USE OF TRANSCUTANEOUS PRESSURE OF OXYGEN IN THE EVALUATION OF EDEMATOUS WOUNDS

Transcutaneous pressure of oxygen (Ptco(2)) was measured in edematous wounds before and after a regimen of hyperbaric oxygen (HBO2) therapy, in patients breathing normobaric air (AIR), 100% normobaric oxygen (O 2), and 100% O-2 at 239 kPa (2.36 atm abs; HBO). Wounds also were scor ed for severity, including three ratings for periwound edema. Only dur ing AIR was pre Ptc O-2 of markedly edematous wounds significantly low er than that of moderately edematous and non-edematous wounds (P < 0.0 01). After HBO2 therapy, wound severity score and periwound edema rati ng decreased significantly (P < 0.001), and periwound edema ratings co uld no longer be distinguished by PtcO(2). Although pre periwound Ptco , measured during both O2 and HBO evaluations was significantly greate r than that measured during AIR (P < 0.0001) and was positively correl ated with subsequent change in wound severity (P < 0.05), regression a nalyses failed to yield a significant prediction equation. The authors conclude: a) dramatically marked increases in Ptco, of normally hypox ic (<30 Torr O-2) edematous wounds during O2 and HBO challenges demons trate that periwound edema is an O-2 diffusion barrier during normal c onditions; b) HBO2 therapy significantly reduces periwound edema in ma rkedly edematous wounds; c) despite significant correlations between p re-therapy periwound Ptco, measured during O2 and HBO challenges and c hanges in wound severity, single Ptco(2) measurements are not predicti ve of changes in periwound edema or overall wound severity.