scholarly journals Hypoxic Exercise Exacerbates Hypoxemia and Acute Mountain Sickness in Obesity: A Case Analysis

Author(s):  
Jing Xu ◽  
Jinshu Zeng ◽  
Yelei Yan ◽  
Fei Xu

Acute mountain sickness (AMS) is a common syndrome characterized by headache, dizziness, loss of appetite, weakness, and nausea. As a major public health issue, obesity has increased in high altitude urban residents and intermittent commuters to high altitudes. The present study investigated acute hypoxic exposure and hypoxic exercise on hypoxemia severity and AMS symptoms in a physically active obese man. In this case analysis, peripheral oxygen saturation (SpO2) was used to evaluate hypoxemia, heart rate (HR) and blood pressure (BP) were used to reflect the function of autonomic nervous system (ANS), and Lake Louise scoring (LLS) was used to assess AMS. The results showed that acute hypoxic exposure led to severe hypoxemia (SpO2 = 72%) and tachycardia (HRrest = 97 bpm), and acute hypoxic exercise exacerbated severe hypoxemia (SpO2 = 59%) and ANS dysfunction (HRpeak = 167 bpm, SBP/DBP = 210/97 mmHg). At the end of the 6-h acute hypoxic exposure, the case developed severe AMS (LLS = 10) symptoms of headache, gastrointestinal distress, cyanosis, vomiting, poor appetite, and fatigue. The findings of the case study suggest that high physical activity level appears did not show a reliable protective effect against severe hypoxemia, ANS dysfunction, and severe AMS symptoms in acute hypoxia exposure and hypoxia exercise.

2013 ◽  
Vol 114 (2) ◽  
pp. 180-185 ◽  
Author(s):  
Thomas Rupp ◽  
Marc Jubeau ◽  
Guillaume Y. Millet ◽  
Stéphane Perrey ◽  
François Esteve ◽  
...  

Performing exercise during the first hours of hypoxic exposure is thought to exacerbate acute mountain sickness (AMS), but whether this is due to increased hypoxemia or other mechanisms associated with exercise remains unclear. In 12 healthy men, AMS symptoms were assessed during three 11-h experimental sessions: 1) in Hypoxia-exercise, inspiratory O2 fraction (FiO2) was 0.12, and subjects performed 4-h cycling at 45% FiO2-specific maximal power output from the 4th to the 8th hour; 2) in Hypoxia-rest, FiO2 was continuously adjusted to match the same arterial oxygen saturation as in Hypoxia-exercise, and subjects remained at rest; and 3) in Normoxia-exercise, FiO2 was 0.21, and subjects cycled as in Hypoxia-exercise at 45% FiO2-specific maximal power output. AMS scores did not differ significantly between Hypoxia-exercise and Hypoxia-rest, while they were significantly lower in Normoxia-exercise (Lake Louise score: 5.5 ± 2.1, 4.4 ± 2.4, and 2.3 ± 1.5, and cerebral Environmental Symptom Questionnaire: 1.2 ± 0.7, 1.0 ± 1.0, and 0.3 ± 0.4, in Hypoxia-exercise, Hypoxia-rest, and Normoxia-exercise, respectively; P < 0.01). Headache scored by visual analog scale was higher in Hypoxia-exercise and Hypoxia-rest compared with Normoxia-exercise (36 ± 22, 35 ± 25, and 5 ± 6, P < 0.001), while the perception of fatigue was higher in Hypoxia-exercise compared with Hypoxia-rest (60 ± 24, 32 ± 22, and 46 ± 23, in Hypoxia-exercise, Hypoxia-rest, and Normoxia-exercise, respectively; P < 0.01). Despite significant physiological stress during hypoxic exercise and some AMS symptoms induced by normoxic cycling at similar relative workload, exercise does not significantly worsen AMS severity during the first hours of hypoxic exposure at a given arterial oxygen desaturation. Hypoxemia per se appears, therefore, to be the main mechanism underlying AMS, whether or not exercise is performed.


2001 ◽  
Vol 90 (4) ◽  
pp. 1431-1440 ◽  
Author(s):  
Keisho Katayama ◽  
Yasutake Sato ◽  
Yoshifumi Morotome ◽  
Norihiro Shima ◽  
Koji Ishida ◽  
...  

The purpose of this study was 1) to test the hypothesis that ventilation and arterial oxygen saturation (SaO2 ) during acute hypoxia may increase during intermittent hypoxia and remain elevated for a week without hypoxic exposure and 2) to clarify whether the changes in ventilation and SaO2 during hypoxic exercise are correlated with the change in hypoxic chemosensitivity. Six subjects were exposed to a simulated altitude of 4,500 m altitude for 7 days (1 h/day). Oxygen uptake (V˙o 2), expired minute ventilation (V˙e), and SaO2 were measured during maximal and submaximal exercise at 432 Torr before (Pre), after intermittent hypoxia (Post), and again after a week at sea level (De). Hypoxic ventilatory response (HVR) was also determined. At both Post and De, significant increases from Pre were found in HVR at rest and in ventilatory equivalent for O2(V˙e/V˙o 2) and SaO2 during submaximal exercise. There were significant correlations among the changes in HVR at rest and inV˙e/V˙o 2 and SaO2 during hypoxic exercise during intermittent hypoxia. We conclude that 1 wk of daily exposure to 1 h of hypoxia significantly improved oxygenation in exercise during subsequent acute hypoxic exposures up to 1 wk after the conditioning, presumably caused by the enhanced hypoxic ventilatory chemosensitivity.


2003 ◽  
Vol 94 (3) ◽  
pp. 991-996 ◽  
Author(s):  
Luke A. Garske ◽  
Michael G. Brown ◽  
Stephen C. Morrison

Acetazolamide (Acz) is used at altitude to prevent acute mountain sickness, but its effect on exercise capacity under hypoxic conditions is uncertain. Nine healthy men completed this double-blind, randomized, crossover study. All subjects underwent incremental exercise to exhaustion with an inspired O2 fraction of 0.13, hypoxic ventilatory responses, and hypercapnic ventilatory responses after Acz (500 mg twice daily for 5 doses) and placebo. Maximum power of 203 ± 38 (SD) W on Acz was less than the placebo value of 225 ± 40 W ( P < 0.01). At peak exercise, arterialized capillary pH was lower and Po 2 higher on Acz ( P < 0.01). Ventilation was 118.6 ± 20.0 l/min at the maximal power on Acz and 102.4 ± 20.7 l/min at the same power on placebo ( P < 0.02), and Borg score for leg fatigue was increased on Acz ( P < 0.02), with no difference in Borg score for dyspnea. Hypercapnic ventilatory response on Acz was greater ( P < 0.02), whereas hypoxic ventilatory response was unchanged. During hypoxic exercise, Acz reduced exercise capacity associated with increased perception of leg fatigue. Despite increased ventilation, dyspnea was not increased.


1995 ◽  
Vol 89 (2) ◽  
pp. 201-204 ◽  
Author(s):  
A. D. Wright ◽  
C. H. E. Imray ◽  
M. S. C. Morrissey ◽  
R. J. Marchbanks ◽  
A. R. Bradwell

1. Raised intracranial pressure has been noted in severe forms of acute mountain sickness and high-altitude cerebral oedema, but the role of intracranial pressure in the pathogenesis of mild to moderate acute mountain sickness is unknown. 2. Serial measurements of intracranial pressure were made indirectly by assessing changes in tympanic membrane displacement in 24 healthy subjects on rapid ascent to 5200 m. 3. Acute hypoxia at 3440 m was associated with a rise in intracranial pressure, but no difference was found in pressure changes at 4120 or 5200 m in subjects with or without symptoms of acute mountain sickness. 4. Raised intracranial pressure, though temporarily associated with acute hypoxia, is not a feature of acute mountain sickness with mild or moderate symptoms.


2008 ◽  
Vol 160 (3) ◽  
pp. 267-276 ◽  
Author(s):  
Edward A.W. Dyer ◽  
Susan R. Hopkins ◽  
Joanna E. Perthen ◽  
Richard B. Buxton ◽  
David J. Dubowitz

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S170-S171
Author(s):  
Ken Kambis ◽  
Julie Barnes ◽  
Michio Yasukawa ◽  
Reina Chamberlain ◽  
Tiffanie Tsui ◽  
...  

2014 ◽  
Vol 116 (7) ◽  
pp. 945-952 ◽  
Author(s):  
Normand A. Richard ◽  
Inderjeet S. Sahota ◽  
Nadia Widmer ◽  
Sherri Ferguson ◽  
A. William Sheel ◽  
...  

We examined the control of breathing, cardiorespiratory effects, and the incidence of acute mountain sickness (AMS) in humans exposed to hypobaric hypoxia (HH) and normobaric hypoxia (NH), and under two control conditions [hypobaric normoxia (HN) and normobaric normoxia (NN)]. Exposures were 6 h in duration, and separated by 2 wk between hypoxic exposures and 1 wk between normoxic exposures. Before and after exposures, subjects ( n = 11) underwent hyperoxic and hypoxic Duffin CO2 rebreathing tests and a hypoxic ventilatory response test (HVR). Inside the environmental chamber, minute ventilation (V̇e), tidal volume (Vt), frequency of breathing ( fB), blood oxygenation, heart rate, and blood pressure were measured at 5 and 30 min and hourly until exit. Symptoms of AMS were evaluated using the Lake Louise score (LLS). Both the hyperoxic and hypoxic CO2 thresholds were lower after HH and NH, whereas CO2 sensitivity was increased after HH and NH in the hypoxic test and after NH in the hyperoxic test. Values for HVR were similar across the four exposures. No major differences were observed for V̇e or any other cardiorespiratory variables between NH and HH. The LLS was greater in AMS-susceptible than in AMS-resistant subjects; however, LLS was alike between HH and NH. In AMS-susceptible subjects, fB correlated positively and Vt negatively with the LLS. We conclude that 6 h of hypoxic exposure is sufficient to lower the peripheral and central CO2 threshold but does not induce differences in cardiorespiratory variables or AMS incidence between HH and NH.


2018 ◽  
Vol 16 (2) ◽  
pp. 42-48
Author(s):  
Oleg V Vetryakov ◽  
Vladimir N Bykov ◽  
Ivan V Fateev ◽  
Yuriy Sh Khalimov

The development of mountain sickness symptoms is one of the limiting factors of successful physical performance in middle mountains and highlands. Among drugs with established effectiveness for the prophylaxis of an acute mountain sickness carbonic anhydrase inhibitor acetazolamidum is also viewed, but at presence there is no universal approach to this issue and drug dosage regimen for its administration have not been elaborated. Aim. А comprehensive analysis of acetazolamidum being administered in the range of effective doses has been carried out. Methods. During the experiment the effect of acetazolamidum on physical performance and resistance of rats to an acute hypobaric hypoxia when administered in the range of effective doses (20, 40 and 80 mg/kg) was studied. During full-scale approbation the effect of acetazolamidum in various dosages on adaptation processes in the course of a rapid dislocation from middle mountains to highlands (glade Azau-the Elbrus mountain) was assessed. Results. The undertaken study showed that the administration of acetazolamidum to rats beginning from a daily dosage 20 mg/kg, that corresponds to human intake of 250 mg of the drug, promotes significant increase of survival time of rats following acute hypoxic exposure as well as growth of an animal performance ability factor under hypoxia. Conclusion. In the course of full-scale approbation it was established that prophylactic intake of acetazolamidum in examined doses prevents the development of symptoms of an acute mountain sickness when rapid dislocation from middle mountains (2300 m) to highlands (5000 m) takes place in the background of physical activity according to the results of sportsmen’s performance of Lake Louise test. (For citation: Vetryakov OV, Bykov VN, Fateev IV, Khalimov YS. The administration of acetazolamidum for the symptom prophylaxis of an acute mountain sickness when short-term dislocation from middle mountains to highlands takes place. Reviews on Clinical Pharmacology and Drug Therapy. 2018;16(2):42-48. doi: 10.17816/RCF16242-48).


2018 ◽  
Vol 3 (3) ◽  
pp. 209 ◽  
Author(s):  
Gopinath Bhaumik ◽  
Deepak Dass ◽  
Dishari Ghosh ◽  
Harish Kumar ◽  
Sanjiva Kumar ◽  
...  

<p>In emergencies/war like situations, rapid deployment of army personnel into high altitude occurs without proper acclimatization. Rapid deployment of unacclimatized soldiers to high mountainous environments may cause debilitating effects on operational capabilities and development of acute mountain sickness (AMS). Altitude acclimatization is the best strategy for the prevention of AMS Use of pharmacological intervention for prevention of AMS is a common practice. The use of intermittent hypoxic exposure (IHE) is an alternative approach for altitude acclimatization and it reduces occurrence and severity of AMS is. But, the use of intermittent normobaric hypoxia exposure at sea level on occurrence of AMS after acute ascent to 3500m altitude in Indian army personnel has not been tested yet.<strong></strong></p>


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