Systematic review and meta-analysis of clinical trials examining the effect of hyperbaric oxygen therapy in people with diabetes-related lower limb ulcers

The role of hyperbaric oxygen therapy in the treatment of diabetic foot ulcers - A literature review

Diabetic Foot Ulcers (DFUs) are chronic foot wounds, in a person with diabetes, which are associated with peripheral arterial insufficiency and/or peripheral neuropathy of the lower limb. Recent UK audit figures report that approximately 50-60 % of DFUs remain unhealed after 12 weeks. Previous research has suggested that ischaemia plays a key role in the pathophysiology of many chronic wounds, including DFUs. For this reason, hyperbaric oxygen therapy (HOT) has been investigated. The study aimed to investigate 1) Current understanding of the physiology of normal wound healing and the pathological mechanisms that occur in DFUs to interrupt these processes; 2) Effectiveness of current DFU treatment approaches; 3) Effectiveness from clinical trials and meta-analyses for any demonstrated therapeutic benefits of HOT in the treatment of DFUs, 4) Patient selection criteria for HOT, and patients who stand to benefit most from treatment. The review found that wound healing is a complex process, involving many cells and signalling molecules, and it remains incompletely understood. However, current evidence suggests that hyperglycaemia, hypoxia, chronic inflammation (due to infection, immune-cell dysfunction or other causes), peripheral neuropathy, and macro- and micro-vascular dysfunction may all adversely affect DFU healing. The review found that current NICE guidelines do not approve HOT therapy in the UK for DFU's, despite encouraging clinical research findings. HOT shows theoretical promise and has been successfully used in the treatment of individual DFUs for several decades. Despite this, there remains a lack of strong clinical evidence of benefits to encourage HOT's wider use. The review found that there were four important patient selection criteria for HOT treatment, including glycaemic control, possible contraindications and complications associated with treatment, ulcer severity and resistance to first and second line treatments. The review concluded that further high-quality clinical research is needed to improve the evidence base.

Prediction of Healing Trajectory of Chronic Wounds Using a Machine Learning Approach

Objective: New treatment options are emerging for chronic wounds, which represent a growing problem because of population ageing and increasing burden of chronic disease. While promising, the existing evidence for advanced modalities is commonly derived from small and/or poorly controlled studies and clear criteria for selecting patients, who are likely to benefit from these expensive options are lacking. In this study, we develop and validate a machine learning model to predict if a chronic wound, independent of etiology, is expected to heal within 12 weeks to identify cases in potential need of advanced treatment options. Approach: Retrospective analysis of electronic health record data from 2014 to 2018 covering 532 wound care clinics in the United States and 261,398 patients with 620,356 unique wounds. Prediction of 12-week healing trajectories with a machine learning model. Results: The best-performing model in a training dataset of a randomly drawn 75% subset of wounds contained variables for patient demographics, comorbidities, wound characteristics at initial presentation, and changes in wound dimensions over time, with the latter group being the most influential predictors. The final machine learning model had a high predictive accuracy with area under the receiver operating characteristic curves of 0.9 and 0.92 after 4 and 5 weeks of treatment, respectively. Innovation: A machine learning model can identify chronic wounds at risk of not healing by week 12 with high accuracy in the early weeks of treatment. Conclusions: If embedded in real-world care, the generated information could be able to guide effective and efficient treatment decisions.

Quality of evidence supporting the role of hyperbaric oxygen therapy for diabetic foot ulcers

The goal of this overview of systematic reviews (SRs) and meta-analyses (MAs) was to methodically gather, evaluate and summarize the data supporting the use of hyperbaric oxygen therapy (HBOT) to treat diabetic foot ulcers (DFUs). The Cochrane Library, Embase, PubMed, Web of Science and Embase were all searched thoroughly to identify SRs/MAs that qualified. AMSTAR-2 tool, PRISMA checklists and GRADE system were applied by two reviewers independently to assess the methodological quality, reporting and evidence quality of the included SRs/MAs, respectively. Eleven SRs/MAs were enrolled in this overview. According to AMSTAR-2, a very low methodological quality assessment was given to the included SRs/MAs due to the limitations of items 2, 4 and 7. For the PRISMA, the overall quality of reporting is not satisfactory due to missing reporting on protocol, search, as well as additional analysis. The majority of outcomes had low- to moderate-quality evidence, and no high-quality evidence was found to support the role of HBOT for DFUs, according to GRADE. To conclude, the potential of HBOT in treating DFUs is supported by evidence of low to moderate quality. More rigorously designed, high-level studies are needed in the future to determine the evidence for HBOT for DFU, including the timing, frequency and duration of HBOT interventions.

Safe Use of Hyperbaric Oxygen Therapy in the Treatment of Diabetic Foot Ulcers: A Multidisciplinary Approach to Minimize Adverse Effects

Purpose

The purpose of this study is to evaluate the side effects associated with hyperbaric oxygen therapy and provide recommendations to prevent them in patients with diabetic foot ulcers.

Introduction

The use of hyperbaric oxygen therapy in the treatment of diabetic foot ulcers remains a contentious issue, and minimizing side effects is critical. While the incidence of side effects related to hyperbaric oxygen (HBO2) therapy is low, it is essential to evaluate cases in a multifaceted and interdisciplinary manner to prevent adverse outcomes.

Methods

A retrospective cohort study was conducted over the period of 2018-2020, involving a dataset of 100 patients. The primary objective of the study was to examine the frequency and types of side effects experienced by patients who underwent hyperbaric oxygen therapy (HBO) for diabetic foot ulcers (DFUs). In addition, we analyzed various wound characteristics, characteristics of hospitalizations, the surgical or medical interventions received by patients, and laboratory parameters including CRP levels, total blood count, culture results, HbA1c levels, duration of diabetes, treatment received for diabetes, and antibiotic therapy regimens.

Results

The percentage of patients who experienced side effects was as low as 6%, and none of them were critical. The most common side effect was discomfort due to the confined space in the chamber.

Conclusion

Appropriate patient selection, combined with a multidisciplinary approach to evaluate eligibility, is crucial to avoid adverse side effects. Patient education and early screening for side effects are also essential. Since various treatment protocols exist for HBO2 therapy, pooled data from different protocols may be misleading. Further studies focused on side effects with specific indications are necessary.

International Union of Angiology Position Statement on no-option chronic limb threatening ischemia

This position paper, written by members of International Union of Angiology (IUA) Youth Committee and senior experts, shows an overview of therapeutical approaches for patients with chronic limb-threatening ischemia (CLTI) and absence of 'standard' solutions for revascularization. The aim was to demonstrate the accurate management of the 'no-option' CLTI patient including the wound treatment and the rehabilitation, considering always the goal of the increase of quality of life of the patients.

The influence of low- intensity laser irradiation versus hyperbaric oxygen therapy on transcutaneous oxygen tension in chronic diabetic foot ulcers: a controlled randomized trial

BACKGROUND AND OBJECTIVE

Evaluation of the stage and severity of the chronic diabetic foot ulcer (CDFU) is vital to increase the healing rate and to select the suitable treatment. We aim to assess the influence of low-intensity laser irradiation (LILI) and hyperbaric oxygenation therapy (HBOT) to accelerate the CDFU healing thru the transcutaneous oxygen tension (TcPO2) measurements.

MATERIALS AND METHODS

Seventy-five diabetic patients (type 2) of both genders, their ages ranged from 40-65 years with CDFUs (duration of ulcer < 6 weeks). All patients were randomly assigned into LILI, HBOT, and the control group. Measurement of TcPO2 using transcutaneous oximetry was performed for all patients once in the baseline and consequently in the second, fourth, and sixth- weeks duration. LILI utilized by a 33-diode cluster contact applicator with output power 1440 mW, energy density (fluency) was adjusted for 4 J/Cm2 at 10 kHz, and for 8 min per session, three times per week for a total of consecutive 6 weeks. HBOT was pressurized up to 2.5 ATA and patients delivered 100% oxygen for 60 min per session for 30 sessions. The Control group received conventional wound care only, twice daily, with saline and apply a new bandage after cleaning.

RESULTS

MANOVA revealed a statistically insignificant difference in the control group, while statistically significant improvement in both the LILI and HBOT groups. The intergroup comparisons showed an insignificant statistical difference in the pre-test, while highly statistically significant differences for the three post-measures in favor of HBOT and LILI groups. The percentage of improvement of the HBOT group was higher than LILI. Post-hoc test using the least significant difference (LSD) revealed statistically significant differences of HBOT in favor of the LILI group.

CONCLUSION

Both LILI and HBOT may be used as adjunctive methods to improve TcPO2 that accelerate healing in CDFUs. HBOT may be favorable in the improvement of TcPO2 than LILI.

Prolonged oxygen exposure causes the mobilization and functional damage of stem or progenitor cells and exacerbates cardiac ischemia or reperfusion injury in healthy mice

Oxygen is often administered to patients and occasionally to healthy individuals as well; however, the cellular toxicity of oxygen, especially following prolonged exposure, is widely known. To evaluate the potential effect of oxygen exposure on circulating stem/progenitor cells and cardiac ischemia/reperfusion (I/R) injury, we exposed healthy adult mice to 100% oxygen for 20 or 60 min. We then examined the c-kit-positive stem/progenitor cells and colony-forming cells and measured the cytokine/chemokine levels in peripheral blood. We also induced cardiac I/R injury in mice at 3 h after 60 min of oxygen exposure and examined the recruitment of inflammatory cells and the fibrotic area in the heart. The proportion of c-kit-positive stem/progenitor cells significantly increased in peripheral blood at 3 and 24 h after oxygen exposure for either 20 or 60 min (p < .01 vs. control). However, the abundance of colony-forming cells in peripheral blood conversely decreased at 3 and 24 h after oxygen exposure for only 60 min (p < .05 vs. control). Oxygen exposure for either 20 or 60 min resulted in significantly decreased plasma vascular endothelial growth factor levels at 3 h, whereas oxygen exposure for only 60 min reduced plasma insulin-like growth factor 1 levels at 24 h (p < .05 vs. control). Protein array indicated the increase in the levels of some cytokines/chemokines, such as CXCL6 (GCP-2) at 24 h after 60 min of oxygen exposure. Moreover, oxygen exposure for 60 min enhanced the recruitment of Ly6g- and CD11c-positive inflammatory cells at 3 days (p < .05 vs. control) and increased the fibrotic area at 14 days in the heart after I/R injury (p < .05 vs. control). Prolonged oxygen exposure induced the mobilization and functional impairment of stem/progenitor cells and likely enhanced inflammatory responses to exacerbate cardiac I/R injury in healthy mice.

Topical oxygen therapy for diabetes-related foot ulcers: A systematic review and meta-analysis

INTRODUCTION

Topical oxygen therapy (TOT) has been suggested as a treatment for diabetes-related foot ulcer (DFU) but no prior meta-analyses of randomised clinical trials (RCT) have been reported. This systematic review and meta-analysis examined the randomised evidence for the benefit of TOT in healing DFU.

METHODS

Publicly available databases were searched for RCTs investigating the effect of TOT on wound healing in participants with a DFU. The primary outcome was ulcer healing defined as full epithelialisation. Meta-analyses were performed using random effect models and reported as risk ratios (RR) and 95% confidence intervals (CI). Study quality and publication bias were assessed using a modified version of the Cochrane Collaboration's tool and funnel plots, respectively.

RESULTS

Six RCTs involving 530 participants with a DFU testing TOT were included. Meta-analysis suggested that TOT significantly increased the likelihood of ulcer healing compared to controls (Risk ratio [RR] 1.94; 95% CI 1.19, 3.17; I²  = 57%; NNT = 5.33) and findings were robust in sensitivity analyses. Risk of bias was high, moderate and low in two, one and three studies, respectively. Analysis of the three trials judged to be at low risk of bias suggested that TOT increased the likelihood of ulcer healing compared to controls (RR 2.37; 95% CI 1.52, 3.68; I²  = 0%). Funnel plots suggested the possibility of publication bias. Data on amputation were too limited for meta-analysis.

CONCLUSION

This meta-analysis suggests that TOT improves the likelihood of DFU healing; however, its effect on amputation and cost-effectiveness are unclear.

Hyperbaric Oxygen Therapy: Descriptive Review of the Technology and Current Application in Chronic Wounds

Hyperbaric oxygen therapy (HBOT) serves as "primary" or "adjunctive" therapy in a wide range of pathologies. It is considered the mainstay of management for potentially life-threatening conditions such as carbon monoxide poisoning, decompression illness, and gas embolisms. Moreover, HBOT has been utilized for decades as an adjunctive therapy in a variety of medical disciplines, including chronic wounds, which affect approximately 6.5 million Americans annually. In general, chronic wounds are characterized by hypoxia, impaired angiogenesis, and prolonged inflammation, all of which may theoretically be ameliorated by HBOT. Nonetheless, the cellular, biochemical, and physiological mechanisms by which HBOT achieves beneficial results in chronic wounds are not fully understood, and there remains significant skepticism regarding its efficacy. This review article provides a comprehensive overview of HBOT, and discusses its history, mechanisms of action, and its implications in management of chronic wounds. In particular, we discuss the current evidence regarding the use of HBOT in diabetic foot ulcers, while digging deeply into the roots of controversy surrounding its efficacy. We discuss how the paucity of high-quality research is a tremendous challenge, and offer future direction to address existing obstacles.

Meta-analyses of randomized controlled trials reporting the effect of home foot temperature monitoring, patient education or offloading footwear on the incidence of diabetes-related foot ulcers

AIM

The aim of this study was to perform an up-to-date systematic review and meta-analysis of randomized controlled trials (RCTs) examining the efficacy of home foot temperature monitoring, patient education and offloading footwear in reducing the incidence of diabetes-related foot ulcers.

METHODS

A literature search was performed using MEDLINE, PubMed, CINAHL, Scopus and Cochrane databases to identify relevant original studies. Meta-analyses were performed using intention-to-treat principals for worst (main analysis) and best (sub-analysis) case scenarios. Leave-one-out sensitivity analyses were used to assess the consistency of findings.

RESULTS

Of 7575 unique records, 17 RCTs involving 2729 participants were included. Four tested home foot temperature monitoring (n = 468), six examined patient education (n = 823) and seven assessed offloading footwear (n = 1438). Participants' who performed home foot temperature monitoring [odds ratio (OR) 0.51, 95% confidence interval (CI) 0.31 to 0.84; n = 468] and those provided offloading footwear (OR 0.48, 95% CI 0.29 to 0.80; n = 1438) were less likely to develop a diabetes-related foot ulcer. Patient education programmes did not significantly reduce diabetes-related foot ulcer incidence (OR 0.59, 95% CI 0.29 to 1.20; n = 823). Sensitivity analyses suggested that offloading footwear findings were consistent, but home foot temperature findings were dependent on the individual inclusion of one trial. All RCTs had either high or unclear risk of bias.

CONCLUSION

This meta-analysis suggests that offloading footwear is effective in reducing the incidence of diabetes-related foot ulcers. Home foot temperature monitoring also appears beneficial but larger trials are needed (PROSPERO registration no.: CRD42019135226).

Opinions of vascular surgeons and podiatrists in Australia and New Zealand on the use of hyperbaric oxygen therapy for lower limb ulcers

INTRODUCTION

Hyperbaric oxygen therapy (HBOT) has been suggested to improve healing of lower limb ulcers, though the quality of available evidence is weak to moderate. This study assessed the opinions and use of HBOT by specialists treating lower limb ulcers.

RESEARCH DESIGN AND METHODS

Accredited vascular surgeons and podiatrists in Australia and New Zealand were sent an online survey via their professional organizations. The survey asked about their use and opinions of HBOT in treating lower limb ischemic, neuropathic and venous ulcers. Data were summarized with descriptive statistics. Non-parametric tests were used to compare survey results obtained from vascular surgeons and podiatrists.

RESULTS

61 vascular surgeons and 40 podiatrists completed the survey. Thirty-seven specialists used HBOT for treating lower limb ulcers, with the remainder indicating they did not feel there was a role for HBOT (n=25) or did not have access to HBOT (n=39). Less than 8% of specialists indicated that HBOT frequently or always had a role in treating ischemic, neuropathic or venous ulcers. Compared with podiatrists, vascular surgeons were significantly less likely to indicate HBOT had a treatment role for any ulcer type (p<0.001, p=0.004, and p<0.001, respectively), though significantly more likely to indicate they currently used HBOT for treating lower limb ulcers (p<0.001). Most specialists (n=76) believed that a large clinical trial is needed to determine the efficacy of HBOT in treating lower limb ulcers.

CONCLUSIONS

Vascular surgeons and podiatrists do not feel HBOT has a frequent role in treating lower limb ulcers, but do feel there needs to be a large clinical trial to test its value.

Effects of adding adjunctive hyperbaric oxygen therapy to standard wound care for diabetic foot ulcers: a protocol for a systematic review with meta-analysis and trial sequential analysis

INTRODUCTION

Diabetic foot ulcer represents a major health problem globally. Preliminary studies have indicated that systemic treatment of diabetic foot ulcer patients with hyperbaric oxygen therapy have beneficial effects on wound healing, risk of amputation, glycaemic control, atherosclerosis, inflammatory markers and other clinical and laboratory parameters. This protocol for a systematic review aims at identifying the beneficial and harmful effects of adding hyperbaric oxygen therapy to standard wound care for diabetic foot ulcers.

METHODS AND ANALYSIS

This protocol was performed following the recommendations of the Cochrane Collaboration and the eight-step assessment procedure suggested by Jakobsen and colleagues. We plan to include all relevant randomised clinical trials assessing the effects of hyperbaric oxygen therapy in the treatment of diabetic foot ulcer versus any control group with any intervention defined as standard wound care or similar, together with sham interventions. Our primary outcome will be: all-cause mortality, serious adverse events and quality of life. Our secondary outcomes will be: healing of index wound, major amputation and wound infection. Any eligible trial will be assessed and classified as either high risk of bias or low risk of bias, and our conclusions will be based on trials with low risk of bias. The analyses of the extracted data will be performed using Review Manager 5 and Trial Sequential Analysis. For both our primary and secondary outcomes, we will create a 'Summary of Findings' table and use GRADE (Grading of Recommendations Assessment, Development and Evaluation) assessment to assess the quality of the evidence.

ETHICS AND DISSEMINATION

We use publicly accessible documents as evidence, there is no participant involvement at an individual level and an institutional ethics approval is not required. The results of the review will be sought published in a peer-reviewed journals, also in the event of insignificant results or null results, and thereby it will be disseminated to clinicians and public available.

PROSPERO REGISTRATION NUMBER

CRD42019139256.