Oxygen Delivery Therapy with EPIFLO Reduces Wound Hyperperfusion in Patients with Chronic Leg Ulcers: A Laser Speckle Contrast Analysis

Abstract

Background: Today transdermal continuous oxygen therapy (TCOT) is used in wound care to promote healing by improving local hypoxia and preventing infection, and it has been described to reduce local inflammation over 1 month of administration. The present study aims to investigate the effects of this treatment on wound microcirculation through laser speckle contrast analysis (LASCA).

Methods: 20 adult patients (mean age: 76 ± 11.5 years) were prospectively enrolled. Inclusion criteria were presence of venous or mixed lower limb ulcers from three or more months without dimension reduction and without indication to surgery and weekly treatment by our outpatient clinic with silver dressings. Subjects underwent 1 month of TCOT (EPIFLO®) in addition to foam dressing. The primary endpoint was the comparison of ulcer and healthy skin perfusion through LASCA, performed before and after the treatment period. Secondary considered endpoints were wound area, wound area severity index and PUSH Tools 3.0 ulcer severity scales, and pain assessment (Numerical Rating Scale [NRS]).

Results: Before treatment, the wound area was significantly more perfused than healthy skin (+45%; P = 0.005). At the end of the study, this difference was not significant anymore (+20.5%; P = 0.11). Ulcer perfusion decreased (-12.5%, P = 0.047), whereas healthy skin perfusion did not vary significantly. A reduction of the wound dimension (median difference: 2 cm; P = 0.009) and pain (median difference: 2 NRS point; P < 0.001) after therapy were assessed.

Conclusions: LASCA shows that 1 month of TCOT can help reduce hyperperfusion of ulcer bed in patients with chronic lower limb ulcers, strengthening the hypothesis that this treatment effectively contrasts inflammation. This could correlate with the area and pain reduction assessed; however, the absence of a control group in this study does not allow a generalization of this hypothesis. Larger, controlled trials are needed to properly assess the relationship between TCOT effects on wound microenvironment and effective healing process.