Introduction: Rapid environmental changes, such as successive hypoxic-hypoxic orthostatic challenges (SHHOC) occur in the aerospace environment, and the ability to remain orthostatically resilient (OR) relies upon orchestration of physiological counter-responses. Counter-responses adjusting for hypoxia may conflict with orthostatic responses, and a misorchestration can lead to orthostatic intolerance (OI). The goal of this study was to pinpoint specific cardiovascular and oxygenation factors associated with OR during a simulated SHHOC. Methods: Thirty one men underwent a simulated SHHOC consisting of baseline (P0), normobaric hypoxia (Fi02 = 12%, P1), and max 60 s of hypoxic lower body negative pressure (LBNP, P2). Alongside anthropometric variables, non-invasive cardiovascular, central and peripheral tissue oxygenation parameters, were recorded. OI was defined as hemodynamic collapse during SHHOC. Comparison of anthropometric, cardiovascular, and oxygenation parameters between OR and OI was performed via Student's t-test. Within groups, a repeated measures ANOVA test with Holm-Sidak post hoc test was performed. Performance diagnostics were performed to assess factors associated with OR/OI (sensitivity, specificity, positive predictive value PPV, and odd's ratio OR). Results: Only 9/31 were OR, and 22/31 were OI. OR had significantly greater body mass index (BMI), weight, peripheral Sp02, longer R-R Interval (RRI) and lower heart rate (HR) at P0. During P1 OR exhibited significantly higher cardiac index (CI), stroke volume index (SVI), and lower systemic vascular resistance index (SVRI) than OI. Both groups exhibited a significant decrease in cerebral oxygenation (TOIc) with an increase in cerebral deoxygenated hemoglobin (dHbc), while the OI group showed a significant decrease in cerebral oxygenated hemoglobin (02Hbc) and peripheral oxygenation (TOIp) with an increase in peripheral deoxygenated hemoglobin (dHbp). During P2, OR maintained significantly greater CI, systolic, mean, and diastolic pressure (SAP, MAP, DAP), with a shortened RRI compared to the OI group, while central and peripheral oxygenation were not different. Body weight and BMI both showed high sensitivity (0.95), low specificity (0.33), a PPV of 0.78, with an OR of 0.92, and 0.61. P0 RRI showed a sensitivity of 0.95, specificity of 0.22, PPV 0.75, and OR of 0.99. Delta SVI had the highest performance diagnostics during P1 (sensitivity 0.91, specificity 0.44, PPV 0.79, and OR 0.8). Delta SAP had the highest overall performance diagnostics for P2 (sensitivity 0.95, specificity 0.67, PPV 0.87, and OR 0.9). Discussion: Maintaining OR during SHHOC is reliant upon greater BMI, body weight, longer RRI, and lower HR at baseline, while increasing CI and SVI, minimizing peripheral 02 utilization and decreasing SVRI during hypoxia. During hypoxic LBNP, the ability to remain OR is dependent upon maintaining SAP, via CI increases rather than SVRI. Cerebral oxygenation parameters, beyond 02Hbc during P1 did not differ between groups, suggesting that the during acute hypoxia, an increase in cerebral 02 consumption, coupled with increased peripheral 02 utilization does seem to play a role in OI risk during SHHOC. However, cardiovascular factors such as SVI are of more value in assessing OR/OI risk. The results can be used to implement effective aerospace crew physiological monitoring strategies.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Acute acoustic trauma (AAT) ranks, among others, as one common cause of inner ear function impairment, especially in terms of military personnel, who are at an increased exposure to impulse noises from firearms. AIM OF THIS STUDY: 1. We wanted to demonstrate whether early treatment of AAT means a higher chance for the patient to improve hearing after trauma. 2. We find the answer to the question of whether hyperbaric oxygen therapy (HBO2) has a positive effect in the treatment of AAT. METHODS: We retrospectively analyzed data for the period 2004-2019 in patients with AAT. We evaluated the therapeutic success of corticosteroids and HBO2 in a cohort of patients with AAT n = 108 patients/n = 141 affected ears. RESULTS: Hearing improvement after treatment was recorded in a total of 111 ears (79%). In terms of the data analysis we were able to ascertain, utilizing success of treatment versus timing: within 24 h following the onset of therapy in 56 (40%) ears-54 (96%) ears had improved; within seven days following the onset the therapy was used in 55 (39%) ears-41 (74%) ears had improved; after seven days the therapy started in 30 (21%) ears-16 (53%) ears had improved. Parameter latency of the beginning of the treatment of AAT was statistically significant (p = 0.001 and 0.017, respectively). The success of the medical protocols was apparent in both groups-group I (treated without HBO2): n = 61 ears, of which 50 (82%) improved, group II (treated with HBO2): n = 73 ears, of which 56 (77%) improved. Group II shows improvement at most frequencies (500-2000 Hz). The most serious sensorineural hearing loss after AAT was at a frequency of 6000 Hz. CONCLUSION: Analysis of our data shows that there is a statistically significant higher rate of improvement if AAT treatment was initiated within the first seven days after acoustic trauma. Early treatment of AAT leads to better treatment success. HBO2 is considered a rescue therapy for the treatment of AAT. According to our recommendation, it is desirable to start corticosteroid therapy immediately after acoustic trauma. If hearing does not improve during the first seven days of corticosteroid therapy, then HBO2 treatment should be initiated.
- MeSH
- hormony kůry nadledvin terapeutické užití MeSH
- hyperbarická oxygenace * MeSH
- lidé MeSH
- nedoslýchavost z hluku * farmakoterapie MeSH
- retrospektivní studie MeSH
- vojenský zdravotní systém * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Background: The goal of our research is to show the effects and impacts of hyperbaric oxygen therapy (HBOT) on acute model wounds in animal subjects. Methods: Three experimental groups were created using injured rabbits (N=36)-randomly divided into three groups (N=12 per group). One group was treated only with standard wound care management. Two groups were additionally treated with HBOT either once or twice a day. The wounds were surgical, uninfected, and in healthy animal test subjects. We compared the immunohistochemical and histological parameters in 4-, 7- and 10-day intervals.Results: The detection of epidermal leaf parameters, the number of microabscesses, the Histopathological Superficial Epithelium Healing Score, Connective Tissue Healing Score, Histopathological Acute Inflammation Score and Total Histopathological Wound Healing Score all showed significant changes between time intervals within the individual groups.Conclusion: The results did not show that HBOT had a significant effect on the healing process of uncomplicated acute wounds.
- Klíčová slova
- Hyperbaric oxygen, Wound healing, Animal models, Adjunctive treatment,
- MeSH
- biopsie MeSH
- hojení ran MeSH
- hyperbarická oxygenace * metody veterinární MeSH
- králíci zranění MeSH
- Check Tag
- králíci zranění MeSH
BACKGROUND: Pneumothorax as a consequence of pulmonary barotrauma during explosive decompression military crew training in a hypobaric chamber is an extremely rare and sparsely diagnosed complication. Extensive bilateral tissue damage is even more unexpected. CASE PRESENTATION: A 26-year-old active duty Air Force pilot was performing an explosive decompression simulation from 8000 ft. (2438.4 m) to 25,000 ft. (7620 m) in a 1.5 s interval. The training was interrupted due to the pilot's apparent health complications. After transfer to the emergency department, a CT scan showed bilateral lung barotrauma with emphysema. CONCLUSIONS: The case report shows extensive emphysema and pneumothorax after a rapid decompression done for training purposes. It is a possible but rare complication. The cause remains unclear, with suspicion of a predisposed lung disease.
- MeSH
- barotrauma etiologie MeSH
- dekomprese explozivní * MeSH
- dospělí MeSH
- lidé MeSH
- plicní emfyzém komplikace MeSH
- pneumotorax komplikace MeSH
- počítačová rentgenová tomografie MeSH
- poškození plic MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
Background: Hyperbaric oxygen (HBO2) therapy can have a positive effect on wound healing, angiogenesis and blood flow. No prior study has described the effects of HBO2 therapy and gene expression of this process. The goal of our research was to show the effects of HBO2 and its impact at the molecular level on angiogenesis, proliferation, differentiation, oxidative stress, inflammation, and extracellular matrix formation. Live animal subjects were used for simulating the process of wound healing under standard conditions and under the influence of HBO2. Methods: Two experimental groups were created using injured rabbits (N=24), one group (N=12) treated with hyperbaric therapy twice a day and one (N=12) with standard wound care management. Wounds were surgical, uninfected, and in healthy animal test subjects. We compared the whole genomic analysis of the transcriptome with the use of microarray technology at three intervals during treatment. Results: The induction of the wounds in rabbit skin increased expression of hundreds of genes in both treatment groups. The numbers of elevated and decreased genes gradually reduced as the wound healed. Gene expression analysis showed elevated expression of several genes associated with inflammation in both groups of injured animals. Genes connected to the process of angiogenesis, proliferation, differentiation, oxidative stress and extracellular matrix formation were without statistically significant changes. Conclusion: The evidence did not support that HBO2 had any significant effect on gene expression during wound healing. Additionally, there was no evidence to support that there were changes in gene expression in either treatment group.
- MeSH
- chirurgická rána genetika terapie MeSH
- čipová analýza tkání metody MeSH
- exprese genu * MeSH
- hojení ran genetika MeSH
- hyperbarická oxygenace * MeSH
- králíci MeSH
- kůže zranění MeSH
- messenger RNA analýza MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- barootitis media,
- MeSH
- barotrauma * etiologie prevence a kontrola MeSH
- Eustachova trubice * patologie zranění MeSH
- letectví MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Orthostatic instability is one of the main consequences of weightlessness or gravity challenge and plays as well a crucial role in public health, being one of the most frequent disease of aging. Therefore, the assessment of effective countermeasures, or even the possibility to predict, and thus prevent orthostatic instability is of great importance. Heat stress affects orthostatic stability and may lead to impaired consciousness and decrease in cerebral perfusion, specifically during the exposure to G-forces. Conversely, peripheral cooling can prevent orthostatic intolerance - even in normothermic healthy subjects. Indicators of peripheral vasodilation, as elevated skin surface temperatures, may mirror blood decentralization and an increased risk of orthostatic instability. Therefore, the aim of this study was to quantify orthostatic instability risk, by assessing in 20 fighter jet pilot candidates' cutaneous limb temperatures, with respect to the occurrence of G-force-induced almost loss of consciousness (ALOC), before and during exposure to a push-pull maneuver, i.e., head-down tilt, combined with lower body negative pressure. Peripheral skin temperatures from the upper and lower (both proximal and distal) extremities and core body temperature via heat-flux approach (i.e., the Double Sensor), were continuously measured before and during the maneuver. The 55% of subjects that suffered an ALOC during the procedure had higher upper arm and thigh temperatures at baseline compared to the 45% that remained stable. No difference in baseline core body temperature and distal limbs (both upper and lower) skin temperatures were found between the two groups. Therefore, peripheral skin temperature data could be considered a predicting factor for ALOC, prior to rapid onset acceleration. Moreover, these findings could also find applications in patient care settings such as in intensive care units.
- Publikační typ
- časopisecké články MeSH
Náhlá idiopatická senzorineurální nedoslýchavost (ISSNHL) představuje jeden ze závažných zdravotních problémů, neboť při vysoké incidenci a nadále nejasné etiologii přetrvávají pochybnosti o efektivnosti léčby a prognóze. Jedná se o akutní neurootologický stav. Její léčba měla být zahájena bez odkladu, a to nejpozději do 10-14 dnů od vzniku poruchy sluchu. Neexistuje jediný jednotný konsenzus stran její léčby. Jako primární léčba je uznávána kortikoterapie. Hyperbarická oxygenoterapie (HBOT) by v léčbě ISSNHL měla mít své místo jako součást komplexní primární léčby. Do programu HBOT je vhodné zařadit pacienta ideálně do 2-4 týdnů od vzniku onemocnění. Jako záchranná léčba (po vyčerpání předchozí léčby) by měla být HBOT podána do 3 měsíců, maximálně do 6 měsíců od vzniku poruchy sluchu. Zahájit HBOT později než 6 měsíců od vzniku ISSNHL se nedoporučuje.
Idiopathic sudden sensorineural hearing loss (ISSNHL) is a serious health problem, as doubt remains about the efficacy of treatment and prognosis at high incidence and etiology still unclear. It is an acute neuro-otologic condition. The treatment should be initiated without delay, within 10-14 days of the occurrence of hearing disorder at the latest. There is no single consensus on the treatment, corticotherapy being recognized as the primary treatment. Hyperbaric Oxygen Therapy (HBOT) should be used in ISSNHL as part of a comprehensive primary therapy. The HBOT treatment of a patient should start ideally within 2-4 weeks of the onset of the disease. HBOT as a rescue treatment (after exhausting previous treatment options) should be administered within 3 months, but no later than within 6 months of the occurrence of hearing impairment. Starting HBOT later than 6 months after the onset of ISSNHL is not recommended.
- MeSH
- hyperbarická oxygenace * metody využití MeSH
- lidé MeSH
- náhlá nedoslýchavost * etiologie terapie MeSH
- percepční nedoslýchavost * etiologie terapie MeSH
- záchranná terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
The main basic effect of hyperbaric oxygenation (HBO2) on the human body, in our study, was an increased partial pressure of oxygen resulting from an increased amount of oxygen dissolved in plasma. Thus the plasma can become capable of carrying enough oxygen to meet the needs of the body's tissues. From 1 January 2004 to 31 December 2007, a total of 61 patients (62 ears) received medical treatment at the ENT clinic of the 3rd Faculty of Medicine, Charles University, and at the Central Military Hospital in Prague. Treatment consisted of a combination of vasodilatation infusion treatment and HBO2 therapy. The results were evaluated in a retrospective study. The overall percentage of patients showing improvement was 59.7%. However, for those patients who started HBO2 treatment within 10 days of onset, complete recovery, or significant improvement was noted in 65.9%. In contrast, patients who started treatment after 10 days of onset, improvement was noted in only 38.9%. NMR examination revealed that two patients had vestibular schwannoma (also known as acoustic neuroma).
- MeSH
- audiometrie MeSH
- časové faktory MeSH
- dospělí MeSH
- glukokortikoidy aplikace a dávkování MeSH
- hyperbarická oxygenace metody MeSH
- kombinovaná terapie metody MeSH
- kyslík krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- methylprednisolon aplikace a dávkování MeSH
- mladý dospělý MeSH
- náhlá nedoslýchavost etiologie terapie MeSH
- parciální tlak MeSH
- pentoxifylin aplikace a dávkování MeSH
- percepční nedoslýchavost etiologie terapie MeSH
- retrospektivní studie MeSH
- senioři MeSH
- vazodilatace MeSH
- vazodilatancia aplikace a dávkování MeSH
- vinca alkaloidy aplikace a dávkování MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
