particular attention where the tubing exits.

Once that is done, turn on the suction pump, and check whether the foam collapses from the negative pressure. It's advisable to position the reservoir lower than the dressing so that if the pump stops working AND the reservoir falls on its side, the suctioned fluids will not flow back into the wound site.