Effects of different negative pressures on reduction of wounds in negative pressure dressings.

Negative pressure dressings stimulate the healing of tissue-deficient wounds by applying continuous or intermittent negative pressure. This study was designed to determine the most effective negative pressure level for the reduction of the wound by using negative pressure dressings in animal studies. Fifty male Wister rats weighting 200-250 grams were used throughout the study. The animals were divided into five groups of ten animals each as follows: group 1: no negative pressure and a closed dressing method using a polyurethane foam and an adhesive drape. Group 2-5: 25, 50, 75 and 125 mmHg negative pressure and a closed dressing method using a polyurethane foam and an adhesive drape. The wounds were measured along the vertical and horizontal lengths of the body axis and the wound area was calculated. The reduction of the wound area was weaker in the group with a negative pressure of 25 mmHg, and similarly higher among the groups with negative pressures of 50, 75, or 125 mmHg. There were no significant differences in the reduction of the wound area among the latter three groups.