Negative-pressure wound therapy
Vacuum therapy (also vacuum sealer, VacuSeal, Vacuum Assisted Closure Therapy (VAC ), Negative pressure wound therapy ( NPWT), and others) for wound healing consists of a wound closure ( occlusion) in combination with a drainage of wound secretions and blood, with a suction through under pressure is maintained.
The naming of the German language was unhappy because no vacuum in the true sense, but a reduced atmospheric pressure is applied.
Active Principle of
Is generated by a pump in a wound, and thereby the healing process in chronic and acute wounds may be accelerated in any case facilitates a controlled, localized negative pressure. This is done by drawing off wound secretions and the concomitant cleaning of the wound. An existing wound edema is reduced, as well as improve blood circulation in the wound. Subsequently, granulation tissue forms, and a moist wound treatment without storage of wound exudate is given. The negative pressure may be continuous, intermittent or constant.
Areas of application
- Acute wounds: Soft tissue defects, infected wounds after surgical debridement, fixation of skin grafts.
- Acute - Subchronic wounds wound conditioning, lymphatic fistulas, sternal wound infection, chest wall window.
- Chronic wounds: pressure ulcers, venous ulcers, chronic wound healing, Strahlenulkus etc. (see Willy 2005, pp. 18f ).
More special areas of application are the abdominal compartment syndrome, septic abdomen and the supply of enteral fistulas.
Contraindications
As part of the consensus conference on vacuum therapy, the representatives of wound healing societies from Austria and Germany agreed on the following contraindications:
- Strong bleeding disorders with increased risk of bleeding
- Exposed blood vessels, which are subject to the risk of being damaged by the vacuum therapy. In this context, it came in March 2011 to a warning from the FDA after a series of deaths.
- Necrotic wound bed,
- Untreated osteomyelitis,
- Malignant wound base (Willy 2005)
- Wounds that are located in the vicinity of the vagus nerve
Assessment
Since the system is closed, the dressing can stay several days on the wound, it is at least theoretically no daily dressing changes required. Due to the suction system in the wound volume decreased, excess fluid and obstructing exudate removed and granulation promoted so. In addition to the comfort of the patient increases (no smell, no harassing exudate, rarely dressing changes, etc.).
The less frequent dressing changes (depending on the condition of the wound ) are compared with the lease costs of the therapy system and the price of consumables. The single dressing change is much more complex, on the other hand less often. The pumps require electricity in principle. It also mobile systems with battery operation are available (eg Acti VAC), so that the patient according to the battery capacity is free to carry out its daily activities.
A systematic review of randomized controlled trials concludes that vacuum therapy may have a positive effect on wound healing, but ultimately still evidence of the advantages or disadvantages over conventional wound therapy are lacking. In particular, the published studies were heterogeneous and the statements distorts. Noticeable is also that apparently a large number of studies has been canceled. A similar result also came a Cochrane review (2008) and a IQWiG assessment (2006).