Hyperbaric oxygen therapy: Antimicrobial mechanisms and clinical application for infections

Fabrication and Evaluation of a Soy Protein Isolate/Collagen/Sodium Alginate Multifunctional Bilayered Wound Dressing: Release of Cinnamaldehyde, Artemisia absinthium, and Oxygen

Chronic wounds, such as diabetic ulcers and pressure sores, pose significant challenges in modern healthcare due to their prolonged healing times and susceptibility to infections. This study aims to engineer a bilayered wound dressing (BLWD) composed of soy protein isolate/collagen with the ability to release Cinnamaldehyde, Artemisia absinthium (AA), and oxygen. Cinnamaldehyde, magnesium peroxide (MgO2), and AA extract were encapsulated. Nanoparticles were evaluated using scanning electron microscopy (SEM), dynamic light scattering, and ZETA potential tests. Swelling, degradation, water vapor penetration, tensile, MTT, SEM, oxygen release, AA extract release, and antibacterial properties were performed. An in vivo study was carried out to assess the final wound dressing under Hematoxiline&Eosin and Masson trichrome staining analysis and compared to a commercial product. According to the results, the synthesized nanoparticles had an average diameter of about 20 nm with a zeta potential in the range of -20 to -30 mV. The layers had uniform and dense surfaces. The maximum swelling and degradation of the dressing was about 130 and 13% respectively. Generally, better mechanical properties were observed in BLWD than in the single-layer case. More than 90% biocompatibility for the wound dressing was reported. The BLWD could inhibit the growth of Gram-positive and Gram-negative microorganisms. Histopathological analysis showed an acceptable wound-healing property. To sum up, the engineered wound dressing can be a good candidate for more clinical trials.

Mechanism-guided strategies for combating antibiotic resistance

Bacterial antibiotic resistance has been recognized as a global threat to public health. It challenges the antibiotics currently used in clinical practice and causes severe and often fatal infectious diseases. Fighting against antibiotic-resistant bacteria (ARB) is growing more urgent. While understanding the molecular mechanisms that underlie resistance is a prerequisite, several major mechanisms have been previously proposed including bacterial efflux systems, reduced cell membrane permeability, antibiotic inactivation by enzymes, target modification, and target protection. In this context, this review presents a panel of promising and potential strategies to combat antibiotic resistance/resistant bacteria. Different types of direct-acting and indirect resistance breakers, such as efflux pump inhibitors, antibiotic adjuvants, and oxidative treatments are discussed. In addition, the emerging multi-omics approaches for rapid resistance identification and promising alternatives to existing antibiotics are highlighted. Overall, this review suggests that continued effort and investment in research are required to develop new antibiotics and alternatives to existing antibiotics and translate them into environmental and clinical applications.

A novel chlorin derivative Shengtaibufen (STBF) mediated photodynamic therapy combined with iodophor for the treatment of chronic superficial leg wounds infected with methicillin-resistant Staphylococcus aureus: A retrospective clinical study

OBJECTIVE

Chronic wounds are costly and difficult to treat, resulting in morbidity and even mortality in some cases due to a high methicillin-resistant Staphylococcus aureus (MRSA) burden contributing to chronicity. We aimed to observe the antimicrobial activity and healing-promoting effect of a novel photosensitizer Shengtaibufen (STBF)-mediated antibacterial photodynamic therapy (PDT) on MRSA-infected chronic leg ulcers.

PATIENTS AND METHODS

This was a retrospective, comparative, single-center clinical study. A total of 32 patients with chronic lower limb wounds infected with MRSA from January 2022 to December 2023 were finally included in this study by searching the electronic medical records of the dermatology department of Huadong Hospital, including a group of red light combined with iodophor (control+iodophor, n=16, receiving red light once a week for 8 weeks and routine dressing change with iodophor once a day) and a group of STBF-mediated PDT (STBF-PDT) combined with iodophor (STBF-PDT+iodophor, n=16, receiving STBF-PDT and routine dressing change with iodophor once a day). STBF-PDT was performed once a week (1 mg/ml STBF, 1 h incubation, 630 nm red light, 80 J/cm2) for 8 weeks. The primary endpoints included wound clinical signs, wound size, wound-related pain, re-epithelialization score, MRSA load and wound-related quality of life (wound-QoL). Any adverse events were also recorded.

RESULTS

We found that STBF-PDT+iodophor could effectively alleviate clinical infection symptoms, accelerate wound closure, reduce average biological burden and improve wound-QoL without severe adverse events in comparison to the control+iodophor group. The STBF-PDT+iodophor group obtained a mean percentage reduction of 65.22% in wound size (from 18.96±11.18 cm2 to 6.59±7.94 cm2) and excellent re-epithelialization scores, as compared with a decrease of 30.17% (from 19.23±9.80 cm2 to 13.43±9.32 cm2) for the control+iodophor group. Significant differences in wound area were observed at week 6 (p=0.028*) and week 8 (p=0.002**). The bacterial load decreased by 99.86% (from 6.45 × 107±2.69 × 107 to 8.94 × 104±1.92 × 105 CFU/cm2, p<0.0001) in the STBF-PDT+iodophor group and 1.82% (from 6.61 × 107±2.13 × 107 to 6.49 × 107±2.01 × 107 CFU/cm2, p=0.029) in the control+iodophor group. The wound-QoL in STBF-PDT+iodophor group had a 51.62% decrease in overall score (from 29.65±9.33 at the initial to 14.34±5.17 at week 8, p<0.0001) compared to those receiving red light and routine wound care (from 30.73±17.16 to 29.32±15.89 at week 8, p=0.003). Moreover, patients undergoing STBF-PDT+iodophor exhibited great improvements in all domains of wound-QoL (physical, psychological and everyday-life), whereas the control+iodophor group ameliorated in only one field (everyday-life).

CONCLUSION

Our data confirmed that a novel photosensitizer, STBF-mediated PDT, when combined with iodophor, served as a potential modality for MRSA infection and a possible therapy for other drug-resistant microorganisms, and as a promising alternative for chronic cutaneous infectious diseases.

The impact of hyperbaric oxygen treatment for cardiovascular implantable electronic devices

Introduction

The safety of hyperbaric oxygen treatment (HBO2) in patients with cardiovascular implanted electronic devices (CIED) remains unclear.

Methods

We conducted a retrospective analysis of seven CIED patients (median age 79 [73-83] years, five males [71.4%]), including five with pacemakers and two with implantable cardioverter defibrillators (ICD), who underwent HBO2 between June 2013 and April 2023. During the initial session, electrocardiogram monitoring was conducted, and CIED checks were performed before and after the treatment. In addition, the medical records were scrutinized to identify any abnormal CIED operations.

Results

All seven CIED patients underwent HBO2 within the safety pressure range specified by the CIED manufacturers or general pressure test by the International Organization for Standardization (2.5 [2.5-2.5] atmosphere absolute × 18 [5-20] sessions). When comparing the CIED parameters before and after HBO2, no significant changes were observed in the waveform amplitudes, pacing thresholds, lead impedance of the atrial and ventricular leads, or battery levels. All seven patients, including two with the rate response function activated, exhibited no significant changes in the pacing rate or pacing failure. Two ICD patients did not deactivate the therapy, including the defibrillation; however, they did not experience any arrhythmia or inappropriate ICD therapy during the HBO2.

Conclusion

CIED patients who underwent HBO2 within the safety pressure range exhibited no significant changes in the parameters immediately after the HBO2 and had no observable abnormal CIED operations during the treatment. The safety of defibrillation by an ICD during HBO2 should be clarified.

Is Prompt Hyperbaric Oxygen Adjunctive Therapy Able to Reduce Mortality and Amputation in Management of Necrotizing Soft-Tissue Infection?

Background: Necrotizing soft-tissue infection (NSTI) is a rare and serious disease with high morbidity and mortality. Standard therapeutic concepts have included urgent surgical intervention, broad-spectrum antibiotic treatment, and intensive care. Hyperbaric oxygen therapy (HBOT) is used as adjuvant therapy in some centers, but its benefits remain controversial. Methods: A retrospective analysis was conducted in which 98 patients with a clinical diagnosis of NSTI were treated with standard treatments plus HBOT. The clinical outcomes were wound healing, performance status, hospital length, complication rate, recurrence rate, morbidity (amputation rate), and mortality. Primary or secondary outcomes were compared between the time interval of HBOT and the clinical outcomes. Results: The average times from diagnosis of NSTI to initial HBO treatment and from initial surgery to initial HBO treatment were both significantly longer in dead patients than in surviving patients (P = 0.031; P = 0.020). These two time intervals were both significantly longer in amputated patients than in preserved patients (P = 0.031; P = 0.037). Conclusions: Using combined treatment with early surgical debridement combined with HBOT, it is possible to reduce hospital stay, intensive care unit stay, number of debridements, improve complete wound healing rate, and lower amputation and mortality rates among patients with NSTI. The early onset of HBOT soon after diagnosis, especially during critical conditions, is proved to be associated with higher survival and preservation rates.

Role of Hyperbaric Oxygen in Filler-Induced Vascular Occlusion

INTRODUCTION

The rising incidence of filler-induced vascular complications in the context of aesthetic procedures necessitates a thorough assessment of therapeutic options. Hyperbaric oxygen therapy (HBOT) has emerged as a potential intervention for filler-induced vascular occlusion (FIVO), although optimal dosing and timing remain undefined.

METHODS

This review explores the pathophysiology of FIVO and elucidates HBOT's multifaceted role in salvaging ischemic tissue. The physical and biochemical mechanisms of HBOT, including its vasodilatory, anti-spasmodic, and anti-inflammatory effects, are examined.

RESULTS

HBOT serves as an adjunctive therapy in FIVO management, emphasizing timely intervention, adherence to specific pressures (two atmosphere absolute), and session durations (60 minutes) to optimize efficacy and minimize complications. While existing HBOT protocols for compromised grafts provide insights, standardized guidelines for FIVO are lacking.

CONCLUSION

HBOT enhances tissue oxygenation, modulates reactive oxygen species, and influences angiogenesis and hypoxia response. However, it does not replace key treatment protocols for filler vascular complications. Further research and standardized protocols are warranted to define HBOT's definitive role in mitigating filler-induced vascular complications. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

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.

Chitosan-based multifunctional oxygenating antibiotic hydrogel dressings for managing chronic infection in diabetic wounds

Current treatment strategies for infection of chronic wounds often result in compromised healing and necrosis due to antibiotic toxicity, and underlying biomarkers affected by treatments are not fully known. Here, a multifunctional dressing was developed leveraging the unique wound-healing properties of chitosan, a natural polysaccharide known for its numerous benefits in wound care. The dressing consists of an oxygenating perfluorocarbon functionalized methacrylic chitosan (MACF) hydrogel incorporated with antibacterial polyhexamethylene biguanide (PHMB). A non-healing diabetic infected wound model with emerging metabolomics tools was used to explore the anti-infective and wound healing properties of the resultant multifunctional dressing. Direct bacterial bioburden assessment demonstrated superior antibacterial properties of hydrogels over a commercial dressing. However, wound tissue quality analyses confirmed that sustained PHMB for 21 days resulted in tissue necrosis and disturbed healing. Therefore, a follow-up comparative study investigated the best treatment course for antiseptic application ranging from 7 to 21 days, followed by the oxygenating chitosan-based MACF treatment for the remainder of the 21 days. Bacterial counts, tissue assessments, and lipidomics studies showed that 14 days of application of MACF-PHMB dressings followed by 7 days of MACF dressings provides a promising treatment for managing infected non-healing diabetic skin ulcers.

Hyperbaric Oxygen Therapy Achieved Fistula Healing in a Young Patient With Severe Refractory Perianal Crohn's Disease

The presence of perianal fistulae constitutes a more severe phenotype of Crohn's disease (CD) that often requires intensive medical therapy, wound care, and surgical intervention. Despite therapeutic advances in inflammatory bowel disease, the treatment of perianal fistulae remains challenging. Hyperbaric oxygen therapy (HBOT) has been proposed as an adjunctive treatment modality for induction of fistula healing. We illustrate a case in which HBOT achieved fistula healing in a young patient with severe refractory perianal Crohn's disease (pCD). We also review the current literature and discuss the role of HBOT in the treatment armamentarium of pCD.

Hyperbaric oxygen therapy ameliorates intestinal and systematic inflammation by modulating dysbiosis of the gut microbiota in Crohn's disease

BACKGROUND

Dysbiosis of the gut microbiota is pivotal in Crohn's disease (CD) and modulated by host physiological conditions. Hyperbaric oxygen therapy (HBOT) is a promising treatment for CD that can regulate gut microbiota. The relationship between HBOT and the gut microbiota in CD remains unknown.

METHODS

CD patients were divided into an HBOT group (n = 10) and a control group (n = 10) in this open-label prospective interventional study. The fecal samples before and after HBOT were used for 16 S rRNA gene sequencing and fecal microbiota transplantation (FMT). A colitis mouse model was constructed using dextran sulfate sodium, and intestinal and systematic inflammation was evaluated. The safety and long-term effect of HBOT were observed.

RESULTS

HBOT significantly reduced the level of C-reactive protein (CRP) (80.79 ± 42.05 mg/L vs. 33.32 ± 18.31 mg/L, P = 0.004) and the Crohn's Disease Activity Index (CDAI) (274.87 ± 65.54 vs. 221.54 ± 41.89, P = 0.044). HBOT elevated the declined microbial diversity and ameliorated the altered composition of gut microbiota in patients with CD. The relative abundance of Escherichia decreased, and that of Bifidobacterium and Clostridium XIVa increased after HBOT. Mice receiving FMT from donors after HBOT had significantly less intestinal inflammation and serum CRP than the group before HBOT. HBOT was safe and well-tolerated by patients with CD. Combined with ustekinumab, more patients treated with HBOT achieved clinical response (30%vs.70%, P = 0.089) and remission (20%vs.50%, P = 0.160) at week 4.

CONCLUSIONS

HBOT modulates the dysbiosis of gut microbiota in CD and ameliorates intestinal and systematic inflammation. HBOT is a safe option for CD and exhibits a promising auxiliary effect to ustekinumab.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2200061193. Registered 15 June 2022, https://www.chictr.org.cn/showproj.html?proj=171605 .

Hyperbaric oxygen therapy: future prospects in regenerative therapy and anti-aging

Hyperbaric Oxygen Therapy (HBOT) utilizes 100% oxygen at high atmospheric pressure for clinical applications. HBOT has proven to be an effective supplementary treatment for a variety of clinical and pathological disorders. HBOT's therapeutic results are based on the physiological effects of increased tissue oxygenation, or improved oxygen bioavailability. HBOT's current indications in illnesses like as wound healing, thermal or radiation burns, and tissue necrosis point to its function in facilitating the regeneration process. Various research has revealed that HBOT plays a function in vascularization, angiogenesis, and collagen production augmentation. Individual regeneration capacity is influenced by both environmental and genetic factors. Furthermore, the regenerating ability of different types of tissues varies, and this ability declines with age. HBOT affects physiological processes at the genetic level by altering gene expression, delaying cell senescence, and assisting in telomere length enhancement. The positive results in a variety of indications, ranging from tissue regeneration to better cognitive function, indicate that it has enormous potential in regenerative and anti-aging therapy.

Non-pharmacological interventions for traumatic brain injury

Heterogeneity and variability of symptoms due to the type, site, age, sex, and severity of injury make each case of traumatic brain injury (TBI) unique. Considering this, a universal treatment strategy may not be fruitful in managing outcomes after TBI. Most of the pharmacological therapies for TBI aim at modifying a particular pathway or molecular process in the sequelae of secondary injury rather than a holistic approach. On the other hand, non-pharmacological interventions such as hypothermia, hyperbaric oxygen, preconditioning with dietary adaptations, exercise, environmental enrichment, deep brain stimulation, decompressive craniectomy, probiotic use, gene therapy, music therapy, and stem cell therapy can promote healing by modulating multiple neuroprotective mechanisms. In this review, we discussed the major non-pharmacological interventions that are being tested in animal models of TBI as well as in clinical trials. We evaluated the functional outcomes of various interventions with an emphasis on the links between molecular mechanisms and outcomes after TBI.

Contemporary national outcomes of hyperbaric oxygen therapy in necrotizing soft tissue infections

BACKGROUND

The role of hyperbaric oxygen therapy (HBOT) in necrotizing soft tissue infections (NSTI) is mainly based on small retrospective studies. A previous study using the 1998-2009 National Inpatient Sample (NIS) found HBOT to be associated with decreased mortality in NSTI. Given the argument of advancements in critical care, we aimed to investigate the continued role of HBOT in NSTI.

METHODS

The 2012-2020 National Inpatient Sample (NIS) was queried for NSTI admissions who received surgery. 60,481 patients between 2012-2020 were included, 600 (<1%) underwent HBOT. Primary outcome was in-hospital mortality. Secondary outcomes included amputation, hospital length of stay, and costs. A multivariate model was constructed to account for baseline differences in groups.

RESULTS

Age, gender, and comorbidities were similar between the two groups. On bivariate comparison, the HBOT group had lower mortality rate (<2% vs 5.9%, p<0.001) and lower amputation rate (11.8% vs 18.3%, p<0.001) however, longer lengths of stay (16.9 days vs 14.6 days, p<0.001) and higher costs ($54,000 vs $46,000, p<0.001). After multivariate analysis, HBOT was associated with decreased mortality (Adjusted Odds Ratio (AOR) 0.22, 95% CI 0.09-0.53, P<0.001) and lower risk of amputation (AOR 0.73, 95% CI 0.55-0.96, P = 0.03). HBO was associated with longer stays by 1.6 days (95% CI 0.4-2.7 days) and increased costs by $7,800 (95% CI $2,200-$13,300), they also had significantly lower risks of non-home discharges (AOR 0.79, 95%CI 0.65-0.96).

CONCLUSIONS

After correction for differences, HBOT was associated with decreased mortality, amputations, and non-home discharges in NSTI with the tradeoff of increase to costs and length of stay.

Effects of hyperbaric oxygen combined cabin ventilator on critically ill patients with liberation difficulty after tracheostomy

BACKGROUND

Critically ill patients undergoing liberation often encounter various physiological and clinical complexities and challenges. However, whether the combination of hyperbaric oxygen and in-cabin ventilator therapy could offer a comprehensive approach that may simultaneously address respiratory and potentially improve outcomes in this challenging patient population remain unclear.

METHODS

This retrospective study involved 148 patients experiencing difficulty in liberation after tracheotomy. Inclusion criteria comprised ongoing mechanical ventilation need, lung inflammation on computed tomography (CT) scans, and Glasgow Coma Scale (GCS) scores of ≤ 9. Exclusion criteria excluded patients with active bleeding, untreated pneumothorax, cerebrospinal fluid leakage, and a heart rate below 50 beats per minute. Following exclusions, 111 cases were treated with hyperbaric oxygen combined cabin ventilator, of which 72 cases were successfully liberated (SL group) and 28 cases (NSL group) were not successfully liberated. The hyperbaric oxygen chamber group received pressurization to 0.20 MPa (2.0 ATA) for 20 min, followed by 60 min of ventilator oxygen inhalation. Successful liberation was determined by a strict process, including subjective and objective criteria, with a prolonged spontaneous breathing trial. GCS assessments were conducted to evaluate consciousness levels, with scores categorized as normal, mildly impaired, moderately impaired, or severely impaired.

RESULTS

Patients who underwent treatment exhibited improved GCS, blood gas indicators, and cardiac function indexes. The improvement of GCS, partial pressure of oxygen (PaO2), oxygen saturation of blood (SaO2), oxygenation index (OI) in the SL group was significantly higher than that of the NSL group. However, there was no significant difference in the improvement of left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and stroke volume (SV) between the SL group and the NSL group after treatment.

CONCLUSIONS

Hyperbaric oxygen combined with in-cabin ventilator therapy effectively enhances respiratory function, cardiopulmonary function, and various indicators of critically ill patients with liberation difficulty after tracheostomy.

Effect of hyperbaric oxygen on the growth and susceptibility of facultatively anaerobic bacteria and bacteria with oxidative metabolism to selected antibiotics

Wild strains of Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were tested in an experimental hyperbaric chamber to determine the possible effect of hyperbaric oxygen on the susceptibility of these strains to the antibiotics ampicillin, ampicillin + sulbactam, cefazolin, cefuroxime, cefoxitin, gentamicin, sulfamethoxazole + trimethoprim, colistin, oxolinic acid, ofloxacin, tetracycline, and aztreonam during their cultivation at 23 °C and 36.5 °C. Ninety-six-well inoculated microplates with tested antibiotics in Mueller-Hinton broth were cultured under standard incubator conditions (normobaric normoxia) for 24 h or in an experimental hyperbaric chamber (HAUX, Germany) for 24 h at 2.8 ATA of 100% oxygen (hyperbaric hyperoxia). The hyperbaric chamber was pressurised with pure oxygen (100%). Both cultures (normoxic and hyperoxic) were carried out at 23 °C and 36.5 °C to study the possible effect of the cultivation temperature. No significant differences were observed between 23 and 36.5 °C cultivation with or without the 2-h lag phase in Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Cultivation in a hyperbaric chamber at 23 °C and 36.5 °C with or without a 2-h lag phase did not produce significant changes in the minimum inhibitory concentration (MIC) of Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. For the tested strains of Pseudomonas aeruginosa, the possible effect of hyperbaric oxygen on their antibiotic sensitivity could not be detected because the growth of these bacteria was completely inhibited by 100% hyperbaric oxygen at 2.8 ATA under all hyperbaric conditions tested at 23 °C and 36.5 °C. Subsequent tests with wild strains of pseudomonads, burkholderias, and stenotrophomonads not only confirmed the fact that these bacteria stop growing under hyperbaric conditions at a pressure of 2.8 ATA of 100% oxygen but also indicated that inhibition of growth of these bacteria under hyperbaric conditions is reversible.

Efficacy and Safety of Hyperbaric Oxygen Therapy in Fistulizing Crohn's Disease: A Systematic Review and Meta-analysis

BACKGROUND

Hyperbaric oxygen therapy (HBOT) delivers 100% oxygen in a pressurized chamber, increasing tissue oxygen levels and regulating inflammatory pathways. Mounting evidence suggests that HBOT may be effective for inflammatory bowel disease. Our systematic review and meta-analysis aimed to quantify the efficacy and safety of HBOT in fistulizing Crohn's disease (CD).

METHODS

A systematic review was conducted using the EMBASE, Web of Science, Pubmed, and Cochrane Library databases according to the "Preferred Reporting Items for Systematic Reviews and Meta-analyses" criteria. Study bias was assessed using the Cochrane Handbook guidelines.

RESULTS

Sixteen studies with 164 patients were included in the analysis. For all fistula subtypes, the pooled overall clinical response was 87% (95% CI: 0.70-0.95, I2 = 0) and the pooled clinical remission was 59% (95% CI: 0.35-0.80, I2 = 0). The overall clinical response was 89%, 84%, and 29% for perianal, enterocutaneous, and rectovaginal fistulas, respectively. On meta-regression, hours in the chamber and the number of HBOT sessions were not found to correlate with clinical response. The pooled number of adverse events was low at 51.7 per 10,000 HBOT sessions for all fistula types (95% CI: 16.8-159.3, I2 = 0). The risk of bias was observed across all studies.

CONCLUSION

HBOT is a safe and potentially effective treatment option for fistulizing CD. Randomized control trials are needed to substantiate the benefit of HBOT in fistulizing CD.

Hyperoxia: Effective Mechanism of Hyperbaric Treatment at Mild-Pressure

HBOT increases the proportion of dissolved oxygen in the blood, generating hyperoxia. This increased oxygen diffuses into the mitochondria, which consume the majority of inhaled oxygen and constitute the epicenter of HBOT effects. In this way, the oxygen entering the mitochondria can reverse tissue hypoxia, activating the electron transport chain to generate energy. Furthermore, intermittent HBOT is sensed by the cell as relative hypoxia, inducing cellular responses such as the activation of the HIF-1α pathway, which in turn, activates numerous cellular processes, including angiogenesis and inflammation, among others. These effects are harnessed for the treatment of various pathologies. This review summarizes the evidence indicating that the use of medium-pressure HBOT generates hyperoxia and activates cellular pathways capable of producing the mentioned effects. The possibility of using medium-pressure HBOT as a direct or adjunctive treatment in different pathologies may yield benefits, potentially leading to transformative therapeutic advancements in the future.

Use of hyperbaric oxygen therapy to treat a pressure ulcer complicated by osteomyelitis: a case report

The development of a pressure ulcer (PU) following hospitalisation and immobility can lead to more severe complications, such as osteomyelitis. We report the case of a 60-year-old female patient with a PU complicated with osteomyelitis who was treated with hyperbaric oxygen therapy (HBOT). The patient was diagnosed with an unstageable PU according to the European Pressure Ulcer Advisory Panel classification. A total of 35 HBOT sessions were administered to manage her condition. HBOT is considered a safe and effective treatment for osteomyelitis and decreases mortality rate.

Hyperbaric oxygen augments susceptibility to C. difficile infection by impairing gut microbiota ability to stimulate the HIF-1α-IL-22 axis in ILC3

Hyperbaric oxygen (HBO) therapy is a well-established method for improving tissue oxygenation and is typically used for the treatment of various inflammatory conditions, including infectious diseases. However, its effect on the intestinal mucosa, a microenvironment known to be physiologically hypoxic, remains unclear. Here, we demonstrated that daily treatment with hyperbaric oxygen affects gut microbiome composition, worsening antibiotic-induced dysbiosis. Accordingly, HBO-treated mice were more susceptible to Clostridioides difficile infection (CDI), an enteric pathogen highly associated with antibiotic-induced colitis. These observations were closely linked with a decline in the level of microbiota-derived short-chain fatty acids (SCFAs). Butyrate, a SCFA produced primarily by anaerobic microbial species, mitigated HBO-induced susceptibility to CDI and increased epithelial barrier integrity by improving group 3 innate lymphoid cell (ILC3) responses. Mice displaying tissue-specific deletion of HIF-1 in RORγt-positive cells exhibited no protective effect of butyrate during CDI. In contrast, the reinforcement of HIF-1 signaling in RORγt-positive cells through the conditional deletion of VHL mitigated disease outcome, even after HBO therapy. Taken together, we conclude that HBO induces intestinal dysbiosis and impairs the production of SCFAs affecting the HIF-1α-IL-22 axis in ILC3 and worsening the response of mice to subsequent C. difficile infection.

Evaluation of oxidative stress in an experimental model of Crohn's disease treated with hyperbaric oxygen therapy

INTRODUCTION

Treatments of Inflammatory Bowel Disease (IBD) are able to control symptoms in most cases, however, a fraction of patients do not improve or have a loss of response to treatments, making it important to explore new therapeutic strategies. Hyperbaric oxygen therapy (HBO) may represent one of them. The aim of this study was to evaluate the effects of HBO therapy in an experimental model of IBD.

METHODS

Sixty male BALBc mice were divided into six groups. Group 1 was colitis-induced with trinitrobenzene sulfonic acid (TNBS) + ethanol, group 2 received TNBS + ethanol plus HBO, group 3 received only ethanol, group 4 received ethanol plus HBO, group 5 received saline solution, and group 6 received saline solution plus HBO. HBO was performed for four days, subsequently, the mice were evaluated daily. At the end of the study, samples from the intestine were collected for histological analysis as well as for measurement of antioxidant enzymes and cytokine levels.

RESULTS

HBO significantly improved the clinical and histological status of the animals. Treatment with HBO increased the activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) in all of the groups; moreover, the difference was only significant between the TNBS and TNBS + HBO groups and treatments promoted a reduction in the proinflammatory cytokines IFN-γ, IL-12, IL-17 and TNF-α and increased the anti-inflammatory cytokines IL-4 and IL-10, with no changes in IL-13.

CONCLUSION

HBO effectively treats TNBS-induced colitis by increasing the activity of antioxidant enzymes and modulating cytokine profiles.

Necrotizing fasciitis in neonates: A case report and review of literature

Early recognition and treatment of necrotizing fasciitis reduce mortality rate which is 24.1% among neonates. Antibiotics and debridement are common treatments. Hyperbaric oxygen and negative pressure wound healing show potential but need further investigation.

Compare the effectiveness of extracorporeal shockwave and hyperbaric oxygen therapy on enhancing wound healing in a streptozotocin-induced diabetic rodent model

Studies have revealed that both extracorporeal shock-wave therapy (ESWT) and hyperbaric oxygen therapy (HBOT) can accelerate wound healing. This study aimed to compare the effectiveness of ESWT and HBOT in enhancing diabetic wound healing. A dorsal skin defect in a streptozotocin-induced diabetes rodent model was used. Postoperative wound healing was assessed once every 3 days. Histologic examination was performed with hematoxylin and eosin staining. Proliferation marker protein Ki-67 (Ki-67), endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and 8-hydroxy-2-deoxyguanosine (8-OHdG) were evaluated with immunohistochemical (IHC) staining. The wound area was significantly reduced in the ESWT and HBOT groups compared to that in the diabetic controls. However, the wound healing time was significantly increased in the HBOT group compared to the ESWT group. Histological findings showed a statistical increase in neovascularization and suppression of the inflammatory response by both HBOT and ESWT compared to the controls. IHC staining revealed a significant increase in Ki-67, VEGF, and eNOS but suppressed 8-OHdG expression in the ESWT group compared to the HBOT group. ESWT facilitated diabetic wound healing more effectively than HBOT by suppressing the inflammatory response and enhancing cellular proliferation and neovascularization and tissue regeneration.

Effect of hyperbaric oxygen therapy on the patients with venous leg ulcer: A systematic review and meta-analysis

This systematic review and meta-analysis aim to explore the adjuvant effect of hyperbaric oxygen therapy (HBOT) in patients with venous leg ulcer (VLU) undergoing surgeries and non-surgeries. Literatures were searched from Web of Science, Cochrane Library, Embase, Pubmed, Wan fang, China National Knowledge Infrastructure (CNKI), and VIP from inception to November 15, 2022. The risk ratio (RR) and weighted mean difference (WMD) were used as effect size for categorical variables and continuous variables, respectively, with 95% confidence interval (95%CI). The heterogeneity was assessed using Q-test and quantified as I2. Sensitivity analysis was performed for all outcomes. A total of 11 studies were finally included in this study, with a total of 617 patients (313 in the HBOT group and 304 in the control group). Results showed that HBOT in combination with surgeries was associated with shorter ulcer healing time (WMD: -13.76, 95%CI: -20.42 to -7.10), lower VAS score (WMD: -0.95, 95% CI: -1.83 to -0.07), and smaller ulcer area (WMD: -2.64, 95%CI: -3.86 to -1.42). HBOT in combination with non-surgeries was associated with higher ulcer PAR (WMD: 20.82, 95%CI: 5.86 to 35.79), but no statistical significance was found in the improvement of ulcer area (WMD: 0.79, 95% CI: -1.54 to 3.12). Our results indicating that HBOT had a good adjuvant effect in surgeries to treat VLU, and its effect in non-surgeries needed further studies.

Hyperbaric oxygen therapy and coenzyme Q10 synergistically attenuates damage progression in spinal cord injury in a rat model

BACKGROUND

Identifying effective spinal cord injury (SCI) treatments remains a major challenge, and current approaches are still unable to effectively improve its. Currently, we investigated the combined effects of hyperbaric oxygen (HBO) along with coenzyme Q10 (CoQ10) in the recovery of SCI in rats.

MATERIAL AND METHODS

Ninety female mature Sprague-Dawley rats were allocated into five equal groups, including; sham group, SCI group, HBO group (underwent SCI and received HBO), CoQ10 group (underwent SCI and received CoQ10), and HBO+CoQ10 group (underwent SCI and received HBO plus CoQ10). Tissue samples at the lesion site were obtained for evaluation of stereological, immunohistochemical, biochemical, molecular. Also, functional tests were performed to evaluate of behavioral properties.

RESULTS

We found that a significant increase in stereological parameters, biochemical factors (GSH, SOD and CAT), IL-10 gene expression and behavioral functions (BBB and EMG Latency) in the treatment groups, especially HBO+CoQ10 group, compared to SCI group. In addition, MDA levels, the density of apoptotic cells, as well as expression of inflammatory genes (TNF-α and IL-1β) were considerably reduced in the treatment groups, especially HBO+CoQ10 group, compared to SCI group.

CONCLUSION

We conclude that co-administration of HBO and HBO+CoQ10 has a synergistic neuroprotective effects in animals undergoing SCI.

Lack of surgical resection is associated with increased early mortality in hematological patients complicated with rhino-orbital-cerebral mucormycosis

Rhino-orbital-cerebral mucormycosis (ROCM), which is an acute fatal infectious disease with a high mortality rate, is increasingly being diagnosed in patients with hematological diseases worldwide. We aimed to investigate the clinical characteristics, treatment, and prognosis of hematological diseases complicated by ROCM. Our sample comprised a total of 60 ROCM patients with hematological diseases. The most common primary disease was acute lymphoblastic leukemia (ALL) (n=27, 45.0%), while 36 patients (60.0%) were diagnosed with a clear type of pathogen, all belonging to the Mucorales, most commonly Rhizopus (41.7%). Of the 32 patients (53.3%) who died, 19 (59.3%) died of mucormycosis, and 84.2% (n=16) of those died within 1 month. Forty-eight cases (80.0%) received antifungal treatment combined with surgical therapy, 12 of whom (25.0%) died of mucormycosis, amounting to a mortality rate that was significantly lower than in patients who received antifungal therapy alone (n=7, 58.3%) (P=0.012). The median neutrophil value of patients who underwent surgery was 0.58 (0.11-2.80) 103/μL, the median platelet value was 58.00 (17.00-93.00) 103/μL, and no surgery-related deaths were reported. Multivariate analysis showed that patient's advanced age (P=0.012, OR=1.035 (1.008-1.064)) and lack of surgical treatment (P=0.030, OR=4.971 (1.173-21.074)) were independent prognostic factors.In this study, hematological diseases associated with ROCM have a high mortality rate. Lack of surgical treatment is an independent prognostic factor for death from mucormycosis. Surgery may therefore be considered in patients with hematological disease even if their neutrophil and platelet values are lower than normal.

Immunologic biomarkers for bacterial meningitis

Meningitis is defined as the inflammation of the meninges that is most often caused by various bacterial and viral pathogens, and is associated with high rates of mortality and morbidity. Early detection of bacterial meningitis is essential to appropriate antibiotic therapy. Alterations in immunologic biomarkers levels have been considered the diagnostic approach in medical laboratories for the identifying of infections. The early increasing immunologic mediators such as cytokines and acute phase proteins (APPs) during bacterial meningitis have made they significant indicators for laboratory diagnosis. Immunology biomarkers showed wide variable sensitivity and specificity values that influenced by different reference values, selected a certain cutoff point, methods of detection, patient characterization and inclusion criteria, as well as etiology of meningitis and time of CSF or blood specimens' collection. This study provides an overview of different immunologic biomarkers as diagnostic markers for the identification of bacterial meningitis and their efficiencies in the differentiating of bacterial from viral meningitis.

Effect of Low-level Light Therapy on Post-operative Healing of Secondary Chronic Osteomyelitis of the Jaws - A Prospective Study

Introduction

Osteomyelitis of the jaws is a common disease of the maxillofacial region. The goal of treatment is to alleviate pain, reduce infection, inhibit the progression of the disease and induce bone and mucosal healing. In addition to surgical management and antibiotic and oxygen hyperbaric therapy, new therapeutic strategies for the treatment of osteomyelitis are developed. One of the novel approaches is photobiomodulation therapy or low-level light therapy (LLLT).

Materials and Methods

After surgical treatment, experimental group patients (n = 4) were treated with LLLT for five sessions with an extraoral pulsed 635-nm LED lamp (Repuls7, Repuls Lichtmedizintechnik GmbH, Austria), maximum output power: 140 mW/cm2, frequency: 2.5 Hz, duty cycle: 50%. Clinical achievement and patient pain perception (through Visual Analogue Scale score) were evaluated at 1-, 3- and 6-month follow-up appointments and compared with control group (n = 4) patients, treated with standard therapy.

Results

At three and six months, clinical achievement was better in patients treated with LLLT. Pain and discomfort resolution was significantly greater in the experimental group.

Discussion

Taking into consideration the results of this study, it can be concluded that LLLT shows potential for improving clinical outcome of surgical and medical treatment of secondary chronic osteomyelitis of the jaws. Furthermore, pain and discomfort were significantly reduced in patients treated with LLLT. Further research with a larger sample size is needed to obtain a more accurate insight into this promising field.

Hyperbaric Oxygen Therapy for Nonhealing Wounds-A Long-term Retrospective Cohort Study

OBJECTIVE

To analyze wound healing results of hyperbaric oxygen therapy (HBOT) for a variety of different wound types.

METHODS

This retrospective cohort study included all patients treated with HBOT and wound care at a single hyperbaric center between January 2017 and December 2020. The primary outcome was wound healing. Secondary outcome measures were quality of life (QoL), number of sessions, adverse effects, and treatment cost. Investigators also examined possible influencing factors, including age, sex, type and duration of wound, socioeconomic status, smoking status, and presence of peripheral vascular disease.

RESULTS

A total of 774 treatment series were recorded, with a median of 39 sessions per patient (interquartile range, 23-51 sessions). In total, 472 wounds (61.0%) healed, 177 (22.9%) partially healed, 41 (5.3%) deteriorated, and 39 (5.0%) minor and 45 (5.8%) major amputations were performed. Following HBOT, median wound surface area decreased from 4.4 cm 2 to 0.2 cm 2 ( P < .01), and patient QoL improved from 60 to 75 on a 100-point scale ( P < .01). The median cost of therapy was €9,188 (interquartile range, €5,947-€12,557). Frequently recorded adverse effects were fatigue, hyperoxic myopia, and middle ear barotrauma. Attending fewer than 30 sessions and having severe arterial disease were both associated with a negative outcome.

CONCLUSIONS

Adding HBOT to standard wound care increases wound healing and QoL in selected wounds. Patients with severe arterial disease should be screened for potential benefits. Most reported adverse effects are mild and transient.

Factors associated with mortality in patients with extremity necrotizing soft-tissue infections: a single academic center experience

PURPOSE

Necrotizing soft-tissue infection (NSTI) is a surgical emergency associated with high mortality. This study primarily aimed to identify the factors associated with in-hospital mortality due to NSTI in the extremities at a single institution. Secondarily, we aimed to clarify the effectiveness of the optimal combination of hyperbaric oxygen therapy (HBOT) and surgery for NSTI treatment.

STUDY DESIGN

Retrospective observational study.

METHODS

This study included all patients newly diagnosed with NSTI in the extremity from 2003 to 2021 in our hospital. Factors associated with mortality, including patient's characteristics, duration from onset to hospitalization, NSTI type, and clinical data at the initial visit; acute disseminated intravascular coagulation (DIC), laboratory risk indicator for necrotizing fasciitis score, and sequential organ failure assessment score; treatment, initial surgery, surgery times, amputation, HBOT, combined surgery with HBOT, and clinical outcomes; amputation rate, mortality rate, and hospitalization duration were examined.

RESULTS

A total of 37 cases were treated for NSTIs. The median age was 64 years (range: 22-86). Five cases (13.5%) died during hospitalization. Ten patients were diagnosed with DIC at the initial visit, of whom four died. HBOT combined with surgery was performed in 23 cases, and 16 cases underwent multiple surgeries. Factors associated with mortality included DIC (p = 0.015, 95% confidence interval [CI]: 0.015-0.633) and multiple surgeries combined with HBOT (p = 0.028, 95% CI: 1.302-95.418).

CONCLUSION

This study demonstrates that DIC at the initial visit is associated with mortality in extremity NSTI. Additionally, HBOT might improve prognosis when combined with multiple surgeries.

Hyperbaric Oxygen Therapy in Orthopaedics: An Adjunct Therapy with an Emerging Role

Introduction

Hyperbaric oxygen therapy (HBOT) has emerged as an adjunct treatment modality in various orthopedic and rheumatological conditions. Undersea and Hyperbaric Medical Society (UHMS) defined the minimum number of HBOT cycles, dose, and frequency for various diseases. UHMS laid the 14 absolute indications for HBOT. This article deals with the mechanism of actions of HBOT and evidence of various musculoskeletal disorders where HBOT was utilized to accelerate the healing process of the diseases.

Materials and methods

The review literature search was conducted by using PubMed, SCOPUS, and other database of medical journals for identifying, reviewing, and evaluating the published clinical trial data, research study, and review articles for the use of HBOT in musculoskeletal disorders.

Results

Various clinical researchers documented cellular and biochemical advantages of HBOT which possess allodynic effects, anti-inflammatory, and prooxygenatory effects in patients with musculoskeletal conditions. Studies on the usage of HBOT in avascular necrosis and wound healing provide a platform for exploring the plausible uses of HBOT in other musculoskeletal conditions. Literature evidence states the complications associated with HBOT therapy.

Conclusion

The existing HBOT protocols have to be optimized for various musculoskeletal disorders. Large scale blinded RCTs have to be performed for demonstrating the level of evidence in the usage of HBOT in various musculoskeletal clinical scenarios.

Flexible Monitoring, Diagnosis, and Therapy by Microneedles with Versatile Materials and Devices toward Multifunction Scope

Microneedles (MNs) have drawn rising attention owing to their merits of convenience, noninvasiveness, flexible applicability, painless microchannels with boosted metabolism, and precisely tailored multifunction control. MNs can be modified to serve as novel transdermal drug delivery, which conventionally confront with the penetration barrier caused by skin stratum corneum. The micrometer-sized needles create channels through stratum corneum, enabling efficient drug delivery to the dermis for gratifying efficacy. Then, incorporating photosensitizer or photothermal agents into MNs can conduct photodynamic or photothermal therapy, respectively. Besides, health monitoring and medical detection by MN sensors can extract information from skin interstitial fluid and other biochemical/electronic signals. Here, this review discloses a novel monitoring, diagnostic, and therapeutic pattern by MNs, with elaborate discussion about the classified formation of MNs together with various applications and inherent mechanism. Hereby, multifunction development and outlook from biomedical/nanotechnology/photoelectric/devices/informatics to multidisciplinary applications are provided. Programmable intelligent MNs enable logic encoding of diverse monitoring and treatment pathways to extract signals, optimize the therapy efficacy, real-time monitoring, remote control, and drug screening, and take instant treatment.

The Role of Hyperbaric Oxygen Therapy in the Treatment of Surgical Site Infections: A Narrative Review

Surgical site infections (SSIs) are among the most prevalent postoperative complications, with significant morbidity and mortality worldwide. In the past half century, hyperbaric oxygen therapy (HBOT), the administration of 100% oxygen intermittently under a certain pressure, has been used as either a primary or alternative therapy for the management or treatment of chronic wounds and infections. This narrative review aims to gather information and evidence supporting the role of HBOT in the treatment of SSIs. We followed the Scale for the Quality Assessment of Narrative Review Articles (SANRA) guidelines and scrutinized the most relevant studies identified in Medline (via PubMed), Scopus, and Web of Science. Our review indicated that HBOT can result in rapid healing and epithelialization of various wounds and has potential beneficial effects in the treatment of SSIs or other similar infections following cardiac, neuromuscular scoliosis, coronary artery bypass, and urogenital surgeries. Moreover, it was a safe therapeutic procedure in most cases. The mechanisms related to the antimicrobial activity of HBOT include direct bactericidal effects through the formation of reactive oxygen species (ROS), the immunomodulatory effect of HBOT that increase the antimicrobial effects of the immune system, and the synergistic effects of HBOT with antibiotics. We emphasized the essential need for further studies, especially randomized clinical trials and longitudinal studies, to better standardize HBOT procedures as well as to determine its full benefits and possible side effects.

A review on the research progress on non-pharmacological therapy of Helicobacter pylori

Helicobacter pylori is a pathogenic microorganism that mainly resides in the human stomach and is the major cause of chronic gastritis, peptic ulcer and gastric cancer. Up to now, the treatment of Helicobacter pylori has been predominantly based on a combination of antibiotics and proton pump inhibitors. However, the increasing antibiotic resistance greatly limits the efficacy of anti-Helicobacter pylori treatment. Turning to non-antibiotic or non-pharmacological treatment is expected to solve this problem and may become a new strategy for treating Helicobacter pylori. In this review, we outline Helicobacter pylori’s colonization and virulence mechanisms. Moreover, a series of non-pharmacological treatment methods for Helicobacter pylori and their mechanisms are carefully summarized, including probiotics, oxygen-rich environment or hyperbaric oxygen therapy, antibacterial photodynamic therapy, nanomaterials, antimicrobial peptide therapy, phage therapy and modified lysins. Finally, we provide a comprehensive overview of the challenges and perspectives in developing new medical technologies for treating Helicobacter pylori without drugs.

Ultrasound activatable microneedles for bilaterally augmented sono-chemodynamic and sonothermal antibacterial therapy

Chemodynamic therapy (CDT) employs Fenton catalysts to kill bacteria by converting hydrogen peroxide (H₂O₂) into toxic hydroxyl radical (•OH). Among them, Fenton-type metal peroxide nanoparticles fascinate nanomaterials with intriguing physiochemical properties, but research on this antibacterial agent is still in its infancy. Herein, a distinct CuO₂/TiO₂ heterostructure constituted of ultrasmall copper peroxide (CuO₂) nanoclusters and sonosensitized ultrathin oxygen vacancy-rich porous titanium oxide (OV-TiO₂) nanosheets was developed and was incorporated into microneedles for bilaterally augmented sono-chemodynamic and sonothermal antibacterial therapy. Engineering CuO₂ nanoclusters on the surface of TiO₂ nanosheets not only endows the Fenton catalytic activity for sono-chemodynamic therapy (SCDT), but also improves the sonodynamic and sonothermal performance of TiO₂ by narrowing the bandgap of TiO₂ and suppressing the recombination of electron-hole pairs. The high efficacy of this CuO₂/TiO₂ integrated microneedle (CTMN) patch was systematically demonstrated both in vitro and in vivo with the eliminating rate >99.9999% against multidrug resistant (MDR) pathogens in 5 min as well as accelerated wound tissue healing. This work highlights a promisingly new and efficient strategy for the development of sonosensitive and chemoreactive nanomedicine for non-antibiotic therapies. STATEMENT OF SIGNIFICANCE: Feton-type metal peroxides, a novel nanomaterial with self-supplied oxygen and hydrogen peroxide, can achieve effective antimicrobial activity in vitro. However, there is a lack of effective nanomaterial delivery systems and suitable means for in vivo activation/enhancement of antimicrobial activity during bacterial infected skin wound treatment. In this study, we designed and prepared efficient ultrasound activable microneedles that effectively addressed the deficiencies mentioned above and established a new paradigm for efficient utilization of metal peroxide nanomaterials and ultrasound based strategies. Noticeably, copper peroxide nanoclusters/oxygen vacancy-rich porous titanium oxide nanosheets (CuO₂/TiO₂) integrated microneedle (CTMN) patch combines advantages of both sono-chemodynamic and sonothermal antibacterial therapy, achieving one of the most instant and effective antibacterial efficacy (>99.9999% in 5 min) in vivo reported till now.

Revisiting the role of hyperbaric oxygen therapy in knee injuries: Potential benefits and mechanisms

Knee injury negatively impacts routine activities and quality of life of millions of people every year. Disruption of tendons, ligaments, and articular cartilage are major causes of knee lesions, leading to social and economic losses. Besides the attempts for an optimal recovery of knee function after surgery, the joint healing process is not always adequate given the nature of intra-articular environment. Based on that, different therapeutic methods attempt to improve healing capacity. Hyperbaric oxygen therapy (HBOT) is an innovative biophysical approach that can be used as an adjuvant treatment post-knee surgery, to potentially prevent chronic disorders that commonly follows knee injuries. Given the well-recognized role of HBOT in improving wound healing, further research is necessary to clarify the benefits of HBOT in damaged musculoskeletal tissues, especially knee disorders. Here, we review important mechanisms of action for HBOT-induced healing including the induction of angiogenesis, modulation of inflammation and extracellular matrix components, and activation of parenchyma cells-key events to restore knee function after injury. This review discusses the basic science of the healing process in knee injuries, the role of oxygen during cicatrization, and shed light on the promising actions of HBOT in treating knee disorders, such as tendon, ligament, and cartilage injuries.

Hyperbaric oxygen treatment in the management of necrotising soft-tissue infections: results from a Danish nationwide registry study

OBJECTIVES

Application of hyperbaric oxygen (HBO₂) treatment in the multidisciplinary setting of necrotising soft-tissue infection (NSTI) is debated as a considerable number of studies are of low quality with marked prognostication bias due to inadequately addressing disease severity. The objective of this study was to associate HBO₂ treatment with mortality in patients with NSTI including disease severity as a prognostic variable.

DESIGN

Nationwide population-based register study.

SETTING

Denmark.

PARTICIPANTS

Danish residents with NSTI patients between January 2011 and June 2016.

PRIMARY AND SECONDARY OUTCOME MEASURES

Thirty-day mortality was compared between patients receiving and patients not receiving HBO₂ treatment using inverse probability of treatment weighting and propensity-score matching with predetermined variables (age, sex and weighted Charlson comorbidity score, presence of septic shock and Simplified Acute Physiology Score II (SAPS II)).

RESULTS

A total of 671 NSTI patients were included with a median age of 63 (52-71), 61% male sex, 30% had septic shock and a median SAPS II of 46 (34-58). Patients who received HBO₂ treatment (n=266) were younger and had lower SAPS II, but a larger fraction had septic shock compared with patients not receiving HBO₂ treatment. Overall, all-cause 30-day mortality was 19% (95% CI 17% to 23%). The statistical models were in general acceptably balanced with covariates reaching <0.1 absolute standardised mean differences and patients receiving HBO₂ treatment were associated with lower 30-day mortality (OR 0.40, 95% CI 0.30 to 0.53, p<0.001).

CONCLUSIONS

In analyses using inverse probability of treatment weighting and propensity score analysis, patients treated with HBO₂ treatment were associated with improved 30-day survival.

Pseudomonas aeruginosa: Infections, Animal Modeling, and Therapeutics

Pseudomonas aeruginosa is an important Gram-negative opportunistic pathogen which causes many severe acute and chronic infections with high morbidity, and mortality rates as high as 40%. What makes P. aeruginosa a particularly challenging pathogen is its high intrinsic and acquired resistance to many of the available antibiotics. In this review, we review the important acute and chronic infections caused by this pathogen. We next discuss various animal models which have been developed to evaluate P. aeruginosa pathogenesis and assess therapeutics against this pathogen. Next, we review current treatments (antibiotics and vaccines) and provide an overview of their efficacies and their limitations. Finally, we highlight exciting literature on novel antibiotic-free strategies to control P. aeruginosa infections.

Management of scleral melt

Scleral melting, while rare, can lead to significant ocular morbidity. Several possible risk factors for scleral melt have been identified, such as infection, autoimmune disease, trauma, and post-surgical state, and these may act in combination with each other. Treatment should be tailored according to the etiology and severity of the scleral melt. Medical management may be indicated, especially in cases of autoimmune-related melt; however, surgical procedures are often necessary due to compromised ocular integrity and limited penetration of medications into the avascular sclera. An understanding of the surgical options available and their operative outcomes is particularly important when choosing the appropriate treatment protocol for each patient.

Pulmonary Fibrosis as a Result of Acute Lung Inflammation: Molecular Mechanisms, Relevant In Vivo Models, Prognostic and Therapeutic Approaches

Pulmonary fibrosis is a chronic progressive lung disease that steadily leads to lung architecture disruption and respiratory failure. The development of pulmonary fibrosis is mostly the result of previous acute lung inflammation, caused by a wide variety of etiological factors, not resolved over time and causing the deposition of fibrotic tissue in the lungs. Despite a long history of study and good coverage of the problem in the scientific literature, the effective therapeutic approaches for pulmonary fibrosis treatment are currently lacking. Thus, the study of the molecular mechanisms underlying the transition from acute lung inflammation to pulmonary fibrosis, and the search for new molecular markers and promising therapeutic targets to prevent pulmonary fibrosis development, remain highly relevant tasks. This review focuses on the etiology, pathogenesis, morphological characteristics and outcomes of acute lung inflammation as a precursor of pulmonary fibrosis; the pathomorphological changes in the lungs during fibrosis development; the known molecular mechanisms and key players of the signaling pathways mediating acute lung inflammation and pulmonary fibrosis, as well as the characteristics of the most common in vivo models of these processes. Moreover, the prognostic markers of acute lung injury severity and pulmonary fibrosis development as well as approved and potential therapeutic approaches suppressing the transition from acute lung inflammation to fibrosis are discussed.

Investigating the Effects of Hyperbaric Oxygen Treatment in Necrotizing Soft Tissue Infection With Transcriptomics and Machine Learning (the HBOmic Study): Protocol for a Prospective Cohort Study With Data Validation

BACKGROUND

Necrotizing soft tissue infections (NSTIs) are complex multifactorial diseases characterized by rapid bacterial proliferation and progressive tissue death. Treatment is multidisciplinary, including surgery, broad-spectrum antibiotics, and intensive care; adjunctive treatment with hyperbaric oxygen (HBO₂) may also be applied. Recent advances in molecular technology and biological computation have given rise to new approaches to infectious diseases based on identifying target groups defined by activated pathophysiological mechanisms.

OBJECTIVE

We aim to capture NSTI disease signatures and mechanisms and responses to treatment in patients that receive the highest standard of care; therefore, we set out to investigate genome-wide transcriptional responses to HBO₂ treatment during NSTI in the host and bacteria.

METHODS

The Effects of Hyperbaric Oxygen Treatment Studied with Omics (HBOmic) study is a prospective cohort study including 95 patients admitted for NSTI at the intensive care unit of Copenhagen University Hospital (Rigshospitalet), Denmark, between January 2013 and June 2017. All participants were treated according to a local protocol for management of NSTI, and biological samples were obtained and stored according to a standard operational procedure. In the proposed study, we will generate genome-wide expression profiles of whole-blood samples and samples of infected tissue taken before and after HBO₂ treatment administered during the initial acute phase of infection, and we will analyze the profiles with unsupervised hierarchical clustering and machine learning. Differential gene expression will be compared in samples taken before and after HBO₂ treatment (N=85), and integration of profiles from blood and tissue samples will be performed. Furthermore, findings will be compared to NSTI patients who did not receive HBO₂ treatment (N=10). Transcriptomic data will be integrated with clinical data to investigate associations and predictors.

RESULTS

The first participant was enrolled on July 27, 2021, and data analysis is expected to begin during autumn 2022, with publication of results immediately thereafter.

CONCLUSIONS

The HBOmic study will provide new insights into personalized patient management in NSTIs.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01790698; https://clinicaltrials.gov/ct2/show/NCT01790698.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/39252.

Delayed diagnosis and management of necrotizing fasciitis of the left lower leg: A case report

INTRODUCTION

Necrotizing fasciitis (NF) is a rare, severe soft tissue infection, characterized by rapid and extensive necrosis of the skin, subcutaneous tissue, and superficial and deep fascia. It is frequently misdiagnosed as other infectious diseases, leading to inappropriate treatment and potentially serious consequences. It may be complicated by septic shock and multiple organ failure with a fatal outcome.

PATIENT CONCERNS

A 73-year-old woman presented with continuous itching, skin lesions, pain, and swelling of the outer side of her left leg. The patient was diagnosed with septic shock and multiorgan failure caused by left leg NF.

DIAGNOSIS

Septic shock and multiorgan failure caused by left leg NF.

INTERVENTIONS

Two surgeries were performed on the patient's leg, which effectively treated her septic shock and multiple organ dysfunction.

OUTCOMES

The patient was followed up three times after her discharge. She had a good recovery, was generally well with no significant sequelae, and returned to her regular life.

CONCLUSION

NF is an acute severe illness with high mortality. It is easily misdiagnosed, leading to delayed or erroneous treatment and serious (or potentially fatal) outcomes. Rapid and accurate diagnosis of NF is essential for patient recovery. In difficult cases, multidisciplinary consultations may be helpful. The management of NF includes early and thorough surgical debridement, antibiotics, and symptomatic treatment.

Hyperbaric oxygen improves depression-like behaviors in chronic stress model mice by remodeling gut microbiota and regulating host metabolism

AIMS

There is growing evidence that the gut microbiota plays a significant part in the pathophysiology of chronic stress. The dysbiosis of the gut microbiota closely relates to dysregulation of microbiota-host cometabolism. Composition changes in the gut microbiota related to perturbations in metabolic profiles are vital risk factors for disease development. Hyperbaric oxygen therapy is commonly applied as an alternative or primary therapy for various diseases. Therefore, a metabolic and gut bacteria perspective is essential to uncover possible mechanisms of chronic stress and the therapeutic effect of hyperbaric oxygenation. We determined that there were significantly disturbed metabolites and disordered gut microbiota between control and chronic stress group. The study aims to offer further information on the interactions between host metabolism, gut microbiota, and chronic stress.

METHODS

At present, chronic unpredictable mild stress is considered the most widespread method of modeling chronic stress in animals, so we used a chronic unpredictable mild stress mouse model to characterize changes in the metabolome and microbiome of depressed mice by combining 16S rRNA gene sequencing and UHPLC-MS/MS-based metabolomics. Pearson's correlation-based clustering analysis was performed with above metabolomics and fecal microbiome data to determine gut microbiota-associated metabolites.

RESULTS

We found that 18 metabolites showed a significant correlation with campylobacterota. Campylobacterota associated metabolites were significantly enriched mainly in the d-glutamate and d-glutamine metabolism. Hyperoxia treatment may improve depression-like behaviors in chronic stress model mice through regulating the disrupted metabolites.

CONCLUSIONS

Hyperbaric oxygen improves depression-like behaviors in chronic stress model mice by remodeling Campylobacterota associated metabolites.

Addition of hyperbaric oxygen therapy versus usual care alone for inflammatory bowel disease: A systematic review and meta-analysis

Objective

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disease that includes ulcerative colitis (UC) and Crohn's disease (CD). Hyperbaric oxygen therapy (HBOT) involves breathing pure oxygen in a pressurized environment. Existing literature suggests that HBOT may be an effective therapy for IBD, but a quantitative analysis is lacking. This study aims to estimate the adjunctive role of HBOT in treating IBD and lowering its recurrence rate.

Design

Systematic review and meta-analysis.

Methods

The Cochrane Library, EMBASE, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), and Wanfang databases were systematically searched by two reviewers independently. Meta-analyses were performed using Review Manager (RevMan, version 5.3). A random-effects model was applied due to the heterogeneity between studies.

Results

Twenty-nine out of the initially identified 606 articles were covered in this review, with a total of 2151 patients (2071 for UC and 80 for CD). No randomized data of HBOT for CD were included. Among UC patients, usual care plus HBOT were more likely to achieve a clinical response than usual care alone (risk ratio [RR], 1.24; 95% confidence interval (CI), 1.17 to 1.31; P < 0.001). Subgroup analysis showed that the number of HBOT sessions had no statistically significant effect on overall efficacy (P > 0.05). The pooled data showed a lower recurrence rate in the usual care plus HBOT group (RR, 0.35; 95% CI, 0.24 to 0.53; P < 0.001). The standardized mean difference in the serum tumor necrosis factor level between HBOT and non-HBOT groups was -2.13 (95% CI, -3.09 to -1.18; P < 0.001). No severe adverse events of HBOT were observed.

Conclusions

HBOT might be an effective and safe adjunctive treatment for IBD. Further studies are required to investigate the optimal protocol of HBOT in IBD treatment.

Upconversion nanoparticles and its based photodynamic therapy for antibacterial applications: A state-of-the-art review

Major medical advances in antibiotics for infectious diseases have dramatically improved the quality of life and greatly increased life expectancy. Nevertheless, the widespread and inappropriate exploitation of antibacterial agents has resulted in the emergence of multi-drug-resistant bacteria (MDR). Consequently, the study of new drugs for the treatment of diseases associated with multi-drug-resistant bacteria and the development of new treatments are urgently needed. Inspiringly, due to the advantages of a wide antimicrobial spectrum, fast sterilization, low resistance, and little damage to host tissues and normal flora, antibacterial photodynamic therapy (APDT), which is based on the interaction between light and a nontoxic photosensitizer (PS) concentrated at the lesion site to generate reactive oxygen species (ROS), has become one of the most promising antibacterial strategies. Recently, a burgeoning APDT based on a variety of upconversion nanoparticles (UCNPs) such as PS and near-infrared (NIR) light has been fully integrated in antibacterial applications and achieved excellent performances. Meanwhile, conjugated nanoparticles have been frequently reported in UCNP design, including surface-modified PS conjugates, antibiotic-PS conjugates, and dual or multiple antibacterial modal PS conjugates. This article provides an overview of the state-of-the-art design and bactericidal effects of UCNPs and their based APDTs. The first part discusses the design and mechanisms for UCNPs currently implemented in biomedicine. The second part focuses on the applications and antimicrobial effects of diverse APDT based on UCNPs in antibacterial-related infectious diseases.

Application of Whole-Body Hyperbaric Oxygen Therapy in the Treatment of Grade III Exposed Dog Bite Wounds

Objective. The aim of the study is to evaluate the therapeutic effect of hyperbaric oxygen in the treatment of grade III exposed dog bite wounds. Method. Fifty-two patients with grade III dog bite wounds who were seen in the emergency department of our hospital from 2017 to 2021 were selected for this research. The participants were randomly divided into an experimental group and a control group, with 26 patients in each group. The experimental group received hyperbaric oxygen therapy (HBOT), and the control group received routine treatment. The patients were followed up for three months after the treatment concluded. The wound healing rate, infection rate, and healing time were measured and compared. Results. The cure rate of the experimental group (96.2%) was higher than that of the control group (69.2%). The infection rate in the experimental group (3.8%) was lower than that of the control group (30.8%). The average cure time of the experimental group (9 ± 2.7) was lower than that of the control group (11 ± 3.4). The number of dressing changes in the experimental group (4 ± 3.0) was lower than that of the control group (7.5 ± 3.5), and there was a significant difference between the two groups ( $P<0.05$ ). Conclusion. According to the results, HBOT of grade III dog bite wounds can promote wound healing, improve the cure, and reduce the wound infection rate. It should have a primary role in the clinical treatment of these wounds.

Modulatory Contribution of Oxygenating Hydrogels and Polyhexamethylene Biguanide on the Antimicrobial Potency of Neutrophil-like Cells

Neutrophils are a first line of host defense against infection and utilize a series of oxygen-dependent processes to eliminate pathogens. Research suggests that oxygen availability can improve anti-infective mechanisms by promoting the formation of reactive oxygen species. Also, oxygen can synergistically upregulate the antibacterial properties of certain antibiotics against bacteria by altering their metabolism and causing an increase in the antibiotic uptake of bacteria. Therefore, understanding the effects of oxygen availability, as provided via a biomaterial treatment alone or along with potent antibacterial agents, on neutrophil functions can lead us to the development of new anti-inflammatory and anti-infective approaches. However, the study of neutrophil functions in vitro is often limited by their short life span and nonreproducibility, which suggests the need for cell line-based models as a substitute for primary neutrophils. Here, we took advantage of the differentiated human leukemia-60 cell line (HL-60), as an in vitro neutrophil model, to test the effects of local oxygen and antibacterial delivery by fluorinated methacrylamide chitosan (MACF) hydrogels incorporated with polyhexamethylene biguanide (PHMB) antibacterial agent. Considering the natural modes of neutrophil actions to combat bacteria, we studied the impact of our dual functioning oxygenating-antibacterial platforms on neutrophil phagocytosis and antibacterial properties as well as the formation of neutrophil extracellular traps (NETs) and reactive oxygen species (ROS). Our results demonstrated that supplemental oxygen and antibacterial delivery from MACF-PHMB hydrogel platforms upregulated neutrophil antibacterial properties and ROS production. NET formation by neutrophils upon treatment with MACF and PHMB varied when chemical and biological stimuli were used. Overall, this study presents a model to study immune responses in vitro and lays the foundation for future studies to investigate if similar responses also occur in vivo.

Is There a Place for Hyperbaric Oxygen Therapy?

Hyperbaric oxygen therapy (HBOT) involves treating patients by providing 100% oxygen through inhalation while inside a treatment pressurized chamber. The oxygen acts as a drug and the hyperbaric chamber as the dosing device. The effect of hyperbaric hyperoxia is dose dependent and, therefore, treatment depth and duration are important when considering its use. HBOT can either be the primary method of treatment or used adjunctively to medications or surgical techniques. The underpinning physiology is to bring oxygen-rich plasma to hypoxic tissue, preventing reperfusion injury, strengthening immune responsiveness, and encouraging new collagen deposition as well as endothelial cell formation.

Strategies for ear elevation and the treatment of relevant complications in autologous cartilage microtia reconstruction

Despite various surgical techniques for ear elevation in autogenous cartilage microtia reconstruction, it is still challenging for plastic surgeons to obtain a satisfactory depth of the cephaloauricular sulcus and stable projection of the reconstructed ear. Here, the authors demonstrate individualized options for surgical approaches and relevant details for complication management. Between January 2014 and June 2020, a series of 895 patients who underwent the second stage of microtia reconstruction were reviewed. Complications occurred in 103 patients aged between 8 and 34 years. Recommended surgical selections, as well as appropriate strategies for complication prophylaxis and treatment, were shown to minimize the negative influence on the contour of the cephaloauricular sulcus according to individual conditions. We found that 78% of the patients were satisfied with the auricle contour with harmonious integrity. Individualized strategies for ear elevation and complication treatment contribute to symmetry and satisfactory projection of the reconstructed auricle.