What is diabetes and what is a foot ulcer?
Diabetes mellitus (DM) is a common condition that leads to high sugar concentrations in the blood. People who have had diabetes for a long time often suffer from foot ulcers. Nearly 35% of all hospital admissions from diabetes clinics are due to them, as are nearly 80% of all non-traumatic amputations of the leg and foot.
What is ozone therapy?
Ozone is a gas, and can be used as a treatment for ulcers in people with diabetes, which can be delivered with ozonised oils (e.g. ozonised sunflower or olive oil), or by a mixture of oxygen and ozone applied directly to the wound, or through rectal insufflation (blown into the final portion of the gut/intestines through the anus).
The purpose of this review
This review tried to find out whether ozone therapy is effective when given alone, or as part of a package of care, to treat foot ulcers in people with DM.
Findings of this review
The review authors searched the medical literature up to March 3 2015, and identified three relevant clinical trials (212 participants) that investigated ozone therapy for the treatment of foot ulcers in people with diabetes. The available evidence was of low quality.
One trial, with 101 participants, compared ozone treatment with antibiotics and followed up for 20 days. The results of this study showed that the reduction in ulcer size was greater, and also the length of hospital stay was shorter, in those receiving ozone treatment, but there was no apparent benefit in terms of the number of foot ulcers healed. No adverse effects (side effects or harms) were observed with either treatment.
The other two trials (111 participants) compared ozone treatment plus usual care with usual care. The results of these two studies showed that there were no apparent differences between the groups for reduction in ulcer size,the number of foot ulcers healed, or occurrence of adverse events and amputation rates.
Quality of life was not reported by either trial.
On the basis of the limited and poor quality information available, the review authors were unable to draw any conclusions about the effectiveness of ozone therapy for treating foot ulcers in people with DM.
The available evidence was three small RCTs with unclear methodology, so we are unable to draw any firm conclusions regarding the effectiveness of ozone therapy for foot ulcers in people with DM.
It has been reported that ozone therapy might be helpful in treating foot ulcers in people with diabetes mellitus (DM).
To assess the effects of ozone therapy on the healing of foot ulcers in people with DM.
In March 2015 we searched: The Cochrane Wounds Group Specialised Register, The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), Ovid MEDLINE, Ovid MEDLINE (In-Process & Other Non-Indexed Citations), Ovid EMBASE, EBSCO CINAHL, Science Citation Index, Chinese Biomedical Literature Database and The Chinese Clinical Registry. There were no restrictions based on language, date or study setting.
We included randomised controlled trials (RCTs) that compared ozone therapy with sham ozone therapy or any other interventions for foot ulcers in people with DM, irrespective of publication date or language.
Two reviewers independently screened all retrieved citations, selected relevant citations and extracted data. Disagreements were resolved by discussion with a third reviewer. The methodological quality of included studies and the evidence level of outcomes were assessed using the Cochrane risk of bias tool and the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach respectively. Data were expressed using risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes with their 95% confidence interval (95% CI). Review Manager (RevMan) software was used to analyse the data.
Three studies (212 participants) were included in this review. The overall risk of bias was high for two trials and unclear for one.
One trial (101 participants) compared ozone treatment with antibiotics for foot ulcers in people with DM. The study had a follow-up period of 20 days. This study showed that ozone treatment was associated with a greater reduction in ulcer area from baseline to the end of the study than treatment with antibiotics (MD -20.54 cm2, 95% CI -20.61 to -20.47), and a shorter duration of hospitalisation (MD -8.00 days, 95% CI -14.17 to -1.83), but did not appear to affect the number of ulcers healed over 20 days (RR 1.10, 95% CI 0.87 to 1.40). No side effects were observed in either group.
The other two trials (111 participants) compared ozone treatment plus usual care with usual care for foot ulcers in people with DM. The meta-analysis results did not show evidence of a difference between groups for the outcomes of reduction of ulcer area (MD -2.11 cm2, 95% CI -5.29 to 1.07), the number of ulcers healed (RR 1.69, 95% CI 0.90 to 3.17), adverse events (RR 2.27, 95% CI 0.48 to 10.79), or amputation rate (RR 2.73, 95%CI 0.12, 64.42).