scholarly journals Urinary physiology and hypoxia: a pilot study of moderate-altitude trekking effects on urodynamic indexes

2019 ◽  
Vol 317 (4) ◽  
pp. F1081-F1086 ◽  
Author(s):  
Vittore Verratti ◽  
Simona Mrakic-Sposta ◽  
Manuela Moriggi ◽  
Alessandro Tonacci ◽  
Suwas Bhandari ◽  
...  
Keyword(s):  
Pilot Study ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Underlying Mechanism ◽  
Bladder Pressure ◽  
Moderate Altitude ◽  
Adaptive Responses ◽  
Flow Measurements ◽  
Urodynamic Testing ◽  
Rate Adaptive

Exposure to high altitude is one of the most widely used models to study the adaptive response to hypoxia in humans. However, little is known about the related effects on micturition. The present study addresses the adaptive urinary responses in four healthy adult lowlanders, comparing urodynamic indexes at Kathmandu [1,450 m above sea level (a.s.l.); K1450] and during a sojourn in Namche Bazar (3,500 m a.s.l.; NB3500). The urodynamic testing consisted of cistomanometry and bladder pressure/flow measurements. Anthropometrics, electrocardiographic, and peripheral capillary oxygen saturation data were also collected. The main findings consisted of significant reductions in bladder power at maximum urine flow by ~30%, bladder contractility index by 13%, and infused volume both at first (by 57%) and urgency sensation (by 14%) to urinate, indicating a reduced cystometric capacity, at NB3500. In addition to the urinary changes, we found that oxygen saturation, body mass index, body surface area, and median RR time were all significantly reduced at altitude. We submit that the hypoxia-related parasympathetic inhibition could be the underlying mechanism of both urodynamic and heart rate adaptive responses to high-altitude exposure. Moreover, increased diuresis and faster bladder filling at altitude may trigger the anticipation of being able to void, a common cause of urgency. We believe that the present pilot study represents an original approach to the study of urinary physiology at altitude.

scholarly journals Simultaneous generalized and low-layer SCIDAR turbulence profiles at san pedro mártir observatory

2019 ◽  
Vol 490 (1) ◽  
pp. 1397-1405 ◽  
Author(s):  
R Avila ◽  
O Valdés-Hernández ◽  
L J Sánchez ◽  
I Cruz-González ◽  
J L Avilés ◽  
...  
Keyword(s):  
High Altitude ◽  
Wind Direction ◽  
Close Agreement ◽  
Baja California ◽  
Ground Level ◽  
Combined Effect ◽  
Moderate Altitude ◽  
San Pedro ◽  
Simultaneous Measurements

ABSTRACT We present optical turbulence profiles obtained with a Generalized SCIDAR (G-SCIDAR) and a low-layer SCIDAR (LOLAS) at the Observatorio Astronómico Nacional in San Pedro Mártir (OAN-SPM), Baja California, Mexico, during three observing campaigns in 2013, 2014, and 2015. The G-SCIDAR delivers profiles with moderate altitude-resolution (a few hundred metres) along the entire turbulent section of the atmosphere, while the LOLAS gives high altitude resolution (on the order of tens of metres) but only within the first few hundred metres. Simultaneous measurements were obtained on 2014 and allowed us to characterize in detail the combined effect of the local orography and wind direction on the turbulence distribution close to the ground. At the beginning of several nights, the LOLAS profiles show that turbulence peaks between 25 and 50 m above the ground, not at ground level as was expected. The G-SCIDAR profiles exhibit a peak within the first kilometre. In 55 per cent and 36 per cent of the nights stable layers are detected between 10 and 15 km and at 3 km, respectively. This distribution is consistent with the results obtained with a G-SCIDAR in 1997 and 2000 observing campaigns. Statistics computed with the 7891 profiles that have been measured at the OAN-SPM with a G-SCIDAR in 1997, 2000, 2014, and 2015 campaigns are presented. The seeing values calculated with each of those profiles have a median of 0.79, first and third quartiles of 0.51 and 1.08 arcsec, which are in close agreement with other long term seeing monitoring performed at the OAN-SPM.

Work-health needs of high-altitude mountain guides (Sherpas) in Nepal – a pilot study

2015 ◽  
Vol 21 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Ewan B Macdonald ◽  
Shrijana Shrestha ◽  
Mahendra Kashari Chhetri ◽  
Lahkpa Rangdu Sherpa ◽  
Da Gelje Sherpa ◽  
...  
Keyword(s):  
Pilot Study ◽  
High Altitude ◽  
Health Needs ◽  
Work Health

Near-Infrared Spectroscopy Monitoring of Cerebral Oxygenation and Influencing Factors in Neonates from High-Altitude Areas

Neonatology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Bi Ze ◽  
Lili Liu ◽  
Ge Sang Yang Jin ◽  
Minna Shan ◽  
Yuehang Geng ◽  
...  
Keyword(s):  
Heart Disease ◽  
Infrared Spectroscopy ◽  
Brain Injury ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Low Altitude ◽  
Normal Neonates

<b><i>Background:</i></b> Accurate detection of cerebral oxygen saturation (rSO<sub>2</sub>) may be useful for neonatal brain injury prevention, and the normal range of rSO<sub>2</sub> of neonates at high altitude remained unclear. <b><i>Objective:</i></b> To compare cerebral rSO<sub>2</sub> and cerebral fractional tissue oxygen extraction (cFTOE) at high-altitude and low-altitude areas in healthy neonates and neonates with underlying diseases. <b><i>Methods:</i></b> 515 neonates from low-altitude areas and 151 from Tibet were enrolled. These neonates were assigned into the normal group, hypoxic-ischemic encephalopathy (HIE) group, and other diseases group. Near-infrared spectroscopy was used to measure rSO<sub>2</sub> in neonates within 24 h after admission. The differences of rSO<sub>2</sub>, pulse oxygen saturation (SpO<sub>2</sub>), and cFTOE levels were compared between neonates from low- and high-altitude areas. <b><i>Results:</i></b> (1) The mean rSO<sub>2</sub> and cFTOE levels in normal neonates from Tibet were 55.0 ± 6.4% and 32.6 ± 8.5%, significantly lower than those from low-altitude areas (<i>p</i> &#x3c; 0.05). (2) At high altitude, neonates with HIE, pneumonia (<i>p</i> &#x3c; 0.05), anemia, and congenital heart disease (<i>p</i> &#x3c; 0.05) have higher cFTOE than healthy neonates. (3) Compared with HIE neonates from plain areas, neonates with HIE at higher altitude had lower cFTOE (<i>p</i> &#x3c; 0.05), while neonates with heart disease in plateau areas had higher cFTOE than those in plain areas (<i>p</i> &#x3c; 0.05). <b><i>Conclusions:</i></b> The rSO<sub>2</sub> and cFTOE levels in normal neonates from high-altitude areas are lower than neonates from the low-altitude areas. Lower cFTOE is possibly because of an increase in blood flow to the brain, and this may be adversely affected by disease states which may increase the risk of brain injury.

Effect of Oral Vitamin C Supplementation on High-Altitude Hyperuricemia in Young Men Initially Migrating to High Altitude: A Pilot Study

2018 ◽  
Vol 19 (4) ◽  
pp. 373-381
Author(s):  
Hui Peng ◽  
Dongfang Feng ◽  
Yingkai Wang ◽  
Zixi Dong ◽  
Qing Chen ◽  
...  
Keyword(s):  
Pilot Study ◽  
Vitamin C ◽  
High Altitude ◽  
Young Men ◽  
Oral Vitamin ◽  
Vitamin C Supplementation

Fiber-optic transmission catheter for regional venous oxygen saturation and blood flow

1992 ◽  
Vol 72 (4) ◽  
pp. 1616-1621 ◽  
Author(s):  
H. Iwasaki ◽  
K. Yoshizaki ◽  
H. Koyano
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Fiber Optics ◽  
Fiber Optic ◽  
Supply And Demand ◽  
Flow Measurements ◽  
Face To Face ◽  
Flexible Polymer ◽  
Venous Oxygen Saturation ◽  
The Face

We have developed a method for monitoring regional venous oxygen saturation. The key feature of this system is the use of highly flexible polymer fiber optics, and this flexibility allowed the production of a new fiber-optic transmission catheter. The space between the “face-to-face” positioned fiber-optic tips forms a remote catheter-based transmission cell. Our method applies Twersky's theory, in which absorption and scattering can be treated independently. Fresh rabbit blood was pumped through a disk oxygenator in which gas exchange occurred and passed the catheter. Simultaneous results obtained by the catheter and a cuvette oximeter were excellent (r = 0.99, SD = 1.1%). Oxygen saturation measured by this catheter was independent of vessel wall artifacts, blood pH, and flow velocity. Another application of this method is measurement of blood flow by the dye- (indocyanine green) dilution technique. The results of flow measurements by the catheter appeared to be satisfactory (r = 0.99, SD = 1.7%). This study concludes that our method is effective for monitoring the balance between regional oxygen supply and demand.

scholarly journals SIMULATION OF THE RELATIONSHIP BETWEEN EXERCISE AND CARDIOPULMONARY FUNCTION AT HIGH ALTITUDE

2021 ◽  
Vol 27 (5) ◽  
pp. 509-513
Author(s):  
Rui Li
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Lower Limb ◽  
Pulmonary Circulation ◽  
Blood Oxygen ◽  
Blood Oxygen Saturation ◽  
Cardiopulmonary Function ◽  
The Relationship

ABSTRACT Introduction: Due to various uncertain and unexpected factors in life such as diseases, natural disasters, traffic accidents, and congenital disabilities, the number and proportion of lower limb amputations are still rising for many reasons, so the research on lower limb prostheses is particularly important. Objective: This work aimed to study the relationship between altitude exercise and cardiopulmonary function. Methods: A model of abnormal changes in cardiopulmonary function was established, and then 40 plateau exercisers were selected, all of whom arrived in Tibet in March 2017. The relationship between pulmonary circulation volume and internal pressure in the chest was observed and compared. The relationship between cardiopulmonary sensory reflex and exercise (high altitude) breathing and heart rate was analyzed. A comparison of the cardiopulmonary function of subjects of different genders was implemented. Moreover, the influence of different altitudes on the subjects’ cardiopulmonary function and the subjects’ cardiopulmonary function changes before departure and during the first, second, and third week after departure were observed and compared. Results: I. As the pressure in the thoracic cavity increased, the subjects’ pulmonary circulation blood volume gradually decreased, and the decrease was most obvious in the stage of thoracic pressure −50 to 0. II. As the cardiorespiratory reflex coefficient increased, the subjects’ breathing and heart rate compensatory acceleration appeared. III. Tracking and monitoring of the subjects’ cardiopulmonary indicators revealed that with the increase in altitude, the subjects’ average arterial pressure, respiratory frequency, and heart rate all showed an upward trend, while the blood oxygen saturation value showed a downward trend. IV. No matter how high the altitude was, the average arterial pressure, respiratory rate, and heart rate monitored of the subjects under exercise were significantly superior to the indicator values under resting state. In contrast, the blood oxygen saturation value showed the opposite trend. V. The subjects’ average arterial pressure, respiration, and heart rate in the first week were higher than other periods, but the blood oxygen saturation was relatively lower. In the second and third weeks, the changes in cardiopulmonary function were relatively smooth (all P<0.05). VI. The changes in the index of the cardiopulmonary function of subjects of different genders were small (p>0.05). Conclusion: Through modeling, the results of the plateau environment on the cardiopulmonary function of the body were made clearer, and these research data provided theoretical references for the training of the sports field in the plateau area. Level of evidence II; Therapeutic studies - investigation of treatment results.

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