Negative-Pressure Wound Therapy I: The Paradox of Negative-Pressure Wound Therapy

  • Nick Kairinos
  • Michael Solomons
  • Donald A Hudson
Keywords: Negative-Pressure Wound Therapy,

Abstract

Background: Does negative-pressure wound therapy reduce or increase the pressure of wound tissues? This seemingly obvious question has never been addressed by a study on living tissues. The aim of this study was to evaluate the nature of tissue pressure changes in relation to negative-pressure wound therapy. Methods: Three negative-pressure wound therapy dressing configurations were evaluated - circumferential, noncircumferential, and those within a cavity - on 15 human wounds, with five wounds in each category. Tissue pressure changes were recorded (using a strain gauge sensor) for each 75-mmHg increment in suction, up to 450 mmHg. In the circumferential and noncircumferential groups, tissue pressure was also measured over a 48-hour period at a set suction pressure of 125 mmHg (n = 10). Results: In all three groups, mean tissue pressure increased proportionately to the amount of suction applied (p < 0.0005). Mean tissue pressure increments resulting from the circumferential dressings were significantly higher than those resulting from the noncircumferential (p < 0.0005) or cavity group (p < 0.0005); however, there was no significant difference between the latter two groups (p = 0.269). Over the 48-hour period, there was a significant mean reduction in the (increased) tissue pressure (p < 0.04 for circumferential and p < 0.0005 for noncircumferential), but in only three of 10 cases did this reduce to pressures less than those before dressing application. Conclusions: Negative-pressure wound therapy increases tissue pressure proportionately to the amount of suction, although this becomes less pronounced over 48 hours. This suggests that negative-pressure wound therapy dressings should be used with caution on tissues with compromised perfusion, particularly when they are circumferential.

Author Biographies

Nick Kairinos
MBChB, MRCS(Eng) Cape Town
Michael Solomons
MBChB, FCS(SA) Cape Town
Donald A Hudson
FRCS(Ed), FCS(SA) Cape Town
Section
Wound Care