Patient Reported Outcome Measures Following Hyperbaric Oxygen Therapy for Radiation Cystitis: Early Results From the Multicenter Registry for Hyperbaric Oxygen Therapy.

PURPOSE: To determine changes in patient reported hematuria and urinary symptoms after hyperbaric oxygen (HBO2) treatment for radiation cystitis (RC). METHODS: We analyzed prospectively data from the Multicenter Registry for Hyperbaric Oxygen Therapy Consortium collected within a week of beginning and ending HBO2. Measures included the modified Radiation Therapy Oncology Group (RTOG) Hematuria Scale, Urinary Distress Inventory Short Form (UDI-6), and EuroQOL EQ-5D-5L. RTOG hematuria and UDI scores were compared using the sign test. Logistic regression was used to evaluate characteristics associated with hematuria improvement. RESULTS: 470 registry patients had RC. The median age, number of HBO2 sessions, and years after radiation were 73 (IQR 12) years, 39 (IQR 10) sessions, and 5 (IQR 8) years respectively. 84% (393/470) had prostate-cancer-related radiation. EQ-5D-5L scores improved from 0.83 (IQR 0.14) to 0.85 (IQR 0.22), P < .001. 370 had complete RTOG hematuria scores which improved from 2 (IQR 2) to 0 (IQR 2), P < .001. 246 had complete UDI-6 ratings which decreased from 33.3 (IQR 44) to 22.2 (IQR 33) P < .001. Regression analysis of those with visible hematuria pre HBO2, showed lower improvement odds associated with higher HBO2 hematuria scores (OR: 0.44; 95% confidence interval (CI) 0.26-0.73, P < .01), a smoking history (OR: 0.44, 95% CI: 0.21-0.92, P = .03), or a non-prostate cancer history (0.32 (95%CI:0.10-0.99, P = .05). CONCLUSIONS: HBO2 for RC improved reported hematuria, urinary function, and quality of life. Higher baseline hematuria scores, smoking, and non-prostate cancer history were associated with a lower odds of hematuria improvement.

Corrigendum: Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies.

[This corrects the article DOI: 10.3389/fimmu.2023.1230049.].

Adjunctive hyperbaric oxygen therapy in the management of severe lower limb soft tissue injuries: a systematic review.

PURPOSE: Traumatic crush injuries of the lower limb often accompany severe complications. The incorporation of hyperbaric oxygen therapy to standard trauma care may have the potential to diminish injury-related complications and improve outcome in such cases. This systematic review aims to evaluate the effectiveness of hyperbaric oxygen therapy in the management of severe lower limb soft tissue injuries. METHODS: The electronic databases Medline, Embase and Cochrane Library were searched to identify studies involving patients with crush-associated sever lower limb soft tissue injuries who received hyperbaric oxygen therapy in conjunction with standard trauma care. Relevant data on type of injury, hyperbaric oxygen therapy protocol and outcome related to wound healing were extracted. RESULTS: In total seven studies met the inclusion criteria, involving 229 patients. The studies included two randomized clinical trials, one retrospective cohort study, three case series and one case report. The randomized placebo-controlled clinical trial showed a significant increase in wound healing and decrease in the need for additional surgical interventions in the patient group receiving hyperbaric oxygen therapy when compared to those undergoing sham therapy. The randomized non-placebo-controlled clinical trial revealed that early hyperbaric oxygen therapy reduces tissue necrosis and the likelihood of long-term complications. The retrospective cohort study indicated that hyperbaric oxygen therapy effectively reduces infection rates and the need for additional surgical interventions. The case series and case report presented beneficial results with regard to wound healing when hyperbaric oxygen therapy was added to the treatment regimen. CONCLUSION: Hyperbaric oxygen therapy is generally considered a safe therapeutic intervention and seems to have a beneficial effect on wound healing in severe lower limb soft tissue injuries when implemented as an addition to standard trauma care.

Adjunctive hyperbaric oxygen therapy for spinal cord ischemia after complex aortic repair.

OBJECTIVE: Spinal cord ischemia (SCI) with paraplegia or paraparesis is a devastating complication of complex aortic repair (CAR). Treatment includes cerebrospinal fluid drainage, maintenance of hemoglobin concentration (>10 g/L), and elevating mean arterial blood pressure. Animal and human case series have reported improvements in SCI outcomes with hyperbaric oxygen therapy (HBOT). We reviewed our center's experience with HBOT as a rescue treatment for spinal cord ischemia post-CAR in addition to standard treatment. METHODS: A retrospective review of the University Health Network's Hyperbaric Medicine Unit treatment database identified HBOT sessions for patients with SCI post-CAR between January 2013 and June 2021. Mean estimates of overall motor function scores were determined for postoperative, pre-HBOT, post-HBOT (within 4 hours of the final HBOT session), and at the final assessment (last available in-hospital evaluation) using a linear mixed model. A subgroup analysis compared the mean estimates of overall motor function scores between improvement and non-improvement groups at given timepoints. Improvement of motor function was defined as either a ≥2 point increase in overall muscle function score in patients with paraparesis or an upward change in motor deficit categorization (para/monoplegia, paraparesis, and no deficit). Subgroup analysis was performed by stratifying by improvement or non-improvement of motor function from pre-HBOT to final evaluation. RESULTS: Thirty patients were treated for SCI. Pre-HBOT, the motor deficit categorization was 10 paraplegia, three monoplegia, 16 paraparesis, and one unable to assess. At the final assessment, 14 patients demonstrated variable degrees of motor function improvement; eight patients demonstrated full motor function recovery. Seven of the 10 patients with paraplegia remained paraplegic despite HBOT. The estimated mean of overall muscle function score for pre-HBOT was 16.6 ± 2.9 (95% confidence interval [CI], 10.9-22.3) and for final assessment was 23.4 ± 2.9 (95% CI, 17.7-29.1). The estimated mean difference between pre-HBOT and final assessment overall muscle function score was 6.7 ± 3.1 (95% CI, 0.6-16.1). The estimated mean difference of the overall muscle function score between pre-HBOT and final assessment for the improved group was 16.6 ± 3.5 (95% CI, 7.5-25.7) vs -4.9 ± 4.2 (95% CI, -16.0 to 6.2) for the non-improved group. CONCLUSIONS: HBOT, in addition to standard treatment, may potentially improve recovery in spinal cord function following SCI post-CAR. However, the potential benefits of HBOT are not equally distributed among subgroups.

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

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

Cerebral Air Embolism After Air-Powder Abrasive Dental Treatment: A Case Report.

Cerebral air embolism (CAE) occurs in various clinical situations such as surgery, angiography, and hemodialysis; most are iatrogenic. Here we report the case of a 57-year-old man who developed CAE immediately after air-powder abrasive treatment, which is commonly used in dentistry. The patient underwent air-powder abrasive treatment for peri-implantitis, and immediately after the treatment, cardiac arrest occurred and cardio- pulmonary resuscitation was performed. After resuscitation, brain computed tomography performed in the emergency room showed scattered dark density presumed to be air. The day after admission, the patient showed right hemiplegia and a multifocal cerebral infarction was observed on brain magnetic resonance imaging. Therefore, CAE was strongly suspected. After hyperbaric oxygen treatment (HBOT), which started 4 days after the incident, the patient regained consciousness and showed improvement in cognitive impairment, and only grade 4 muscle weakness was observed in the right lower extremity on the manual muscle test. This case highlights the importance of considering CAE as a possible cause of neurological symptoms occurring during clinical procedures involving air, and adds to the accumulation of evidence of therapeutic effects of delayed HBOT.

Challenges in the management of high-altitude illnesses and emergencies in Bhutan and Nepal.

Many popular tourist attractions and trekking routes in Bhutan and Nepal are situated between 3000 and 6000 m in elevation. High-altitude emergencies are becoming more common and medical providers must be aware of the practical and medical issues in managing these disorders. We reflect on the challenges in providing high-altitude emergency medical services in Bhutan and Nepal.

Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies.

Iatrogenic vascular air embolism is a relatively infrequent event but is associated with significant morbidity and mortality. These emboli can arise in many clinical settings such as neurosurgery, cardiac surgery, and liver transplantation, but more recently, endoscopy, hemodialysis, thoracentesis, tissue biopsy, angiography, and central and peripheral venous access and removal have overtaken surgery and trauma as significant causes of vascular air embolism. The true incidence may be greater since many of these air emboli are asymptomatic and frequently go undiagnosed or unreported. Due to the rarity of vascular air embolism and because of the many manifestations, diagnoses can be difficult and require immediate therapeutic intervention. An iatrogenic air embolism can result in both venous and arterial emboli whose anatomic locations dictate the clinical course. Most clinically significant iatrogenic air emboli are caused by arterial obstruction of small vessels because the pulmonary gas exchange filters the more frequent, smaller volume bubbles that gain access to the venous circulation. However, there is a subset of patients with venous air emboli caused by larger volumes of air who present with more protean manifestations. There have been significant gains in the understanding of the interactions of fluid dynamics, hemostasis, and inflammation caused by air emboli due to in vitro and in vivo studies on flow dynamics of bubbles in small vessels. Intensive research regarding the thromboinflammatory changes at the level of the endothelium has been described recently. The obstruction of vessels by air emboli causes immediate pathoanatomic and immunologic and thromboinflammatory responses at the level of the endothelium. In this review, we describe those immunologic and thromboinflammatory responses at the level of the endothelium as well as evaluate traditional and novel forms of therapy for this rare and often unrecognized clinical condition.

Immediate and Long-Term Effects of Hyperbaric Oxygenation in Patients with Long COVID-19 Syndrome Using SF-36 Survey and VAS Score: A Clinical Pilot Study.

(1) Background: Long COVID syndrome (LCS) is a heterogeneous long-standing condition following COVID-19 infection. Treatment options are limited to symptomatic measures, and no specific medication has been established. Hyperbaric oxygenation (HBO) has been found to have a positive impact on the treatment of COVID-19 infection. This study evaluates both the feasibility and outcome of supportive HBO in patients with LCS. (2) Methods: Within 17 months, 70 patients with proven LCS were prospectively included. Each patient underwent a cycle of 10 subsequent HBO treatment sessions administered for 75 min at 2.2 atmospheres. Evaluation of the patients was performed before the first and after the last HBO session and 3 months afterwards. Statistical evaluation was based on an intention-to-treat analysis using Fisher's exact test and Student's t-test for paired samples. (3) Results: In total, 59 patients (33 females, 26 males; mean age: 43.9 years; range: 23-74 years; median: 45.0) were evaluable. After HBO, a statistically significant improvement of physical functioning (p < 0.001), physical role (p = 0.01), energy (p < 0.001), emotional well-being (p < 0.001), social functioning (p < 0.001), pain (p = 0.01) and reduced limitation of activities (p < 0.001) was confirmed. (4) Conclusions: Physical functioning and both the physical and emotional role improved significantly and sustainably, suggesting HBO as a promising supportive therapeutic tool for the treatment of LCS.

Hyperbaric oxygen therapy as a complementary treatment in neuroblastoma - a narrative review.

Neuroblastoma is the most frequently diagnosed cancer during the first year of life. This neoplasm originates from neural crest cells derived from the sympathetic nervous system, adrenal medulla, or paraspinal ganglia. The clinical presentation can vary from an asymptomatic mass to symptoms resulting from local invasion and/or spread of distant disease spread. The natural history of neuroblastoma is highly variable, ranging from relatively indolent biological behavior to a high-risk clinical phenotype with a dismal prognosis. Age, stage, and biological features are important prognostic risk stratification and treatment assignment prognostic factors. The multimodal therapy approach includes myeloablative chemotherapy, radiotherapy, immunotherapy, and aggressive surgical resection. Hyperbaric oxygen therapy (HBOT) has been proposed as a complementary measure to overcome tumor hypoxia, which is considered one of the hallmarks of this cancer treatment resistance. This article aims to review the relevant literature on the neuroblastoma pathophysiology, clinical presentation, and different biological and genetic profiles, and to discuss its management, focusing on HBOT.

Hyperbaric oxygen mitigates KIM-1 and inflammatory cytokine levels in kidney transplantation.

Background: The aim of this study was to investigate the effect of hyperbaric oxygen (HBO2) administration during cold ischemic time to organs removed from donors before kidney transplantation. A total of 24 rats were divided into three groups: Group 1 was the control group, Group 2 received 60 minutes of HBO2 at 2.5 atmospheres absolute, and Group 3 received 120 minutes of 2.5 ATA HBO2. The renal artery was entered with a polyethylene catheter and perfused with a standard organ preservation solution. Falcon tubes containing organs obtained from rats in Groups 2 and 3 were placed in a box supported by ice blocks. The temperature was kept constant at 4°C and the box was placed in a pressure tank with 2.5 ATA HBO2. HBO2 was applied for 60 and 120 minutes, respectively. Organ samples were harvested at the end of 24 hours for histopathological evaluation, immunohistochemical analysis of TNF-α and IL-18, TUNEL analysis for apoptosis, and gene expression levels of kidney injury molecule-1 (KIM-1) and caspase-3. In histopathological examinations, hematoxylin and eosin staining was performed and samples were evaluated for tubular necrosis and vacuolization criteria. Group 2 and Group 3 had significant decreases compared to Group one in this regard. Immunohistochemical staining was performed for TNF-α, IL-18, and apoptosis levels; significant decreases were found in Groups 2 and 3. There were significant decreases in Groups 2 and 3 for KIM-1 and caspase-3 gene expression levels compared to Group 1, as well. Thus, it was demonstrated that during the cold ischemic period before kidney transplantation, HBO2 administration to organs removed from donors can reduce apoptotic cell numbers, inflammatory cytokine release, and histopathological damage to the organs as well as decreasing the expression of the KIM-1 gene, which is an indicator of kidney damage.

The effectiveness of hyperbaric oxygen therapy for managing radiation-induced proctitis - results of a 10-year retrospective cohort study.

Introduction: Despite modern radiotherapy (RT) techniques, radiation-induced proctitis (RIP) remains a significant complication of RT for pelvic organ malignancies. Over the last decades, an enormous therapeutic armamentarium has been considered in RIP, including hyperbaric oxygen therapy (HBOT). However, the evidence regarding the impact of HBOT on RIP is conflicting. This study aims to evaluate the effectiveness and safety of HBOT in the treatment of RIP. Methods: Ten-year (2013-2023) retrospective analysis of all consecutive patients with RIP treated with HBOT at Centro de Medicina Subaquática e Hiperbárica (CMSH) (Armed Forces Hospital - Lisbon, Portugal). Patients were exposed to 100% oxygen at 2.5 ATA, in a multiplace first-class hyperbaric chamber, for 70-min periods, once daily, five times per week. Fisher's exact test was performed using SPSS (version 23.0); p<0.05 was accepted as statistically significant. Results: Of a total of 151 patients with RIP, 88 were included in the final analysis, of whom 38.6% evidenced other concurrent radiation-induced soft tissue lesions. The most reported primary pelvic tumor treated with RT was prostate cancer (77.3%), followed by cervical cancer (10.2%). Hematochezia was the most observed clinical manifestation (86.4%). After a median of 60 HBOT sessions (interquartile range [IQR]: 40-87.5), 62.5% and 31.8% of patients achieved a clinical complete and partial response, respectively, with a hematochezia resolution rate of 93.7% (complete or partial). While partial and complete responses require fewer than 70 sessions of HBOT in terms of overall RIP symptoms (p=0.069), isolated hematochezia tends to require at least 70 sessions (p=0.075). Individuals with at least two concurrent late radiation tissue injuries were associated with a complete response to HBOT (p=0.029). Only about 5.7% of patients did not respond to the treatment. Eighteen patients (20.5%) developed reversible ear barotrauma. The number of HBOT sessions was a predictor of HBOT side effects (odds ratio: 1.010; 95% confidence interval, 1.000-1.020; p=0.047). Conclusion: The HBOT proved to be an effective and safe treatment for RIP refractory to medical and/or endoscopic treatments. This real-world evidence study adds value to published data on the management of RIP with HBOT.

Osteoradionecrosis treatment in head and neck cancer patients: An overview of systematic reviews.

AIMS: Evaluate the existing evidence of osteoradionecrosis (ORN) treatment in adults with head and neck cancer, the methodological quality and the evidence grade within systematic reviews (SRs). METHODS: An extensive systematic literature search of SRs that addressed ORN in head and neck cancer patients was conducted with screening of eligible studies, data extraction, methodological (AMSTAR 2) and evidence quality assessment (GRADE) of the SRs by independent and calibrated authors. RESULTS: A total of six SRs were enrolled. Based primarily on studies from the 1990s, there is critically low- or moderate-quality evidence that hyperbaric oxygen therapy (HBO) improves ORN healing. From 2005 onward, evidence has been discovered in relation to treatment with pentoxifylline and tocopherol (PENTO). The SRs indicate that the management of ORN with PENTO appears to be promising. The greatest rates of healing are seen in mild and moderate stages of ORN. However, the quality of evidence regarding PENTO, surgery and other treatments remains critically low. CONCLUSION: There is no standardized protocol to treat ORN. PENTO appears to be the most promising conservative treatment; however, the current level of evidence regarding PENTO is still critically low. More robust clinical studies are needed to establish the best treatment for ORN.

Early hyperbaric oxygen therapy is associated with favorable outcome in patients with iatrogenic cerebral arterial gas embolism: systematic review and individual patient data meta-analysis of observational studies.

BACKGROUND: Iatrogenic cerebral arterial gas embolism (CAGE) caused by invasive medical procedures may be treated with hyperbaric oxygen therapy (HBOT). Previous studies suggested that initiation of HBOT within 6-8 h is associated with higher probability of favorable outcome, when compared to time-to-HBOT beyond 8 h. We performed a group level and individual patient level meta-analysis of observational studies, to evaluate the relationship between time-to-HBOT and outcome after iatrogenic CAGE. METHODS: We systematically searched for studies reporting on time-to-HBOT and outcome in patients with iatrogenic CAGE. On group level, we meta-analyzed the differences between median time-to-HBOT in patients with favorable versus unfavorable outcome. On individual patient level, we analyzed the relationship between time-to-HBOT and probability of favorable outcome in a generalized linear mixed effects model. RESULTS: Group level meta-analysis (ten studies, 263 patients) shows that patients with favorable outcome were treated with HBOT 2.4 h (95% CI 0.6-9.7) earlier than patients with unfavorable outcome. The generalized linear mixed effects model (eight studies, 126 patients) shows a significant relationship between time-to-HBOT and probability of favorable outcome (p = 0.013) that remains significant after correcting for severity of manifestations (p = 0.041). Probability of favorable outcome decreases from approximately 65% when HBOT is started immediately, to 30% when HBOT is delayed for 15 h. CONCLUSIONS: Increased time-to-HBOT is associated with decreased probability of favorable outcome in iatrogenic CAGE. This suggests that early initiation of HBOT in iatrogenic CAGE is of vital importance.

Management of Malignant Otitis Externa with Hyperbaric Oxygen Therapy: A Case Series of 20 Patients.

Malignant otitis externa (MOE) is an aggressive infection of the external auditory canal that primarily affects diabetic patients. Some literature supports the effectiveness of hyperbaric oxygen therapy (HBOT) as a treatment modality for MOE. A case series was conducted of all patients diagnosed with MOE and treated with HBOT at the Said Bin Sultan Naval Base Polyclinic in Oman between January 2014 and December 2019. A total of 20 patients were included in the study. All participants presented with persistent ear discharge, 95.0% with otalgia, and 75.0% with granulation in the external auditory canal. Moreover, 100% showed abnormally high levels of inflammatory markers and abnormal computed tomography findings. The patients underwent an average of 29.0±8.9 HBOT sessions. Overall, 19 (95.0%) patients were considered cured by the end of the treatment. The use of HBOT in the management of MOE appears promising and may cure MOE.

Hyperbaric oxygenation improve red blood cell deformability in patients with acute or chronic inflammation.

INTRODUCTION: Red blood cells (RBC) are one of the key elements of the microcirculation. Their ability to pass through capillaries and to deliver oxygen to cells is due to their large degree of deformability linked to the characteristics of the RBC membrane. Alterations in RBC deformability as a result of membrane damage, linked in part to increased synthesis of reactive oxygen species (ROS), can be observed in several diseases, such as sepsis, and may contribute to the altered microcirculation observed in these pathologies. Hyperbaric oxygen therapy (HBOT), with inhalation of 100 % oxygen, has been proposed in several acute or chronic pathologies, including carbon monoxide poisoning. OBJECTIVE: We investigated the effects of HBOT on oxidative stress from ROS produced by myeloperoxidase (MPO) and on RBC deformability in patients with acute or chronic inflammation (n = 10), in patients with acute carbon monoxide poisoning (n = 10), and in healthy volunteers (n = 10). METHODS: RBC deformability was evaluated before and after HBOT in the various populations using the ektacytometry technique (Laser-assisted Optical Rotational Red Cell Analyzer - LORRCA). Deformability was determined by the elongation index (EI) in relation to the shear stress (SS) over a range of 0.3 to 50 Pa. Oxidative stress was estimated through changes in proteins (chlorotyrosine and homocitrulline) induced by MPO activity measured by liquid chromatography-tandem mass spectrometry analysis. RESULTS: Before HBOT, EI was significantly lower in patients with acute or chronic inflammation than in healthy volunteers and patients with acute carbon monoxide poisoning for the majority of SS values studied. After one session of HBOT, the EI was significantly higher than before HBOT for SS values of 1.93 Pa or higher in patients with acute or chronic inflammation. This effect remains constant after 10 sessions. There were no differences before and after HBOT in protein or amino acid oxidation due to ROS generation mediated by MPO in the three populations. CONCLUSIONS: Our results confirm altered RBC deformability in patients with acute and chronic conditions associated with an underlying inflammatory process. HBOT improves deformability only after one session and therefore may improve microcirculation in this population. According to our results, this improvement does not seem mediated by the ROS pathway via MPO. These results need to be confirmed in a larger population.

Prevalence of Carbon Monoxide Poisoning and Hyperbaric Oxygen Therapy in Korea: Analysis of National Claims Data in 2010-2019.

This study aimed to investigate the prevalence of carbon monoxide (CO) poisoning and the provision of hyperbaric oxygen therapy (HBOT) in South Korea. We used data from the Korea Health Insurance Review and Assessment service. In total, 44,361 patients with CO poisoning were identified across 10 years (2010-2019). The prevalence of CO poisoning was found to be 8.64/10,000 people, with a gradual annual increment. The highest prevalence was 11.01/10,000 individuals, among those aged 30-39 years. In 2010, HBOT was claimed from 15 hospitals, and increased to 30 hospitals in 2019. A total of 4,473 patients received HBOT in 10 years and 2,684 (60%) were treated for more than 2 hours. This study suggested that the prevalence of both CO poisoning and HBOT in Korea gradually increased over the past 10 years, and disparities in prevalence were observed by region.

Hyperbaric Oxygenation Prevents Loss of Immature Neurons in the Adult Hippocampal Dentate Gyrus Following Brain Injury.

A growing body of evidence suggests that hyperbaric oxygenation (HBO) may affect the activity of adult neural stem cells (NSCs). Since the role of NSCs in recovery from brain injury is still unclear, the purpose of this study was to investigate the effects of sensorimotor cortex ablation (SCA) and HBO treatment (HBOT) on the processes of neurogenesis in the adult dentate gyrus (DG), a region of the hippocampus that is the site of adult neurogenesis. Ten-week-old Wistar rats were divided into groups: Control (C, intact animals), Sham control (S, animals that underwent the surgical procedure without opening the skull), SCA (animals in whom the right sensorimotor cortex was removed via suction ablation), and SCA + HBO (operated animals that passed HBOT). HBOT protocol: pressure applied at 2.5 absolute atmospheres for 60 min, once daily for 10 days. Using immunohistochemistry and double immunofluorescence labeling, we show that SCA causes significant loss of neurons in the DG. Newborn neurons in the subgranular zone (SGZ), inner-third, and partially mid-third of the granule cell layer are predominantly affected by SCA. HBOT decreases the SCA-caused loss of immature neurons, prevents reduction of dendritic arborization, and increases proliferation of progenitor cells. Our results suggest a protective effect of HBO by reducing the vulnerability of immature neurons in the adult DG to SCA injury.

Hyperbaric oxygen preconditioning for prevention of acute high-altitude diseases: Fact or fiction?

Acute high-altitude diseases, including acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE), have been recognized as potentially lethal diseases for altitude climbers. Various preconditioning stimuli, including hyperbaric oxygen (HBO), have been proposed to prevent acute high-altitude diseases. Herein, we reviewed whether and how HBO preconditioning could affect high-altitude diseases and summarized the results of current trials. Evidence suggests that HBO preconditioning may be a safe and effective preventive method for acute high-altitude diseases. The proposed mechanisms of HBO preconditioning in preventing high-altitude diseases may involve: 1) protection of the blood-brain barrier and prevention of brain edema, 2) inhibition of the inflammatory responses, 3) induction of the hypoxia-inducible factor and its target genes, and 4) increase in antioxidant activity. However, the optimal protocol of HBO preconditioning needs further exploration. Translating the beneficial effects of HBO preconditioning into current practice requires the "conditioning strategies" approach. More large-scale and high-quality randomized controlled studies are needed in the future.

Oxigenoterapia hiperbárica como tratamiento complementario en mucormicosis asociada a COVID-19: a propósito de dos casos / Hyperbaric oxygen therapy as an adjunctive treatment for COVID-19-associated mucormycosis: a report of two cases

Reportamos los dos primeros casos, en Perú, sobre el uso del tratamiento con oxigeno hiperbárico coadyuvante (TOHC) en pacientes con mucormicosis asociado a COVID-19 (MAC). El primer caso es una mujer de 41 años, con dolor en hemicara y región palatina izquierdas con rinorrea purulenta de un mes de evolución. Al examen físico, solo evidencia fístula oroantral. El segundo caso se trata de un varón de 35 años, con disminución de agudeza visual izquierda y dolor palatino con fístula que drena secreción purulenta de cuatro meses de evolución. Ambos pacientes tienen el antecedente de diabetes, tuvieron COVID-19 moderado cuatro meses antes del ingreso, y recibieron corticoterapia por este diagnóstico. Ambos pacientes tuvieron una evaluación tomográfica que mostró compromiso del seno maxilar y tejido óseo circundante, con endoscopia nasal diagnóstica y terapéutica para desbridamiento. Se obtuvieron muestras compatibles con mucormicosis en estudio histológico. Los pacientes fueron tratados con limpieza quirúrgica y anfotericina B desoxicolato, sin embargo, presentaron evoluciones tórpidas. Por lo tanto, se adicionó la TOHC y mostraron una mejoría evidente tras cuatro semanas de tratamiento con controles subsiguientes sin presencia de mucormicosis. Resaltamos la evolución de estos pacientes con TOHC, en una enfermedad con importante morbimortalidad, que ha sido emergente durante la pandemia.

We present the first two cases reported in Peru of the use of adjuvant hyperbaric oxygen therapy (HBOT) in patients with COVID-19-associated mucormycosis (CAM). The first case is a 41-year-old woman, with pain in the left side of the face and palatine region with purulent rhinorrhea for a month. Only an oroantral fistula was found during physical examination. The second case is a 35-year-old male, with decreased left visual acuity and palatal pain with a fistula, draining purulent secretion for four months. Both patients have history of diabetes, had moderate COVID-19 four months prior to admission, and received corticosteroid therapy for this diagnosis. Tomographic evaluation of both patients showed involvement of the maxillary sinus and surrounding bone tissue; both received diagnostic and therapeutic nasal endoscopy for debridement. Histological analysis showed that the samples were compatible with mucormycosis. The patients underwent debridement and were treated with amphotericin B deoxycholate; however, they presented torpid evolution. Then, HBOT was added and the patients showed an evident improvement after four weeks of treatment with subsequent controls without the presence of mucormycosis. We highlight the favorable evolution of these patients while receiving HBOT as treatment for a disease with high morbimortality, which emerged during the pandemic.