placeholder
and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Document type
Language
Year
  • 1
    Language: English
    In: The Journal of physiology, 2019-05-15, Vol.597 (10), p.2623-2638
    Description: Key points A physiological response to increase microcirculatory oxygen extraction capacity at high altitude is to recruit capillaries. In the present study, we report that high altitude‐induced sublingual capillary recruitment is an intrinsic mechanism of the sublingual microcirculation that is independent of changes in cardiac output, arterial blood pressure or systemic vascular hindrance. Using a topical nitroglycerin challenge to the sublingual microcirculation, we show that high altitude‐related capillary recruitment is a functional response of the sublingual microcirculation as opposed to an anatomical response associated with angiogenesis. The concurrent presence of a low capillary density and high microvascular reactivity to topical nitroglycerin at sea level was found to be associated with a failure to reach the summit, whereas the presence of a high baseline capillary density with the ability to further increase maximum recruitable capillary density upon ascent to an extreme altitude was associated with summit success. A high altitude (HA) stay is associated with an increase in sublingual capillary total vessel density (TVD), suggesting microvascular recruitment. We hypothesized that microvascular recruitment occurs independent of cardiac output changes, that it relies on haemodynamic changes within the microcirculation as opposed to structural changes and that microcirculatory function is related to individual performance at HA. In 41 healthy subjects, sublingual handheld vital microscopy and echocardiography were performed at sea level (SL), as well as at 6022 m (C2) and 7042 m (C3), during ascent to 7126 m within 21 days. Sublingual topical nitroglycerin was applied to measure microvascular reactivity and maximum recruitable TVD (TVDNG). HA exposure decreased resting cardiac output, whereas TVD (mean ± SD) increased from 18.81 ± 3.92 to 20.92 ± 3.66 and 21.25 ± 2.27 mm mm−2 (P 〈 0.01). The difference between TVD and TVDNG was 2.28 ± 4.59 mm mm−2 at SL (P 〈 0.01) but remained undetectable at HA. Maximal TVDNG was observed at C3. Those who reached the summit (n = 15) demonstrated higher TVD at SL (P 〈 0.01), comparable to TVDNG in non‐summiters (n = 21) at SL and in both groups at C2. Recruitment of sublingual capillary TVD to increase microcirculatory oxygen extraction capacity at HA was found to be an intrinsic mechanism of the microcirculation independent of cardiac output changes. Microvascular reactivity to topical nitroglycerin demonstrated that HA‐related capillary recruitment is a functional response as opposed to a structural change. The performance of the vascular microcirculation needed to reach the summit was found to be associated with a higher TVD at SL and the ability to further increase TVDNG upon ascent to extreme altitude. Key points A physiological response to increase microcirculatory oxygen extraction capacity at high altitude is to recruit capillaries. In the present study, we report that high altitude‐induced sublingual capillary recruitment is an intrinsic mechanism of the sublingual microcirculation that is independent of changes in cardiac output, arterial blood pressure or systemic vascular hindrance. Using a topical nitroglycerin challenge to the sublingual microcirculation, we show that high altitude‐related capillary recruitment is a functional response of the sublingual microcirculation as opposed to an anatomical response associated with angiogenesis. The concurrent presence of a low capillary density and high microvascular reactivity to topical nitroglycerin at sea level was found to be associated with a failure to reach the summit, whereas the presence of a high baseline capillary density with the ability to further increase maximum recruitable capillary density upon ascent to an extreme altitude was associated with summit success.
    Subject(s): Adult ; Altitude ; Animals ; Capacity ; capillary density ; Cardiovascular ; Cohort Studies ; Female ; hand‐held video microscopy ; hemodynamic monitoring ; Humans ; hypoxia ; Life Sciences & Biomedicine ; Male ; Mice ; microcirculation ; Microcirculation - physiology ; Middle Aged ; Mouth Floor - blood supply ; Neurosciences ; Neurosciences & Neurology ; Nitrates ; Nitroglycerin - pharmacology ; Oxygen - metabolism ; Physiology ; Research Paper ; Science & Technology ; vascular reactivity ; Vasodilator Agents - pharmacology
    ISSN: 0022-3751
    E-ISSN: 1469-7793
    Source: Hellenic Academic Libraries Link
    Source: Web of Science - Science Citation Index Expanded - 2019〈img src="http://exlibris-pub.s3.amazonaws.com/fromwos-v2.jpg" /〉
    Source: PubMed Central
    Source: Web of Science - Social Sciences Citation Index – 2019〈img src="http://exlibris-pub.s3.amazonaws.com/fromwos-v2.jpg" /〉
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: PloS one, 2015, Vol.10 (10), p.e0141097-e0141097
    Description: Findings of cerebral cortical atrophy, white matter lesions and microhemorrhages have been reported in high-altitude climbers. The aim of this study was to evaluate structural cerebral changes in a large cohort of climbers after an ascent to extreme altitudes and to correlate these findings with the severity of hypoxia and neurological signs during the climb. Magnetic resonance imaging (MRI) studies were performed in 38 mountaineers before and after participating in a high altitude (7126 m) climbing expedition. The imaging studies were assessed for occurrence of new WM hyperintensities and microhemorrhages. Changes of partial volume estimates of cerebrospinal fluid, grey matter, and white matter were evaluated by voxel-based morphometry. Arterial oxygen saturation and acute mountain sickness scores were recorded daily during the climb. On post-expedition imaging no new white matter hyperintensities were observed. Compared to baseline testing, we observed a significant cerebrospinal fluid fraction increase (0.34% [95% CI 0.10-0.58], p = 0.006) and a white matter fraction reduction (-0.18% [95% CI -0.32--0.04], p = 0.012), whereas the grey matter fraction remained stable (0.16% [95% CI -0.46-0.13], p = 0.278). Post-expedition imaging revealed new microhemorrhages in 3 of 15 climbers reaching an altitude of over 7000 m. Affected climbers had significantly lower oxygen saturation values but not higher acute mountain sickness scores than climbers without microhemorrhages. A single sojourn to extreme altitudes is not associated with development of focal white matter hyperintensities and grey matter atrophy but leads to a decrease in brain white matter fraction. Microhemorrhages indicative of substantial blood-brain barrier disruption occur in a significant number of climbers attaining extreme altitudes.
    Subject(s): Altitude ; Altitude Sickness ; Anorexia ; Ascent ; Atrophy ; Blood-brain barrier ; Brain ; Brain - cytology ; Brain research ; Cerebrospinal fluid ; Cohort Studies ; Cortex ; Edema ; Environmental aspects ; Expeditions ; Extreme values ; Fourier transforms ; Gray Matter - cytology ; High altitude ; High-altitude environments ; Hospitals ; Humans ; Hypoxia ; Illnesses ; Intensive care ; Lesions ; Magnetic resonance ; Magnetic Resonance Imaging ; Medicine ; Morphometry ; Mountaineering ; Neuroimaging ; Neurosciences ; NMR ; Nuclear magnetic resonance ; Oxidative stress ; Oxygen ; Oxygen content ; Physiological aspects ; Physiological research ; Physiology ; Prospective Studies ; Saturation ; Sleep apnea ; Studies ; Substantia alba ; Substantia grisea
    ISSN: 1932-6203
    E-ISSN: 1932-6203
    Source: Academic Search Ultimate
    Source: PubMed Central
    Source: DOAJ Directory of Open Access Journals - Not for CDI Discovery
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: European journal of applied physiology, 2013-04-06, Vol.113 (8), p.2025-2037
    Description: Impairment of cognitive performance during and after high-altitude climbing has been described in numerous studies and has mostly been attributed to cerebral hypoxia and resulting functional and structural cerebral alterations. To investigate the hypothesis that high-altitude climbing leads to cognitive impairment, we used of neuropsychological tests and measurements of eye movement (EM) performance during different stimulus conditions. The study was conducted in 32 mountaineers participating in an expedition to Muztagh Ata (7,546 m). Neuropsychological tests comprised figural fluency, line bisection, letter and number cancellation, and a modified pegboard task. Saccadic performance was evaluated under three stimulus conditions with varying degrees of cortical involvement: visually guided pro- and anti-saccades, and visuo-visual interaction. Typical saccade parameters (latency, mean sequence, post-saccadic stability, and error rate) were computed off-line. Measurements were taken at a baseline level of 440 m and at altitudes of 4,497, 5,533, 6,265, and again at 440 m. All subjects reached 5,533 m, and 28 reached 6,265 m. The neuropsychological test results did not reveal any cognitive impairment. Complete eye movement recordings for all stimulus conditions were obtained in 24 subjects at baseline and at least two altitudes and in 10 subjects at baseline and all altitudes. Measurements of saccade performances showed no dependence on any altitude-related parameter and were well within normal limits. Our data indicates that acclimatized climbers do not seem to suffer from significant cognitive deficits during or after climbs to altitudes above 7,500 m. We demonstrated that investigation of EMs is feasible during high-altitude expeditions.
    Subject(s): Adult ; Altitude ; Biomedical and Life Sciences ; Biomedicine ; Cognition ; Cognitive function ; Female ; High altitude ; Human Physiology ; Humans ; Hypoxia ; Male ; Middle Aged ; Mountaineering - physiology ; Neuropsychological testing ; Neuropsychological Tests ; Occupational Medicine/Industrial Medicine ; Original Article ; Saccades ; Saccadic eye movement ; Sports Medicine
    ISSN: 1439-6319
    E-ISSN: 1439-6327
    Source: Alma/SFX Local Collection
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Sports medicine and health science, 2021-06-01, Vol.3 (2), p.59-69
    Description: Areas at high-altitude, annually attract millions of tourists, skiers, trekkers, and climbers. If not adequately prepared and not considering certain ascent rules, a considerable proportion of those people will suffer from acute mountain sickness (AMS) or even from life-threatening high-altitude cerebral (HACE) or/and pulmonary edema (HAPE). Reduced inspired oxygen partial pressure with gain in altitude and consequently reduced oxygen availability is primarily responsible for getting sick in this setting. Appropriate acclimatization by slowly raising the hypoxic stimulus (e.g., slow ascent to high altitude) and/or repeated exposures to altitude or artificial, normobaric hypoxia will largely prevent those illnesses. Understanding physiological mechanisms of acclimatization and pathophysiological mechanisms of high-altitude diseases, knowledge of symptoms and signs, treatment and prevention strategies will largely contribute to the risk reduction and increased safety, success and enjoyment at high altitude. Thus, this review is intended to provide a sound basis for both physicians counseling high-altitude visitors and high-altitude visitors themselves.
    Subject(s): Acute mountain sickness ; Altitude ; Climbing ; Disease ; Hypoxia ; Trekking
    ISSN: 2666-3376
    E-ISSN: 2666-3376
    Source: Alma/SFX Local Collection
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: American journal of respiratory and critical care medicine, 2010, Vol.182 (4), p.562-568
    Description: Quantitative data on ventilation during acclimatization at very high altitude are scant. Therefore, we monitored nocturnal ventilation and oxygen saturation in mountaineers ascending Mt. Muztagh Ata (7,546 m). To investigate whether periodic breathing persists during prolonged stay at very high altitude. A total of 34 mountaineers (median age, 46 yr; 7 women) climbed from 3,750 m within 19-20 days to the summit at 7,546 m. During ascent, repeated nocturnal recordings of calibrated respiratory inductive plethysmography, pulse oximetry, and scores of acute mountain sickness were obtained. Nocturnal oxygen saturation decreased, whereas minute ventilation and the number of periodic breathing cycles increased with increasing altitude. At the highest camp (6,850 m), median nocturnal oxygen saturation, minute ventilation, and the number of periodic breathing cycles were 64%, 11.3 L/min, and 132.3 cycles/h. Repeated recordings within 5-8 days at 4,497 m and 5,533 m, respectively, revealed increased oxygen saturation, but no decrease in periodic breathing. The number of periodic breathing cycles was positively correlated with days of acclimatization, even when controlled for altitude, oxygen saturation, and other potential confounders, whereas symptoms of acute mountain sickness had no independent effect on periodic breathing. Our field study provides novel data on nocturnal oxygen saturation, breathing patterns, and ventilation at very high altitude. It demonstrates that periodic breathing increases during acclimatization over 2 weeks at altitudes greater than 3,730 m, despite improved oxygen saturation consistent with a progressive increase in loop gain of the respiratory control system. Clinical trial registered with www.clinicaltrials.gov (NCT00514826).
    Subject(s): Abridged Index Medicus ; Acclimatization - physiology ; Adult ; Aged ; Altitude Sickness - complications ; Altitude Sickness - diagnosis ; Altitude Sickness - physiopathology ; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy ; Biological and medical sciences ; China ; Emergency and intensive respiratory care ; Female ; Humans ; Hypoxia - complications ; Hypoxia - diagnosis ; Hypoxia - physiopathology ; Intensive care medicine ; Male ; Medical sciences ; Middle Aged ; Mountaineering - physiology ; Oximetry - methods ; Oxygen Consumption - physiology ; Plethysmography - methods ; Plethysmography - statistics & numerical data ; Polysomnography - methods ; Polysomnography - statistics & numerical data ; Respiration ; Sleep Apnea, Central - complications ; Sleep Apnea, Central - diagnosis ; Sleep Apnea, Central - physiopathology
    ISSN: 1073-449X
    E-ISSN: 1535-4970
    Source: ProQuest Central
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: European journal of applied physiology, 2016-01-28, Vol.116 (4), p.739-748
    Description: Purpose Hypoxia and oxidative stress affect endothelial function. Endothelial microparticles (MP) are established measures of endothelial dysfunction and influence vascular reactivity. To evaluate the effects of hypoxia and antioxidant supplementation on endothelial MP profiles, a double-blind, placebo-controlled trial, during a high altitude expedition was performed. Methods 29 participants were randomly assigned to a treatment group ( n  = 14), receiving vitamin E, C, A, and N -acetylcysteine daily, and a control group ( n  = 15), receiving placebo. Blood samples were obtained at 490 m (baseline), 3530, 4590, and 6210 m. A sensitive tandem mass spectrometry method was used to measure 8-iso-prostaglandin F 2α and hydroxyoctadecadienoic acids as markers of oxidative stress. Assessment of MP profiles including endothelial activation markers (CD62+MP and CD144+MP) and cell apoptosis markers (phosphatidylserine+MP and CD31+MP) was performed using a standardized flow cytometry-based protocol. Results 15 subjects reached all altitudes and were included in the final analysis. Oxidative stress increased significantly at altitude. No statistically significant changes were observed comparing baseline to altitude measurements of phosphatidylserine expressing MP ( p  = 0.1718) and CD31+MP ( p  = 0.1305). Compared to baseline measurements, a significant increase in CD62+MP ( p  = 0.0079) and of CD144+MP was detected ( p  = 0.0315) at high altitudes. No significant difference in any MP level or oxidative stress markers were found between the treatment and the control group. Conclusion Hypobaric hypoxia is associated with increased oxidative stress and induces a significant increase in CD62+ and CD144+MP, whereas phosphatidylserine+MP and CD31+MP remain unchanged. This indicates that endothelial activation rather than an apoptosis is the primary factor of hypoxia induced endothelial dysfunction.
    Subject(s): Acetylcysteine - administration & dosage ; Acetylcysteine - therapeutic use ; Adult ; Altitude ; Antioxidants - administration & dosage ; Antioxidants - therapeutic use ; Apoptosis ; Biomarkers - blood ; Biomedical and Life Sciences ; Biomedicine ; Cell-Derived Microparticles - pathology ; Double-Blind Method ; Endothelial dysfunction ; Endothelium, Vascular - pathology ; Endothelium, Vascular - physiopathology ; Extreme altitude ; Female ; Human Physiology ; Humans ; Hypoxia ; Hypoxia - blood ; Hypoxia - drug therapy ; Hypoxia - etiology ; Male ; Microparticles ; Middle Aged ; Occupational Medicine/Industrial Medicine ; Original Article ; Oxidative Stress ; Prostaglandins - blood ; Sports Medicine ; Vitamins - administration & dosage ; Vitamins - therapeutic use
    ISSN: 1439-6319
    E-ISSN: 1439-6327
    Source: Alma/SFX Local Collection
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Wilderness & environmental medicine, 2011, Vol.22 (1), p.46-51
    Description: Objective Variations in definitions, scores, and methodologies have created differences in the results and conclusions obtained from studies on mountaineering and climbing sports injuries and illnesses; this has made interstudy comparisons difficult or impossible. To develop a common, simple, and sport-specific scoring system to classify injuries and illnesses in mountaineering and climbing studies; such retrospective scoring would facilitate the analysis and surveillance of their frequencies, severity and fatalities, and outcomes of any treatment. Methods The UIAA (The International Mountaineering and Climbing Federation) makes recommendations, sets policy, and advocates on behalf of the climbing and mountaineering community internationally through its various commissions. Using a nominal group consensus model approach, a working group was formed during the UIAA Medical Commission's meeting in Adršpach – Zdoňov, in the Czech Republic, 2008. This group critically examined climbing and other relevant literature for various methodological approaches in measuring injury incident rates and severity, including data sources, and produced a working document that was later edited and ratified by all members of the UIAA Medical Commission. Results Definitions of injury location, injury classification, and fatality risk are proposed. Case fatality, time-related injury risk, and a standardized metric climbing difficulty scale are also defined. Conclusions The medical commission of the UIAA recommends the use of the described criteria and scores for future research in mountaineering and climbing sports in order to enable robust and comprehensive interstudy comparisons and epidemiological analysis.
    Subject(s): Athletic Injuries - classification ; Athletic Injuries - epidemiology ; climbing epidemiology ; climbing injuries ; Emergency ; Humans ; ice climbing ; Internationality ; Mortality - trends ; mountaineering ; Mountaineering - injuries ; Population Surveillance ; Risk Factors ; rock climbing ; Trauma Severity Indices
    ISSN: 1080-6032
    E-ISSN: 1545-1534
    Source: Freely Accessible Journals
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Journal of Applied Physiology, 2009-02-01, Vol.106 (2), p.454-460
    Description: Little is known about the ocular and cerebral blood flow during exposure to increasingly hypoxic conditions at high altitudes. There is evidence that an increase in cerebral blood flow resulting from altered autoregulation constitutes a risk factor for acute mountain sickness (AMS) and high-altitude cerebral edema (HACE) by leading to capillary overperfusion and vasogenic cerebral edema. The retina represents the only part of the central nervous system where capillary blood flow is visible and can be measured by noninvasive means. In this study we aimed to gain insights into retinal and choroidal autoregulatory properties during hypoxia and to correlate circulatory changes to symptoms of AMS and clinical signs of HACE. This observational study was performed within the scope of a high-altitude medical research expedition to Mount Muztagh Ata (7,546 m). Twenty seven participants underwent general and ophthalmic examinations up to a maximal height of 6,800 m. Examinations included fundus photography and measurements of retinal and choroidal blood flow, as well as measurement of arterial oxygen saturation and hematocrit. The initial increase in retinal blood velocity was followed by a decrease despite further ascent, whereas choroidal flow increase occurred later, at even higher altitudes. The sum of all adaptational mechanisms resulted in a stable oxygen delivery to the retina and the choroid. Parameters reflecting the retinal circulation and optic disc swelling correlated well with the occurrence of AMS-related symptoms. We demonstrate that sojourns at high altitudes trigger distinct behavior of retinal and choroidal blood flow. Increase in retinal but not in choroidal blood flow correlated with the occurrence of AMS-related symptoms.
    Subject(s): Acclimatization ; Adaptation, Physiological ; Adult ; Altitude ; Altitude Sickness - physiopathology ; Biological and medical sciences ; Blood Flow Velocity ; Blood Pressure ; Cerebrovascular Circulation ; Choroid - blood supply ; Female ; Fluorescein Angiography ; Fundamental and applied biological sciences. Psychology ; Hematocrit ; Homeostasis ; Humans ; Hypoxia - physiopathology ; Intraocular Pressure ; Laser-Doppler Flowmetry ; Logistic Models ; Male ; Middle Aged ; Odds Ratio ; Oxygen - blood ; Prospective Studies ; Regional Blood Flow ; Retinal Vessels - diagnostic imaging ; Retinal Vessels - physiopathology ; Risk Assessment ; Switzerland ; Time Factors ; Ultrasonography ; Visual Acuity
    ISSN: 8750-7587
    E-ISSN: 1522-1601
    Source: Alma/SFX Local Collection
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: PloS one, 2011-02-17, Vol.6 (2), p.e11532-e11532
    Description: Retinal hemorrhages have been described as a component of high altitude retinopathy (HAR) in association with altitude illness. In this prospective high altitude study, we aimed to gain new insights into the pathophysiology of HAR and explored whether HAR could be a valid early indicator of altitude illness. 28 mountaineers were randomly assigned to two ascent profiles during a research expedition to Mt. Muztagh Ata (7546 m/24,751 ft). Digital fundus photographs were taken prior to expedition at 490 m (1,607 ft), during expedition at 4497 m (14,750 ft = base camp), 5533 m (18,148 ft), 6265 m (20,549 ft), 6865 m (22,517 ft) and 4.5 months thereafter at 490 m. Number, size and time of occurrence of hemorrhages were recorded. Oxygen saturation (SpO₂) and hematocrit were also assessed. 79% of all climbers exhibited retinal hemorrhages during the expedition. Number and area of retinal bleeding increased moderately to medium altitudes (6265 m). Most retinal hemorrhages were detected after return to base camp from a high altitude. No post-expeditional ophthalmic sequelae were detected. Significant negative (SpO₂ Beta: -0.4, p〈0.001) and positive (hematocrit Beta: 0.2, p = 0.002, time at altitude Beta: 0.33, p = 0.003) correlations with hemorrhages were found. When closely examined, a very large amount of climbers exhibit retinal hemorrhages during exposure to high altitudes. The incidence of retinal hemorrhages may be greater than previously appreciated as a definite time lag was observed between highest altitude reached and development of retinal bleeding. Retinal hemorrhages should not be considered warning signs of impending severe altitude illness due to their delayed appearance.
    Subject(s): Adult ; Aged ; Altitude ; Altitude Sickness - complications ; Altitude Sickness - diagnosis ; Altitude Sickness - physiopathology ; Ascent ; Bleeding ; Blood Pressure - physiology ; Complications ; Delayed Diagnosis ; Edema ; Endothelium ; Expeditions ; Female ; Fundus Oculi ; Hematocrit ; Hemorrhage ; High altitude ; High-altitude environments ; Hospitals ; Humans ; Hypoxia ; Illnesses ; Intensive care ; Ischemia ; Male ; Medical research ; Medicine, Experimental ; Middle Aged ; Mountain climbing ; Mountain sickness ; Mountaineering - physiology ; Ophthalmology ; Ophthalmoscopy ; Oxygen ; Oxygen content ; Photographs ; Physiology ; Radiography ; Research ; Research expeditions ; Retina ; Retinal Disorders ; Retinal Hemorrhage - diagnosis ; Retinal Hemorrhage - diagnostic imaging ; Retinal Hemorrhage - etiology ; Retinal Hemorrhage - physiopathology ; Retinopathy ; Saturation ; Time Factors ; Time lag ; Young Adult
    ISSN: 1932-6203
    E-ISSN: 1932-6203
    Source: Academic Search Ultimate
    Source: PubMed Central
    Source: DOAJ Directory of Open Access Journals - Not for CDI Discovery
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Intensive care medicine experimental, 2017, Vol.5 (1), p.26-26
    Description: Assessment of the microcirculation is a promising target for the hemodynamic management of critically ill patients. However, just as the sole reliance on macrocirculatory parameters, single static parameters of the microcirculation may not represent a sufficient guide. Our hypothesis was that by serial topical application of acetylcholine (ACH) and nitroglycerin (NG), the sublingual microcirculation can be challenged to determine its endothelial cell-dependent and smooth muscle-dependent physiological reserve capacity. In 41 healthy subjects, sublingual capillary microscopy was performed before and after topical application of ACH and NG. Total vessel density (TVD) was assessed in parallel using manual computer-assisted image analysis as well as a fully automated analysis pathway utilizing a newly developed computer algorithm. Flow velocity was assessed using space-time diagrams of the venules as well as the algorithm-based calculation of an average perfused speed indicator (APSI). No change in all measured parameters was detected after sublingual topical application of ACH. Sublingual topical application of NG however led to an increase in TVD, space-time diagram-derived venular flow velocity and APSI. No difference was detected in heart rate, blood pressure, and cardiac output as measured by echocardiography, as well as in plasma nitric oxide metabolite content before and after the topical application of ACH and NG. In healthy subjects, the sublingual microcirculatory physiological reserve can be assessed non-invasively by topical application of nitroglycerin without affecting systemic circulation
    Subject(s): Circulatory system ; Critical Care Medicine ; Endothelial cell function ; Hemodynamic monitoring ; Incident dark field ; Intensive ; Medicine ; Medicine & Public Health ; Microcirculation ; Microscopy ; Physiology ; Research ; Spacetime ; Vasodilator ; Video microscopy
    ISSN: 2197-425X
    E-ISSN: 2197-425X
    Source: BioMedCentral Open Access
    Source: PubMed Central
    Source: DOAJ Directory of Open Access Journals - Not for CDI Discovery
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...