Negative pressure wound therapy (NPWT) is a technique used to facilitate faster wound healing. The basic goal of NPWT is to use a suction or vacuum procedure to draw excess fluid from a wound, thereby improving circulation and disposing of cellular waste. This technique is used for several types of wounds, especially large and chronic wounds as well as burns. Based on the type of wound involved, NPWT may employ the use of gauze, foam pads, or a special sponge placed atop or within the wound and a tubing system connected to a vacuum pump.
It is generally believed that negative pressure wound therapy benefits wound healing in several areas. It creates a moist and closed wound environment, balances fluids, removes dead tissue, increases circulation, decreases bacteria, and promotes growth of white blood cells. However, the physiological effects of this therapy are still not completely understood, and some have questioned whether or not it truly speeds wound healing faster than other methods.
Without knowing the details of how the vacuum pressure causes the different biological mechanisms to interplay, it is difficult to establish the most appropriate protocol for using the technique on individual patients. Nevertheless, many health practitioners have had success with NPWT and simply experiment with the length of time the vacuum pressure is applied and the level of intensity with which it is administered. Dressing changes occur when the negative pressure wound therapy ends, which may be anywhere from every 48 to 72 hours, and doctors select the spongy material used to absorb the fluids based on what size and density of pore is appropriate for a particular wound.
A common setup for negative pressure wound therapy is to cut a piece of porous black polyurethane foam designed for NPWT to fit the size and shape of a wound. Then, tubing is placed on top of the foam or inside the foam and a clear piece of plastic adhesive covering is placed over both to hold the foam and tube against the wound bed to ensure everything is properly sealed. The tubing is connected to the vacuum pump, the pump is turned on, then the pump sucks the excess liquid from the wound and drains it into an attached container for a prescribed amount of time. The suction may be constant or periodic, depending on the type of wound and type of vacuum pump or suction device attached.