Effect Of Hyperbaric Oxygen Treatment Research Articles

Perioperative hyperbaric oxygen treatment and postoperative complications following secondary breast reconstruction after radiotherapy: a case-control study of 45 patients.

Radiotherapy reduces the risk of locoregional recurrence of breast cancer. As a side-effect, tissue can become hypocellular, hypovascular, and hypoxic and late radiation tissue injury can develop months or years later. Radiotherapy increases the risk of complications following secondary breast reconstruction. Hyperbaric oxygen treatment (HBOT) improves oxygenation of irradiated tissue and induces neovascularisation. This study evaluated whether the incidence of complications following secondary breast reconstruction after radiotherapy is decreased with perioperative HBOT. In this retrospective case-control chart review study, patients who underwent perioperative HBOT (n = 15) were compared to lifestyle-matched (n = 15) and radiation damage-matched (n = 15) patients who underwent secondary breast reconstruction without HBOT. The HBOT group had significantly more severe radiation damage of the breast than the lifestyle- and radiation-damage-matched control groups (scoring grade 1-4, mean 3.55 versus 1.75 and 2.89 respectively, P = 0.001). Patients underwent on average 33 sessions of HBOT (18 sessions preoperatively and 15 sessions postoperatively). There was no significant difference in the incidence of postoperative complications between the HBOT group, lifestyle-matched group and radiation damage-matched group. Logistic regression analysis showed a lower risk of postoperative complications in patients who underwent HBOT. Although the HBOT group had more radiation damage than the control groups, the incidence of postoperative complications was not significantly different. This implied a beneficial effect of HBOT, which was supported by the logistic regression analysis. Definitive conclusions cannot be drawn due to the small sample size. Future research is justified, preferably a large randomised controlled trial.

Hyperbaric oxygen treatment on keloid tumor immune gene expression.

Background:Hyperbaric oxygen treatment (HBOT) has been demonstrated to influence the keloid recurrence rate after surgery and to relieve keloid symptoms and other pathological processes in keloids. To explore the mechanism of the effect of HBOT on keloids, tumor immune gene expression and immune cell infiltration were studied in this work.Methods:From February 2021 to April 2021, HBOT was carried out on keloid patients four times before surgery. Keloid tissue samples were collected and divided into an HBOT group (keloid with HBOT before surgery [HK] group, n = 6) and a non-HBOT group (K group, n = 6). Tumor gene expression was analyzed with an Oncomine Immune Response Research Assay kit. Data were mined with R package. The differentially expressed genes between the groups were compared. Hub genes between the groups were determined and verified with Quantitative Real-time PCR. Immune cell infiltration was analyzed based on CIBERSORT deconvolution algorithm analysis of gene expression and verified with immunohistochemistry (IHC).Results:Inflammatory cell infiltration was reduced in the HK group. There were 178 upregulated genes and 217 downregulated genes. Ten hub genes were identified, including Integrin Subunit Alpha M (ITGAM), interleukin (IL)-4, IL-6, IL-2, Protein Tyrosine Phosphatase Receptor Type C (PTPRC), CD86, transforming growth factor (TGF), CD80, CTLA4, and IL-10. CD80, ITGAM, IL-4, and PTPRC with significantly downregulated expression were identified. IL-10 and IL-2 were upregulated in the HK group but without a significant difference. Infiltration differences of CD8 lymphocyte T cells, CD4 lymphocyte T-activated memory cells, and dendritic resting cells were identified with gene CIBERSORT deconvolution algorithm analysis. Infiltration levels of CD4 lymphocyte T cell in the HK group were significantly higher than those of the K group in IHC verification.Conclusion:HBOT affected tumor gene expression and immune cell infiltration in keloids. CD4 lymphocyte T cell, especially activated memory CD4+T, might be the key regulatory immune cell, and its related gene expression needs further study.

Hyperbaric oxygen suppressed tumor progression through the improvement of tumor hypoxia and induction of tumor apoptosis in A549-cell-transferred lung cancer

Tumor cells have long been recognized as a relative contraindication to hyperbaric oxygen treatment (HBOT) since HBOT might enhance progressive cancer growth. However, in an oxygen deficit condition, tumor cells are more progressive and can be metastatic. HBOT increasing in oxygen partial pressure may benefit tumor suppression. In this study, we investigated the effects of HBOT on solid tumors, such as lung cancer. Non-small cell human lung carcinoma A549-cell-transferred severe combined immunodeficiency mice (SCID) mice were selected as an in vivo model to detect the potential mechanism of HBOT in lung tumors. HBOT not only improved tumor hypoxia but also suppressed tumor growth in murine xenograft tumor models. Platelet endothelial cell adhesion molecule (PECAM-1/CD31) was significantly increased after HBOT. Immunostaining of cleaved caspase-3 was demonstrated and apoptotic tumor cells with nuclear debris were aggregated starting on the 14th-day after HBOT. In vitro, HBOT suppressed the growth of A549 cells in a time-dependent manner and immediately downregulated the expression of p53 protein after HBOT in A549 cells. Furthermore, HBOT-reduced p53 protein could be rescued by a proteasome degradation inhibitor, but not an autophagy inhibitor in A549 cells. Our results demonstrated that HBOT improved tissue angiogenesis, tumor hypoxia and increased tumor apoptosis to lung cancer cells in murine xenograft tumor models, through modifying the tumor hypoxic microenvironment. HBOT will merit further cancer therapy as an adjuvant treatment for solid tumors, such as lung cancer.

Effect of antiplatelet and/or anticoagulation medication on the risk of tympanic barotrauma in hyperbaric oxygen treatment patients, and development of a predictive model.

Middle ear barotrauma (MEBt) is a common side effect of hyperbaric oxygen treatment (HBOT) and can result in pain, hearing loss, tinnitus and otorrhagia. The use of antiplatelet/anticoagulant drugs is thought to increase the risk and severity of MEBt during HBOT. Single centre, retrospective observational cohort study of all patients treated with HBOT over a 4-year period (between 01 January 2015 to 31 December 2018) looking at the incidence of MEBt and the concurrent use of antiplatelet and/or anticoagulant drugs. MEBt was assessed by direct otoscopy of the tympanic membrane post-HBOT and scored using the modified Teed classification. Multivariate modelling assessed the relationship between antiplatelet and/or anticoagulation drug use, age, sex, and MEBt during HBOT. There was no evidence that antiplatelet and/or anticoagulation drugs increase the risk of tympanic barotrauma in HBOT patients. The prevalence of MEBt was higher in female patients than in males (χ2 P = 0.004), and increased with age (χ2 P = 0.048). No MEBt was recorded in patients undergoing recompression therapy for decompression sickness or cerebral arterial gas embolism. In this retrospective single-centre study, antiplatelet and/or anticoagulation drugs did not affect the risk of MEBt, but both age and sex did, with greater prevalence of MEBt among older patients and females compared with younger patients and males. A predictive model, requiring further validation, may be helpful in assessing the likelihood of MEBt in patients undergoing HBOT.

Hyperbaric oxygen ameliorates cognitive impairment in patients with Alzheimer’s disease and amnestic mild cognitive impairment

AbstractBackgroundIt is reported that environmental factors such as hypoxia could contribute to the pathogenesis of Alzheimer’s disease (AD). Therapeutics like hyperbaric oxygen treatment which improves tissue oxygen supply and ameliorates hypoxic conditions in the brain may be a strategy for AD and amnestic mild cognitive impairment (aMCI) treatment. The present work aims to investigate the potential therapeutic effect of hyperbaric oxygen treatment in patients with AD and aMCI.MethodWe included 42 AD and 11 aMCI patients in this study. All participants were continuously treated with hyperbaric oxygen treatment once daily for 20 days and assessed by neuropsychiatric assessments before and at 1, 3, and 6 months after the hyperbaric oxygen treatment. We also applied fluorodeoxyglucose positron emission tomography (FDG‐PET) in some of the patients.ResultHyperbaric oxygen treatment could improve the global cognitive functions, especially visuospatial and executive functions, language and abstract thinking abilities at 1 month after treatment in AD patients and improved the memory of aMCI patients in 1, 3, and 6 months after treatment. The ADL scores were improved in 1, 3, and 6 months after treatment in AD patients. Hyperbaric oxygen treatment also ameliorated the reduced brain glucose metabolism in AD and aMCI patients.ConclusionBased on the previous studies and our recent findings, hyperbaric oxygen treatment may be a potential therapeutic and preventive strategy for AD and aMCI.

An observational trial to establish the effect of hyperbaric oxygen treatment on pelvic late radiation tissue injury due to radiotherapy.

Rates of pelvic cancer are growing globally with around half of these patients receiving radiotherapy. In a small proportion, radiotherapy results in significant late radiation tissue injury (LRTI) to surrounding tissue, most commonly affecting the bladder and bowel mucosa. We conducted a combined prospective and retrospective observational trial to establish the effectiveness of hyperbaric oxygen treatment (HBOT) in improving the symptoms and signs of LRTI in these patients. Fifty-two patients were included after receiving radiotherapy for cancers of the bowel, bladder, cervix, prostate or vulva. They received HBOT at 203-243 kPa (2.0-2.4 atmospheres absolute (atm abs)) for 90 minutes with the median number of treatments being 30 (IQR 1). Late effects normal tissues - subjective, objective, management, analytic (LENT-SOMA) scores were recorded before and after treatment. The mean LENT-SOMA scores before and after HBOT were 11.7 (SD 5.3) and 8.1 (5.1) respectively. This reduction in score of 3.7 (95% CI 2.6 to 4.8) was statistically significant (P < 0.001). For radiation cystitis the mean reduction was 3.7 (95% CI 2.4 to 5.0, P < 0.001) and for radiation proctitis was 3.8 (95% CI 1.4 to 6.1, P = 0.004). There were no significant adverse effects recorded. Hyperbaric oxygen treatment may be an effective and safe treatment for pelvic late tissue radiation injury.

The effect of hyperbaric oxygen treatment on late radiation tissue injury after breast cancer: A case-series of 67 patients.

Late radiation tissue injury (LRTI) after breast cancer may benefit from hyperbaric oxygen treatment (HBOT). This study aimed to report the LRTI symptom scores up to 12 months after HBOT and identify risk factors for poor scores. A case-series of 67 patients who underwent a mean of 44 sessions of HBOT was analysed. LRTI symptoms were scored at four time points using the LENT-SOMA scale (Late Effects in Normal Tissues - Subjective, Objective, Management, and Analytic), a visual analog scale for pain, and the range of shoulder motion. Between starting HBOT and 12 months after HBOT 57 patients (85%) reported at least one point improvement in their LENT-SOMA score. Median pain and fibrosis scores improved significantly between the start and end of HBOT (P < 0.001), and remained stable three and 12 months after HBOT. The median breast oedema score improved significantly 12 months after HBOT (P = 0.003). Median shoulder abduction increased significantly from 90 to 165 degrees (P = 0.001) and median shoulder anteflexion increased significantly from 115 to 150 degrees (P = 0.004). Various risk factors were identified for poor scores despite HBOT; the most common risk factor was a poor score at start of HBOT. In this case-series, patients who underwent HBOT for LRTI after breast cancer reported significant improvement in pain, fibrosis, oedema, and shoulder movement. The improvement persisted up to 12 months after HBOT. A poor score at the start of HBOT was predictive for a poor score 12 months after HBOT.

Assessment of insulin sensitivity during hyperbaric oxygen treatment.

Previous studies using a hyperinsulinaemic, euglycaemic glucose clamp have demonstrated an increase in peripheral insulin sensitivity in men with and without Type-2 diabetes mellitus on the third and thirtieth hyperbaric oxygen treatment (HBOT) session. In two studies using different techniques for assessment of insulin sensitivity, we investigated the onset and duration of this insulin-sensitising effect of HBOT. Men who were obese or overweight but without diabetes were recruited. One study performed a hyperinsulinaemic euglycaemic glucose clamp (80 mU.m-2.min-1) at baseline and during the first HBOT exposure (n = 9) at a pressure of 203 kPa. Data were analysed by paired t-test. The other study assessed insulin sensitivity by a frequently sampled intravenous glucose tolerance test (FSIGT) at three time points: baseline, during the third HBOT and 24-hours post-HBOT (n = 9). Results were analysed by repeated-measures ANOVA. There was a significant 23% increase in insulin sensitivity by clamp measured during the first HBOT exposure. The FSIGT showed no significant changes in insulin sensitivity. The hyperinsulinaemic, euglycaemic glucose clamp demonstrated a significant increase in peripheral insulin sensitivity during a single, 2-hour HBOT session in a group of men who were obese or overweight but without diabetes. As an alternate technique for assessing insulin sensitivity during HBOT, the FSIGT failed to show any changes during the third HBOT and 24-hours later, however modification of the study protocol should be considered.

Hyperbaric Oxygen as Salvage Therapy for Neonates Suffering From Critical Ischemia of the Glans Penis After Circumcision

Ischemic complications of glans penis following circumcision are rare, and if occurs can culminate in irreversible necrosis with severe long-term consequences. Here we present 2 challenging cases of neonates suffering from acute severe glans penis ischemia after circumcision that were treated by hyperbaric oxygen treatment (HBOT). In addition to case presentations, the literature related to complications of circumcision and the physiological effects of HBOT are being reviewed. Based on the review and the case presented, we conclude that HBOT can be used as salvage treatment for circumcision induced glans ischemia as early as possible before full necrosis develops.

Effects of hyperbaric oxygen treatment on calvarial bone regeneration in young and adult mice

ObjectiveThe present study aimed to investigate the effects of hyperbaric oxygen (HBO) treatment on calvarial bone regeneration in young and adult mice. MethodsCalvarial defects of 6.0 mm diameter were created in sixteen 3-week (young) and sixteen 32-week old (adult) mice. The mice were divided into two groups of eight animals each (HBO-treated and control). The 90-min HBO treatment at 2.5 absolute atmospheric pressure and 100 % oxygen was performed for five days a week for 12 weeks. After 2-weeks from the operation, micro-computerized tomography and video microscopy were used to evaluate the regenerated bone volume and microcirculation every two weeks. The protein concentrations of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in exudates of the calvarial tissue field were measured at 1, 2, 3, and 4 weeks after surgery. After 12 weeks, histochemical examination of regenerated calvarial bone was conducted. ResultsRegenerated bone was formed earlier in young mice than in adult mice treated with HBO. HBO stimulates angiogenesis in the periosteum around regenerated bone area in both young and adult mice at 2 weeks. VEGF concentrations in the calvarial tissue field were lower in the HBO group than in the control 1 week after operation, although bFGF were higher till the 2nd week in the HBO group than in the control. ConclusionsHBO accelerates bone regeneration earlier in young mice than in adult mice. In the HBO-treated group, bFGF expression was promoted at an early stage, although the expression of VEGF was inhibited.

Evaluation of the Abbot FreeStyle Optium Neo H blood glucose meter in the hyperbaric oxygen environment.

This study investigated the effects of hyperbaric oxygen treatment (HBOT) on the accuracy and reliability of point-of-care fingertip capillary blood glucose values in euglycaemic non-diabetic participants compared against venous serum blood glucose samples processed in an accredited pathology laboratory. Ten non-diabetic hyperbaric staff members (age 35-55 years) underwent a standard 243 kPa HBOT exposure for 95 minutes. Blood glucose levels were measured via (i) finger-prick capillary test using the FreeStyle Optium™ Neo H glucometer and (ii) venous serum test using the Cobas 6000 laboratory analyser. Samples were taken at (T1) 0 minutes (pre-HBOT), (T2) 25 minutes, and (T3) 55 minutes into HBOT. All participants were euglycaemic at T1 (BGL 3.8-5.4 mmol·L⁻¹). The highest venous serum value was 5.90 mmol·L⁻¹ at T3 and the highest capillary value was 6.30 mmol·L⁻¹ at T1. Post hoc tests showed a statistically significant difference between the mean capillary result pre-dive (T1) and readings at T2 (P = 0.001) and T3 (P < 0.001) while differences between T2 and T3 capillary results were not statistically significant, illustrating the effect of HBOT on capillary beds. Differences in venous values across the time points were not significant. Venous serum glucose samples processed in an accredited laboratory may be more consistently accurate, but capillary point-of-care testing avoids delays in sample processing and provides glucose data that are of clinical relevance. The FreeStyle Optium™ Neo H glucometer is safe to use and provides a reliable measurement of blood glucose in the HBOT environment.

Experimental use of flow cytometry to detect bacteria viability after hyperbaric oxygen exposure: Work in progress report.

Hyperbaric oxygen treatment (HBOT), based on inhaling pure oxygen under elevated ambient pressure, is used as adjuvant intervention to promote healing in infected wounds. Despite extensive clinical evidence of beneficial effects of HBOT in soft tissue infections the mechanism of action remains to be elucidated. The aim of this study was to evaluate the use of flow cytometry as a novel method to assess the viability of pathogenic bacteria after hyperbaric oxygen (HBO) exposure. Bacterial strains associated with soft tissues infections: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus were exposed to oxygen at 2.8 atmospheres absolute (atm abs) (283.6 kPa) pressure for 45, 90, or 120 min, then stained with propidium iodide and thiazole orange and analysed by flow cytometry. Escherichia coli and Staphylococcus aureus showed no change in viability, nor morphology, the viability of Pseudomonas aeruginosa reduced in a dose-dependent manner and Klebsiella pneumoniae also showed dye uptake after HBO. These initial results, indicate diverse sensitivity of bacteria to HBO, and suggest that flow cytometry can be used to monitor viability and morphological changes triggered by HBO exposure in bacteria.

Engagement of people with multiple sclerosis to enhance research into the physiological effect of hyperbaric oxygen therapy

BackgroundThousands of people with multiple sclerosis (MS) have used self-administered oxygen therapy in the UK. Clinical trials have been performed, with scant evidence that people with MS have been consulted to explore how they benefit from or how to optimize this treatment. The conventional MS disease disability scores used in trials seldom reflect the effects individuals report when using oxygen therapy to treat their symptoms. MethodsThree people with MS and the manager of an MS Centre formed a public involvement group and collaborated with clinicians and scientists to inform a lab-based study to investigate the physiological effects of oxygen therapy on microvascular brain endothelial cells. ResultsPeople with MS often use oxygen therapy at a later stage when their symptoms worsen and only after using other treatments. The frequency of oxygen therapy sessions and hyperbaric pressure is individualized and varies for people with MS. Despite direct comparisons of efficacy proving difficult, most individuals are exposed to 100% O2 at 1.5 atmosphere absolute (ATA; 1140 mmHg absolute) for 60 min. In a laboratory-based study human brain endothelial cells were exposed in vitro to 152 mmHg O2 for 60 min with and without pressure, as this equates to 20% O2 achievable via hyperbarics, which was then replicated at atmospheric pressure. A significant reduction in endothelial cells ICAM-1 (CD54) implicated in inflammatory cell margination across the blood brain barrier was observed under oxygen treatment. ConclusionsBy collaborating with people living with MS, we were able to design laboratory-based experimental protocols that replicate their treatment regimens to advance our understanding of the physiological effects of hyperbaric oxygen treatment on brain cells and their role in neuroinflammation.

Hyperbaric oxygen ameliorates cognitive impairment in patients with Alzheimer's disease and amnestic mild cognitive impairment.

IntroductionIt has been reported that environmental factors such as hypoxia could contribute to the pathogenesis of Alzheimer's disease (AD). Therapeutics like hyperbaric oxygen treatment, which improves tissue oxygen supply and ameliorates hypoxic conditions in the brain, may be an alternative therapy for AD and amnestic mild cognitive impairment (aMCI). The present work aims to investigate the potential therapeutic effect of hyperbaric oxygen treatment for AD and aMCI.MethodsWe recruited 42 AD, 11 aMCI, and 30 control AD patients in this study. AD and aMCI patients were treated with 40 minutes of hyperbaric oxygen once a day for 20 days and assessed by neuropsychiatric assessments including Mini‐Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Activities of Daily Living (ADL) scale before and at 1‐, 3‐, and 6‐month follow‐up after treatment. Control AD patients who were not given hyperbaric oxygen treatment had similar clinical profile as hyperbaric oxygen treated AD. We examined 10 of the AD/aMCI patients with fluorodeoxyglucose positron emission tomography.ResultsIn self‐comparison study, one course of hyperbaric oxygen treatment significantly improved the cognitive function assessed by MMSE and MoCA in AD patients after 1‐month follow‐up; such treatment also significantly improved MMSE score at 3‐month follow‐up and MoCA score at 1‐ and 3‐month follow‐up in aMCI patients. The ADL scale was significantly improved in AD patients after 1‐ and 3‐month follow‐up. Compared to the control AD patients, the MMSE and MoCA in hyperbaric oxygen treated AD patients were significantly improved after 1‐month follow‐up. Hyperbaric oxygen treatment also ameliorated the reduced brain glucose metabolism in some of the AD and aMCI patients.ConclusionBased on previous studies and our recent findings, we propose that hyperbaric oxygen treatment may be a promising alternative therapy for AD and aMCI.

Protective effect of hyperbaric oxygen treatment on rat intestinal mucosa after mesenteric ischaemia and reperfusion.

Mesenteric ischaemia results from a lack of adequate blood flow to and oxygenation of the mesentery and intestines. The aim of the present study was to evaluate the effect of hyperbaric oxygen treatment (HBOT) on the healing process in intestinal mucosa of rats undergoing mesenteric ischaemia and reperfusion. Thirty-two Wistar-Albino rats were divided into four groups of eight: 1) ischaemia/reperfusion (I/R); 2) sham operation; 3) I/R+HBOT started 6 hours after reperfusion; 4) I/R+HBOT started 12 hours after reperfusion. In the I/R groups, a vascular clamp was placed across the superior mesenteric artery to occlude arterial circulation for 60 minutes, followed by reperfusion. A dose of HBOT consisted of 100% oxygen breathing for 90 minutes at 2.5 atmospheres absolute pressure. Thirteen doses of HBOT were administered after ischaemia. The rats were sacrificed on the eighth day, and their intestinal tissues were harvested for histopathologic analysis. The tissue levels of catalase, malondialdehyde, and glutathione were determined. The histopathological scores (HSCORE) were consistent with macroscopic examinations. The scores were significantly higher (worse) in Group 1 compared to Group 2, Group 3, and Group 4 (for all comparisons, P < 0.05). Group 4's HSCORE was significantly higher than those of Group 2 and Group 3 (for both comparisons P < 0.05). Group 3's HSCOREs were only marginally higher than Group 2. Group 3 exhibited higher glutathione levels than Group 1 (P < 0.05). There were no significant differences across the groups with respect to malondialdehyde and catalase levels. A beneficial effect of HBOT was observed on oxidative stress and inflammation in acute mesenteric ischaemia-reperfusion.

Observation on clinical efficacy of hyperbaric oxygen combined with neurosurgery in treating craniocerebral trauma

&lt;p&gt;The probability of craniocerebral trauma is higher and higher, along with the increasing number of traffic and construction accidents in our lives which cause physical injuries. Main symptoms of such injuries are headache, dizziness, and impairment in language function and limb activity to varying degrees. For patients with severe craniocerebral trauma whose nerve tissue are greatly damaged, there are difficulties in effectively recovering, which may lead to some obstacles in consciousness, intelligence and even action. The current treatment research has found that inappropriate treatment method will increase patients' mortality or disability rate. At present, the effect of hyperbaric oxygen treatment for craniocerebral trauma has been recognized in many clinical trails, seen from increased cure rate.&lt;/p&gt;

The Effect of Hyperbaric Oxygen Treatment on Myoblasts and Muscles After Contusion Injury.

The recommended treatment varies depending on the severity of muscle injuries. The aim of this study was to evaluate the in vitro myoblast proliferation and the in vivo histologic and physiologic effects of hyperbaric oxygen treatment on muscle healing after contusion. Cells from the C2C12 myoblast cell line were exposed to 100% O2 for 25 min then to air for 5 min at 2.5 atmospheres absolute in a hyperbaric chamber for a total treatment duration of 90 min per 48 h at intervals of 2, 4, 6 and 8 days. Cell growth measurements and western blot analysis of myogenin and actin were performed. Then, 18 mice aged 8-10 weeks were used in the muscle contusion model. The histologic and physiologic effects and muscle regeneration after hyperbaric oxygen treatment were evaluated. The myoblast growth rate was significantly higher (p < 0.05) after hyperbaric oxygen treatment. Densitometric evaluation demonstrated a 39% (p < 0.05) and 25% (p < 0.05) increase in myogenin and actin protein levels, respectively, in the cells treated with 1 dose of hyperbaric oxygen. Similarly, the myogenin and actin protein levels increased for samples receiving multiple hyperbaric oxygen treatments when compared with the control. Physiologic evaluation of fast twitch and tetanus strength revealed a significant difference between the control group and the 14-day hyperbaric oxygen group. In conclusion, hyperbaric oxygen treatment increases the myoblast growth rate and myogenin and actin production. Better histologic and physiologic performance were found after hyperbaric oxygen treatment in animal contusion model. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:329-335, 2020.

Hyperbaric Oxygen Treatment Ameliorates Hearing Loss and Auditory Cortex Injury in Noise Exposed Mice by Repressing Local Ceramide Accumulation

Noise-induced hearing loss (NIHL) relates closely to auditory cortex (AC) injury, so countermeasures aiming at the AC recovery would be of benefit. In this work, the effect of hyperbaric oxygen treatment on NIHL was elucidated, which was imposed on mice before (HBOP), during (HBOD) or after (HBOA) noise exposure. Morphology of neurons was assayed by hematoxylin-eosin or Nissl staining. Ceramide (Cer) level was measured through immunohistochemistry analysis. Apoptotic neurons were counted using transferase-mediated dUTP nick end labeling (TUNEL) staining. We demonstrated that the intense, broad band noise raised the threshold of auditory brainstem response, evoked neuronal degeneration or apoptosis and triggered the Cer accumulation in AC, all of which were restored significantly by HBOP, but not HBOD or HBOA. Cer over-generation reversed the advantages of HBOP significantly, while its curtailment recapitulated the effect. Next, noise exposure raised the superoxide or malondialdehyde (MDA) production which was blocked by HBOP or Cer repression. Oxidative control not only attenuated the hearing loss or neurodegeneration but, in turn, reduced the Cer formation significantly. In summary, mutual regulation between Cer and oxidative stress underlies the HBOP’s curative effect on hearing loss and neuronal damage in noise-exposed mice.

Malignant (necrotizing) externa otitis: the experience of a single hyperbaric centre

Malignant otitis externa (MOE) is a potentially life-threatening infection of the soft tissues of the external ear, quickly spreading to involve the periosteum and bone of the skull base. Treatment includes antibiotics and eventually surgery. Hyperbaric oxygen treatment (HBOT) has been proposed as an adjunctive therapy. However, in the tenth consensus conference, this disease was considered as a non-indication for HBOT. The aim of this study was to evaluate the effectiveness of HBOT in MOE treatment. Retrospective and observational study was conducted of patients with MOE treated in our centre. Staging of the disease was made according to the clinicopathological classification system. From March 1998 to November 2016, 16 patients were referred. 6% patients were on stage 1 of the disease at the time they were referred, 20% in stage 2, 7% in stage 3a, 13% in stage 3b and 53% in stage 4. Seven (43.75%) patients had VII nerve palsy and three (18.75%) patients had multiple nerve palsy. Average length of symptoms of disease was 5months (maximum 11months). Average number of sessions was 33 and the length of hospitalization prior to HBOT (median 90 days) was significantly longer than the time between beginning HBOT and cure (p = 0.028, Wilcoxon signed rank test). There were no fatalities due to MOE and all patients were considered free of disease after HBOT. HBOT was well tolerated and revealed to be a helpful adjuvant treatment in MOE. According to our data, HBOT should be considered for patients who failed conventional treatments and in severe cases.

Dose-Dependent Effect of Hyperbaric Oxygen Treatment on Burn-Induced Neuropathic Pain in Rats.

Hyperbaric oxygen treatment (HBOT) has been used to reduce neuropathic pain. Melatonin and opioid receptors are involved in neuropathic pain, but it is not known if HBOT works through these pathways to achieve its antinociceptive effect. We divided anesthetized rats into two treatment and three sham groups. The two treatment groups received third-degree burns on their right hind paws, one treated in a hyperbaric chamber for a week and the other for two weeks. We evaluated the mechanical paw-withdrawal threshold (MWT) and expression of melatonin receptor 1 (MT1), melatonin receptor 2 (MT2), μ (MOR) and κ (KOR) opioid receptor, brain-derived neurotrophic factor (BDNF), Substance P, and calcitonin gene-related peptide (CGRP) in cuneate nucleus, dorsal horn, and hind paw skin by immunohistochemical, immunofluorescence assays and real-time quantitative polymerase chain reaction (RT-PCR). The group receiving one-week HBOT had increased expressions of MT1, MT2, MOR and KOR and decreased expressions of BDNF, Substance P, and CGRP. Their mechanically measured pain levels returned to normal within a week and lasted three weeks. This anti-allodynia effect lasted twice as long in those treated for two weeks. Our findings suggest that increasing the duration of HBOT can reduce burn-induced mechanical allodynia for an extended period of time in rats. The upregulation of melatonin and opioid receptors observed after one week of HBOT suggests they may be partly involved in attenuation of the mechanical allodynia. Downregulation of BDNF, substance P and CGRP may have also contributed to the overall beneficial effect of HBOT.