Hyperbaric oxygen: its mechanisms and efficacy

Early Recovery of Exercise-Related Muscular Injury by HBOT

Early recovery from muscular injury is crucial for elite athletes. Hyperbaric oxygen therapy (HBOT) has been reported to be beneficial in terms of accelerating cell recovery and tissue repair, which are considered to be helpful for eliminating fatigue and recovering stamina. This study was performed to evaluate the efficacy of HBOT for exercise-related muscular injury. Forty-one athletes with exercise-related muscular injuries were recruited and randomized into an HBOT group and a control group. All participants received 10 sessions of either HBOT or placebo treatment. The brief pain inventory (BPI) was completed, and serum samples were analyzed. Data were collected before treatment (T1), at the end of the fifth treatment session (T2), at the end of the tenth treatment session (T3), and two weeks after T3 (T4). At T3, the HBOT group showed prominent reductions in the levels of creatine phosphokinase (CK), glutamic oxaloacetate transaminase (GOT), and myoglobin (MB), which lasted until T4. However, the control group did not present any statistical differences in levels from T1 to T4. In terms of pain intensity and interference, the HBOT group showed significant improvements at T3, while no improvements were observed in the control group. In conclusion, HBOT facilitates the early recovery of exercise-related muscular injury. This trial is registered with ISRCTN17817041.

Protective Effect of Hyperbaric Oxygen Therapy on Cognitive Function in Patients with Vascular Dementia

Recent studies have shown that hyperbaric oxygen (HBO) has a therapeutic effect on vascular dementia (VD); however, the exact mechanism remains unclear. This article aims to reveal the protective effects and underlying mechanisms of HBO on VD. A total of 158 patients with VD were prospectively included in the study and were randomly divided into control group and HBO group. The control group was given conventional treatment and the HBO group was treated with HBO in addition to conventional treatment. The following HBO protocol was practiced: 5 days per week, 60 min each, 100% oxygen at 2 standard atmospheric pressures for 12 weeks. The Mini-Mental State Examination (MMSE) scores and serum Humanin levels were detected before and after treatments in both groups. The baseline characteristics were not different dramatically between groups (p > 0.05). There was no significant difference in MMSE scores and serum Humanin levels between the two groups before treatment (p > 0.05). After treatment, compared with the control group, the MMSE scores and serum Humanin levels in the HBO group were significantly increased (p < 0.05). Spearman correlation analysis showed that the serum Humanin levels were positively correlated with MMSE scores (r = 0.409, p < 0.05) and this correlation was independent of baseline characteristics (β = 0.312, p < 0.05). HBO therapy can improve cognitive function in patients with VD, and its mechanism may be related to elevated serum Humanin levels.

Effect of hyperoxia on the immune status of oxygen divers and endurance athletes

Physical activity, particularly that, exerted by endurance athletes, impacts the immune status of the human body. Prolonged duration and high-intensity endurance training lead to increased production of reactive oxygen species (ROS) and thereby to oxidative stress. Military combat swimmers (O₂-divers) are regularly exposed to hyperbaric hyperoxia (HBO) in addition to intensive endurance training intervals. They are, therefore, exposed to extreme levels of oxidative stress. Several studies support that the intensity of oxidative stress essentially determines the effect on immune status. The aim of this study was to comparatively characterise peripheral blood mononuclear cells (PBMCs) of O₂-divers (military combat swimmers), endurance athletes (amateur triathletes), and healthy control volunteers with respect to DNA fragmentation, immune status and signs of inflammation. Furthermore, it was investigated how PBMCs from these groups responded acutely to exposure to HBO. We showed that DNA fragmentation was comparable in PBMCs of all three groups under basal conditions directly after HBO exposure. However, significantly higher DNA fragmentation was observed in O₂-divers 18 hours after HBO, possibly indicating a slower recovery. O₂-divers also exhibited a proinflammatory immune status exemplified by an elevated number of CD4⁺CD25⁺ T cells, elevated expression of proinflammatory cytokine IL-12, and diminished expression of anti-inflammatory TGF-β1 compared to controls. Supported by a decreased basal gene expression and prolonged upregulation of anti-oxidative HO-1, these data suggest that higher oxidative stress levels, as present under intermitted hyperbaric hyperoxia, e.g. through oxygen diving, promote a higher inflammatory immune status than oxidative stress through endurance training alone.

Hyperbaric Oxygen Therapy and Radiation-Induced Injuries

Initial clinical uses of hyperbaric oxygen (HBO₂) capitalized upon physical effects to drive offending gases back into solution and deliver more oxygen to tissues in early treatments of decompression sickness. HBO₂ has a myriad of other effects, including stimulating angiogenesis and new cellular in growth for healing.

Use of Gases to Treat Cochlear Conditions

Although the cochlear vascular supply (stria vascularis) is designed to block to certain compounds and molecules, it must enable gas exchange to survive. The inner ear capillaries must deliver oxygen and remove carbon dioxide for the cochlea to function. These gases diffuse through tissues across a concentration gradient to reach the desired target. Tight junctions or the endothelial basement membrane do not impede them. Therefore, gases that can diffuse into the inner ear are attractive as therapeutic agents. The two gases most often used in this way are oxygen and hydrogen, although carbon dioxide, ozone, and argon have also been investigated. Typically, oxygen is delivered as hyperbaric oxygen (HBO) (oxygen at pressure higher than atmospheric) to provide increased oxygen levels to the inner ear. This not only relieves hypoxia, but also has anti-inflammatory and other biochemical effects. HBO is used clinically to treat idiopathic sudden sensorineural hearing loss, and both animal and human studies suggest it may also assist recovery after acute acoustic trauma. Laboratory studies suggest hydrogen works as a free radical scavenger and reduces the strong oxidants hydroxyl radicals and peroxynitrite. It also has anti-apoptotic effects. Because of its anti-oxidant and anti-inflammatory effects, it has been studied as a treatment for ototoxicity and shows benefit in an animal model of cisplatinum toxicity. Gas diffusion offers an effective way to provide therapy to the inner ear, particularly since some gases (oxygen, hydrogen, carbon dioxide, ozone, argon) have important therapeutic effects for minimizing cochlear damage.

Hyperbaric oxygen facilitates the effect of endothelial progenitor cell therapy on improving outcome of rat critical limb ischemia

We tested the hypothesis that hyperbaric oxygen (HBO) (100% oxygen/2.4 atmospheres) facilitated the effect of autologous endothelial progenitor cell (EPC) therapy on restoring the blood flow in rat critical-limb ischemia (CLI). Adult-male-SD rats (n = 8/each group) were categorized into group 1 [sham control (SC)], group 2 (CLI-treated with culture medium), group 3 [CLI-intermittent HBO (3 h/day for 5 consecutive days after CLI), group 4 (CLI-EPC/2.0 × 10⁶ cells), and group 5 (CLI-HBO-EPC). By day 5 after CLI, flow cytometry showed that the circulating EPC (Sca-1/CD31+/C-kit/CD31+/CD34+) levels were highest in group 5 and lowest in group 2 (all P < 0.001). By day 14, laser Doppler demonstrated that the ratio of blood flow (i.e., CLI to normal hind-limb) was highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3 and 4 (all P < 0.0001). The protein expressions of endothelial-cell biomarkers (CD31/vWF/eNOS), and numbers of endothelial-cell markers (CD31+/vWF+) and small vessels exhibited a similar pattern to blood-flow ratio among five groups, whereas the angiogenesis parameters in protein (CXCR4/SDF-1α/HIF-1α/VEGF) and cellular (HIF-1α/SDF-1α/CXCR4+) levels were progressively increased from groups 1 to 5 (all P < 0.0001). The protein expression of apoptotic (mitochondrial-Bax/cleaved-capspase-3/PARP), fibrotic (p-Smad3/TGF-ß) and mitochondrial-damaged (cytosolic-cytochrome C) exhibited an opposite pattern, whereas the protein expressions of anti-fibrotic (BMP-2/p-Smad1/5) and mitochondrial integrity (mitochondrial-cytochrome C) exhibited an identical pattern of ratio of blood flow among the five groups (all P < 0.0001). Combined HBO-EPC therapy is superior to either one alone in improving ischemia in rodent CLI.

Prophylactic treatment of hyperbaric oxygen treatment mitigates inflammatory response via mitochondria transfer

Aims

Hyperbaric oxygen therapy (HBOT) has been widely used as postinjury treatment; however, we investigate its ability to mitigate potential damage as a preconditioning option. Here, we tested the hypothesis that HBOT preconditioning mitigates cell death in primary rat neuronal cells (PRNCs) through the transfer of mitochondria from astrocytes.

Methods

Primary rat neuronal cells were subjected to a 90‐minute HBOT treatment at 2.5 absolute atmospheres prior to either tumor necrosis factor‐alpha (TNF‐alpha) or lipopolysaccharide (LPS) injury to simulate the inflammation‐plagued secondary cell death associated with stroke and traumatic brain injury (TBI). After incubation with TNF‐alpha or LPS, the cell viability of each group was examined.

Results

There was a significant increase of cell viability accompanied by mitochondrial transfer in the injury groups that received HBOT preconditioning compared to the injury alone groups (44 ± 5.2 vs 68 ± 4.48, n = 20, P < 0.05). The transfer of mitochondria directly after HBOT treatment was visualized by capturing images in 5‐minute intervals, which revealed that the robust transfer of mitochondria begins soon after HBOT and persisted throughout the treatment.

Conclusion

This study shows that HBOT preconditioning stands as a robust prophylactic treatment for sequestration of inflammation inherent in stroke and TBI, possibly facilitating the transfer of resilient mitochondria from astrocytes to inflammation‐susceptible neuronal cells in mitigating cell death.

Acute Encephalopathy Following Hyperbaric Oxygen Therapy in a Patient on Metronidazole

This case describes a patient who presented to the emergency department for an acute onset of encephalopathy following hyperbaric oxygen treatment and antibiotic therapy for radiation-induced osteonecrosis of the jaw.

Hyperbaric Oxygen Therapy for Second-Degree Burn Healing: An Experimental Study in Rabbits

BACKGROUND

The wound healing process includes inflammation, proliferation, and remodelling phases, the main features of which are inflammation, neoangiogenesis, and epithelialization. Hyperbaric oxygen therapy (HBOT) is one modality postulated to improve wound healing. The objective of this study was to determine whether HBOT could improve selected features of burn wound healing in an experimental rabbit model.

METHODS

Researchers conducted an experimental study with 36 rabbits given second-degree burns. Subjects were separated into two groups: a control group (n = 18) and an intervention group that was given HBOT at 2.4 atmospheres absolute for 6 days (n = 18). The main outcome measure was wound healing.

RESULTS

Compared with the control group, the HBOT group showed more robust inflammatory cells (P = .025) and epithelialization (P = .024), but no significant difference in angiogenesis (P = .442).

CONCLUSIONS

The authors conclude that HBOT may improve second-degree burn healing by increasing inflammatory cell migration and re-epithelialization.

Adjunctive hyperbaric oxygen therapy for irradiated rat calvarial defects

Purpose

The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy.

Methods

Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses.

Results

New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2.

Conclusions

HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

Hyperbaric Oxygen Therapy Enhanced Circulating Levels of Endothelial Progenitor Cells and Angiogenesis Biomarkers, Blood Flow, in Ischemic Areas in Patients with Peripheral Arterial Occlusive Disease

Background: This study tested the hypothesis that hyperbaric oxygen (HBO) therapy enhanced the circulating levels of endothelial progenitor cells (EPCs), soluble angiogenesis factors, and blood flow in ischemic areas in patients with peripheral arterial occlusive disease (PAOD). Methods: In total, 57 consecutive patients with PAOD undergoing the HBO therapy (3 atmospheres (atm) for 2 h each time) were prospectively enrolled into the present study. Venous blood sampling was performed to assess the circulating levels of EPCs and soluble angiogenesis factors prior to and during five sessions of HBO therapy. Additionally, skin perfusion pressure (SPP), an indicator of blood flow in ischemic areas, was measured by moorVMS-PRES. Results: The results demonstrated that the circulating levels of EPCs (cluster of differentiation (CD)34⁺/CD133⁺/CD45^dim, CD31⁺/CD133⁺/CD45^dim, CD34⁺) and soluble angiogenesis factors—vascular endothelial growth factor/stromal cell-derived factor 1/hepatocyte growth factor/fibroblast growth factor (VEGF/SDF-1α/HGF/FGF) were significantly increased post-HBO therapy as compared to pre-HBO therapy (all p < 0.01). Additionally, Matrigel assay showed that the angiogenesis was significantly increased in post-HBO therapy as compared to prior to therapy (p < 0.001). Furthermore, SPP was significantly increased in the ischemic area (i.e., plantar foot and mean SPP of the ischemic foot) in post-HBO therapy as compared to pre-HBO therapy (all p < 0.01). Importantly, the HBO therapy did appear to result in complications, and all the patients were uneventfully discharged without amputation. Conclusions: HBO therapy augmented circulating levels of EPCs and angiogenesis factors, and improved the blood flow in the ischemic area.

Effects of intermittent hyperbaric exposure on endurance and interval exercise performance in well-trained mice

NEW FINDINGS

What is the central question of this study? Intermittent hyperbaric exposure (1.3 atmospheres absolute with 20.9% O₂ ) enhances endurance capacity by facilitating oxidative and glycolytic capacities in skeletal muscle. It remains unclear whether this strategy enhances endurance performance in well-trained individuals. What is the main finding and its importance? Hyperbaric exposure with endurance training enhanced oxidative and glycolytic capacities and protein levels of mitochondrial transcription factor A, dynamin-related protein-1 and heat shock protein 70. Hyperbaric exposure with sprint interval training increased the proportion of type I muscle fibres and promoted capillary growth and muscle fibre hypertrophy. These results may lead to a new strategy for enhancing exercise capacity in well-trained mice.

ABSTRACT

The study was designed to clarify the mechanisms by which hyperbaric exposure (1.3 atmospheres absolute with 20.9% O₂ ) improves endurance and interval exercise capacities in highly trained mice. Male mice in the training group were housed in a cage with a wheel activity device for 7 weeks from 5 weeks old. Voluntary running markedly increased maximal endurance capacity by 6.4-fold. Trained mice were then subjected to either endurance treadmill training (20-32.5 m min^-1 ) or sprint interval training (5 s run-10 s rest, 30-42.5 m min^-1 ) with (HypET or HypSIT, respectively) and without (ET or SIT, respectively) 1 h hyperbaric exposure for 4 weeks. Maximal endurance capacity was significantly increased by HypET and HypSIT, and maximal interval capacity was significantly enhanced by HypSIT. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha expression levels were markedly increased after HypET and HypSIT. Activity levels of 3-hydroxyacyl-CoA-dehydrogenase, citrate synthase and phosphofructokinase in the red gastrocnemius muscle were increased more by HypET than by ET. Protein levels of mitochondrial transcription factor A, dynamin-related protein-1 and heat shock protein 70 were increased more by HypET than by ET. The proportion of type I fibres in the soleus muscle was remarkably increased by HypSIT. Capillary-to-fibre ratio values in the white gastrocnemius were increased more by HypSIT than by SIT. These results suggest that hyperbaric exposure has beneficial effects for endurance and interval training to improve exercise capacity in highly trained mice.

Hyperbaric oxygen therapy: Antimicrobial mechanisms and clinical application for infections

Hyperbaric oxygen therapy (HBOT) is a treatment procedure that involves breathing 100% O₂ for a certain time and under a certain pressure. HBOT is commonly administrated as a primary or alternative therapy for different diseases such as infections. In this paper, we reviewed the general aspect of HBOT procedures, the mechanisms of antimicrobial effects and the application in the treatment of infections. Parts of the antimicrobial effects of HBOT are believed to result of reactive from the formation of reactive oxygen species (ROS). It is also said that HBOT enhances the antimicrobial effects of the immune system and has an additive or synergistic effect with certain antimicrobial agents. HBOT has been described as a useful procedure for different infections, particularly in deep and chronic infections such as necrotizing fasciitis, osteomyelitis, chronic soft tissue infections, and infective endocarditis. The anti-inflammation property of HBOT has demonstrated that it may play a significant role in decreasing tissue damage and infection expansion. Patients treated by HBOT need carful pre-examination and monitoring. If safety standards are strictly tracked, HBOT can be considered a suitable procedure with an apt rate of complication.

Hyperbaric oxygen therapy for postoperative ischemic bronchitis after resection of lung cancer

Background

Hyperbaric oxygen therapy (HBOT) has been used successfully in the treatment of specific ischemic injuries, but has been a little evaluated specifically in postoperative ischemic bronchitis (POIB). The purpose of this study was to evaluate the effect of HBOT when used for POIB after resection of lung cancer.

Methods

From January 1999 to December 2016, 1,100 patients underwent lymph node dissection (LND) and either anatomic pulmonary resection or lung resection with bronchoplasty for lung cancer. POIB was diagnosed by bronchoscopy. HBOT was administered after POIB was diagnosed. HBOT comprised one 60-minute session daily in the hyperbaric chamber at 2.0 absolute atmospheres with 100% oxygen. We retrospectively analyzed the clinical course, timing of onset of POIB, outcomes, and any adverse events.

Results

Seven patients were identified to have had POIB treated with HBOT, all of whom were men with a smoking history and a median age of 65 years (range, 57-72 years). The operative procedures included three lung resections with bronchoplasty, three right lower lobectomies, and one right middle lobectomy performed owing to torsion of the middle lobe after right upper sleeve lobectomy. All 7 patients underwent subcarinal LND. POIB was diagnosed at a median of 11 days (range, 4-41 days) postoperatively. The median duration of an HBOT session was 7 days (range, 3-11 days). POIB resolved in 5 patients but worsened in 2, both of whom required further surgery.

Conclusions

Prospective clinical trials are now needed to confirm the potential benefits of HBOT in POIB.

Hyperbaric oxygen therapy for digital ulcers due to Raynaud's disease

We present a case of Raynaud's disease with digital ulcers that was successfully treated with hyperbaric oxygen therapy. Hyperbaric oxygen therapy can be considered as a safe and useful adjunct treatment for intractable digital ulcers in patients with Raynaud's disease.

Hyperbaric Oxygen for Hospitalized patients with Ulcerative Colitis

One quarter of patients with ulcerative colitis will develop a severe acute exacerbation of disease during their lifetime. Despite high dose corticosteroids, half of these patients will fail subsequent medical rescue therapy, and half will require colectomy within 5 years. Dulai and colleagues report the results of a fascinating, double blind, sham controlled, proof of concept trial which demonstrated that administration of short term hyperbaric oxygen therapy (HBOT) at the point of presentation with severe UC was able to rapidly induce short term remission and avoid the need for urgent second line medical rescue therapy. Further dose finding studies are underway.

Ozone therapy as a primary and sole treatment for acute bacterial infection: case report

The world is facing a crisis of antibiotic resistance, which impacts every treating physician on the planet. Thousands of patients die yearly in the USA from infections that have failed to respond to anti-infectives. Alarms have been ringing about bacterial infection fatality resurgence, the end of the antibiotic era, a calamity in progress. Ozone therapy has been used in medicine since World War I. However, it is not patentable and has suffered from lack of private source funding for research sufficient to have it accepted by the mainstream. Basic science, both in vivo and in vitro, research has found it to have several effects including modulating the immune system, enhancing circulation, destroying microorganisms including bacteria and viruses, and enhancing oxygen delivery and consumption by the body. This report presents background basic ozone science and a case report of acute bacterial infection - tick bite cellulitis, which immediately responded to ozone therapy as the sole treatment, and which fully resolved within 24-48 hours. Ozone therapy could be considered as an adjunctive or alternative therapy for bacterial infection.

Topical oxygen therapy stimulates healing in difficult, chronic wounds: a tertiary centre experience

OBJECTIVE

Oxygen plays a central role in wound healing. Recent technological advances have miniaturised oxygen delivery systems, with novel topical oxygen therapy allowing patients to receive oxygen therapy 24 hours a day while remaining completely mobile. Here we aim to examine the efficacy and safety of continuous topical oxygen diffusion in a 'real-world' setting.

METHODS

Topical oxygen therapy (TOT) was evaluated in patients with chronic, non-healing wounds in a tertiary referral specialist clinic.

RESULTS

The mean wound duration before TOT was 15 months. Regardless of treatment duration, in this previously non-healing group complete wound closure was observed in 32% of the total patients treated with the TOT device. However, optimal wound healing occurred when the device was used for >25 days, with an 83% wound area reduction and 47% wound closure rate seen in venous leg ulcers (VLUs) and a 74% reduction and a 57% wound closure rate in arterial foot ulcers.

CONCLUSION

Use of TOT in chronic wounds stimulates a healing state. In our study, almost half of the previously non-healing wounds closed.

Femoral condylar necrosis: treatment with hyperbaric oxygen therapy

Background

Osteonecrosis of the knee (ONK) is a form of aseptic necrosis resulting from ischemia to subchondral bone tissue. Typically, treatment is invasive. Hyperbaric oxygen therapy (HBOT) may provide a noninvasive alternative by improving oxygenation and reperfusion of ischemic areas. This study evaluates the efficacy of HBOT in a series of ONK patients.

Methods

This retrospective study evaluates 37 ONK patients (29 male, 8 female; mean age ± 1 standard deviation: 54 ± 14); 83.7% of patients presented with Aglietti stage I-II; 16.3% presented with Aglietti stage III. Patients were treated with HBOT once a day, 5 days a week, at 2.5 atmosphere absolute with 100% inspired oxygen by mask for an average of 67.9 ± 15 sessions. Magnetic resonance imaging was performed before HBOT, within 1 year after completion of HBOT, and in 14 patients, 7 years after treatment. Oxford Knee Scores (OKSs) were recorded before HBOT and at the end of each HBOT treatment cycle.

Results

After the 30 sessions of HBOT, 86% of patients experienced improvement in their OKS, 11% worsened, and 3% did not change. All patients improved in OKS after 50 sessions. Magnetic resonance imaging evaluation 1 year after HBOT completion showed that edema at the femoral condyle had resolved in all but 1 patient.

Conclusions

HBOT is beneficial for treating ONK. Patients experienced improvements in pain and mobility as demonstrated by improvement in OKS. Radiographic improvements were also seen upon post-treatment follow-up. Aglietti staging for the entire sample saw an aggregate decrease (P < .01) from 1.7 ± 0.7 to 0.3 ± 0.6.

Hyperbaric oxygen treatment for the management of radiation-induced xerostomia

INTRODUCTION

Hyperbaric oxygen therapy (HBOT) is widely used for the treatment of the late effects of radiation therapy. We report a prospective observational cohort study of 51 patients designed to examine the effectiveness of hyperbaric oxygen treatment (HBOT) for xerostomia following radiotherapy.

METHODS

Objective (saliva volume) and subjective (quality of life scoring and visual analogue scale (VAS) of discomfort) measurements associated with xerostomia were compared prior to commencement of HBOT, after 30 sessions (over 6 weeks) of HBOT at 243 kPa for 90 minutes daily for five days per week and at 6-week review (12 weeks from commencement).

RESULTS

One hundred and one courses of treatment in 99 patients were examined. For 53 (53%) courses in 51 patients, data were recorded before and after HBOT and so could be included in the analysis. Thirty-four (34%) of these patients had complete data for all three time points. The unit of study was per treatment course, not per person. There were no major complications to HBOT. There was a statistically significant difference in saliva volume following HBOT (P = 0.016). The mean saliva volume increase was 0.9 mL over a 5-min collection period (95% CI 0.2-1.5). There was also a statistically significant improvement in discomfort after HBOT (P < 0.001) and QOL (P < 0.001). The mean visual analogue scale for discomfort (VAS on a 0-10 scale) score decreased by 1.4 units (95% CI 0.7-2.1), whilst the mean QOL score was 10 points lower after treatment (95% CI 5.9-14.4).

CONCLUSION

Hyperbaric oxygen therapy may be a safe and effective treatment for symptoms of xerostomia after radiation therapy and should be considered when available.

A Pilot Study of Short-Duration Hyperbaric Oxygen Therapy to Improve HbA1c, Leukocyte, and Serum Creatinine in Patients with Diabetic Foot Ulcer Wagner 3-4

Objective

To evaluate the short-duration hyperbaric oxygen therapy (HBOT) can improve HbA1c levels, leukocyte count, and serum creatinine levels in patients with diabetic foot ulcer (DFU) Wagner 3-4.

Methods

Blood samples from all DFU patients at Sanglah General Hospital, Denpasar, were taken for HbA1c, leukocyte, and serum creatinine test before debridement procedure, and the patients were then grouped into either standard therapy or standard therapy with HBOT for 10 sessions (combination therapy). At the end of therapy, all blood tests were resumed.

Results

Each group consisted of 15 patients. Results of laboratory analysis before and after treatment were significant regarding decrease of HbA1c levels in standard therapy (10.98 ± 2.37 % to 9.70 ± 2.46 %; p = 0.006), HbA1c levels in combination therapy (9.42 ± 1.96 % to 7.07 ± 1.16 %; p < 0.001), and leukocyte count in combination therapy (13.97 ± 6.24 x 10³ cells/μL to 8.84 ± 2.88 x 10³ cells/μL; p = 0.009). The HbA1c levels at the end of therapy were significantly different between groups (p = 0.001). Serum creatinine level was decreased only in combination therapy but it was not significant. The effect size of all variables was larger in the combination therapy, but it was not significant (p > 0.05).

Conclusion

The use of short-duration HBOT on DFU reduces HbA1c levels, leukocyte count, and serum creatinine levels better than standard therapy alone. This protocol would save time and effort in future HBOT implementation. This trial is registered with ClinicalTrials.gov Identifier: NCT03615755.

Ozone therapy in conjunction with oral antibiotics as a successful primary and sole treatment for chronic septic prosthetic joint: review and case report

The world is facing crisis in management of infectious diseases. The mainstay of treatment has been chemical anti-infectives. These drugs are failing, as superbugs emerge and medicine becomes more sophisticated with treatments such as prosthetic devices, which can harbor bacteria protected by biofilm. This case report describes a 68-year-old woman who received bilateral artificial hips on October 27, 2015. The right hip prosthesis subsequently became septic by June 2016. Three orthopedic surgeons offered her a several month program, which included removal of the prosthesis, implantation of an antibiotic impregnated “spacer” and months of intravenous antibiotics. Instead, she sought and received intravenous ozone therapy, local joint ozone gas injection, and nutritional supplements. She quickly improved. Subsequently, she was given oral Augmentin (875 mg three times daily) beginning at September 19, 2016 for 1 month, when a third culture returned positive for two oral organisms. She experienced even more rapid improvement. By October 12, she reported total resolution of symptoms. A subsequent MRI on November 30, 2016 showed total clearance of infection. This is the first report of a septic prosthetic joint infection completely resolving without some form of surgical intervention, debridement at the least. It is also the first to report such cure without the use of any parenteral antibiotics. This case and world literature suggest that ozone therapy could be considered as a useful adjunctive treatment for hard to treat infection and biofilm.

Effectiveness of Hyperbaric Oxygen Therapy for the Management of Chronic Osteomyelitis: A Systematic Review of the Literature

Hyperbaric oxygen has been used as an adjunctive measure in the treatment of chronic osteomyelitis. The aim of this systematic literature review was to analyze the outcome and the complications of hyperbaric oxygen for chronic osteomyelitis. Forty-five of 96 studies reporting the use of hyper-baric oxygen for 460 patients with chronic osteomyelitis met the inclusion criteria and were analyzed qualitatively. All patients previously received antibiotics and surgical debridement. Mixed bacterial flora was detected in most of the studies. Staphylococcus aureus was the isolated pathogen in 12 (60%) of the 20 cohort and in 4 (20%) of the 20 case studies. Adjuvant hyperbaric oxygen was effective in 16 (80%) of the 20 cohort and 19 (95%) of the 20 case studies. Overall, 308 (73.5%) of 419 patients with complete data had a successful outcome and no reported relapse. Available evidence supports a potentially beneficial role of adjunctive hyperbaric oxygen, especially in refractory cases of chronic osteomyelitis. [Orthopedics. 2018; 41(4):193-199.].

Hyperbaric oxygen therapy of air embolus in the cerebral venous sinuses after intracranial surgery: a case report

A case with cerebral venous air embolism (CVAE) after neurosurgery and treated with hyperbaric oxygen therapy (HBOT) is presented. This is a rare and potentially fatal complication that neurosurgeons should be aware of. A 52-year-old male was diagnosed with an intracerebral hematoma. An emergency evacuation of the hematoma was performed with a craniotomy and the postoperative CT scan showed a complete evacuation of the hematoma, but it also revealed a CVAE. The patient was immediately referred to HBOT and received three sessions within 48 h. The CT scan after the first HBOT showed no CVAE, venous thrombosis, or new hematoma.

A Dual Role for Hyperbaric Oxygen in Stroke Neuroprotection: Preconditioning of the Brain and Stem Cells

Stroke continues to be an extremely prevalent disease and poses a great challenge in developing safe and effective therapeutic options. Hyperbaric oxygen therapy (HBOT) has demonstrated significant pre-clinical effectiveness for the treatment of acute ischemic stroke, and limited potential in treating chronic neurological deficits. Reported benefits include reductions in oxidative stress, inflammation, neural apoptosis, and improved physiological metrics such as edema and oxygen perfusion, all of which contribute to improved functional recovery. This pre-clinical evidence has failed to translate into an effective evidence-based therapy, however, due in large part to significant inconsistencies in treatment protocols and design of clinical studies. While the medical community works to standardize clinical protocols in an effort to advance HBOT for acute stroke, pre-clinical investigations continue to probe novel applications of HBOT in an effort to optimize stroke neuroprotection. One such promising strategy is HBOT preconditioning. Based upon the premise of mild oxidative stress priming the brain for tolerating the full-blown oxidative stress inherent in stroke, HBOT preconditioning has displayed extensive efficacy. Here, we first review the pre-clinical and clinical evidence supporting HBOT delivery following ischemic stroke and then discuss the scientific basis for HBOT preconditioning as a neuroprotective strategy. Finally, we propose the innovative concept of stem cell preconditioning, in tandem with brain preconditioning, as a promising regenerative pathway for maximizing the application of HBOT for ischemic stroke treatment.

Using advanced wound care and hyperbaric oxygen to manage wound complications following treatment of vulvovaginal carcinoma

Postoperative management of patients with vulvar cancer is associated with a high incidence of poor wound healing and radiation -induced late tissue necrosis. This case series demonstrates the impact on wound healing with the use of hyperbaric oxygen therapy and advanced wound care following radical vulvectomy and/or radiation therapy. A retrospective case series was performed of all patients from 2016 to 2017 with lower genital cancer who underwent radical surgery with or without chemoradiation treatment, experienced wound dehiscence or late tissue radionecrosis, and were treated with advanced wound care, including hyperbaric oxygen therapy (HBO). Five patients were included with a mean age of 63; four had squamous cell carcinoma and one patient had vaginal adenocarcinoma secondary to prior diethylstilbestrol exposure. Three patients underwent radical vulvectomy. All received pelvic radiation therapy, subsequently experienced wound complications, and were managed with advanced wound care and HBO. The mean reduction in wound area at the final wound follow up visit after completion of HBO therapy was found to be 76%, ranging 42-95%, with an average follow up of five months. The mean number of HBO sessions per patient was 58. Complete tissue granulation or significant improvement in tissue radionecrosis was present in all patients. Advanced wound care and hyperbaric oxygen therapy are beneficial in the management of postoperative wound complications. Prospective studies are needed to identify the optimal use of perioperative hyperbaric oxygen and appropriate wound care for patients with gynecologic malignancies.

Benefits of hyperbaric oxygen pretreatment for decompression sickness in Bama pigs

Decompression sickness (DCS) occurs when ambient pressure is severely reduced during diving and aviation. Hyperbaric oxygen (HBO) pretreatment has been shown to exert beneficial effects on DCS in rats via heat-shock proteins (HSPs). We hypothesized that HBO pretreatment will also reduce DCS via HSPs in swine models. In the first part of our investigation, six swine were subjected to a session of HBO treatment. HSP32, 60, 70 and 90 were detected, before and at 6, 12, 18, 24 and 30 h following exposure in lymphocytes. In the second part of our investigation, another 10 swine were randomly assigned into two groups (five per group). All swine were subjected to two simulated air dives in a hyperbaric chamber with an interval of 7 days. Eighteen hours before each dive, the swine were pretreated with HBO or air: the first group received air pretreatment prior to the first dive and HBO pretreatment prior to the second; the second group were pretreated with HBO first and then air. Bubble loads, skin lesions, inflammation and endothelial markers were detected after each dive. In lymphocytes, all HSPs increased significantly (P<0.05), with the greatest expression appearing at 18 h for HSP32 and 70. HBO pretreatment significantly reduced all the determined changes compared with air pretreatment. The results demonstrate that a single exposure to HBO 18 h prior to diving effectively protects against DCS in the swine model, possibly via induction of HSPs.

Highs and lows of hyperoxia: physiological, performance, and clinical aspects

Molecular oxygen (O₂) is a vital element in human survival and plays a major role in a diverse range of biological and physiological processes. Although normobaric hyperoxia can increase arterial oxygen content ([Formula: see text]), it also causes vasoconstriction and hence reduces O₂ delivery in various vascular beds, including the heart, skeletal muscle, and brain. Thus, a seemingly paradoxical situation exists in which the administration of oxygen may place tissues at increased risk of hypoxic stress. Nevertheless, with various degrees of effectiveness, and not without consequences, supplemental oxygen is used clinically in an attempt to correct tissue hypoxia (e.g., brain ischemia, traumatic brain injury, carbon monoxide poisoning, etc.) and chronic hypoxemia (e.g., severe COPD, etc.) and to help with wound healing, necrosis, or reperfusion injuries (e.g., compromised grafts). Hyperoxia has also been used liberally by athletes in a belief that it offers performance-enhancing benefits; such benefits also extend to hypoxemic patients both at rest and during rehabilitation. This review aims to provide a comprehensive overview of the effects of hyperoxia in humans from the "bench to bedside." The first section will focus on the basic physiological principles of partial pressure of arterial O₂, [Formula: see text], and barometric pressure and how these changes lead to variation in regional O₂ delivery. This review provides an overview of the evidence for and against the use of hyperoxia as an aid to enhance physical performance. The final section addresses pathophysiological concepts, clinical studies, and implications for therapy. The potential of O₂ toxicity and future research directions are also considered.

Hyperbaric Oxygen Reduces Aspergillus fumigatus Proliferation In Vitro and Influences In Vivo Disease Outcomes

Recent estimates suggest that more than 3 million people have chronic or invasive fungal infections, causing more than 600,000 deaths every year. Aspergillus fumigatus causes invasive pulmonary aspergillosis (IPA) in patients with compromised immune systems and is a primary contributor to increases in human fungal infections. Thus, the development of new clinical modalities as stand-alone or adjunctive therapy for improving IPA patient outcomes is critically needed. Here we tested the in vitro and in vivo impacts of hyperbaric oxygen (HBO) (100% oxygen, >1 atmosphere absolute [ATA]) on A. fumigatus proliferation and murine IPA outcomes. Our findings indicate that HBO reduces established fungal biofilm proliferation in vitro by over 50%. The effect of HBO under the treatment conditions was transient and fungistatic, with A. fumigatus metabolic activity rebounding within 6 h of HBO treatment being removed. In vivo, daily HBO provides a dose-dependent but modest improvement in murine IPA disease outcomes as measured by survival analysis. Intriguingly, no synergy was observed between subtherapeutic voriconazole or amphotericin B and HBO in vitro or in vivo with daily HBO dosing, though the loss of fungal superoxide dismutase genes enhanced HBO antifungal activity. Further studies are needed to optimize the HBO treatment regimen and better understand the effects of HBO on both the host and the pathogen during a pulmonary invasive fungal infection.

Alterations in mitochondrial respiration and reactive oxygen species in patients poisoned with carbon monoxide treated with hyperbaric oxygen

Background

Carbon monoxide (CO) poisoning is the leading cause of poisoning mortality and morbidity in the USA. Carboxyhemoglobin (COHb) levels are not predictive of severity or prognosis. At this time, the measurement of mitochondrial respiration may serve as a biomarker in CO poisoning. The primary objective of this study was to assess changes in mitochondrial function consisting of respiration and generation of reactive oxygen species (ROS) in peripheral blood mononuclear cells (PBMCs) obtained from patients with CO poisoning.

Methods

PBMCs from patients having confirmed CO exposure treated with hyperbaric oxygen or HBO (CO group) and healthy controls (control group) were analyzed with high-resolution respirometry. PBMCs were placed in a 2-ml chamber at a final concentration of 3–4 × 10⁶ cells/ml to simultaneously obtain both respiration and hydrogen peroxide (H₂O₂) production. In the CO group, we performed measurements before and after patients underwent their first HBO treatment.

Results

We enrolled a total of 17 subjects, including 7 subjects with confirmed CO poisoning and 10 subjects in the control group. The CO group included five (71.4%) men and two (28.6%) women having a median COHb of 28%. There was a significant decrease in respiration as measured in pmol O₂ × s^− 1 × 10^− 6 PBMCs in the CO group (pre-HBO) when compared to the control group: maximal respiration (18.4 ± 2.4 versus 35.4 ± 2.8, P < 0.001); uncoupled Complex I respiration (19.8 ± 1.8 versus 41.1 ± 3.8, P < 0.001); uncoupled Complex I + II respiration (32.3 ± 3.2 versus 58.3 ± 3.1, P < 0.001); Complex IV respiration (43.5 ± 2.9 versus 63.6 ± 6.31, P < 0.05). There were also similar differences measured in the CO group before and after HBO treatment with an overall increase in respiration present after treatment. We also determined the rate of H₂O₂ production simultaneously with the measurement of respiration. There was an overall significant increase in the H₂O₂ production in the CO group after HBO treatment when compared to prior HBO treatment and the control group.

Conclusions

In this study, PBMCs obtained from subjects with CO poisoning have an overall decrease in respiration (similar H₂O₂ production) when compared to controls. The inhibition of Complex IV respiration is from CO binding leading to a downstream decrease in respiration at other complexes. PBMCs obtained from CO-poisoned individuals immediately following initial HBO therapy displayed an overall increase in both respiration and H₂O₂ production. The study findings demonstrate that treatment with HBO resulted in improved cellular respiration but a higher H₂O₂ production. It is unclear if the increased production of H₂O₂ in HBO treatment is detrimental.

The Effects of Short- and Long-Term Exposure to Hyperbaric Oxygen on Nasal Mucociliary Clearance

The aim of this study is to assess the effects of short- and long-term exposure to hyperbaric oxygen (HBO) on nasal mucociliary clearance (MCC). This study included 47 consecutive nondiabetic patients treated with hyperbaric oxygen therapy (HBOT). Participants were divided into 2 groups according to the taken number of HBOT sessions. Nineteen patients who received <11 HBOT sessions comprised short-term HBOT group, 28 patients who received more than 15 sessions comprised the long-term HBOT group. Mucociliary clearance was measured using a saccharin clearance test, which was performed 3 times on patients: prior to, at completion of, and 6 months after HBOT. The average number of HBOT sessions was 8 ± 1.9 in short-term HBOT group and 20 ± 4.8 in long-term group. Both short- and long-term exposure to HBO led to significant influence on MCC upon treatment completion (both P < 0.001). In addition, only long-term exposure to HBO caused significant elongation of MCC at long-term evaluation (6 months after HBOT). From these objective measurements, the authors can conclude that long-term exposure to HBO can cause irreversible damage to MCC compared with short-term exposure and HBOT appears to affect MCC in a dose-dependent manner. The clinical significance of this effect is of concern for patients undergoing HBOT for middle ear, sinonasal, or respiratory tract infections. Patients who undergo chronic HBOT should be monitored closely and informed about the possible negative effects.

An Injectable Oxygen Release System to Augment Cell Survival and Promote Cardiac Repair Following Myocardial Infarction

Oxygen deficiency after myocardial infarction (MI) leads to massive cardiac cell death. Protection of cardiac cells and promotion of cardiac repair are key therapeutic goals. These goals may be achieved by re-introducing oxygen into the infarcted area. Yet current systemic oxygen delivery approaches cannot efficiently diffuse oxygen into the infarcted area that has extremely low blood flow. In this work, we developed a new oxygen delivery system that can be delivered specifically to the infarcted tissue, and continuously release oxygen to protect the cardiac cells. The system was based on a thermosensitive, injectable and fast gelation hydrogel, and oxygen releasing microspheres. The fast gelation hydrogel was used to increase microsphere retention in the heart tissue. The system was able to continuously release oxygen for 4 weeks. The released oxygen significantly increased survival of cardiac cells under the hypoxic condition (1% O₂) mimicking that of the infarcted hearts. It also reduced myofibroblast formation under hypoxic condition (1% O₂). After implanting into infarcted hearts for 4 weeks, the released oxygen significantly augmented cell survival, decreased macrophage density, reduced collagen deposition and myofibroblast density, and stimulated tissue angiogenesis, leading to a significant increase in cardiac function.

Strategies to Restore Adenosine Triphosphate (ATP) Level After More than 20 Hours of Cold Ischemia Time in Human Marginal Kidney Grafts

Background

The persisting organ shortage in the field of transplantation recommends the use of marginal kidneys which poorly tolerate ischemic damage. Adenosine triphosphate (ATP) depletion during cold ischemia time (CIT) is considered crucial for graft function. We tested different strategies of kidney perfusion before transplantation in the attempt to improve the technique.

Material/Methods

Twenty human discarded kidneys from donors after brain death and with at least 20 hours of CIT were randomized to the following experimental groups (treatment time three-hours at 4°C): a) static cold storage (CS); b) static cold hyperbaric oxygenation (Hyp); c) hypothermic perfusion (PE); d) hypothermic perfusion in hyperbaric oxygenation (PE-Hyp); and e) hypothermic oxygenated perfusion (PE-O₂).

Results

Histological results showed that perfusion with or without oxygen did not produce any endothelial damage. A depletion of ATP content following the preservation procedure was observed in CS, PE, and Hyp, while PE-Hyp and PE-O₂ were associated with a net increase of ATP content with respect to baseline level. In addition, PE-Hyp was associated with a significant downregulation of endothelial isoform of nitric oxide synthase (eNOS) gene expression and of hypoxia inducible factor-1α (HIF-1α).

Conclusions

Hyperbaric or normobaric oxygenation with perfusion improves organ metabolic preservation compared to other methods. This approach may prevent the onset of delayed graft function, but clinical trials are needed to confirm this.

Hyperbaric Oxygen for Ischemia due to Injection of Cosmetic Fillers: Case Report and Issues

Natural and synthetic fillers have revolutionized aesthetic facial rejuvenation and soft-tissue augmentation. We present a case highlighting the dangers of filler self-injection. A 37-year-old woman self-injected a dermal filler around both temples. She immediately experienced left--side hearing loss, blanching over the left face, and pain. Prompt treatment with hyaluronidase, topical nitro paste, and warm compresses ensued. An emergency computed tomography angiogram showed occlusion of a superficial temporal artery branch. We treated her with enoxaparin, aspirin, dexamethasone, piperacillin-tazobactam, and intradermal lidocaine. After 6 hyperbaric oxygen therapy (HBO2) treatments in 3 days, the patient showed improvement in appearance with markedly decreased ischemic discoloration and her hearing returned to baseline. Algorithms for treating such injuries generally neglect HBO2. HBO2 is thought to be efficacious in these situations by a variety of mechanisms: oxygenation of ischemic tissues, reduction of edema, amelioration of ischemic/reperfusion injury, promotion of angiogenesis and collagen maturation. Her resolved hearing highlights the utility of HBO2 in sudden hearing loss as well. Injectors should have guidelines for using product, not only on patients but staff as well. Filler courses should include handling complications and include HBO2 in their guidelines. Clinicians should remind patients to seek treatment from qualified clinicians. The goal of a bargain price using self-injection may quickly become expensive and disfiguring.

Topical oxygen therapy & micro/nanobubbles: a new modality for tissue oxygen delivery

Up to 15 billion dollars of US health care expenditure each year is consumed by treatment of poorly healing wounds whose etiologies are often associated with aberrancies in tissue oxygenation. To address this issue, several modes of tissue oxygen delivery systems exist, including Hyperbaric Oxygen Therapy (HBOT) and Topical Oxygen Therapy (TOT), but their efficacies have yet to be fully substantiated. Micro/nanobubbles (MNBs), which range anywhere from 100 μm to <1 μm in diameter and are relatively stable for hours, offer a new mode of oxygen delivery to wounds. The aim of this article is to systematically review literature examining the use of TOT for wound healing and use of MNBs for tissue oxygenation using the MEDLINE database. The search yielded 87 articles (12 MNB articles and 75 TOT articles), of which 52 met the inclusion criteria for this literature review (12 MNB articles and 40 TOT articles). Additionally, we present an analysis on the efficacy of our MNB generating technology and propose its use as a wound healing agent.

Cerebral arterial gas embolism from attempted mechanical thrombectomy: recovery following hyperbaric oxygen therapy

Cerebral arterial gas embolism is a recognised complication of endovascular intervention with an estimated incidence of 0.08%. Its diagnosis is predominantly clinical, supported by neuroimaging. The treatment relies on alleviating mechanical obstruction and reversing the proinflammatory processes that contribute to tissue ischaemia. Hyperbaric oxygen therapy is an effective treatment and has multiple mechanisms to reverse the pathological processes involved in cerebral arterial gas embolism. Symptomatic cerebral arterial gas embolism is a rare complication of endovascular intervention for acute ischaemic stroke. Although there are no previous descriptions of its successful treatment with hyperbaric oxygen therapy following mechanical thrombectomy, this is likely to become more common as mechanical thrombectomy is increasingly used worldwide to treat acute ischaemic stroke.

Salvage of Unilateral Complete Ear Amputation with Continuous Local Hyperbaric Oxygen, Platelet-Rich Plasma and Polydeoxyribonucleotide without Micro-Revascularization

In many cases of complete ear amputation, microvascular surgery is required for tissue perfusion and organ survival. However, microvascular reconstruction is not always feasible in the absence of suitable vessels. Here, we present the case of a 76-year-old man who underwent complete amputation of the left ear after a collapse at home because of cardiogenic syncope. He was treated with primary replantation and underwent a postoperative salvage course including continuous local hyperbaric oxygen therapy (HBOT), platelet-rich plasma (PRP) injections, and polydeoxyribonucleotide (PDRN) injections. The ear was almost completely salvaged, with a tiny eschar at the mid-scapha on both the anterior and posterior aspects. This case demonstrates the efficacy of local HBOT with PRP and PDRN injections.

A Double-Blind, Randomized Trial on the Efficacy and Safety of Hyperbaric Oxygenation Therapy in the Preservation of Erectile Function after Radical Prostatectomy

PURPOSE

We evaluated the efficacy and safety of hyperbaric oxygenation therapy to preserve erectile function as part of penile rehabilitation after robot assisted bilateral nerve sparing radical prostatectomy for prostate cancer.

MATERIALS AND METHODS

We performed a prospective, randomized, double-blind study from January 2009 to April 2013. Men 40 to 65 years old who underwent robot assisted bilateral nerve sparing radical prostatectomy were randomized 1:1 to the control or the treatment group. Participants were exposed to air as the control or to 100% oxygen as the treatment in hyperbaric conditions. The primary outcome was erectile function at 18 months as measured by IIEF (International Index of Erectile Function). Secondary outcomes were 12-month urinary symptoms, and 18-month sexual, urinary, bowel and hormonal related symptoms as measured by EPIC-26 (Expanded Prostate Index Composite-26). Adverse events and long-term cancer outcomes were monitored. Primary and secondary outcomes in the 2 groups were compared by the independent group t-test, the Wilcoxon rank sum test and the chi-square test of proportion.

RESULTS

A total of 109 potent men were randomized to hyperbaric oxygenation therapy or the control group. A total of 43 men in the air group and 40 in the hyperbaric oxygenation therapy group completed the 18-month followup. No statistically significant differences were observed between the 2 groups on any outcome measure.

CONCLUSIONS

This study revealed no difference in erectile recovery in men treated with hyperbaric oxygenation therapy vs placebo. Larger studies involving more diverse comorbidities and different hyperbaric oxygenation therapy regimens are needed to better evaluate the usefulness of hyperbaric oxygenation therapy for penile rehabilitation after radical prostatectomy.

How biomarkers reflect the prognosis and treatment of necrotising soft tissue infections and the effects of hyperbaric oxygen therapy: the protocol of the prospective cohort PROTREAT study conducted at a tertiary hospital in Copenhagen, Denmark

INTRODUCTION

Not enough is known regarding the prognosis and treatment of necrotising soft tissue infections (NSTIs). Mortality has been shown to be 25%-35%, with survivors coping with amputations and prolonged rehabilitation. This study will evaluate soluble urokinase-type plasminogen activator receptor (suPAR) as a possible prognostic marker of NSTI severity and mortality, as well as whether hyperbaric oxygen therapy (HBOT) can modulate markers of endothelial damage during NSTI. We hypothesise that in patients with NSTI, suPAR can provide prognostic risk assessment on hospital admission and that HBOT can reduce the endothelial damage that these patients are exposed to.

METHODS AND ANALYSIS

This is a prospective observational study. Biomarkers will be measured in 150 patients who have been diagnosed with NSTI. On admission, baseline blood samples will be obtained. Following surgery and HBOT, daily blood samples will be obtained in order to measure endothelial and prognostic biomarkers (soluble thrombomodulin, syndecan-1, sE-selectin, vascular endothelial (VE)-cadherin, protein C and suPAR levels). Clinical data will be acquired during the first 7 days of stay in the intensive care unit. The primary outcomes in studies I and II will be endothelial biomarker levels after HBOT, and in study III suPAR levels as a marker of disease prognosis and severity.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Scientific Ethical Committee of Copenhagen (H-16021845) and the Danish Data Protection Agency (RH-2016-199). Results will be presented at national and international conferences and published in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier NCT03147352. (Pre-results).

Treatment of ulcerative compared to non-ulcerative interstitial cystitis with hyperbaric oxygen: a pilot study

Background

The etiology of interstitial cystitis (IC) is often idiopathic but can be due to Hunner's ulcers. Hyperbaric oxygen (HBO) is used to treat ulcerative disease of the superficial skin. We hypothesized that HBO can treat ulcerative IC (UIC) but would be less efficacious for non-ulcerative IC (NIC).

Methods

Patients with NIC and UIC enrolled in this study. Following informed consent, demographic information was collected. A visual analog pain scale and validated questionnaires were collected; each patient underwent cystoscopy prior to treatment. Each subject met with a hyperbaric specialist and after clearance underwent 30 treatments over 6 weeks. Adverse events were monitored. Patients repeated questionnaires, visual analog pain scale and global response assessment (GRA) immediately, 2 weeks, 3, 6 and 12 months after treatment. Patients also underwent cystoscopy 6 months after treatment. Differences before and after treatment were compared.

Results

Nine patients were recruited to this study. One was unable to participate, leaving two subjects with NIC and six with UIC. All patients completed HBO without adverse events. Three patients completed HBO but pursued other therapies 7, 8.5 and 11 months after treatment. On GRA, 83% of patients with UIC were improved. This treatment effect persisted, as 66% of UIC patients remained better at 6 months. In contrast, only one patient in the NIC group improved. Questionnaire scores improved in both groups. Pain scores improved by 2 points in the UIC group but worsened by 1.5 points in the NIC group. Two patients with ulcers resolved at 6-month cystoscopy.

Conclusion

HBO appeared beneficial for both UIC and NIC. Data shows slightly better benefit in patients with UIC compared to NIC; both groups showed improvement. Given the small sample size, it is difficult to draw definitive conclusions from these data. Larger studies with randomization would be beneficial to show treatment effect.