Modified Negative Pressure Therapy in Clinical Wound Care-National Cheng Kung University Hospital Experience

Abstract

Background: Negative pressure therapy has been shown to be an effective way to accelerate the wound healing process and stimulates the rapid formation of granulation tissue. However, the cost to rent the vaccum assisted closure (VAC) device is high and the indication for it's application is limited by National Health Insurance. Aim and Objectives: A system of ”modified negative pressure therapy (MNPT)” in clinical wound care was applied in this hospital and the experience of treatment is delineated in this article. Materials and Methods: There were 49 cases (male: 27, female: 22, mean age: 56.8 years old) received MNPT from 2007 Nov. to 2008 Aug. The sponges are disinfected. The negative pressure system included wall suction in ward with the negative pressure set about 120 mmHg with two hours on and one hour off alternately from 8AM to 12PM and lower continuous pressure (60 mmHg) from 12PM to 8AM. Several parameters were measured such as wound size, depth, vital structure exposure, wound culture, patient wound pain scale, and patient satisfaction scale before and after MNPT. Results: The wound size is 247.95cm^2 in average (1.5~1875cm^2). The final reconstruction methods after MNPT were STSG (16 patients, 63.3%), flap reconstruction (9 patients, 18.3%), healed by secondary intention healing (4 patients, 8.2%), wound closure (3 patients, 6.1%) and amputation (2 patients, 4.1%). Overall complication rate was 6.1%. Daily decrease of wound size was 3.43% per day, the shrinkage rate of vital structure exposure area was 6.82% per day and wound depth decrease rate was 5.58% per day. Overall nursing time in MNPT method is significantly shorter than that in wet dressing group (7.53mins vs. 23.76mins per day) There was no difference of daily cost in MNPT group and wet dressing group. The period of therapy was 10.86 days in average, and the duration of MNPT for deeper wounds with vital structure exposure was 13.67 days in average. The satisfaction and pain scales were better in MNPT group. Conclusion: Negative pressure therapy provides as the alternative way that accelerates the wound healing process and stimulates the rapid formation of granulation tissue. The commercial VAC device offers a constant negative pressure, good alarm system and good result of granulation. For financially unfavorable patients without coverage of National Health Insurance or those still awaiting for the approval of VAC, the MNPT was a good alternative method for obstinate wounds management compared with wet dressing method, not only in facilitating wound healing but also in saving nursing times as well as in reducing patient's suffering.