Negative Pressure Therapy Demonstration- Part 3

In Part 3 of the Negative Pressure Therapy Demonstration, Japa Volchok, DO demonstrates operation of the “Wound V.A.C.” device. This is a step-by-step instruction of preparing a wound for negative pressure therapy. This demonstration is performed by a trained wound care physician for educational purposes only and should not be tried at home.


Understand Wound Care:
Negative Pressure Therapy Demonstration- Part 3
Device Operation
Commentary: Japa Volchok, DO

There are a variety of negative pressure therapy systems. This is a K.C.I system known as a V.A.C. The V.A.C. is supplied in a portable model that is battery operated as well as A.C. current operated. In addition, there are other larger units that are based on direct, non-battery operated power use for different indications.

This device has two components to it. One is the permanent device itself. That has the generating device that creates the suction or negative pressure. There is then a disposable component which is the canister that will collect the drainage from the wound. It includes the edema fluid as well as the exudate and other fluids that are removed from the wound. This canister is supplied with a chemical absorbent. That absorbs the fluid as well as graduated marking that measures the volume of the fluid that is removed from the wound.

One would take the generator device and attach the suction canister to it until there is an audible click and the canister is adhered to the machine. At this point, the machine is now ready to be connected to the tubing that has been previously attached to the patient’s wound.

The tubing that we have attached to the patient model, or in your case, your patient’s wound, is supplied with a closure device as well as a locking connection. Similarly, the canister that attaches to the generator has a matching paired locking device as well as an interlocking connection.

To lock the device portion of the tubing to the patient portion of the tubing, one would push the female and male end together and turn part of a turn to lock. Similarly, you would turn and pull this apart to disconnect the patient from the generator.

It is important that when disconnecting the generating device from the patient, one would close off the patient side before disconnecting. This prevents outside air from being sucked back into the wound through the tubing. Once continuous negative pressure has been created by the generator, you will see the suction tubing adhere more closely to the wound.

The generators are designed so that there are a variety of audible alarms. Most commonly, an alarm will generate if the collection canister is full or if in application of the dressing, the seal that allows the continuous negative pressure suction to be generated directed at the wound bed, is broken.

If the seal is broken, you may hear an audible alarm from your generating device. If this occurs, one would need to examine the dressing application. There are a variety of ways to seal an area where there may be a leak. One common way is to apply skin prep over the dressing. This may seal a minor leak. Another method that may be required is application of an additional piece of adhesive over the area where there is leakage.

One way to determine if there is leaking, or failure to achieve complete sealant with the adhesive, is to examine around the wound circumferentially and palpate. If you suddenly achieve suction at one particular point, you can identify that as your leak.

In a subsequent video, we will demonstrate tips and tricks to deal with difficult wounds, where leaking or failing to achieve suction may be more likely.

There are several specific indications and contraindications to negative pressure therapy. One should carefully review the manufacturer’s educational materials and the indications for use of a specific dressing and negative pressure therapy system.

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