The Study of Wound Dressings for Portable Negative Pressure Wound Therapy

Introduction Negative pressure wound therapy (NPWT), also known as topical negative pressure, has become a popular therapy for the treatment of many acute and chronic wounds. In many randomized controlled trials(RCTs), NPWT also has benefit in diabetic foot ulcer and pressure ulcer. However, most studies used commercial VAC device in combined with polyurethane (PU) foam. It is not yet clear where NPWT combined with gauze as wound filler is as effective as the PU foam. This RCT evaluated the efficacy of the gauze and PU foam, two kinds of fillers routinely used in negative pressure wound therapy, on the healing of the diabetic lower-extremity ulcers and the pressure ulcer.

Methods From 2010/1 to 2015/01, the in-patient persons with difficult to heal diabetic ulcer or Grade 4 pressure ulcer were enrolled. These patients were divided into two groups randomly. The letter of consent was signed by the patient or patient's family. After debridement of the infective wound, the wound of experimental group was packed with a moistened Polyhexamethylene biguamide (PHMB) impregnated gauze (Kerlix AMD, Covidien). A noncollapsible drainage tube (Blake drain, Ethicon) was applied to the wound, and then sealed with 3M Tegaderm Film. The system was connected to a 1-bottle water-seal chest drainage system and to standard wall suction at 125 mmHg negative pressure. The dressing was changed at 72- to 96-hour intervals (twice a week) for a period of 3 weeks. To the control group, the PU foam dressing from KCI was packed and sealed to the wound with the same continuous wall suction at -125mmHg. Investigators observed and recorded the ulcer area twice a week on each time of changing dressing in the following 3 weeks. The percentage of wound area reduction(PWAR) was used as a predictor of wound healing. The repeated measuring data were analyzed using linear mixed mode with SPSS statistical software. This clinical study was approved and monitored by Institutional Review Board of Show Chwan Memorial Hospital.