When a wound is complicated by infection, excessive exudate production, swelling, and necrotic tissue, tissue recovery becomes significantly more difficult. In such cases, it is important not only to control the infection but also to create conditions that support tissue repair.
One of the methods that can complement comprehensive treatment is NPWT—negative pressure wound therapy.
Infected Wounds: Why a Standard Approach Is Not Always Enough
Infection changes the conditions under which a wound needs to heal. Excess exudate maintains a moist environment, swelling may impair microcirculation, and non-viable tissue interferes with normal tissue repair.
Therefore, treatment is not limited to local therapy alone. NPWT can be used as an adjunctive method in the comprehensive treatment of an infected wound. Under negative pressure, the system removes exudate and wound contents, helping clear damaged and non-viable tissue and creating conditions for further healing. When necessary, treatment is supplemented with surgical debridement, while antibacterial therapy is prescribed based on clinical indications.
What Is NPWT, and How Does a Negative Pressure Wound Therapy System Work?
NPWT creates controlled negative pressure in the wound area using a specialized dressing and vacuum system. It removes exudate into a collection canister, helping maintain a controlled wound environment.
By continuously removing exudate, negative pressure may reduce swelling in the surrounding tissues. At the same time, mechanical stimulation of the wound bed promotes the formation of granulation tissue — new tissue that gradually fills the wound defect.
As a result, NPWT can help prepare a complex wound for the next stage of treatment, such as secondary healing, secondary closure, or reconstructive surgery.
The terms NPWT, vacuum-assisted wound therapy, and negative pressure wound therapy essentially describe the same technology. Clinicians also use the term "VAC therapy", although VAC is a trade name for specific systems.
What Benefits Does NPWT Offer for Infected Wounds?
In infected and purulent wounds, NPWT continuously removes exudate, pus, and wound contents into a dedicated collection canister. For wounds with heavy drainage, this reduces the need to repeatedly disrupt the dressing seal and helps maintain stable wound conditions throughout therapy.
Negative pressure affects microcirculation and mechanically stimulates the wound bed, promoting granulation tissue formation. At the same time, tissue swelling decreases, and the wound edges gradually come closer together. As the wound bed changes, the physician can adjust the treatment approach and determine when the defect is ready for definitive closure.
NPWT can be used between surgical treatment stages for large postoperative, traumatic, and purulent wounds. If a wound requires repeated debridement, reconstruction, or plastic surgery, the system can continue to manage the wound during the interim period. Another option is NPWT with instillation, in which a specialized solution is periodically introduced directly into the wound and subsequently removed under negative pressure.
Modern Methods for Treating Purulent Wounds: Where Does NPWT Fit?
For a purulent wound, the primary goal remains controlling the source of infection. If an abscess is present, it must be drained, and necrotic tissue must be removed. In cases of systemic infection or other clinical indications, the physician may prescribe antibacterial therapy.
At this stage, NPWT can complement treatment. The method helps control exudate and maintain the wound environment following surgical debridement. For certain complex wounds, NPWT with instillation may also be used, combining negative pressure with periodic delivery of a specialized solution. This is a separate technology with its own indications and limitations.
When May NPWT Be Appropriate?
NPWT may be considered for complex postoperative, traumatic, and other wounds when the condition of the patient and the wound meet the requirements for this type of treatment. The method is particularly useful when a significant amount of exudate needs to be controlled or when the wound bed needs to be prepared for subsequent closure.
At the same time, direct treatment of the infection should not be considered the expected outcome of NPWT. NPWT works with the wound environment and can be one component of a comprehensive wound treatment approach.
Limitations and Risks of NPWT for Infected Wounds
Negative pressure does not replace surgical debridement. If pus or another source of infection remains in the wound or surrounding tissues, address this issue as a priority.
Caution is required for wounds with active or uncontrolled bleeding, exposed blood vessels, organs, or other critical structures. In these situations, assess the suitability of NPWT individually, and protect critical structures adequately.
If the infection progresses during therapy, the wound condition deteriorates, or the expected improvement is not observed, the treatment approach should be reassessed.
How to Assess the Effectiveness of NPWT in Clinical Practice
Assess treatment effectiveness based on changes in the wound and the patient's overall condition. It is important to monitor the amount and character of exudate, the condition of the wound bed, granulation tissue formation, the condition of the surrounding skin, and possible signs of infection.
NPWT duration is not determined solely by the number of treatment days. Once the wound reaches the planned condition, the physician may proceed to the next stage, such as secondary closure, skin grafting, or another reconstructive procedure.
NPWT in Modern Complex Wound Care
NPWT enables effective management of a complex wound throughout the treatment process. For patients, this means controlled conditions for tissue repair, while for physicians, it provides a tool for managing complex infected and purulent wounds and monitoring their progression at every stage of treatment.
A comprehensive approach incorporating NPWT allows clinicians to manage the wound process step by step, monitor its progression, and move to the next stage at the appropriate time — secondary closure, skin grafting, or another reconstructive procedure. For complex wounds, this makes NPWT an important component of modern treatment when continuous wound monitoring and active support of the healing process are required.