Background Negative-pressure wound therapy (NPWT) is believed to accelerate wound healing by
altering wound microvascular blood flow. Although many studies using laser Doppler
have found that NPWT increases perfusion, recent work using other modalities has demonstrated
that perfusion is reduced. The purpose of this study was to investigate the influence
of NPWT on tissue oxygenation of the foot, which is the most sensitive region of the
body to ischemia.
Methods Transcutaneous partial pressure of oxygen (TcpO2) was used to determine perfusion beneath NPWT dressings of 10 healthy feet. The sensor
was placed on the tarso-metatarsal area of the foot and the NPWT dressing was placed
above the sensor. TcpO2 was measured until it reached a steady plateau state. The readings obtained at the
suction-on period were compared with the initial baseline (pre-suction) readings.
Results TcpO2 decreased significantly immediately after applying NPWT, but gradually increased
over time until reaching a steady plateau state. The decrease in TcpO2 from baseline to the steady state was 2.9 to 13.9 mm Hg (mean, 9.3±3.6 mm Hg; 13.5±5.8%;
P<0.01). All feet reached a plateau within 20 to 65 minutes after suction was applied.
Conclusions NPWT significantly decrease tissue oxygenation of the foot by 2.9 to 13.9 mm Hg.
NPWT should be used with caution on feet that do not have adequate tissue oxygenation
for wound healing.
Keywords
Negative-pressure wound therapy - Oxygen partial pressure determination, Transcutaneous
- Foot
