Hyperbaric oxygen therapy in diabetic foot ulceration: Useless or useful? A battle

Bayesian Modeling of the Impact of HBOT on the Reduction in Cytokine Storms

Since the initial identification of SARS-CoV-2 infections, numerous clinical challenges have arisen, revealing both acute and long-term effects associated with COVID-19. These effects impact various systems within the body, including the respiratory, cardiovascular, and nervous systems. Background/Objectives: This study aimed to investigate the immunological and inflammatory parameters in patients with severe COVID-19 and evaluate the effects of hyperbaric oxygen therapy (HBOT) on these parameters. Methods: This study enrolled thirty patients from the Military Medical Institute-National Research Institute in Warsaw, who were hospitalized for SARS-CoV-2 infection. Patients were screened for eligibility based on pre-defined inclusion criteria. The subjects were randomly assigned to one of two groups: hyperbaric oxygen therapy (HBOT) or a control group. Immune profiling was performed, measuring cytokine concentrations and leukocyte subpopulations in serum samples. Outcomes were assessed using Bayesian modeling. Results: Bayesian regression analysis confirmed previous findings, indicating that HBOT may reduce inflammatory cytokine levels while improving oxygen saturation (SpO2) in patients with moderate and severe COVID-19. Moreover, the analysis suggested a higher probability of HBOT success in modulating the immune response and reducing inflammatory parameters, particularly in T lymphocyte subpopulations. Conclusions: Hyperbaric oxygen therapy (HBOT) may serve as an effective adjunctive treatment for patients with COVID-19 by enhancing oxygen saturation and modulating the immune response. Further studies are needed to elucidate the underlying mechanisms of HBOT on inflammatory and immunological parameters in COVID-19 patients.

Adjunctive hyperbaric oxygen therapy and negative pressure wound therapy for hard-to-heal wounds: a systematic review and meta-analysis

OBJECTIVE

Negative pressure wound therapy (NPWT) and hyperbaric oxygen therapy (HBOT) have been widely used in the treatment of hard-to-heal (chronic) wounds, but there is still a lack of sufficient evidence for their combined use for the treatment of hard-to-heal wounds. This systematic review aimed to identify the clinical efficacy and safety of adding adjunctive HBOT to NPWT for hard-to-heal wounds.

METHOD

Embase, PubMed, Cochrane Library, Web of Science, China National Knowledge Infrastructure and Wanfang were searched from the establishment of the database to March 2022. The literature was screened according to the inclusion criteria and exclusion criteria. We assessed the quality of each included study with the Cochrane Collaboration Risk of Bias tool and Newcastle-Ottawa Scale. A meta-analysis was performed using R programming software version 4.1.0 (R Project for Statistical Computing, US). The PRISMA 2020 guidelines were used to report data from systematic reviews and meta-analysis.

RESULTS

A total of 15 studies were identified, including nine randomised clinical controlled trials and six retrospective studies. Meta-analysis results showed that NPWT combined with HBOT had better outcomes compared with the NPWT alone with regards to: wound healing rate (odds ratio (OR)=6.77; 95% confidence interval (Cl): 3.53-12.98; p<0.0001); bacterial positive rate of wound (OR=0.16; 95% CI: 0.05-0.55; p=0.0037); wound healing time (mean difference (MD)= -3.86; 95% Cl: -5.18 - -2.53; p<0.0001); wound area (standardised mean difference (SMD)=1.50; 95% Cl: 0.35-2.65; p=0.0104); hospitalisation time (MD= -3.14; 95% Cl: -4.93 - -1.36; p=0.005); and hospitalisation cost (OR= -202.64; 95% Cl: -404.53 - -0.75; p=0.0492). There was no significant difference in pain score (MD= -0.43; 95% Cl: -1.15-0.30; p=0.25).

CONCLUSION

The findings of this study demonstrated that adjunctive HBOT with NPWT is safe and effective in the treatment of hard-to-heal wounds. However, these findings should be interpreted with great caution given the limitations of the studies included.

Reactive Oxygen Species (ROS)-Mediated Antibacterial Oxidative Therapies: Available Methods to Generate ROS and a Novel Option Proposal

The increasing emergence of multidrug-resistant (MDR) pathogens causes difficult-to-treat infections with long-term hospitalizations and a high incidence of death, thus representing a global public health problem. To manage MDR bacteria bugs, new antimicrobial strategies are necessary, and their introduction in practice is a daily challenge for scientists in the field. An extensively studied approach to treating MDR infections consists of inducing high levels of reactive oxygen species (ROS) by several methods. Although further clinical investigations are mandatory on the possible toxic effects of ROS on mammalian cells, clinical evaluations are extremely promising, and their topical use to treat infected wounds and ulcers, also in presence of biofilm, is already clinically approved. Biochar (BC) is a carbonaceous material obtained by pyrolysis of different vegetable and animal biomass feedstocks at 200-1000 °C in the limited presence of O2. Recently, it has been demonstrated that BC's capability of removing organic and inorganic xenobiotics is mainly due to the presence of persistent free radicals (PFRs), which can activate oxygen, H2O2, or persulfate in the presence or absence of transition metals by electron transfer, thus generating ROS, which in turn degrade pollutants by advanced oxidation processes (AOPs). In this context, the antibacterial effects of BC-containing PFRs have been demonstrated by some authors against Escherichia coli and Staphylococcus aureus, thus giving birth to our idea of the possible use of BC-derived PFRs as a novel method capable of inducing ROS generation for antimicrobial oxidative therapy. Here, the general aspects concerning ROS physiological and pathological production and regulation and the mechanism by which they could exert antimicrobial effects have been reviewed. The methods currently adopted to induce ROS production for antimicrobial oxidative therapy have been discussed. Finally, for the first time, BC-related PFRs have been proposed as a new source of ROS for antimicrobial therapy via AOPs.

Physical Treatment of Diabetic Foot Ulcers—Preliminary Study for Topical Application of Oxygen or Ozone Auxiliary Treatment of Diabetic Foot Ulcers

Diabetes mellitus is one of the most common metabolic diseases in which one of the most serious complications is the diabetic foot ulcer (DFU). The aim of the study was to compare the efficacy of two physical therapeutic methods: topical oxygen therapy and topical ozone therapy in the treatment of DFU with the calculation of the financial costs for both applied physical methods. The study included 85 patients, 47 male (55.2%) and 38 female (44.7%) in age range between 40 and 90 years (mean age: 67.82 ± 12.42 years) with hard to heal diabetic foot ulcers. The mean diabetic foot ulcer duration was 3.6 ± 1.23 years. Patients were randomized into two study groups not significantly different in terms of age, body mass index (BMI) value, and baseline ulcer surface area value, who underwent topical oxygen therapy (group I) and topical ozone therapy (group II), respectively. Both the groups underwent a total of 30 daily treatments lasting 30 minutes, in 2 sessions of 15 treatments with a 14-day break between sessions. Progress in wound healing was evaluated by computerized planimetry and the pain intensity was assessed with use of a VAS scale. After the treatment, the ulcer area in group I decreased by an average of 33.25 ± 10.97% and by an average of 28.67 ± 14.47% in group II $\left(p=0.030\right)$ . On the other hand, the intensity of pain ailments after the treatment was statistically significantly decreased in group I by an average of 57.13 ± 16.24% while in group II by an average of 40.21 ± 14.53% ( $p<0.001$ ). After application of topical oxygen therapy and topical ozone therapy in the treatment of diabetic foot ulcers a statistically significant reduction in the surface area of treated ulcers in objective planimetric assessment was observed, with local oxygen therapy showing only a slight advantage in this regard. Both compared methods also caused a statistically significant reduction in the pain intensity, while local oxygen therapy shows statistically significantly better analgesic effectiveness. Due to the calculated moderate cost, both applied methods appeared to be cost-effective.

Local Hyperbaric Oxygen Therapy in the Treatment of Diabetic Foot Ulcers

Background: Diabetes mellitus is one of the most common metabolic diseases. The most serious complication of diabetes is diabetic foot ulcer, which affects several million people around the world each year. In recent years, increasingly modern methods of physical medicine including hyperbaric oxygen therapy have been used often in the complex therapy of this complication. Methods: This study included 45 patients, 24 male (53.3%) and 21 female (46.6%), whose age was between 49 and 83 years (mean age: 66.7 ± 8.8 years) with diabetes lasting for 1.5-18 years, who underwent local hyperbaric oxygen therapy at the pressure of 2.5 ATA (30 exposures for 30 min each) due to diabetic foot ulcers. The progress in wound healing before and after the end of therapy was evaluated by computerized planimetry, and the pain intensity was assessed with the use of a VAS. Results: The analysis of results showed a statistically significant reduction in the wound surface area after the treatment, from 8.54 ± 3.34 cm to 4.23 ± 3.23 cm² (p = 0.000001). In 5 patients (11.1%), the wounds were healed completely. In 25 patients (55.5%), the topical state of the wound surface was significantly decreased by 50% on average. There was also a significant reduction in the perceived pain on the VAS in all examined patients from 4.64 ± 1.68 points before treatment to 1.51 ± 0.92 points after treatment (p = 0.000001). Conclusions: The application of local HBO therapy in the treatment of diabetic foot ulcers accelerates the ulcer healing process, as judged in objective planimetric assessment, and reduces the intensity of perceived pain ailments.

Nonpharmacological Management of Diabetic Foot Ulcers: An Update

Diabetic foot ulcers (DFUs) are a common and serious complication of diabetes mellitus that is associated with increased morbidity and mortality, as well as substantial economic burden for the health care system. The standard of care for DFUs includes pressure off-loading, sharp debridement, and wound moisture balance, along with infection control and management of peripheral arterial disease. A variety of advanced modalities that target distinct pathophysiological aspects of impaired wound healing in diabetes are being studied as possible adjunct therapies for difficult to heal ulcers. These modalities include growth factors, stem cells, cultured fibroblasts and keratinocytes, bioengineered skin substitutes, acellular bioproducts, human amniotic membranes, oxygen therapy, negative pressure wound therapy, and energy therapies. Additionally, the use of advanced biomaterials and gene delivery systems is being investigated as a method of effective delivery of substances to the wound bed. In the present narrative review, we outline the latest advances in the nonpharmacological management of DFUs and summarize the efficacy of various standard and advanced treatment modalities.

The role of hyperbaric oxygen therapy in the treatment of diabetic foot ulcers: a systematic review with meta-analysis of randomized controlled trials on limb amputation and ulcer healing

INTRODUCTION

Hyperbaric Oxygen Therapy (HBOT) is increasingly being used in the treatment of as diabetic foot ulcers (DFU). However, definitive evidence regarding its beneficial effects is still scarce. The present systematic review aims to analyse the role of HBOT in the prevention of limb amputation along with improvement of ulcer healing in patients with lower limbs DFU.

EVIDENCE ACQUISITION

Three databases were searched: PubMed, Scopus, and ISI Web of Knowledge. The search was enrolled during October 2020. Both titles and abstracts were examined by two independent reviewers. Only randomized controlled trials (RCTs) reporting a comparison between standard DFU treatment and standard treatment associated with HBOT were included. In all studies eligibility was assessed and data regarding studies characteristics, methods and considered outcomes was obtained. Odds ratio (OR) was used to evaluate amputation and complete ulcer healing rates. Percentage of ulcer reduction at two weeks was evaluated using the inverse variance method, and the values were compared using mean difference values. Meta-analysis was done using a fixed-effect model if I2 values were under 50%, and a random-effects model if not.

EVIDENCE SYNTHESIS

Eleven RCTs were included, with a total of 668 patients studied. Patients undergoing HBOT had lower risk of amputation (OR 0.53 95% CI 0.32-0.90, I2=31%). No difference was found in minor amputations (OR 0.89 95% CI 0.35-2.24, I2=69%). Regarding, healing rates, HBOT patients had greater chances of ulcer healing (OR 4,00 95% CI 1.54-10.44, I2=70%). It has also shown higher percentage of ulcer area reduction after two weeks of treatment in the HBOT group (mean difference 23.19%; 95% CI 14.86-31.52; I2=0%).

CONCLUSIONS

The present review offers evidence that adjuvant HBOT decreases risk of major amputation while promoting wound healing when combined to standard treatment in the management of DFU. These findings may have clinical relevance in a selected group of patients, yet further larger studies are still needed.

Hyperbaric oxygen therapy for nonhealing wounds: Treatment results of a single center

The present article evaluates the results of the treatment with adjuvant hyperbaric oxygen therapy (HBOT) of patients with nonhealing, chronic wounds. In the period 2013 to 2016, 248 patients were referred from various hospitals because of chronic wounds that were recalcitrant in healing despite standard wound care as described in national and international guidelines. After inclusion, all patients were treated with HBOT and subjected to a weekly standard wound care treatment. During each HBOT session, 100% O2 was administered for 75 minutes under increased pressure of 2.4 ATA. Wounds and quality of life were assessed before and after the total treatment period. A total of 248 patients have been evaluated. Diabetic foot ulcers were present in 134 patients, the remainder (114 patients) showed a variety of wound locations and etiologies. The number of HBOT treatments amounted to an average of 48 (range 20-68) sessions. Before referral to our clinic, 31% of all wounds had existed for at least 18 months (72 patients). After HBOT, 81% of all wounds were near complete healing or completely healed, in 13% of the cases the wound was stable, and in 2% minor or major amputation had to be carried out. The mean treatment time for wounds pre-existing fewer than 6 weeks ("early referrals") was 67 days, and 119 days for wounds pre-existing more than 18 months ("late referrals"). A majority of the patients in our study referred with nonhealing wounds clinically improved when adjuvant HBOT was added to standard wound care protocols. No differences in success rate were seen between diabetic and nondiabetic wounds. It showed that HBOT is a well-tolerated treatment.

Unlocking mammalian regeneration through hypoxia inducible factor one alpha signaling

Historically, the field of regenerative medicine has aimed to heal damaged tissue through the use of biomaterials scaffolds or delivery of foreign progenitor cells. Despite 30 years of research, however, translation and commercialization of these techniques has been limited. To enable mammalian regeneration, a more practical approach may instead be to develop therapies that evoke endogenous processes reminiscent of those seen in innate regenerators. Recently, investigations into tadpole tail regrowth, zebrafish limb restoration, and the super-healing Murphy Roths Large (MRL) mouse strain, have identified ancient oxygen-sensing pathways as a possible target to achieve this goal. Specifically, upregulation of the transcription factor, hypoxia-inducible factor one alpha (HIF-1α) has been shown to modulate cell metabolism and plasticity, as well as inflammation and tissue remodeling, possibly priming injuries for regeneration. Since HIF-1α signaling is conserved across species, environmental or pharmacological manipulation of oxygen-dependent pathways may elicit a regenerative response in non-healing mammals. In this review, we will explore the emerging role of HIF-1α in mammalian healing and regeneration, as well as attempts to modulate protein stability through hyperbaric oxygen treatment, intermittent hypoxia therapy, and pharmacological targeting. We believe that these therapies could breathe new life into the field of regenerative medicine.