Hyperbaric Chamber Research Articles

Characteristics of Side Effects in Non-Emergency Indications Using Computer-Controlled Pressurized Monoplace Hyperbaric Chambers: A Retrospective Multicenter Study

Background: Hyperbaric oxygen therapy (HBOT) involves inhaling nearly 100% oxygen in a pressurized environment and is commonly used to treat various diseases and injuries. Despite its well-known safety, HBOT is associated with side effects, with frequent middle ear barotrauma (MEB) and oxygen toxicity. Understanding the characteristics and risk factors associated with these side effects is critical for improving patient compliance and treatment outcomes. Methods: This retrospective multicenter study aimed to analyze the characteristics and factors associated with side effects during HBOT using a computer-controlled pressurized monoplace hyperbaric chamber. We conducted a retrospective observational study across the two tertiary hospitals in Korea, involving patients who received HBOT from October 2016 for one hospital and October 2017 for another hospital to June 2020. Data were extracted from electronic medical records and hyperbaric chamber logs, including patient demographics, medical history, HBOT indications, and details of side effects. Statistical analyses, including chi-square and t-tests, were used to compare variables. Results: A total of 247 patients (mean age: 59.35 ± 15.05 years, 63.56% male) were included. The most common indications for HBOT were sudden sensorineural hearing loss (27.94%) and post-graft/flap (24.29%). Hypertension (46.15%) and diabetes mellitus (39.27%) were the most frequent comorbidities. Otalgia was the most prevalent side effect (33.20%), followed by chest discomfort (2.02%) and headache (1.62%). A significant proportion of patients (11.74%) terminated HBOT due to side effects, with most pauses occurring at pressures between 1.2 and 1.4 ATA (26.67%). Side effects, particularly otalgia, significantly impact patient compliance with HBOT. Conclusions: The incidence of side effects varies by pressure level during treatment, suggesting the need for tailored strategies to minimize side effects. This study highlights the importance of patient monitoring and education to improve the safety and efficacy of HBOT in monoplace chambers.

Experience of Hyperbaric Chamber Usage in Aesthetic Plastic Surgery Practice for Recovery and Complication Prevention.

Hyperbaric oxygen therapy (HBOT) increases oxygen concentration in affected tissues that enhance the cellular hypoxia recovery process, neovascularization, fibroblast proliferation, increased reactive oxygen species, suppression of proinflammatory states, and vascular compression. The aim of this article is to demonstrate the experience in the use of the hyperbaric chamber as an adjunctive management for the prompt recovery of patients who underwent aesthetic plastic surgery. A retrospective descriptive study was conducted between 2021 and 2023, involving 296 patients who received HBOT after aesthetic surgical procedures, to demonstrate the recuperation time rate and the complication incidence in postoperative patients using HBOT. Most participants were women, with a median age of 33.5 years. Surgical procedures were grouped in liposculpture, abdominoplasty, and breast interventions. Complications related to the surgical event were low (10.7%), with occurrences of hematomas (n = 14, 4.72%), anemias (n = 9, 3.04%), and wound dehiscence (n = 8, 2.70%). There were no reports of surgical site infections or necrosis. Recovery times to get back to work were 10 days for liposuction, 3 days for breast interventions, and 21 days for abdominoplasty. This study demonstrated the experience of using a postoperative hyperbaric chamber in aesthetic plastic surgery to promote recovery processes. The patient cohort in this study showed shortened recovery times than the data obtained from the major international plastic surgery organizations. Also, HBOT patients had a low complication rate, without infections, indicating the potential efficacy of this adjunctive therapy. Overall, this study underscores the promising role of hyperbaric chamber therapy in facilitating postoperative recovery and mitigating complications.

Heart Rate and Rhythm Changes in Dogs Treated in a Hyperbaric Oxygen Chamber

In veterinary medicine, hyperbaric oxygen chamber treatment (HBOT) is gaining popularity. Therefore, an increasing number of patients referred for this therapy are being recorded, mainly due to ischemic events, wound healing support, and a high risk of reperfusion damage. During the HBOT procedure, several changes occur in the body’s micro- and macroenvironments. This study involved 34 dogs of various ages and health statuses. The atmospheric conditions in the test hyperbaric chamber included a pressure of 1.5 atmosphere absolute (ATA) at 100% oxygenation. The individuals were divided into three groups: (1) individuals with degenerative mitral valve disease (DMVD), (2) individuals with diseases other than cardiac issues, and (3) healthy individuals who qualified for the HBOT procedure. The period of measurement using the Holter apparatus was divided into four stages: 30 min before the subject’s placement in the hyperbaric chamber; a 4-min compression period (setting chamber conditions); a 90 min HBOT period; and a 1 min decompression period of the hyperbaric chamber. During the HBOT, there was a statistically significant decrease in heart rate in groups 2 and 3 compared to group 1. The heart rate in group 1 remained unchanged through every period of the study. In addition, some of the dogs developed respiratory arrhythmia; in two dogs, premature ventricle beats occurred. The changes observed during the ventricular period indicate that the HBOT procedure causes a significant change in heart rate in dogs without cardiac diseases.

Transcranial doppler to detect high-risk PFO and predict decompression illness in divers

Abstract Background It has not yet been clearly demonstrated whether it is feasible to diagnose patent foramen ovale (PFO) using transcranial doppler (TCD) and to use it in strategies to prevent decompression illness (DCI) in self-contained breathing apparatus (SCUBA) divers. Purpose DIVER-PFO study confirmed that high-risk PFO is associated with an increased risk of DCI in SCUBA divers. In this prespecified post-hoc analysis, we aimed to prospectively evaluate the accuracy of TCD to diagnose high-risk PFO and to predict the occurrence of DCI. Methods Eighty-two consecutive divers (mean age; 41 years, male 80.5%) underwent transesophageal echocardiogram (TEE) and TCD with a saline bubble test to determine the presence of PFO and were subsequently divided into high-risk and low-risk groups by TEE findings. Divers in the high-risk PFO group included those with the following conditions: PFO with atrial septal aneurysm, hypermobility, PFO size ≥2 mm, or right to left shunt at resting state. The enrolled divers were then followed-up using a self-reported questionnaire through e-mail or telephone interview for 3 years, while they were blinded to their PFO status. The primary endpoint of the study was PFO-related DCI, comprising cases of cutaneous or neurologic DCI, DCI symptoms requiring hyperbaric chamber therapy, DCI symptoms within 30 minutes after surfacing, or unexplained death occurring within 2 weeks after diving. Results PFO was detected in 47 (57.3%) and 59 (72.0%) divers by TCD and TEE, respectively. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of TCD were 68.3%, 67.8%, 69.6% 85.1%, and 45.7% for the diagnosis of PFO, and 65.9%, 82.8%, 56.6%, 51.1% and 85.7% for the diagnosis of high-risk PFO, respectively. PFO-related DCI occurred in 9 divers in the PFO group (PFO vs non-PFO: 6.4 vs 0.7 incidences per 10,000 person dives; p=0.03) during a mean follow-up of 25.6 months. Integrated time-dependent Area Under the Curves for TCD and TEE to predict DCI occurrence using Cox’s proportional hazards regression model were 0.714 and 0.675, respectively. Conclusions TCD was moderately accurate to diagnose high-risk PFO in divers. However, it predicted DCI as much as TEE.Study flowIncidence of DCI in the PFO vs No PFO

A broad appraisal of decompression-induced physiological stress in different simulated dive profiles

Background: The present study was designed to observe if different decompression profiles, calculated as a function of tissue supersaturation during ascent, would result in significantly different outcomes, measured through different physiological stress indicators, even in the absence of symptoms of decompression sickness. Aim: The aim of this study was to evaluate if simulated decompression profiles would affect the immune system, oxidative stress indicators, and heart rate variability. Methods: A total of 23 volunteers participated in two different experimental protocols in a dry hyperbaric chamber. These simulated dives comprised two different compression–decompression arrangements with the same maximum pressure and duration but different decompression profiles. Results: The shallow decompression profile with shorter deeper stops and longer shallow stops presented an increase in the standard deviation of the normal-to-normal R-R interval (a wide indicator of overall variability); the deep decompression profile with longer deeper stops and shorter shallow stops did not exhibit such increase. The shallow decompression profile resulted in an increase in neutrophil count and its microparticles (MPs), but no changes were observed for platelet count and its MPs, as well as for endothelial-derived MPs. In contrast, the deep decompression profile resulted in no changes in neutrophil count and its MPs, but a decrease in platelet count along with an increase in MPs from both platelets and endothelial cells. The observed difference might be related to different levels of decompression-related activation of immune system responses and oxidative processes triggered by different levels of inert gas supersaturation upon surfacing. Conclusion: From previous results and literature data, we present a tentative schematic of how the velocity of ascent would trigger (or not) pro-inflammatory and immune system responses that could ultimately lead to the development of decompression sickness. Relevance for patients: Increasing safety in exposure to hyperbaric environments and subsequent decompression by evaluating individual physiological responses to the process.

Hyperbaric oxygen therapy in the ATLS/ACLS resuscitative management of acutely ill or severely injured patients with severe anemia: a review.

For short periods, even without the presence of red blood cells, hyperbaric oxygen can safely allow plasma to meet the oxygen delivery requirements of a human at rest. By this means, hyperbaric oxygen, in special instances, may be used as a bridge to lessen blood transfusion requirements. Hyperbaric oxygen, applied intermittently, can readily avert oxygen toxicity while meeting the body's oxygen requirements. In acute injury or illness, accumulated oxygen debt is shadowed by adenosine triphosphate debt. Hyperbaric oxygen efficiently provides superior diffusion distances of oxygen in tissue compared to those provided by breathing normobaric oxygen. Intermittent application of hyperbaric oxygen can resupply adenosine triphosphate for energy for gene expression and reparative and anti-inflammatory cellular function. This advantageous effect is termed the hyperbaric oxygen paradox. Similarly, the normobaric oxygen paradox has been used to elicit erythropoietin expression. Referfusion injury after an ischemic insult can be ameliorated by hyperbaric oxygen administration. Oxygen toxicity can be averted by short hyperbaric oxygen exposure times with air breaks during treatments and also by lengthening the time between hyperbaric oxygen sessions as the treatment advances. Hyperbaric chambers can be assembled to provide everything available to a patient in modern-day intensive care units. The complication rate of hyperbaric oxygen therapy is very low. Accordingly, hyperbaric oxygen, when safely available in hospital settings, should be considered as an adjunct for the management of critically injured or ill patients with disabling anemia.

Evaluation of a new hyperbaric oxygen ventilator during pressure-controlled ventilation.

The stability of a new hyperbaric ventilator (Shangrila590, Beijing Aeonmed Company, Beijing, China) at different clinically relevant pressures in a hyperbaric chamber during pressure-controlled ventilation (PCV) was investigated. The ventilator was connected to a test lung in the multiplace hyperbaric chamber. The inspiratory pressure (PI) of the ventilator was set to 1.0, 1.5, 2.0, 2.5 and 3.0 kPa (approximately 10, 15, 20, 25 and 30 cmH₂O). The compliance and resistance of the test lung were set to 200 mL·kPa⁻¹ and 2 kPa·L⁻¹·s⁻¹, respectively. Experiments were conducted at 101, 203 and 284 kPa ambient pressure (1.0, 2.0 and 2.8 atmospheres absolute respectively). At each of the 5 PI values, the tidal volume (VT), peak inspiratory pressure (Ppeak) and peak inspiratory flow (Fpeak) displayed by the ventilator and the test lung were recorded for 20 cycles. Test lung data were considered the actual ventilation values. The ventilation data were compared among the three groups to evaluate the stability of the ventilator. At every PI, the Ppeak detected by the ventilator decreased slightly with increasing ambient pressure. The Fpeak values measured by the test lung decreased substantially as the ambient pressure increased. Nevertheless, the reduction in VT at 284 kPa and PI 30 cmH₂O (compared to performance at 101 kPa) was comparatively small (approximately 60 ml). In PCV mode this ventilator provided relatively stable VT across clinically relevant PI values to ambient pressures as high as 284 kPa. However, because Fpeak decreases at higher ambient pressure, some user adjustment might be necessary for precise VT maintenance during clinical use at higher PIs and ambient pressures.

Ear diseases due to diving with an aqualung

Due to the growing popularity of diving, more and more people suffer from injuries related to this activity and ear injuries are among the most common ones. During diving, dysfunction of both the external, middle and inner ear are likely to occur. Inflammation is the most common disease of the external ear, which, in most cases, requires only local treatment with ear drops. Barotrauma of the middle and inner ear may occur due to Eustachian tube failure and difficulties in equalizing underwater pressure, also manifested as hearing loss and dizziness. In most cases, conservative treatment is applied, however, under specific conditions such as perforation of the tympanic membrane or the presence of persistent perilymphatic fistulas, surgical treatment may be necessary. In the case of severe dizziness or hearing loss during ascent after diving at great depths, a preliminary diagnosis of inner ear decompression sickness should be made and the patient should be placed in a hyperbaric oxygen chamber as a matter of urgency.

Hyperbaric Treatment Stimulates Chaperone-Mediated Macroautophagy and Autophagy in the Liver Cells of Healthy Female Rats.

The role of autophagy goes far beyond the elimination of damaged cellular components and the quality control of proteins. It also cleanses cells from inclusions, including pathogenic viruses, and provides energy-forming components. The liver, which is an organ with increased metabolism, is made up of cells that are particularly vulnerable to damage. Therefore, detoxification of liver cells in the process of autophagy has become a very important issue clinically. The aim of this study was an immunohistochemical evaluation of proteins activated in rat liver cells at different stages of hyperbaric autophagy. The rats used for the study were randomly divided into six equivalent groups-three control groups and three experimental groups. Animals from the experimental groups were subjected to hyperbaric treatment in a hyperbaric chamber, with a pressure of 1.6 ATA for 120 min. They breathed atmospheric air. Rats were decapitated within 5 or 10 days after removal from the chamber. Immunohistochemical reactions with beclin 1, LC3B, RAB7, and HSC73 proteins were carried out on preparations made from liver slices. A three-step labeled streptavidin-biotin detection method of paraffin blocks (LSAB three-step) was used for immunohistochemical research. The results were evaluated using computer programs for morphometric analysis of microscopic images by calculating the mean surface areas occupied by a positive immunohistochemical reaction in individual groups for all antibodies tested. Increased closure of substrates in the autophagosome (beclin 1) induced late endosome transport and accelerated autophagosome maturation process (RAB7). Furthermore, a larger number of autophagosomes (LC3B) was observed in liver cells immediately after the cessation of hyperbaric activity; however, this decreased after 5 days. During this time, chaperone-mediated autophagy (HSC73) was observed on a larger scale. This means that increased macroautophagy induced by hyperbaric treatment weakens with time that has elapsed since the cessation of high pressure, whereas similarly induced chaperone-mediated autophagy intensifies over time.

CO2 Breathing Prior to Simulated Diving Increases Decompression Sickness Risk in a Mouse Model: The Microbiota Trail Is Not Forgotten.

Decompression sickness (DCS) with neurological disorders is the leading cause of major diving accidents treated in hyperbaric chambers. Exposure to high levels of CO2 during diving is a safety concern for occupational groups at risk of DCS. However, the effects of prior exposure to CO2 have never been evaluated. The purpose of this study was to evaluate the effect of CO2 breathing prior to a provocative dive on the occurrence of DCS in mice. Fifty mice were exposed to a maximum CO2 concentration of 70 hPa, i.e., 7% at atmospheric pressure, for one hour at atmospheric pressure. Another 50 mice breathing air under similar conditions served as controls. In the AIR group (control), 22 out of 50 mice showed post-dive symptoms compared to 44 out of 50 in the CO2 group (p < 0.001). We found that CO2 breathing is associated with a decrease in body temperature in mice and that CO2 exposure dramatically increases the incidence of DCS (p < 0.001). More unexpectedly, it appears that the lower temperature of the animals even before exposure to the accident-prone protocol leads to an unfavorable prognosis (p = 0.046). This study also suggests that the composition of the microbiota may influence thermogenesis and thus accidentology. Depending on prior exposure, some of the bacterial genera identified in this work could be perceived as beneficial or pathogenic.

Establishment of NK Cell Natural Immunotherapy for Cancer Prevention and Treatment Using the Natural Terpenes Derived from Forest Phytoncide

The active ingredient of forest phytoncide has many remarkable biological activities, especially in the aspect of anti-tumor. It can activate NK cells, increase the number of NK cells and the expression level of anti-cancer protein in NK cells, induce the self-apoptosis of cancer cells, and help the human body effectively complete the cellular immune anti-cancer mechanism. If we replace ordinary air with natural forest air as a new pressurizing medium and input it into the hyperbaric oxygen chamber, after being processed by hyperbaric oxygen chamber oxygen production technology, the high pressure oxygen of forest phytoncide is generated. At this time, the high pressure oxygen inhaled into the body is different from natural forest air or ordinary air. The fundamental difference is that the high pressure oxygen inhaled into the body at this time contains both high concentration of oxygen and high concentration of phytoncide, moreover the phytoncide concentration and oxygen concentration are much higher than the natural forest air or ordinary air. After it is inhaled by the human body into the alveoli, it can reach the peripheral blood through the pulmonary circulation and systemic circulation, and the high concentration of the active component terpene of phytoncide has an opportunity to directly contact NK cells and fully play the biological activity of activating NK cells. The high pressure oxygen that enters the alveoli simultaneously with phytoncide gas also passes through the pulmonary and systemic circulation, reaches the peripheral blood, Oxygen is released from the oxygenated hemoglobin, passes through the cell membrane and enters the mitochondria in the cells to provide sufficient energy for the physiological activities of NK cells. By applying this basic principle, we can establish a satisfactory NK cell natural immunotherapy for cancer prevention and treatment that can be accepted by humanity in the long run.

Integrated Approach for the Management of Osteonecrosis: Photodynamic Therapy and Hyperbaric Chamber Synergy

Integrated Approach for the Management of Osteonecrosis: Photodynamic Therapy and Hyperbaric Chamber Synergy

Buckle propagation failure of subsea pipelines; experimental, analytical, and numerical simulations

This research program investigates buckle propagation in subsea pipeline systems, The study aims to understand and predict propagation pressure (PP ), essential for ensuring the structural integrity and safe operation of these pipelines, hypothesizing that incorporating strain hardening effects into the strain energy approach can significantly enhance the prediction of propagation pressure (PP ) and that geometric parameters, particularly the diameter-to-thickness (D/t) ratio, play a major role in PP prediction. Accurate PP prediction is essential for ensuring the structural integrity and safe operation of these pipelines. The investigation is conducted through analytical, experimental, numerical, and machine learning approaches. A new analytical solution for PP is proposed, incorporating strain hardening effects using a strain energy approach. Experimental tests conducted using a hyperbaric chamber cover a wide range of pipeline configurations and materials, including steel, aluminum, and stainless steel. Complementing experimental data, numerical simulations using finite element methods facilitate parametric dependence analysis and the visualization of results through 3D charts. More than 600 FE models were simulated to investigate the influence of geometric and material parameters on PP . The findings from both experimental and numerical analyses indicated that the geometric and material properties have a significant impact on PP , specifically, the diameter-to-thickness (D/t) ratio, yield stress (σy ), and tangent modulus (E′). Furthermore, Machine Learning (ML) techniques have been used to predict the PP value and have concluded that the Random Forest (RF) technique outperformed the K-Nearest Neighbors (KNN), and Multi-layer Perceptron (MLP) neural network techniques. Overall, this study concludes that analytical, numerical, and machine learning approaches offer valuable insights into buckle propagation in subsea pipelines, contributing to improved safety and reliability in offshore oil and gas operations.

Nathanial Henshaw: Not history’s pioneering hyperbaric practitioner

ABSTRACT Clarke R. Nathanial Henshaw: Not history’s pioneering hyperbaric practitioner. Undersea Hyperb Med. 2024 Second Quarter; 51(2):107-113. A widely accepted belief is that Nathaniel Henshaw was the first practitioner of hyperbaric medicine. He is said to have constructed the first hyperbaric chamber where he treated several disorders and provided opportunities to prevent disease and optimize well-being. While there is little doubt Henshaw was the first to conceptualize this unique medical technology, careful analysis of his treatise has convinced this writer that his was nothing more than a proposal. Henshaw’s air chamber was never built. He would have failed to appreciate how its structural integrity could be maintained in the presence of enormous forces generated by envisioned changes in its internal pressure and, likewise, how its door could effectively seal the chamber during hypo-and hyperbaric use. Henshaw would have also failed to appreciate the limitations of his two proposed measuring devices and the toxic nature of one. Neither of these would have provided any quantitative information. The impracticality of his proposed method of compressing and decompressing the chamber is readily apparent. So, too, the likely toxic accumulation of carbon dioxide within the unventilated chamber during lengthy laborious periods required to operate it. Henshaw recommended pressures up to three times atmospheric pressure and durations for acute conditions until their resolution. Such exposures would likely result in fatal decompression sickness upon eventual chamber ascent, a condition of which nothing was known at the time. It would be another 170 years before a functional air chamber would finally become a reality. Henshaw’s legacy, then, is limited to the concept of hyperbaric medicine rather than being its first practitioner.

Inner ear decompression sickness after a routine dive and recompression chamber drill

ABSTRACT Parsons D, Utz E, Kidd G, Virgilio G. Inner ear decompression sickness after a routine dive and recompression chamber drill. Undersea Hyperb Med. 2024 Second Quarter; 51(2):129-135. Inner ear decompression sickness (IEDCS) is an uncommon diving-related injury affecting the vestibulocochlear system, with symptoms typically including vertigo, tinnitus, and hearing loss, either in isolation or combination. Classically associated with deep, mixed-gas diving, more recent case series have shown that IEDCS is indeed possible after seemingly innocuous recreational dives, and there has been one previous report of IEDCS following routine hyperbaric chamber operations. The presence of right-to-left shunt (RLS), dehydration, and increases in intrathoracic pressure have been identified as risk factors for IEDCS, and previous studies have shown a predominance of vestibular rather than cochlear symptoms, with a preference for lateralization to the right side. Most importantly, rapid identification and initiation of recompression treatment are critical to preventing long-term or permanent inner ear deficits. This case of a U.S. Navy (USN) diver with previously unidentified RLS reemphasizes the potential for IEDCS following uncomplicated diving and recompression chamber operations – only the second reported instance of the latter.

Narcotic Nitrogen Effects Persist after a Simulated Deep Dive.

Background and Objectives: Scuba divers often experience persistent inert gas narcosis (IGN) even after surfacing. This study aimed to test the hypothesis that breathing oxygen (O2) before surfacing can reduce postdive IGN. Materials and Methods: A group of 58 experienced divers underwent a 5 min dive at a depth of 50 m in a multi-place hyperbaric chamber. They were decompressed using air (air group). Another group of 28 divers (O2 group) breathed 100% O2 during the end of decompression. Prior to and after the dive, all participants performed the Sharpened Romberg test (SRT) and a modified tweezers test. Results: In the air group, the number of positive SRT results increased postdive (47% vs. 67%), indicating a greater impairment in the vestibular system (Cohen's d = 0.41). In the O2 group, the percentage of positive SRT results remained constant at 68% both before and after the dive. In terms of the modified tweezers test, the air group showed no significant change in the number of picked beads (40 ± 9 vs. 39 ± 7), while the O2 group demonstrated an increase (36 ± 7 vs. 44 ± 10) (Cohen's d = 0.34). Conclusion: The results reveal that the SRT revealed a negative effect of nitrogen (N2) on the vestibular system in the air group. The increased number of beads picked in the O2 group can be attributed to the learning effect, which was hindered in the air group. Consistent with our hypothesis, breathing O2 during decompression appears to reduce postdive IGN.

Hyperbaric oxygen preconditioning rescues prolonged underwater exercise-induced hippocampal dysfunction by regulating microglia activation and polarization

Underwater exercise is becoming increasingly prevalent, during which brain function is necessary but is also at risk. However, no study has explored how prolonged exercise affect the brain in underwater environment. Previous studies have indicated that excessive exercise in common environment causes brain dysfunction but have failed to provide appropriate interventions. Numerous evidence has indicated the neuroprotective effect of hyperbaric oxygen preconditioning (HBO-PC). The objective of this study was to investigate the cognitive effect of prolonged underwater exercise (PUE) and to explore the potential neuroprotective effect of HBO-PC in underwater environment. Rats swimming for 3 h in a simulated hyperbaric chamber (2.0 ATA) was used to establish the PUE animal model and HBO-PC (2.5 ATA for 1, 3,5 times respectively) was administrated before PUE. The results demonstrated that PUE triggers anxiety-like behaviors, cognitive impairment accompanied by hippocampal dysfunction, microglia activation and neuroinflammation. Conversely, 3 HBO-PC rescued anxiety-like behaviors and cognitive impairment. Mechanistically, 3 HBO-PC reduced microglia activation and switched the activated microglia from a pro-inflammatory to neuroprotective phenotype. These findings illustrated that PUE induces anxiety-like behaviors and cognitive impairment and HBO-PC of proper frequency may provide an appropriate and less invasive intervention for protecting the brain in underwater exercise.

Effects of functional treatment of V metatarsal bone fracture in athletes – an evaluation of cases

This study presents the rehabilitation process for the management of six cases of fractures of the fifth metatarsal bone in players of various sports playing at high levels of competition in Poland. The course of treatment was based on an intensive rehabilitation protocol with the need for orthopaedic shoe inserts, with full weight bearing on the limb and under close supervision of a physiotherapist. The effectiveness of rehabilitation was assessed by physical examination, X-ray examination and the numerical pain rating scale - NRS. This study focuses on the rehabilitation process for managing fractures of the fifth metatarsal bone in high-level athletes in Poland. The treatment involved an intensive rehabilitation protocol with orthopaedic shoe inserts, full weight bearing, and physiotherapist supervision. The effectiveness of rehabilitation was evaluated through physical exams, X-rays, and the numerical pain rating scale. Introduction Fractures of the fifth metatarsal bone are common in athletes aged 10-29, especially in football, basketball, and dance. Complications include delayed bone fusion and repeat fractures, emphasizing the importance of quick return to fitness. The involvement of physiotherapists and patient positivity is crucial. The debate among clinicians stems from classification variations and interpretations of 'Jones fractures'. Diagnostic and Classification Methods The Lawrence and Bottle classification distinguishes three types of metatarsal fractures: avulsion, Jones, and fatigue fractures. The study presents six cases of conservative treatment for these fractures, showing positive outcomes in returning athletes to competition. Rehabilitation Procedure Patients underwent functional treatment with orthopaedic insoles, immediate weight-bearing, and various therapies like Orthokine®, Exogen, hyperbaric chamber sessions, ESWT, and EPTA. Post-workout treatments included Game Ready®, flossing, manual therapy, dry needling, and lymphatic drainage. Patients also engaged in self-managed rehabilitation exercises. Treatment Results Radiographic examinations showed progressive healing in all cases, with reduced pain and no edema after two weeks. Patients returned to sports within three weeks, with no complaints after 13 months. The study highlights the success of functional treatment in achieving full recovery without complications. Conclusion The study challenges the need for surgical intervention and immobilization in treating fifth metatarsal fractures. Functional treatment led to excellent outcomes and quick return to sports. Literature review supports early mobilization and functional therapy for optimal results. Further research is needed to establish a standard treatment protocol based on evidence-based medicine.

Exposure to hyperbaric O2 levels leads to blood-brain barrier breakdown in rodents

IntroductionHyperbaric oxygen has been used as a medical treatment tool in hyperbaric chambers and is an integral part of professional and combat divers’ activity. In extreme cases, exposure to hyperbaric oxygen can develop central nervous system oxygen toxicity (CNS-OT), which leads to seizures and eventually death. CNS-OT is caused by neuronal hyperactivity due to high oxygen levels, potentially damaging brain cells including the blood-brain barrier (BBB). However, the effect of hyperbaric oxygen levels on the healthy BBB has not been characterized directly yet.MethodsSix or three different groups of ~ eight rats or mice, respectively, were exposed to increasing levels of partial pressure of oxygen (0.21 to 5 ATA) in a hyperbaric chamber, followed by MRI scanning with gadolinium. Statistical significance (adjusted p-value ≤ 0.05) was assessed using linear regression and ordinary one-way (rats) or two-way (mice) ANOVA with correction of multiple comparison tests. In rats, the effect of 100% oxygen at 5 ATA was independently validated using FITC-Dextran (5 kDa). Statistical significance (p-value ≤ 0.05) was assessed using Welch’s t-test and effect size was calculated by Cohen’s D.ResultsIn rats, analyzed MRI scans showed a significant trend of increase in the % gadolinium in brain tissues as a result of hyperbaric oxygen pressures (p-value = 0.0079). The most significant increase was measured at 4 ATA compared to air (adjusted p-value = 0.0461). Significant increased FITC-Dextran levels were measured in the rats’ brains under 100% oxygen at 5 ATA versus air (p-value = 0.0327; Effect size = 2.0). In mice, a significant increase in gadolinium penetration into the hippocampus and frontal cortex was measured over time (adjusted p-value < 0.05) under 100% oxygen at 3 and 5 ATA versus air, and between the treatments (adjusted p-value < 0.0001).ConclusionsThe BBB is increasingly disrupted due to higher levels of hyperbaric oxygen in rodents, indicating a direct relation between hyperbaric oxygen and BBB dysregulation for the first time. We suggest considering this risk in different diving activities, and protocols using a hyperbaric chamber. On the other hand, this study highlights the potential therapeutic usage of hyperbaric oxygen for controlled drug delivery through the BBB into brain tissues in different brain-related diseases.

The involvement of oxidative stress and the TLR4/NF-κB/NLRP3 pathway in acute lung injury induced by high-altitude hypoxia

ObjectiveThis study investigated the effect of oxidative stress and the TLR4/NF-κB/NLRP3 pathway on the pathogenesis of acute lung injury (ALI) induced by high-altitude hypoxia. MethodsRats were placed in an animal hyperbaric oxygen chamber to establish a rat model of ALI induced by high-altitude hypoxia after treatment with N-acetylcysteine (NAC; a reactive oxygen species [ROS] inhibitor) or/and MCC950 (an NLPR3 inflammasome inhibitor). After modeling, the wet-to-dry weight ratio (W/D) of rat lung tissues was calculated. In lung tissues, ROS levels were detected with immunofluorescence, the enzyme activity was tested with the kit, and the expression of TLR4/NF-κB/NLRP3 pathway-related genes and proteins was measured with western blotting and qRT-PCR. The levels of inflammatory factors in the serum were quantified with ELISA. ResultsAfter modeling, rats showed significantly increased W/D, ROS levels, and Malondialdehyde (MDA) concentrations and markedly diminished Superoxide dismutase (SOD) and Glutathione (GSH) concentrations in lung tissues (all P < 0.01), accompanied by substantially enhanced serum levels of TNF-α, IL-6, and IL-1β, significantly reduced serum levels of IL-10, and remarkably augmented TLR4, NLRP3, p-NF-κB p65, NF-κB p65 mRNA, and Caspase-1 expression in lung tissues (all P < 0.01). Furthermore, treatment with NAC or MCC950 alone or in combination prominently lowered the W/D of lung tissues (P < 0.01), serum levels of TNF-α (P < 0.05), IL-6 (P < 0.05), and IL-1β (P < 0.01), and NF-κB p65 expression and phosphorylation (P < 0.05, P < 0.01) while significantly increasing SOD and GSH concentrations (P < 0.05, P < 0.01) and serum levels of IL-10 (P < 0.01) in modeled rats. Meanwhile, treatment of NAC alone or combined with MCC950 significantly reduced MDA concentration and ROS levels (P < 0.05, P < 0.01) in modeled rats, and treatment of MCC950 alone or combined with NAC considerably declined TLR4, NLRP3, and Caspase-1 expression in modeled rats (P < 0.05, P < 0.01). ConclusionInhibition of oxidative stress and the TLR4/NF-κB/NLRP3 pathway can ameliorate ALI in rats exposed to high-altitude hypoxia.