Intermittent NPWT and lower negative pressures--exploring the disparity between science and current practice: a review.

Negative pressure wound therapy (NPWT) is used to treat a wide and growing range of problematic acute and chronic wounds. Continuous therapy delivered at -125 mm Hg has been routinely recommended, despite consistent research findings suggesting potential advantages to the use of lower pressures and intermittent therapy. To enhance understanding and document the disparity between the body of NPWT science and current practice with respect to negative pressure levels and modes of therapy, a search of the English-language literature from June 1989 through May 2009 was conducted. Thirty-six publications found to contain directly relevant information (in vitro, in vivo, and clinical data) were examined. While lower negative pressures and intermittent therapy were associated in earlier studies with improved microvascular blood flow in porcine wound models and with reduced pain in patients, early system shortcomings discourage adoption of intermittent therapy. Subsequent preclinical studies confirmed the beneficial effects of intermittent therapy compared to continuous therapy on blood flow and granulation tissue formation and lower pressures (-75 mm Hg or -100 mm Hg) compared to higher pressure (-125 mm Hg) on soft tissue blood flow. Considering the available preclinical evidence, reported patient pain, and common use of high-pressure continuous NPWT in clinical practice, high-quality randomized controlled clinical trials must be conducted to help clinicians optimize care.