Clinical features and predictors of delayed neurological syndrome in carbon monoxide poisoning: the AMICO study. / Caracterización clínica y factores predictivos de desarrollo de síndrome neurológico tardío en la intoxicación por monóxido de carbono: estudio AMICO.

OBJECTIVES: To identify predictors for developing delayed neurological syndrome (DNS) after an initial episode of carbon monoxide (CO) poisoning in the interest of detecting patients most likely to develop DNS so that they can be followed. MATERIAL AND METHODS: Retrospective review of cases of CO poisoning treated in the past 10 years in the emergency departments of 4 hospitals in the AMICO study (Spanish acronym for the multicenter analysis of CO poisoning). We analyzed demographic characteristics of the patients and the clinical characteristics of the initial episode. The records of the cohort of patients with available follow-up information were reviewed to find cases of DNS. Data were analyzed by multivariant analysis to determine the relationship to characteristics of the initial exposure to CO. RESULTS: A total of 240 cases were identified. The median (interquartile range) age of the patients was 36.2 years (17.6-49.6 years); 108 patients (45.0%) were men, and the poisoning was accidental in 223 cases (92.9%). The median carboxyhemoglobin concentration on presentation was 12.7% (6.2%-18.7%). Follow-up details were available for 44 patients (18.3%). Eleven of those patients (25%) developed DNS. A low initial Glasgow Coma Scale score predicted the development of DNS with an odds ratio (OR) of 0.61 (95% CI, 0.41-0.92) and an area under the receiver operating characteristic curve of 0.876 (95% CI, 0.761-0.990) (P .001). CONCLUSION: The initial Glasgow Coma Scale score seems to be a clinical predictor of DNS after CO poisoning. We consider it important to establish follow-up protocols for patients with CO poisoning treated in hospital EDs.

OBJETIVO: Identificar factores pronósticos de desarrollo de síndrome neurológico tardío (SNT) después de un episodio inicial de intoxicación por monóxido de carbono (ICO), con el fin detectar precozmente a la población más susceptible y facilitar su acceso a un seguimiento específico. METODO: Revisión retrospectiva de todos los casos de ICO que acudieron a los servicios de urgencias (SU) de 4 hospitales durante los últimos 10 años. Se analizaron datos demográficos y características clínicas en el momento del episodio. En la cohorte de pacientes con datos de seguimiento disponibles, se evaluó la aparición de SNT y su relación con diferentes variables en la exposición inicial al CO a través de técnicas de análisis multivariante. RESULTADOS: Se identificaron 240 pacientes. La mediana de edad fue de 36,2 años (17,6-49,6). De ellos 108 (45,0%) eran hombres y 223 casos (92,9%) fueron accidentales. El nivel medio de COHb fue del 12,7% (6,2-18,7). En 44 (18,3%) episodios se disponía de datos de un seguimiento específico. En esta cohorte, 11 (25%) pacientes desarrollaron SNT. Una puntuación inicial más baja en la Escala Coma de Glasgow (GCS) (OR: 0,61, IC 95%: 0,41-0,92) fue predictor independiente del desarrollo del SNT, con un ABC en la curva COR de 0,876 (IC 95%: 0,761-0,990, p 0,001). CONCLUSIONES: Una puntuación inicial baja en la GCS parece ser un predictor clínico de desarrollo de SNT en la ICO. Dada la incidencia de SNT, consideramos fundamental establecer protocolos de seguimiento específico de estos pacientes tras su asistencia inicial en los SU.

Application of hyperbaric oxygen therapy in diabetic foot ulcers: A meta-analysis.

Hyperbaric oxygen therapy (HBOT) has been used in patients with diabetic foot ulcers (DFU) for many years, but its clinical efficacy is still controversial. Therefore, this study explored the efficacy of HBOT applied to DFU by means of meta-analysis. PubMed, Cochrane Library, Embase, CNKI and Wanfang databases were searched, from database inception to October 2023, and published randomised controlled trials (RCTs) of HBOT in DFU were collected. Two investigators independently screened the collected literature, extracted relevant data and assessed the quality of the literature. Review Manager 5.4 software was applied for data analysis. Twenty-nine RCTs with 1764 patients were included. According to the combined results, when compared with conventional treatment, HBOT significantly increased the complete healing rate of DFUs (46.76% vs. 24.46%, odds ratio [OR]: 2.83, 95% CI: 2.29-3.51, p < 0.00001) and decreased the amputation rate (26.03% vs. 45.00%, OR: 0.41, 95% CI: 0.18-0.95, p = 0.04), but the incidence of adverse events was significantly higher in patients (17.37% vs. 8.27%, OR: 2.49, 95% CI: 1.35-4.57, p = 0.003), whereas there was no significant difference in the mortality (6.96% vs. 12.71%, OR: 0.52, 95% CI: 0.21-1.28, p = 0.16). Our results suggest that HBOT is effective in increasing the complete healing rate and decreasing the amputation rate in patients with DFUs, but increases the incidence of adverse events, while it has no significant effect on mortality.

Use of hyperbaric oxygen therapy in severe earthquake injuries.

BACKGROUND: Earthquakes are natural disasters that can often cause severe injuries and traumatic situations. These injuries can include crush injuries, fractures, tissue damage, and blood circulation problems. Hyperbaric oxygen therapy (HBOT) has recently become a frequently used treatment modality for individuals suffering from severe injuries. HBOT is a form of treatment that involves administering pure oxygen to the patient under high pressure. This treatment aims to promote tissue healing by increasing cellular oxygenation. It is thought to have a positive effect on factors such as accelerating tissue healing, reducing inflammation, and controlling infection in severe post-earthquake injuries, particularly crush injuries. This study aimed to retrospectively evaluate the clinical effects, contributions to the healing process, and potential advantages of HBOT in 35 patients with severe injuries after the Kahramanmaras earthquake that occurred on 06.02.2023 and to contribute to the development of emergency intervention strategies. METHODS: This study was carried out after ethics committee approval. In the study, the data of patients with a MESS Score between 7-14 who were admitted as earthquake victims and treated in the HBOT Unit due to severe earthquake-related injuries were obtained from records and retrospectively analyzed. Demographic information, general distribution of patient data, mean values, number of HBOT sessions, and functional outcomes were recorded. RESULTS: The gender distribution of the 35 patients who received HBOT was 31.4% male and 68.6% female. 45.7% of patients were aged 18 years or younger, and 54.3% were aged 19 years or older. The most common injuries in the treated patients were observed in the lower extremities. After HBOT, sensory recovery (54.3%) and functional recovery (51.4%) were achieved in the majority of patients. The minor amputation rate was 20.0% and the major amputation rate was 11.4% after HBOT. CONCLUSION: This study evaluated the possible effects of HBOT on patients with severe earthquake injuries in Türkiye, and the results showed that HBOT may have a beneficial effect on critical factors such as sensory recovery, functional recovery, and amputation rates in this particular group of patients, and that this benefit may be more pronounced in those who started treatment early.

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

BACKGROUND: Critically ill patients undergoing liberation often encounter various physiological and clinical complexities and challenges. However, whether the combination of hyperbaric oxygen and in-cabin ventilator therapy could offer a comprehensive approach that may simultaneously address respiratory and potentially improve outcomes in this challenging patient population remain unclear. METHODS: This retrospective study involved 148 patients experiencing difficulty in liberation after tracheotomy. Inclusion criteria comprised ongoing mechanical ventilation need, lung inflammation on computed tomography (CT) scans, and Glasgow Coma Scale (GCS) scores of ≤ 9. Exclusion criteria excluded patients with active bleeding, untreated pneumothorax, cerebrospinal fluid leakage, and a heart rate below 50 beats per minute. Following exclusions, 111 cases were treated with hyperbaric oxygen combined cabin ventilator, of which 72 cases were successfully liberated (SL group) and 28 cases (NSL group) were not successfully liberated. The hyperbaric oxygen chamber group received pressurization to 0.20 MPa (2.0 ATA) for 20 min, followed by 60 min of ventilator oxygen inhalation. Successful liberation was determined by a strict process, including subjective and objective criteria, with a prolonged spontaneous breathing trial. GCS assessments were conducted to evaluate consciousness levels, with scores categorized as normal, mildly impaired, moderately impaired, or severely impaired. RESULTS: Patients who underwent treatment exhibited improved GCS, blood gas indicators, and cardiac function indexes. The improvement of GCS, partial pressure of oxygen (PaO2), oxygen saturation of blood (SaO2), oxygenation index (OI) in the SL group was significantly higher than that of the NSL group. However, there was no significant difference in the improvement of left ventricular ejection fraction (LVEF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and stroke volume (SV) between the SL group and the NSL group after treatment. CONCLUSIONS: Hyperbaric oxygen combined with in-cabin ventilator therapy effectively enhances respiratory function, cardiopulmonary function, and various indicators of critically ill patients with liberation difficulty after tracheostomy.

Hyperbaric oxygen for the treatment of carbon monoxide-induced delayed neurological sequelae: a case report and review of the literature.

Introduction: Hyperbaric oxygen treatment (HBOT) remains a recognised treatment for acute carbon monoxide (CO) poisoning, but the utility of HBOT in treating CO-induced delayed neurological sequelae (DNS) is not yet established. Case description: A 26-year old woman presented with reduced consciousness secondary to CO exposure from burning charcoal. She underwent a single session of HBOT with US Navy Treatment Table 5 within six hours of presentation, with full neurological recovery. Eight weeks later, she represented with progressive, debilitating neurological symptoms mimicking Parkinsonism. Magnetic resonance imaging of her brain demonstrated changes consistent with hypoxic ischaemic encephalopathy. The patient underwent 20 sessions of HBOT at 203 kPa (2 atmospheres absolute) for 115 minutes, and received intravenous methylprednisolone 1 g per day for three days. The patient's neurological symptoms completely resolved, and she returned to full-time professional work with no further recurrence. Discussion: Delayed neurological sequelae is a well-described complication of CO poisoning. In this case, the patient's debilitating neurocognitive symptoms resolved following HBOT. Existing literature on treatment of CO-induced DNS with HBOT consists mainly of small-scale studies and case reports, many of which similarly suggest that HBOT is effective in treating this complication. However, a large, randomised trial is required to adequately determine the effectiveness of HBOT in the treatment of CO-induced DNS, and an optimal treatment protocol.

Safety of hyperbaric medicine in clinical scenarios.

Hyperbaric therapy is generally considered a safe therapy for the treatment of wounds, mucormycosis, and orthopedic injuries. It is fraught with complications such as barotrauma, pulmonary toxicity, fire hazards, and claustrophobia. This article discusses the safety protocols and preventive aspects on usefulness of this new emerging therapy.

Résumé La thérapie hyperbare est généralement considérée comme une thérapie sûre pour le traitement des plaies, de la mucormycose et des blessures orthopédiques. Elle entraîne de nombreuses complications telles que le barotraumatisme, la toxicité pulmonaire, les risques d'incendie et la claustrophobie. Cet article traite des protocoles de sécurité et des aspects préventifs sur l'utilité de cette nouvelle thérapie émergente. Mots-clés: Claustrophobie, médecine hyperbare, sécurité.

A novel method for tracking nitrogen kinetics in vivo under hyperbaric conditions using radioactive nitrogen-13 gas and positron emission tomography.

Decompression sickness (DCS) is caused by gaseous nitrogen dissolved in tissues forming bubbles during decompression. To date, no method exists to identify nitrogen within tissues, but with advances in positron-emission tomography (PET) technology, it may be possible to track gaseous radionuclides into tissues. We aimed to develop a method to track nitrogen movement in vivo and under hyperbaric pressure that could then be used to further our understanding of DCS using nitrogen-13 (13N2). A single anesthetized female Sprague-Dawley rat was exposed to 625 kPa, composed of air, isoflurane, and 13N2 for 10 min. The PET scanner recorded 13N2 during the hyperbaric exposure with energy windows of 250-750 keV. The PET showed an increase in 13N2 concentration in the lung, heart, and abdominal regions, which all reached a plateau after ∼4 min. This showed that it is possible to gain noninvasive in vivo measurements of nitrogen kinetics through the body while at hyperbaric pressures. Tissue samples showed radioactivity above background levels in the blood, brain, liver, femur, and thigh muscle when assessed using a γ counter. The method can be used to evaluate an array of challenges to our understanding of decompression physiology by quantifying nitrogen load through γ counts of 13N2, and signal intensity of the PET. Further development of the method will improve the specificity of the measured outcomes, and enable it to be used with larger mammals, including humans.NEW & NOTEWORTHY This article describes a method for the in vivo quantification and tracking of nitrogen through the mammalian body whilst exposed to hyperbaric pressure. The method has the potential to further our understanding of decompression sickness, and quantitatively evaluate the effectiveness of both the treatment and prevention of decompression sickness.

Non-pharmacological interventions for traumatic brain injury.

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

Long term outcomes of hyperbaric oxygen therapy in post covid condition: longitudinal follow-up of a randomized controlled trial.

In our previous randomized controlled trial, we documented significant improvements in cognitive, psychiatric, fatigue, sleep, and pain symptoms among long Coronavirus disease 2019 (COVID) patients who underwent hyperbaric oxygen therapy (HBOT). The primary objective of the present study was to evaluate the enduring 1 year long term effects of HBOT on long COVID syndrome. This longitudinal long-term follow-up included 31 patients with reported post COVID-19 cognitive symptoms, who underwent 40 daily sessions of HBOT. Participants were recruited more than one year (486 ± 73) after completion of the last HBOT session. Quality of life, assessed using the short form-36 (SF-36) questionnaire revealed, that the long-term results exhibited a similar magnitude of improvement as the short-term outcomes following HBOT across most domains. Regarding sleep quality, improvements were observed in global score and across five sleep domains with effect sizes of moderate magnitude during the short-term evaluation, and these improvements persisted in the long-term assessment (effect size (ES1) = 0.47-0.79). In the realm of neuropsychiatric symptoms, as evaluated by the brief symptom inventory-18 (BSI-18), the short-term assessment following HBOT demonstrated a large effect size, and this effect persisted at the long-term evaluation. Both pain severity (ES1 = 0.69) and pain interference (ES1 = 0.83), had significant improvements during the short-term assessment post HBOT, which persisted at long term. The results indicate HBOT can improve the quality of life, quality of sleep, psychiatric and pain symptoms of patients suffering from long COVID. The clinical improvements gained by HBOT are persistent even 1 year after the last HBOT session.

Hyperbaric treatment deviations for U.S. Navy divers: Spinal DCS.

Introduction: The United States Navy (USN) developed and refined standardized oxygen treatment tables for diving injuries, but USN tables may not address all situations of spinal decompression sickness (DCS). We describe a detailed recompression treatment regimen that deviated from standard USN protocol for an active-duty USN diver with a severe, delayed presentation of spinal cord DCS. Case Report: A USN diver surfaced from his second of three dives on a standard Navy 'no-Decompression' Air SCUBA dive (Max depth 101 fsw utilizing a Navy Dive Computer) and developed mid-thoracic back pain, intense nausea, paresthesias of bilateral feet, and penile erection. Either not recognizing the con- stellation of symptoms as DCS and after resolution of the aforementioned symptoms, he completed the third planned dive (essentially an in-water recompression). Several hours later, he developed paresthesias and numbness of bilateral feet and legs and bowel incontinence. He presented for hyperbaric treatment twenty hours after surfacing from the final dive and was diagnosed with severe spinal DCS. Based on the severity of clinical presentation and delay to treatment, the initial and follow-on treatments were modified from standard USN protocol. MRI of the spine four days after initial presentation demonstrated a 2.2 cm lesion at the T4 vertebral level extending caudally. Follow-up examinations over two years demonstrated almost complete return of motor and sensory function; however, the patient continued to suffer fecal incontinence and demonstrated an abnormal post-void residual urinary volume. An atypical presenting symptom, a discussion of MRI findings, and clinical correlations to the syndrome of spinal DCS are discussed throughout treatment and long-term recovery of the patient.

Treatment of pediatric cerebral radiation necrosis using hyperbaric oxygenation.

Introduction: Cerebral radiation necrosis is rarely encountered in pediatric patients. This case report describes a child with cerebral radiation necrosis who was successfully treated using corticosteroids, bevacizumab, and hyperbaric oxygenation. Case report: A 3-year-old boy developed progressive extremity weakness six months after the completion of radiation therapy for the treatment of a neuroepithelial malignancy. Treatment with corticosteroids and bevacizumab was initiated, but his symptoms did not improve, and he was then referred for hyperbaric oxygen therapy. After completing 60 hyperbaric treatments, he experienced significant improvements in mobility, which remained stable over the next year. Discussion: Cerebral radiation necrosis typically presents in children with symptoms of ataxia or headache. Corticosteroids and bevacizumab are common treatments, but hyperbaric oxygen therapy has also been studied as a therapeutic modality for this condition. When considering the use of hyperbaric oxygenation in pediatric patients, careful attention to treatment planning and patient safety can reduce the risks of adverse events such as middle ear barotrauma and confinement anxiety. Conclusion: In addition to other available pharmacologic therapies, hyperbaric oxygenation should be considered for the treatment of pediatric patients with cerebral radiation necrosis.

Hyperbaric oxygen therapy as a treatment for erectile dysfunction: a meta-analysis.

INTRODUCTION: Hyperbaric oxygen therapy (HBOT) is a medical treatment in which the patient is exposed to 100% oxygen at a higher than atmospheric pressure. Over the past few decades, HBOT has been used to treat a variety of medical conditions. In recent times, there has been a rising curiosity regarding the potential therapeutic benefits of HBOT in the treatment of erectile dysfunction (ED). AIMS: The study sought to review and meta-analyze available data regarding the use of HBOT for ED, including its potential mechanisms of action and effectiveness. METHODS: We included only articles that evaluated the impact of HBOT on ED symptoms using the International Index of Erectile Function score. Prospective nonrandomized studies or randomized controlled clinical trials were included. Data extraction was performed in duplicate. Data analysis was conducted using Review Manager 5.41, and the presence of heterogeneity between studies was evaluated. The results were presented as the mean difference (MD) with 95% confidence interval (CI). RESULTS: A total of 5 studies that reported outcomes using the International Index of Erectile Function scores were included in this analysis. In patients with post-robotic-assisted laparoscopic prostatectomy-induced ED, the analysis showed a significant MD of -4.13 (95% CI, -6.08 to -2.18; P < .0001) in favor of the control group. Conversely, patients who received HBOT for reasons other than ED exhibited an MD of 4.58 (95% CI, 2.63 to 6.52; P < .00001). In the group that received HBOT for pure vasculogenic ED, the MD was 10.50 (95% CI, 9.92 to 11.08) in favor of HBOT. A meta-analysis of these data revealed a nonsignificant difference in erectile function scores, with an MD of 3.86 (95% CI, -2.13 to 9.86; P = .21). CONCLUSION: The use of HBOT in the treatment of ED appears to be a promising approach. While further research is needed to establish the efficacy and long-term effects of this treatment, preliminary studies have shown encouraging results in terms of improving erectile function in men with vasculogenic ED.

Case Report: Leptospirosis Complicated by Persistent, Bilateral Sensorineural Hearing Loss.

The clinical manifestations of leptospirosis range from mild to life-threatening and can impact on multiple organ systems. A wide array of neurological manifestations of leptospirosis have been reported, although the pathophysiology of neuroleptospirosis remains incompletely understood. We present a case of leptospirosis complicated by bilateral sensorineural deafness, with nodular meningitis demonstrated in the internal auditory meatus on magnetic resonance imaging. The patient was treated with doxycycline, ceftriaxone, systemic and topical steroids, and hyperbaric oxygen therapy, with modest, but incomplete, improvement.

Hyperbaric Oxygen Treatment for Long COVID: From Molecular Mechanism to Clinical Practice.

Long COVID symptoms typically occur within 3 months of an initial COVID-19 infection, last for more than 2 months, and cannot be explained by other diagnoses. The most common symptoms include fatigue, dyspnea, coughing, and cognitive impairment. The mechanisms of long COVID are not fully understood, but several hypotheses have been put forth. These include coagulation and fibrosis pathway activation, inflammatory and autoimmune manifestations, persistent virus presence, and Epstein-Barr virus reactivation. Hyperbaric oxygen therapy (HBOT) is a therapeutic method in which a person inhales 100% oxygen under pressure greater than that of the atmosphere. HBOT has some therapeutic effects, including improvement of microcirculation, inhibition of cytokine release leading to a reduction in inflammatory responses, inhibition of autoimmune responses, and promotion of neurological repair. Several clinical trials have been carried out using HBOT to treat long COVID. The results suggest that HBOT helps to improve symptom severity, reduce symptom duration, and enhance patients' quality of life. It is believed that HBOT is an effective option for patients with long COVID, which is worth actively promoting.

Identifying the Target Traumatic Brain Injury Population for Hyperbaric Oxygen Therapy.

Traumatic brain injury (TBI) results from direct penetrating and indirect non-penetrating forces that alters brain functions, affecting millions of individuals annually. Primary injury following TBI is exacerbated by secondary brain injury; foremost is the deleterious inflammatory response. One therapeutic intervention being increasingly explored for TBI is hyperbaric oxygen therapy (HBOT), which is already approved clinically for treating open wounds. HBOT consists of 100% oxygen administration, usually between 1.5 and 3 atm and has been found to increase brain oxygenation levels after hypoxia in addition to decreasing levels of inflammation, apoptosis, intracranial pressure, and edema, reducing subsequent secondary injury. The following review examines recent preclinical and clinical studies on HBOT in the context of TBI with a focus on contributing mechanisms and clinical potential. Several preclinical studies have identified pathways, such as TLR4/NF-kB, that are affected by HBOT and contribute to its therapeutic effect. Thus far, the mechanisms mediating HBOT treatment have yet to be fully elucidated and are of interest to researchers. Nonetheless, multiple clinical studies presented in this review have examined the safety of HBOT and demonstrated the improved neurological function of TBI patients after HBOT, deeming it a promising avenue for treatment.

Indications of Effective Hyperbaric Oxygen Therapy Combined With Steroid Therapy for Sudden Hearing Loss.

OBJECTIVE: This study evaluated the therapeutic effect of hyperbaric oxygen therapy (HBOT) combined with steroid therapy to treat sudden hearing loss and examined the index associated with excellent therapeutic effect. METHODS: We included 109 patients with sudden hearing loss. Patients were divided into the HBOT combination group (59 sides) treated with HBOT and steroid therapy and HBOT noncombination group (50 sides) involving steroid therapy only. The recovery rate of each group was compared according to the severity of hearing loss. Blood samples were evaluated and inflammatory markers, such as neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), were calculated and compared by severity. We evaluated the usefulness of inflammatory markers for predicting recovery rate, and calculated cutoff values were also evaluated. RESULTS: The HBOT combination group exhibited a higher overall recovery rate than the HBOT noncombination group, particularly in severe cases. However, there was no significant difference in the severity of hearing loss based on various inflammatory markers. NLR and PLR are useful for predicting the effect in patients treated with concomitant HBOT. By setting 2.43 and 146.67 as cutoff values for NLR and PLR, respectively, we observed that lower values resulted in better recovery rates. CONCLUSION: The use of HBOT is effective for severe cases and early blood flow disorders with low NLR and PLR and less inflammation. When determining treatment, not only should the severity of hearing loss be considered, but also the NLR and PLR should be evaluated and examined based on the cutoff values.

Hyperbaric oxygen improves cerebral ischemia-reperfusion injury in rats via inhibition of ferroptosis.

BACKGROUND: Our previous study found that hyperbaric oxygen (HBO) attenuated cognitive impairment in mice induced by cerebral ischemia-reperfusion injury (CIRI). However, its mechanism of action is not fully understood. In this study, we aimed to establish a rat model of cerebral ischemia-reperfusion, explore the possible role of ferroptosis in the pathogenesis of CIRI, and observe the effect of HBO on ferroptosis-mediated CIRI. METHODS: Sprague Dawley (SD) rats were randomly divided into control, model, Ferrostatin-1 (Fer-1), HBO and Fer-1+ HBO groups. Morris water maze, myelin basic protein (MBP) and ß-tubulin immunoreactivity were assessed to evaluate the neuroprotective effects of HBO on cerebral ischemia reperfusion injury. Ferroptosis were examined to investigate the mechanism underlying the effects of HBO. RESULTS: Our result showed that Fer-1 and HBO improved learning and memory ability in the navigation trail and probe trail of the Morris water maze and increased MBP and ß-tubulin immunoreactivity of the cortex in the model rats. The levels of ferritin, malondialdehyde (MDA) and glutathione (GSH) in the serum were also reversed by Fer-1 and HBO treatment. Mitochondrial cristae dissolution and vacuolization were observed in the model group by transmission electron microscopy and these conditions were improved in the Fer-1 and HBO groups. Furthermore, Fer-1 and HBO treatment reversed Prostaglandin-Endoperoxide Synthase 2 (PTGS2), Iron Responsive Element Binding Protein 2 (IREB2), acyl-CoA synthetase long chain family member 4 (ACSL4) and Solute Carrier Family 7 Member 11 (SLC7A11) mRNA levels and Transferrin Receptor 1 (TFR1), ferritin light chain (FTL), ferritin heavy chain 1 (FTH1), glutathione peroxidase 4 (GPX4), Nuclear factor E2-related factor 2 (Nrf2), lysophosphatidylcholine acyltransferase 3 (LPCAT3), c-Jun N-terminal kinase (JNK), phosphorylated c-Jun N-terminal kinase (P-JNK) phosphorylated Extracellular signal-regulated protein kinase (P-ERK) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) protein levels. The above changes were more pronounced in Fer-1+ HBOGroup. DISCUSSION: The results of the present study indicated that HBO improves cerebral ischemia-reperfusion injury in rats, which may be related to inhibition of ferroptosis. This also means that ferroptosis may become a new target of HBO against CIRI.

Hyperbaric Oxygen Therapy Inhibits Neuronal Ferroptosis After Spinal Cord Injury in Mice.

STUDY DESIGN: Basic science study investigating the potential molecular mechanisms of hyperbaric oxygen (HBO) therapy in mice with spinal cord injury (SCI). OBJECTIVE: We aimed to explore the intrinsic mechanisms of HBO for SCI through the lens of ferroptosis in the subacute phase. SUMMARY OF BACKGROUND DATA: HBO has been observed to facilitate the restoration of neurological function subsequent to SCI. Ferroptosis is a distinct cellular death mechanism that can be distinguished from apoptosis, necrosis, and autophagy. However, the precise relationship between these two phenomena remains poorly understood. METHODS: We established an SCI model and employed a range of techniques, including behavioral assessments, electron microscopy, immunofluorescence, RT-qPCR, Western blotting (WB), Glutathione (GSH) measurement, and iron assay, to investigate various aspects of HBO therapy on SCI in mice. These included analyzing mitochondrial morphology, neuronal count, GSH levels, iron levels, and the expression of genes (Acyl-CoA synthetase family member-2, Iron-responsive element-binding protein-2) and proteins (Glutathione peroxidase 4; system Xc-light chain) associated with ferroptosis. The study included three groups: Sham-operated, SCI, and HBO. Group comparisons were performed using one-way analysis of variance and one-way repeated measures analysis of variance, followed by Tukey's post hoc test. Statistical significance was set at a P < 0.05. RESULTS: Our findings revealed that HBO therapy significantly enhanced the recovery of lower limb motor function in mice following SCI in the subacute phase. This was accompanied by upregulated expression of GPX4 and system Xc-light chain proteins, elevated GSH levels, increased number of NeuN+ cells, decreased expression of the iron-responsive element-binding protein-2 gene, and reduced iron concentration. CONCLUSIONS: Our research suggests that HBO therapy has the potential to be an effective treatment for SCI in the subacute phase by mitigating ferroptosis.

Hyperbaric oxygen therapy for late radiation tissue injury.

BACKGROUND: This is the third update of the original Cochrane Review published in July 2005 and updated previously in 2012 and 2016. Cancer is a significant global health issue. Radiotherapy is a treatment modality for many malignancies, and about 50% of people having radiotherapy will be long-term survivors. Some will experience late radiation tissue injury (LRTI), developing months or years following radiotherapy. Hyperbaric oxygen therapy (HBOT) has been suggested as a treatment for LRTI based on the ability to improve the blood supply to these tissues. It is postulated that HBOT may result in both healing of tissues and the prevention of complications following surgery and radiotherapy. OBJECTIVES: To evaluate the benefits and harms of hyperbaric oxygen therapy (HBOT) for treating or preventing late radiation tissue injury (LRTI) compared to regimens that excluded HBOT. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 24 January 2022. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing the effect of HBOT versus no HBOT on LRTI prevention or healing. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. survival from time of randomisation to death from any cause; 2. complete or substantial resolution of clinical problem; 3. site-specific outcomes; and 4. ADVERSE EVENTS: Our secondary outcomes were 5. resolution of pain; 6. improvement in quality of life, function, or both; and 7. site-specific outcomes. We used GRADE to assess certainty of evidence. MAIN RESULTS: Eighteen studies contributed to this review (1071 participants) with publications ranging from 1985 to 2022. We added four new studies to this updated review and evidence for the treatment of radiation proctitis, radiation cystitis, and the prevention and treatment of osteoradionecrosis (ORN). HBOT may not prevent death at one year (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.47 to 1.83; I2 = 0%; 3 RCTs, 166 participants; low-certainty evidence). There is some evidence that HBOT may result in complete resolution or provide significant improvement of LRTI (RR 1.39, 95% CI 1.02 to 1.89; I2 = 64%; 5 RCTs, 468 participants; low-certainty evidence) and HBOT may result in a large reduction in wound dehiscence following head and neck soft tissue surgery (RR 0.24, 95% CI 0.06 to 0.94; I2 = 70%; 2 RCTs, 264 participants; low-certainty evidence). In addition, pain scores in ORN improve slightly after HBOT at 12 months (mean difference (MD) -10.72, 95% CI -18.97 to -2.47; I2 = 40%; 2 RCTs, 157 participants; moderate-certainty evidence). Regarding adverse events, HBOT results in a higher risk of a reduction in visual acuity (RR 4.03, 95% CI 1.65 to 9.84; 5 RCTs, 438 participants; high-certainty evidence). There was a risk of ear barotrauma in people receiving HBOT when no sham pressurisation was used for the control group (RR 9.08, 95% CI 2.21 to 37.26; I2 = 0%; 4 RCTs, 357 participants; high-certainty evidence), but no such increase when a sham pressurisation was employed (RR 1.07, 95% CI 0.52 to 2.21; I2 = 74%; 2 RCTs, 158 participants; high-certainty evidence). AUTHORS' CONCLUSIONS: These small studies suggest that for people with LRTI affecting tissues of the head, neck, bladder and rectum, HBOT may be associated with improved outcomes (low- to moderate-certainty evidence). HBOT may also result in a reduced risk of wound dehiscence and a modest reduction in pain following head and neck irradiation. However, HBOT is unlikely to influence the risk of death in the short term. HBOT also carries a risk of adverse events, including an increased risk of a reduction in visual acuity (usually temporary) and of ear barotrauma on compression. Hence, the application of HBOT to selected participants may be justified. The small number of studies and participants, and the methodological and reporting inadequacies of some of the primary studies included in this review demand a cautious interpretation. More information is required on the subset of disease severity and tissue type affected that is most likely to benefit from this therapy, the time for which we can expect any benefits to persist and the most appropriate oxygen dose. Further research is required to establish the optimum participant selection and timing of any therapy. An economic evaluation should also be undertaken.