Hyperbaric Chamber Research Articles

CONCUSSION REHABILITATION INTERVENTIONS

Sports-related concussions (SRC) are a common injury among athletes. Despite our growing understanding of concussion pathophysiology, comprehensive rehabilitation programs remain a clinical challenge. The accepted view of SRC rehabilitation emphasizes physical and cognitive rest. However, some conflicting studies report rest may facilitate prolonged symptoms. In this review article, we report on alternative SRC rehabilitation strategies to address the complex symptom variations, including physical activity, neuro-visual training, vestibular training, music therapy, speech-language therapy, and hyperbaric oxygen chamber therapy. The mass of published works supports the utility of these alternative therapies to aid recovery, but more research is vital to clarifying these relationships. In this review, we explore the relationships between symptoms and therapies. As there is a growing body of evidence to support these alternative therapies, many questions remain when concerning the role these alternative methods play in the bigger picture of standardizing a thorough SRC rehabilitation program.

Prediction of central nervous system oxygen toxicity symptoms using electrodermal activity and machine learning

ObjectiveBreathing elevated oxygen partial pressures (PO2) prior to SCUBA diving increases the risk of developing central nervous system oxygen toxicity (CNS-OT), which could impair performance or result in seizure and subsequent drowning. We aimed to study the dynamics of electrodermal activity (EDA) while breathing elevated PO2 in the hyperbaric environment (HBO2) as a possible means to predict impending CNS-OT. To this end, we used machine learning to automatically detect and predict the onset of symptoms associated with CNS-OT in humans by using features derived from EDA in both time and frequency domains. MethodsWe collected electrodermal activity (EDA) data from forty-nine exposures to HBO2 while subjects were undergoing cognitive load and exercise in a hyperbaric oxygen chamber. Four independent experts were present during the experiment to monitor and classify any symptoms associated with hyperbaric oxygen toxicity. We computed a highly sensitive time varying spectral EDA index, named TVSymp, and extracted informative features from skin conductance responses (SCRs). Machine learning algorithms were trained and validated for classifying features from SCRs and TVSymp as CNS-OT related or non-CNS-OT related. Machine learning models were validated using a subject-independent leave one subject out (LOSO) validation scheme. ResultsOur machine learning model was able to classify EDA dynamics related to CNS-OT with 100 % sensitivity and 84 % specificity via LOSO validation. Moreover, the median prediction time for CNS-OT symptoms was ∼ 250 s preceding the occurrence of actual symptoms. SignificanceThis study shows that EDA can potentially be used for early prediction of CNS-OT in divers with a high sensitivity and sufficient prediction time for countermeasures. While the study results are promising, independent validation datasets are warranted to confirm the findings. However, the current results are well corroborated in an animal study, which consistently showed seizure prediction time of 2 min prior to seizure.

Delayed surgical treatment of Pipkin type II fracture in a patient with infection COVID-19. A case report

A 25-year-old man with a hip dislocation and Pipkin II type femoral head fracture, whose surgical treatment was postponed for 15 days due to Covid 19 pandemic, is described. For 2 months after surgery, treatment was supported by therapy in a hyperbaric chamber and with a continuous passive motion (CPM) splint. Four months after surgery, bone fusion of the femoral head fracture was achieved with its normal revascularization. Two years after the operation, the patient was moving efficiently and had no complaints of hip pain. Delayed open reduction and internal fixation of the femoral head fracture resulted in a very good functional and radiological outcome.

Decompression sickness of the inner ear and relationship with a patent oval foramen: a study of 61 cases.

To discuss the link between inner ear decompression sickness and patent foramen ovale. Monocentric and retrospective study on decompression sickness of the inner ear requiring hyperbaric chamber treatment, from 2014 to 2021. Sixty-one patients of inner ear decompression sickness were included in this study. Twenty-four patients had vestibular injuries, 28 cochlear injuries and 9 cochleo-vestibular injuries. Compression chamber treatment was given, using an oxygen-helium mixture with oxygen partial pressure (PIO2) limited to 2.8 atmosphere absolute (ATA). All vestibular accidents completely recovered without clinical sequelae. For cochlear accident only 10 out of 37 patients (27%) recovered completely. A right-left shunt (patent foramen oval or intra-pulmonary shunt) was found in 31.1% of patients with inner ear decompression sickness (p > 0.05). The presence of patent foramen oval in patients with inner ear decompression was not statistically significant in our study. Understanding of the pathophysiology of decompression illness and the physiology and anatomy of the labyrinth would suggest a mechanism of supersaturation with degassing in intra-labyrinthine liquids.

An overview of remedial treatment for sudden hearing loss

In the acute phase of sudden hearing loss, in patients for whom two weeks of standardized treatment is ineffective or unsatisfactory, or patients for whom the condition has accumulated for more than three weeks, remedial treatment for about 1 week-1 month can be actively pursued to provide an opportunity for hearing recovery. The mainstay of remedial therapy is intratympanic and retro auricular hormone injections. If the disease has progressed beyond 6 weeks and there is still no significant improvement with local hormone injections, the overall efficacy of the treatment can be improved by a combination of Chinese and Western medicine, such as hyperbaric oxygen chambers, acupuncture, and massage (tui na). However, remedial treatments combining Chinese and Western medicine have not been standardized, and attention should be paid to the diagnosis and treatment during the remedial period.

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

BackgroundCritically 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.MethodsThis 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.ResultsPatients 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.ConclusionsHyperbaric 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.

Complex Hippocampal Response to Thermal Skin Injury and Protocols with Hyperbaric Oxygen Therapy and Filipendula ulmaria Extract in Rats.

The aim of this study was to evaluate the alterations of the hippocampal function that may be related to anxiogenic response to thermal skin injury, including the morpho-functional alterations, and the effects of hyperbaric oxygen (HBO) and Filipendula ulmaria (FU) extract in the treatment of anxiety-like behavior that coincides with thermal skin injury. A rat thermal skin injury experimental model was performed on 2-month-old male Wistar albino rats. The evaluated therapeutic protocols included HBO and/or antioxidant supplementation. HBO was applied for 7 days in the hyperbaric chamber (100% O2, 2.5 ATA, 60 min). Oral administration of FU extract (final concentration of 100 mg/kg b.w.) to achieve antioxidant supplementation was also applied for 7 days. Anxiety level was estimated in the open field and elevated plus-maze test, which was followed by anesthesia, sacrifice, and collection of hippocampal tissue samples. HBO treatment and FU supplementation significantly abolished anxiogenic response to thermal skin injury. This beneficial effect was accompanied by the reduction in hippocampal pro-inflammatory and pro-apoptotic indicators, and enhanced BDNF and GABA-ARα2S gene expression, previously observed in untreated burns. The hippocampal relative gene expression of melatonin receptors and NPY positively responded to the applied protocols, in the same manner as µ and δ opioid receptors, while the opposite response was observed for κ receptors. The results of this study provide some confirmations that adjuvant strategies, such as HBO and antioxidant supplementation, may be simultaneously applied in the treatment of the anxiety-like behavior that coincides with thermal skin injury.

Towards real-time decompression sickness mitigation using wearable capacitive micromachined ultrasonic transducer arrays

Decompression sickness (DCS) due to inert gas supersaturation remains one of the major risks for scuba divers and can occur despite adherence to prevention schedules for staged decompression. Post-dive echocardiography for venous gas emboli (VGE) detection has low sensitivity for DCS outcome and is unable to provide real-time physiological monitoring underwater. Alternatively, we present progress towards collecting ultrasound data while at pressure and an exploration into a quantitative assessment for decompression stress. Ultrasound data of an imaging phantom were collected in a hyperbaric chamber up to 9 ATA using a Verasonics V1 system and custom capacitive micromachined ultrasonic transducer (CMUT). The DC voltage requirement for CMUT operation decreased as ambient pressure increased. Separately, a mouse model was used to simulate an extreme pressure profile and echocardiograms were collected every 20 min over 2-h post-decompression. Towards enhancement of DCS assessment, a quantitative analysis of the murine echocardiograms was implemented. Preliminary results show an increase in signal intensity within the venous blood from pre- to post-dive, indicating potential gas presence despite VGE absence. Our findings demonstrate the ability to obtain ultrasound data at pressure and a potential continuous assessment method, which may provide a practical direction for real- time decompression stress quantification.

A Descriptive Study on the Impacts of Hyperbaric Oxygen Therapy on Autistic Individuals Using Parent Testimonies.

Introduction Hyperbaric oxygen therapy (HBOT) has been influential in treating many physical and psychological ailments, including the symptoms of autism. This current study aims to evaluate HBOT parents' goals and exit interviews describing the positive, negative, or no impacts experienced from the HBOT dives, asking the question, "Are your child's symptoms improving?" Methods Between January 2020 and July 2023, a Class B monoplace hyperbaric chamber (Sechrist 3300H, Sechrist Industries, Inc., Anaheim, California, United States) was used to administer HBOT sessions to patients with autism. Medical-grade oxygen was pressurized to 1.5-2.0 atmospheres absolute at a rate of 1-2 psi/min, with an average oxygen percentage of 100%, for up to five sessions per week. Retrospective descriptive data and patient information through parent testimonials were collected through a chart review of 30 children and one adult with autism who experienced HBOT sessions. Data were presented through exit interviews describing how parents felt about their child's progress toward goals. Four raters rated parent testimonies on a 5-point Likert scale (1 = Much worse, 2 = Somewhat worse, 3 = Stayed the same, 4 = Somewhat improved, and 5 = Much improved), and an inter-rater reliability estimate using interclass correlation (2) (r = 0.831) was derived, indicating excellent agreement between raters. Results Parents/caregivers provided testimony in an exit interview with a registered nurse after the individual with autism received an entire course of HBOT dives. Descriptive statistics resulted in Rater #1 (M = 4.19, median = 4, SD = 0.654): 87.1% of Rater #1 ratings were Somewhat improved and Much improved; Rater #2 (M = 4.23, median = 4, SD = 0.717): 83.9% of Rater #2 ratings were Somewhat improved and Much improved; Rater #3 (M = 4.23, median = 4, SD = 0.560): 93.5% of Rater #3 ratings were Somewhat improved and Much improved; and Rater #4 (M = 4.26, median = 4, SD = 0.631): 90.3% of Rater #4 ratings were Somewhat improved and Much improved. One-way ANOVA resulted in F (3,123) = 0.052, p = 0.984, which indicated a nonstatistically significant mean difference between rater groups. Conclusions The current study assessed HBOT parents'/caregivers' goals and exit interviews, describing the effects experienced from the complete course of HBOT dives on their children/individuals. A majority of parents/caregivers declared that their condition had "Much improved" or "Somewhat improved," based on the 5-point Likert scale. Based on parents'/caregivers' testimonies, HBOT was demonstrated as a safe and effective intervention, and side effects were primarily mild and did not lead to treatment discontinuation. As a result of this analysis, we recommend continued use of HBOT for treatment.

Experimental and analytical evaluation of the performance of hybrid steel-CFRP pipelines at high external pressures

Behavior of hybrid steel-CFRP pipe systems under external pressures is studied herein using a combination of experimental, analytical, and finite element (FE) methods. Hyperbaric chamber tests are conducted on steel tubes and those wrapped with CFRP of different thicknesses and winding orientations to evaluate their performances. Based on the experimental observations and using analytical methods, new equations are proposed that can predict the collapse and propagation pressures of the hybrid steel-CFRP pipelines. The results revealed a significant enhancement in the collapse and buckle propagation capacities of the hybrid steel-CFRP pipes, with average increases of 60% and 200% respectively, compared to bare steel pipes. The failure mode observed in the hybrid steel-CFRP pipe was characterized by a U-shaped pattern, which occurred at higher pressures than the dog-bone shape mode observed in bare steel pipes. As evidenced in the FE results, the presence of CFRP in the hybrid steel-CFRP pipe system led to improved stress distribution, enhanced buckle propagation capacity, and reduced ovality. These findings demonstrate the effectiveness of CFRP in reinforcing steel pipes and highlight the potential for the hybrid steel-CFRP pipe system to offer superior performance in deep-waters.

Heart Rate Variability to Automatically Identify Hyperbaric States Considering Respiratory Component.

This study's primary objective was to identify individuals whose physiological responses deviated from the rest of the study population by automatically monitoring atmospheric pressure levels to which they are exposed and using parameters derived from their heart rate variability (HRV). To achieve this, 28 volunteers were placed in a dry hyperbaric chamber, where they experienced varying pressures from 1 to 5 atmospheres, with five sequential stops lasting five minutes each at different atmospheric pressures. The HRV was dissected into two components: the respiratory component, which is linked to respiration; and the residual component, which is influenced by factors beyond respiration. Nine parameters were assessed, including the respiratory rate, four classic HRV temporal parameters, and four frequency parameters. A k-nearest neighbors classifier based on cosine distance successfully identified the atmospheric pressures to which the subjects were exposed to. The classifier achieved an 88.5% accuracy rate in distinguishing between the 5 atm and 3 atm stages using only four features: respiratory rate, heart rate, and two frequency parameters associated with the subjects' sympathetic responses. Furthermore, the study identified 6 out of 28 subjects as having atypical responses across all pressure levels when compared to the majority. Interestingly, two of these subjects stood out in terms of gender and having less prior diving experience, but they still exhibited normal responses to immersion. This suggests the potential for establishing distinct safety protocols for divers based on their previous experience and gender.

Critical flicker fusion frequency results during oxygen decompression in standard HBOT session - observational study.

Most hyperbaric medicine reports concentrate on the patient and his morbidities. In addition to the well-known indications for hyperbaric oxygen therapy (HBOT), we cannot discount possible side effects. Among medical staff regularly exposed to hyperbaric conditions the best described so far is decompression sickness. A non-invasive and easily available way to assess cognitive functioning involves the use of the critical flicker fusion frequency (CFFF) test. In the current study, the flicker test was performed several times on 21 subjects, both under normobaric and hyperbaric conditions. The test was conducted using the device that flickering was programmed according to the method of limits. While in the hyperbaric chamber, 15 of the participants breathed oxygen to reduce the risk of decompression sickness. Flicker and fusion frequencies differed from each other in both normo- and hyperbaric conditions (p < 0.01). CFFF results were dependent on oxygen breathing during decompression.

Hyperbaric Chamber as Complementary Treatment to Standard Therapy for Brain Tumors: beneficial or not?

Hyperbaric Chamber as Complementary Treatment to Standard Therapy for Brain Tumors: beneficial or not?

A Comparative Analysis of HBOT and L-HBOT: An Innovative Possibility to Enhance HBOT?

Oxygen is a vital component of wound healing. When trauma occurs, causing a wound, it is difficult to get oxygen to the wound site because of the damage that is present. Hyperbaric oxygen chamber therapy (HBOT) is employed to combat hypoxia in wounds by having the patient inhale high concentrations of oxygen at elevated atmospheric pressures, accelerating the rate at which oxygen dissolves into the bloodstream at a faster rate. HBOT has been used to treat a variety of conditions like diabetic foot ulcers, Crohn’s disease, and chronic wounds. Yet, the limited body of literature and the risk of complications have limited the application of HBOT. Medical professionals have proven the significance of oxygen on wound healing from stimulating most of the vital functions to initiating the production of certain genes, oxygen is the keystone for successful complete wound healing. On the other hand, the risk of oxygen toxicity is one of the main contraindications of HBOT. Contrary to common knowledge, recent studies have shown that HBOT administered at a lower atmospheric pressure with a lower oxygen concentration can decrease this risk significantly. Low-pressure hyperbaric oxygen therapy (L-HBOT) may still be as effective as traditional high-pressure hyperbaric oxygen therapy (H-HBOT) without the unpredictable complications that medical professionals are unsure of. In all, this review aims to analyze recent studies to provide a clear comparison between these two variations of HBOT.

Mechanical Improvement of Gas Monitoring System in Monoplace Hyperbaric Chamber to Advance the Safety and Efficacy.

A Monoplace hyperbaric chamber delivers oxygen to the patient's tissues through breathing. Gas monitoring inside the chamber is important because oxygen (O2) is consumed, and carbon dioxide (CO2) is increased because treatment is performed in a closed volume. This study aimed to advance the safety and efficacy of the monoplace hyperbaric chamber (MHC) through mechanical improvement in a gas monitoring system (GMS). First, as the oxygen supply method was changed to the direction of the patient's face, it was compared the values of O2, CO2, humidity, and temperature were measured in the MHC and the GMS when operating at 2.0 atmosphere absolute (ATA) and 3.0 ATA. Second, to evaluate the effects of variables across measuring time, it was analyzed in a 3-way repeated measure ANOVA (10 min.×20 min.×30 min.). Lastly, the values before and after the optimization of the MHC were compared by applying a cooler to prevent temperature rise inside the MHC. In 2.0 ATA, the average humidity was higher in the MHC than in the GMS (p<0.001). Also, the average temperature was lower in the MHC than in the GMS (p<0.001). In 3.0 ATA, the average CO2 and humidity were higher in the MHC than in the GMS, respectively (p<0.001, p=0.004). The 3-way repeated measures ANOVA revealed a significant difference in most main and interacted factors (p<0.05). O2 and temperature, comparing before and after MHC optimization, revealed a significant difference (p<0.05). Few studies have verified safety and effectiveness by evaluating the pressure, oxygen concentration, etc. of a monoplace hyperbaric chamber. Further research is expected to verify the effectiveness of providing comfort to patients receiving hyperbaric oxygen treatment and increase the treatment effect.

Hyperbaric Exposure Effects on Pulmonary Functions in Hyperbaric Chamber Workers

Hyperbaric Exposure Effects on Pulmonary Functions in Hyperbaric Chamber Workers

Hyperbaric Oxygen Therapy Impact for the Function of Kidney in Metabolic Syndrome (SM) Patients

Hyperbaric Oxygen Therapy (HBOT) is the therapy of inhaling 100% pure oxygen in a hyperbaric chamber of more than 1 absolute atmosphere. Currently, the use of hyperbaric oxygen therapy is increasingly widespread, not only for decompression sickness and diving problems. But it has been used for clinical therapy, cosmetics, and geriatric care. The American Food and Drug Administration (FDA) has also confirmed various clinical indications, especially those related to metabolic syndromes such as Diabetes Mellitus (DM) and Diabetic Foot Ulcers (DFU). Then how is the use of Hyperbaric Oxygen Therapy for kidney disease? Through this literature review, it is hoped that information will be obtained regarding the effect of Hyperbaric Oxygen Therapy on kidney function, both benefits and side effects, especially in kidney disease due to metabolic syndrome (MetS).

Hyperbaric oxygen therapy—a new hope for Alzheimer’s patients: a case report and literature review

The currently available pharmacological anti-dementia treatments provide only temporary and limited benefits. Not surprisingly, patients and professionals increasingly explore non-pharmacological interventions that may alleviate dementia symptoms. Among these interventions is hyperbaric oxygen therapy (HBOT). A brief review is presented on HBOT use in medicine, with its mode of action in dementia, specifically Alzheimer’s disease, as well as a case report of self-initiated HBOT in a 63-year-old man with a clinical diagnosis of probable Alzheimer’s disease. He had over 400 HBOT sessions [2–3 times weekly, with a duration of 30–50 min, in a multi-place hyperbaric chamber at 2 atmospheres absolute (ATA)] over 7 years and use of donepezil (10 mg daily) for the last 3 years when formally diagnosed by the National Health Service (NHS) Memory Service. The patient’s longitudinal neurocognitive and neuroradiological evidence over 7 years of follow-up remained stable (with no major cognitive decline and no behavioral changes) when compared to his initial presentation when diagnosed by the private health provider. His driving remains unimpaired, and he continues to be independent. This highlights the potential HBOT benefits including those on visuospatial ability and activities of daily living in people with Alzheimer’s disease. This case report argues for more extensive research into the clinical effects of HBOT in Alzheimer’s disease. Discussion of HBOT use is along with the latest advances in anti-amyloid immunotherapy for Alzheimer’s disease, as well as HBOT augmentation of current and novel dementia drug delivery via nanotechnology.

Effect of hyperbaric chamber on saturation and heart frequency

Introduction: (1) Background: The use of oxygen under pressure greater than atmospheric represents progress that can be measured in terms of importance with the introduction of blood transfusion and antibiotics in therapy. The aim of the research was to determine the impact of using a hyperbaric chamber (HC) on muscle, arterial saturation and heart rate.; (2) Methods: Twelve respondents who engaged in recreational exercise. HC Macy Pan O2 801 was used for oxygen delivery. Muscle saturation was assessed with the IDIAG Moxy device. Arterial saturation was monitored with an Omron OM-35 device, and intraventricular heart rate with a Polar FT2 device. All parameters were monitored before and after HC treatment for 50 min. and constant pressure of 2.5 ATA.; (3) Results: There was a significant increase in saturation in the pectoralis, (+8.99%) p=.038, hamstring (+8.62%) p=.042. In capillary saturation (+1.42%) p=.008. Heart rate was reduced on average by about 8.5 beats p= .003. In the region of the latissimus do not record a statistically significant change in oxygen (+6.64%) p=060, however, numerical differences were determined.; (4) Conclusions: HC is an effective means of achieving positive physiological effects. It needs to be determined whether a higher ATA or duration of treatment gives better effects.

Comparing the EMMA capnograph with sidestream capnography and arterial carbon dioxide pressure at 284 kPa.

Capnography aids assessment of the adequacy of mechanical patient ventilation. Physical and physiological changes in hyperbaric environments create ventilation challenges which make end-tidal carbon dioxide (ETCO2) measurement particularly important. However, obtaining accurate capnography in hyperbaric environments is widely considered difficult. This study investigated the EMMA capnograph for hyperbaric use. We compared the EMMA capnograph to sidestream capnography and the gold standard arterial carbon dioxide blood gas analysis in a hyperbaric chamber. In 12 resting subjects breathing air at 284 kPa, we recorded ETCO2 readings simultaneously derived from the EMMA and sidestream capnographs during two series of five breaths (total 24 measurements). An arterial blood gas sample was also taken simultaneously in five participants. Across all measurements there was a difference of about 0.1 kPa between the EMMA and sidestream capnographs indicating a very slight over-estimation of ETCO2 by the EMMA capnograph, but fundamentally good agreement between the two end-tidal measurement methods. Compared to arterial blood gas pressure the non-significant difference was about 0.3 and 0.4 kPa for the EMMA and sidestream capnographs respectively. In this study, the EMMA capnograph performed equally to the sidestream capnograph when compared directly, and both capnography measures gave clinically acceptable estimates of arterial PCO2.