Impact of topical oxygen therapy on diabetic foot ulcer healing rates: a systematic review

Objective: The aim of this systematic review was to determine the impact of topical oxygen therapy (TOT) on diabetic foot ulcer (DFU) healing. Method: Using systematic review methodology, we considered randomised controlled trials (RCTs), controlled trials, pilot studies and observational studies. The search was conducted in January 2019, using PubMed, CINAHL, Ovid, Cochrane, Web of Science and EMBASE databases. Data analysis was undertaken using RevMan and a narrative synthesis. The article titles were assessed by two authors independently, and the abstracts (when available) of the studies identified by the search strategy were screened for their eligibility, according to the inclusion and exclusion criteria. The full-text version of potentially relevant studies was obtained and two authors independently screened this against the inclusion criteria. Data were extracted using a predesigned extraction tool and all included studies were quality appraised using the Evidence-Based Librarianship checklist. Results: The search returned 565 records of which eight met the inclusion criteria. Of the included studies, three were set in single centre outpatient wound clinics, two studies were set in an outpatient wound care research clinic and three studies were multisite. Meta- analysis of four studies was undertaken. DFUs are >2 times more likely to heal with TOT than with standard care alone. The odds ratio (OR)=2.49 (95% confidence interval (CI): 1.59-3.90, p=0.00001). The remaining four studies also showed that using TOT increased healing rates. An included study reported that time to 50% DFU closure was significantly shorter in participants who received the TOT, mean 18.4 days versus 28.9 days in the sham therapy group (p=0.001). However, the validity of 65.5% of the eight studies was assessed as low. Conclusion: The findings suggest that TOT enhances healing for patients with hard-to-heal DFUs when used with standard care. The results from the trials reviewed also indicate a benefit for patients over standard care alone. However, the sample sizes in the studies were generally small, thus, more RCTs are warranted to further validate these findings. Declaration of interest: The authors have no conflicts of interest to declare.