scholarly journals Effect of Intermittent Normobaric Hypoxia Exposures on Acute Mountain Sickness During Acute Ascent to 3500 m in Indian Military Personnel

2018 ◽  
Vol 3 (3) ◽  
pp. 209 ◽  
Author(s):  
Gopinath Bhaumik ◽  
Deepak Dass ◽  
Dishari Ghosh ◽  
Harish Kumar ◽  
Sanjiva Kumar ◽  
...  
Keyword(s):  
Acute Mountain Sickness ◽  
Normobaric Hypoxia ◽  
Pharmacological Intervention ◽  
Hypoxic Exposure ◽  
Hypoxia Exposure ◽  
Altitude Acclimatization ◽  
Intermittent Normobaric Hypoxia ◽  
Mountain Sickness ◽  
Army Personnel ◽  
Rapid Deployment

<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>

Acute mountain sickness, chemosensitivity, and cardiorespiratory responses in humans exposed to hypobaric and normobaric hypoxia

2014 ◽  
Vol 116 (7) ◽  
pp. 945-952 ◽  
Author(s):  
Normand A. Richard ◽  
Inderjeet S. Sahota ◽  
Nadia Widmer ◽  
Sherri Ferguson ◽  
A. William Sheel ◽  
...  
Keyword(s):  
Ventilatory Response ◽  
Minute Ventilation ◽  
Acute Mountain Sickness ◽  
Blood Oxygenation ◽  
Normobaric Hypoxia ◽  
Hypoxic Exposure ◽  
Hypoxic Ventilatory Response ◽  
Before And After ◽  
Mountain Sickness ◽  
Normobaric Normoxia

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.

Effect of intermittent normobaric hypoxia exposure on acclimatization to high altitude by air induction

2021 ◽  
Vol 12 (10) ◽  
pp. 58-63
Author(s):  
Gopinath Bhaumik ◽  
Deepak Dass ◽  
Dishari Ghosh ◽  
Kishan Singh ◽  
Maram Prasanna Kumar Reddy
Keyword(s):  
Oxygen Saturation ◽  
High Altitude ◽  
Sea Level ◽  
Acute Mountain Sickness ◽  
Treated Group ◽  
Physiological Parameters ◽  
Normobaric Hypoxia ◽  
Hypoxia Exposure ◽  
Intermittent Normobaric Hypoxia ◽  
High Altitude Illness

Background: In emergency like condition, defence personnel are deployed to high altitude without proper acclimatization. Maladaption at high altitude leads to high altitude illness like acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE) which hampers the operational capabilities. Aims and Objectives: The aim of the present study was to assess the effect of intermittent normobaric hypoxia exposure (IHE) at sea level on different physiological responses during initial days of acclimatization at 3500m and 4000m altitudes in acute induction. Materials and Methods: The IHE subjects were exposed to 12% FIO2 (equivalent altitude 14500 ft) for 4 hrs/day for 4 consecutive days at sea level and 5th day they were inducted by air to 3500m altitude. Baseline recording of different physiological parameters like cardiovascular, respiratory, oxygen saturation and AMS score were measured at sea level as well as 3500m altitude on daily basis for 6 days to assess acclimatization status. To confirm acclimatization status at 3500m, on fifth day the IHE group subjects were transported by road to 4000m and again measured different basal physiological parameters (like cardiovascular, oxygen saturation and AMS score) for four consecutive days. Results: Different physiological parameters of IHE treated group were stabilized by day 4 of air induction at 3500m altitude. Whereas, at 4000m altitude, these parameters were stabilized by day 2 of induction. Conclusion: Acclimatization schedules of four days at 3500m and two days at 4000m are essential to avoid malacclimatization/or high-altitude illness.

No effect of patent foramen ovale on acute mountain sickness and pulmonary pressure in normobaric hypoxia

2021 ◽  
Author(s):  
Kaitlyn G. DiMarco ◽  
Kara M. Beasley ◽  
Karina Shah ◽  
Julia P. Speros ◽  
Jonathan E. Elliott ◽  
...  
Keyword(s):  
Patent Foramen Ovale ◽  
Acute Mountain Sickness ◽  
Normobaric Hypoxia ◽  
Foramen Ovale ◽  
Pulmonary Pressure ◽  
Mountain Sickness

The Effect of an Expiratory Resistance Mask with Dead Space on Sleep, Acute Mountain Sickness, Cognition, and Ventilatory Acclimatization in Normobaric Hypoxia

2019 ◽  
Vol 20 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Alexander Patrician ◽  
Michael M. Tymko ◽  
Hannah G. Caldwell ◽  
Connor A. Howe ◽  
Geoff B. Coombs ◽  
...  
Keyword(s):  
Dead Space ◽  
Acute Mountain Sickness ◽  
Normobaric Hypoxia ◽  
Expiratory Resistance ◽  
Mountain Sickness

Effect of repeated normobaric hypoxia exposures during sleep on acute mountain sickness, exercise performance, and sleep during exposure to terrestrial altitude

2011 ◽  
Vol 300 (2) ◽  
pp. R428-R436 ◽  
Author(s):  
Charles S. Fulco ◽  
Stephen R. Muza ◽  
Beth A. Beidleman ◽  
Robby Demes ◽  
Janet E. Staab ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Performance ◽  
Hypobaric Hypoxia ◽  
Sham Group ◽  
Acute Mountain Sickness ◽  
Time Trial ◽  
Normobaric Hypoxia ◽  
Performance Decrement ◽  
Mountain Sickness ◽  
End Tidal

There is an expectation that repeated daily exposures to normobaric hypoxia (NH) will induce ventilatory acclimatization and lessen acute mountain sickness (AMS) and the exercise performance decrement during subsequent hypobaric hypoxia (HH) exposure. However, this notion has not been tested objectively. Healthy, unacclimatized sea-level (SL) residents slept for 7.5 h each night for 7 consecutive nights in hypoxia rooms under NH [ n = 14, 24 ± 5 (SD) yr] or “sham” ( n = 9, 25 ± 6 yr) conditions. The ambient percent O2 for the NH group was progressively reduced by 0.3% [150 m equivalent (equiv)] each night from 16.2% (2,200 m equiv) on night 1 to 14.4% (3,100 m equiv) on night 7, while that for the ventilatory- and exercise-matched sham group remained at 20.9%. Beginning at 25 h after sham or NH treatment, all subjects ascended and lived for 5 days at HH (4,300 m). End-tidal Pco2, O2 saturation (SaO2), AMS, and heart rate were measured repeatedly during daytime rest, sleep, or exercise (11.3-km treadmill time trial). From pre- to posttreatment at SL, resting end-tidal Pco2 decreased ( P < 0.01) for the NH (from 39 ± 3 to 35 ± 3 mmHg), but not for the sham (from 39 ± 2 to 38 ± 3 mmHg), group. Throughout HH, only sleep SaO2 was higher (80 ± 1 vs. 76 ± 1%, P < 0.05) and only AMS upon awakening was lower (0.34 ± 0.12 vs. 0.83 ± 0.14, P < 0.02) in the NH than the sham group; no other between-group rest, sleep, or exercise differences were observed at HH. These results indicate that the ventilatory acclimatization induced by NH sleep was primarily expressed during HH sleep. Under HH conditions, the higher sleep SaO2 may have contributed to a lessening of AMS upon awakening but had no impact on AMS or exercise performance for the remainder of each day.

scholarly journals Remote ischemic preconditioning delays the onset of acute mountain sickness in normobaric hypoxia

2015 ◽  
Vol 3 (3) ◽  
pp. e12325 ◽  
Author(s):  
Marc M. Berger ◽  
Hannah Köhne ◽  
Lorenz Hotz ◽  
Moritz Hammer ◽  
Kai Schommer ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Acute Mountain Sickness ◽  
Normobaric Hypoxia ◽  
Remote Ischemic Preconditioning ◽  
Mountain Sickness

scholarly journals Respiratory alkalinization and posterior cerebral artery dilatation predict acute mountain sickness severity during 10 h normobaric hypoxia

2020 ◽  
Vol 106 (1) ◽  
pp. 175-190
Author(s):  
Holly Barclay ◽  
Saptarshi Mukerji ◽  
Bengt Kayser ◽  
Terrence O'Donnell ◽  
Yu‐Chieh Tzeng ◽  
...  
Keyword(s):  
Cerebral Artery ◽  
Posterior Cerebral Artery ◽  
Acute Mountain Sickness ◽  
Normobaric Hypoxia ◽  
Mountain Sickness
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