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.

Acclimatization at high altitude in gradual and acute induction

1995 ◽  
Vol 79 (2) ◽  
pp. 487-492 ◽  
Author(s):  
S. S. Purkayastha ◽  
U. S. Ray ◽  
B. S. Arora ◽  
P. C. Chhabra ◽  
L. Thakur ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Time Course ◽  
Physiological Responses ◽  
Acute Mountain Sickness ◽  
Blood Gases ◽  
Blood Gas ◽  
Mountain Sickness ◽  
High Altitude Illness ◽  
In Transit

The study assessed physiological responses to induction to high altitude first to 3,500 m and then to 4,200 m and compared the time course of altitude acclimatization in two groups of male volunteers. The acutely inducted group was transported by aircraft (AI) to 3,500 m in 1 h, whereas the gradually inducted group was transported by road (RI) in 4 days. Baseline recordings of basal cardiovascular, respiratory, and blood gas variables were monitored at sea level as well as at 3,500 m on days 1, 3, 5, and 7. Blood gases were measured on day 10 also. After 15 days at 3,500 m, the subjects were inducted to 4,200 m by road, and measurements were repeated on days 1, 3, and 5, except blood gas variables, which were done on day 10 only. Acute mountain sickness symptoms were recorded throughout. The responses of RI were stable by day 3 of induction at 3,500 m, whereas it took 5 days for AI. Four days in transit for RI appear equivalent to 2 days at 3,500 m for AI. Acclimatization schedules of 3 and 5 days, respectively, for RI and AI are essential to avoid malacclimatization and/or high-altitude illness. Both groups took 3 days at 4,200 m to attain stability for achieving acclimatization.

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>

Is normobaric hypoxia an effective treatment for sustaining previously acquired altitude acclimatization?

2017 ◽  
Vol 123 (5) ◽  
pp. 1214-1227 ◽  
Author(s):  
Beth A. Beidleman ◽  
Charles S. Fulco ◽  
Bruce S. Cadarette ◽  
Allen Cymerman ◽  
Mark J. Buller ◽  
...  
Keyword(s):  
Cognitive Function ◽  
High Altitude ◽  
Sea Level ◽  
Performance Test ◽  
Acute Mountain Sickness ◽  
Normobaric Hypoxia ◽  
Time Period ◽  
Carbon Dioxide Pressure ◽  
End Tidal ◽  
Extraordinary Means

This study examined whether normobaric hypoxia (NH) treatment is more efficacious for sustaining high-altitude (HA) acclimatization-induced improvements in ventilatory and hematologic responses, acute mountain sickness (AMS), and cognitive function during reintroduction to altitude (RA) than no treatment at all. Seventeen sea-level (SL) residents (age = 23 ± 6 yr; means ± SE) completed in the following order: 1) 4 days of SL testing; 2) 12 days of HA acclimatization at 4,300 m; 3) 12 days at SL post-HA acclimatization (Post) where each received either NH ( n = 9, [Formula: see text] = 0.122) or Sham ( n = 8; [Formula: see text] = 0.207) treatment; and 4) 24-h reintroduction to 4,300-m altitude (RA) in a hypobaric chamber (460 Torr). End-tidal carbon dioxide pressure ([Formula: see text]), hematocrit (Hct), and AMS cerebral factor score were assessed at SL, on HA2 and HA11, and after 20 h of RA. Cognitive function was assessed using the SynWin multitask performance test at SL, on HA1 and HA11, and after 4 h of RA. There was no difference between NH and Sham treatment, so data were combined. [Formula: see text] (mmHg) decreased from SL (37.2 ± 0.5) to HA2 (32.2 ± 0.6), decreased further by HA11 (27.1 ± 0.4), and then increased from HA11 during RA (29.3 ± 0.6). Hct (%) increased from SL (42.3 ± 1.1) to HA2 (45.9 ± 1.0), increased again from HA2 to HA11 (48.5 ± 0.8), and then decreased from HA11 during RA (46.4 ± 1.2). AMS prevalence (%) increased from SL (0 ± 0) to HA2 (76 ± 11) and then decreased at HA11 (0 ± 0) and remained depressed during RA (17 ± 10). SynWin scores decreased from SL (1,615 ± 62) to HA1 (1,306 ± 94), improved from HA1 to HA11 (1,770 ± 82), and remained increased during RA (1,707 ± 75). These results demonstrate that HA acclimatization-induced improvements in ventilatory and hematologic responses, AMS, and cognitive function are partially retained during RA after 12 days at SL whether or not NH treatment is utilized. NEW & NOTEWORTHY This study demonstrates that normobaric hypoxia treatment over a 12-day period at sea level was not more effective for sustaining high-altitude (HA) acclimatization during reintroduction to HA than no treatment at all. The noteworthy aspect is that athletes, mountaineers, and military personnel do not have to go to extraordinary means to retain HA acclimatization to an easily accessible and relevant altitude if reexposure occurs within a 2-wk time period.

scholarly journals Rapid Acclimatisation to High Altitude by Intermittent Hypoxia Training at Sea Level Role of Biochemical Markers

2021 ◽  
Vol 6 (2) ◽  
pp. 138-145
Author(s):  
Geetha Suryakumar ◽  
Dishari Ghosh ◽  
Richa Rathor ◽  
Gopinath Bhaumik ◽  
Som Nath Singh ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Biochemical Markers ◽  
Intermittent Hypoxia ◽  
Stress Proteins ◽  
Acute Mountain Sickness ◽  
Emergency Situation ◽  
High Altitude Illness ◽  
Army Personnel

Rapid induction of soldiers to high altitude under emergency situation may lead to higher incidence of acute mountain sickness (AMS) and other high altitude illness. Intermittent Hypoxia Training (IHT) at sea level before going to high altitude is an approach for rapid acclimatisation. This approach may be helpful to reduce the occurrence of AMS and leads to better acclimatisation at high altitude in shorter duration. The present study evaluates the role of biochemical markers of acclimatisation after IHT before induction to actual high altitude. The study participants were Indian Army Personnel (n=30) and they were divided into two groups of control (n=16) and IHT exposed (n=14). The intermittent hypoxia training was administered at 12 per cent Oxygen for 4h/day for 4 days at sea level using normobaric hypoxia chamber and within 24 hrs - 48 hrs the subjects were airlifted to Leh, Ladakh, India at 11,700 ft. Preconditioning with IHT may be beneficial in maintaining antioxidant levels and ameliorate oxidative stress at high altitude. The hypoxia responsive proteins like Hemeoxygenase -1 (HO-1) and Vascular endothelial growth factor (VEGF) and the cytoprotective stress proteins, which facilitate the acclimatisation, may also get benefited by IHT exposure.

scholarly journals The Use of Pulse Oximetry in the Assessment of Acclimatization to High Altitude

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1263
Author(s):  
Tobias Dünnwald ◽  
Roland Kienast ◽  
David Niederseer ◽  
Martin Burtscher
Keyword(s):  
Pulse Oximetry ◽  
High Altitude ◽  
Acute Mountain Sickness ◽  
Measurement Methods ◽  
Peripheral Oxygen Saturation ◽  
Hypoxia Exposure ◽  
Lower Spo2 ◽  
Time Courses ◽  
Finger Pulse ◽  
Pulse Oximeters

Background: Finger pulse oximeters are widely used to monitor physiological responses to high-altitude exposure, the progress of acclimatization, and/or the potential development of high-altitude related diseases. Although there is increasing evidence for its invaluable support at high altitude, some controversy remains, largely due to differences in individual preconditions, evaluation purposes, measurement methods, the use of different devices, and the lacking ability to interpret data correctly. Therefore, this review is aimed at providing information on the functioning of pulse oximeters, appropriate measurement methods and published time courses of pulse oximetry data (peripheral oxygen saturation, (SpO2) and heart rate (HR), recorded at rest and submaximal exercise during exposure to various altitudes. Results: The presented findings from the literature review confirm rather large variations of pulse oximetry measures (SpO2 and HR) during acute exposure and acclimatization to high altitude, related to the varying conditions between studies mentioned above. It turned out that particularly SpO2 levels decrease with acute altitude/hypoxia exposure and partly recover during acclimatization, with an opposite trend of HR. Moreover, the development of acute mountain sickness (AMS) was consistently associated with lower SpO2 values compared to individuals free from AMS. Conclusions: The use of finger pulse oximetry at high altitude is considered as a valuable tool in the evaluation of individual acclimatization to high altitude but also to monitor AMS progression and treatment efficacy.

Effect of beta-adrenoceptor blockade on renin-aldosterone and alpha-ANF during exercise at altitude

1989 ◽  
Vol 67 (1) ◽  
pp. 141-146 ◽  
Author(s):  
P. Bouissou ◽  
J. P. Richalet ◽  
F. X. Galen ◽  
M. Lartigue ◽  
P. Larmignat ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Acute Mountain Sickness ◽  
Plasma Renin ◽  
Barometric Pressure ◽  
Suppressive Effect ◽  
Beta Blockade ◽  
Plasma Norepinephrine ◽  
Plasma Aldosterone Concentration ◽  
Ergometer Exercise

The renin-aldosterone system may be depressed in subjects exercising at high altitude, thereby preventing excessive angiotensin I (ANG I) and aldosterone levels, which could favor the onset of acute mountain sickness. The role of beta-adrenoceptors in hormonal responses to hypoxia was investigated in 12 subjects treated with a nonselective beta-blocker, pindolol. The subjects performed a standardized maximal bicycle ergometer exercise with (P) and without (C) acute pindolol treatment (15 mg/day) at sea level, as well as during a 5-day period at high altitude (4,350 m, barometric pressure 450 mmHg). During sea-level exercise, pindolol caused a reduction in plasma renin activity (PRA, 2.83 +/- 0.35 vs. 5.13 +/- 0.7 ng ANG I.ml-1.h-1, P less than 0.01), an increase in plasma alpha-atrial natriuretic factor (alpha-ANF) level (23.1 +/- 2.9 (P) vs. 10.4 +/- 1.5 (C) pmol/1, P less than 0.01), and no change in plasma aldosterone concentration [0.50 +/- 0.04 (P) vs. 0.53 +/- 0.03 (C) nmol/1]. Compared with sea-level values, PRA (3.45 +/- 0.7 ng ANG I.ml-1.h-1) and PA (0.39 +/- 0.03 nmol/1) were significantly lower (P less than 0.05) during exercise at high altitude. alpha-ANF was not affected by hypoxia. When beta-blockade was achieved at high altitude, exercise-induced elevation in PRA was completely abolished, but no additional decline in PA occurred. Plasma norepinephrine and epinephrine concentrations tended to be lower during maximal exercise at altitude; however, these differences were not statistically significant. Our results provide further evidence that hypoxia has a suppressive effect on the renin-aldosterone system. However, beta-adrenergic mechanisms do not appear to be responsible for inhibition of renin secretion at high altitude.

scholarly journals Acute Lung Edema as a Presentation of Severe Acute Reentry High-Altitude Illness in a Pediatric Patient

2020 ◽  
Vol 2020 ◽  
pp. 1-3
Author(s):  
Alfredo Merino-Luna ◽  
Julio Vizcarra-Anaya
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Edema ◽  
High Altitude ◽  
Sea Level ◽  
Pediatric Patient ◽  
Lung Edema ◽  
High Altitude Pulmonary Edema ◽  
High Altitude Illness ◽  
The City ◽  
Determining Factor

Acute high-altitude pulmonary edema (HAPE) is a pathology involving multifactorial triggers that are associated with ascents to altitudes over 2,500 meters above sea level (m). Here, we report two pediatric cases of reentry HAPE, from the city of Huaraz, Peru, located at 3,052 m. The characteristics of both cases were similar, wherein acclimatization to sea level and a subsequent return to the city of origin occurred, and we speculate that it was caused by activation of predisposing factors to HAPE. The diagnosis and management associated with pulmonary hypertension became a determining factor for therapy.

scholarly journals High-Altitude Illness Death Investigation

2018 ◽  
Vol 8 (1) ◽  
pp. 83-97 ◽  
Author(s):  
Robert A. Kurtzman ◽  
James L. Caruso
Keyword(s):  
High Altitude ◽  
Cerebral Edema ◽  
Acute Mountain Sickness ◽  
Physical Conditioning ◽  
Postmortem Diagnosis ◽  
High Altitude Cerebral Edema ◽  
Diagnosis And Classification ◽  
High Altitude Illness ◽  
Death Investigation ◽  
Medical Examiners

High altitude illness (HAI) is the current accepted clinical term for a group of disorders including acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE), which occur in travelers visiting high-altitude locations. High-altitude illness is due to hypobaric hypoxia, is not associated with age or physical conditioning, and mild forms are easily treated. High-altitude cerebral edema and HAPE are medical emergencies that are fatal if not promptly treated and fortunately are uncommon. The cause of most high-altitude fatalities is not related to HAI and can be easily distinguished from HACE and HAPE; however, other causes of death may have symptoms and physical findings that overlap with HAI, making postmortem diagnosis challenging. Fatalities due to HAPE and HACE are diagnoses of exclusion. Medical examiners and coroners who work in jurisdictions with high-altitude locations should be aware of the risk factors, physiology, pathology, differential diagnosis, and classification of HAI to accurately recognize HAI as a cause of death. Medical examiners who do not work in jurisdictions with high-altitude locations may be asked to evaluate deaths that occur overseas associated with high-altitude trekking and mountaineering activities.

P6480Asymmetric dimethylarginine (ADMA) predicts altitude-associated hypoxic pulmonary arterial hypertension

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R H Boeger ◽  
P Siques ◽  
J Brito ◽  
E Schwedhelm ◽  
E Pena ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Logistic Regression ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Sea Level ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Arterial Blood ◽  
Pulmonary Arterial

Abstract Prolonged exposure to altitude-associated chronic hypoxia (CH) may cause high altitude pulmonary hypertension (HAPH). Chronic intermittent hypobaric hypoxia (CIH) occurs in individuals who commute between sea level and high altitude. CIH is associated with repetitive acute hypoxic acclimatization and conveys the long-term risk of HAPH. As nitric oxide (NO) is an important regulator of systemic and pulmonary vascular tone and asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthesis that increases in hypoxia, we aimed to investigate whether ADMA predicts the incidence of HAPH among Chilean frontiers personnel exposed to six months of CIH. We performed a prospective study of 123 healthy male subjects who were subjected to CIH (5 days at appr. 3,550 m, followed by 2 days at sea level) for six months. ADMA, SDMA, L-arginine, arterial oxygen saturation, systemic arterial blood pressure, and haematocrit were measured at baseline and at months 1, 4, and 6 at high altitude. Acclimatization to high altitude was determined using the Lake Louise Score and the presence of acute mountain sickness (AMS). Echocardiography was performed after six months of CIH in a subgroup of 43 individuals with either good (n=23) or poor (n=20) aclimatization to altitude, respectively. Logistic regression was used to assess the association of biomarkers with HAPH. 100 study participants aged 18.3±1.3 years with complete data sets were included in the final analysis. Arterial oxygen saturation decreased upon the first ascent to altitude and plateaued at about 90% during the further course of the study. Haematocrit increased to about 47% after one month and remained stable thereafter. ADMA continuously increased and SDMA decreased during the study course, whilst L-arginine levels showed no distinct pattern. The incidence of AMS and the Lake Louise Score were high after the first ascent (53 and 3.1±2.4, respectively) and at one month of CIH (47 and 3.0±2.6, respectively), but decreased to 20 and 1.4±2.0 at month 6, respectively (both p<0.001 for trend). In echocardiography, 18 participants (42%) showed a mean pulmonary arterial pressure (mPAP) greater than 25 mm Hg (mean ± SD, 30.4±3.9 mm Hg), out of which 9 (21%) were classified as HAPH (mPAP ≥30 mm Hg; mean ± SD, 33.9±2.2 mm Hg). Baseline ADMA, but not SDMA, was significantly associated with mPAP at month 6 in univariate logistic regression analysis (R = 0.413; p=0.007). In ROC analysis, a cut-off for baseline ADMA of 0.665 μmol/l was determined as the optimal cut-off level to predict HAPH (mPAP >30 mm Hg) with a sensitivity of 100% and a specificity of 63.6%. ADMA concentration increases during long-term CIH. It is an independent predictive biomarker for the incidence of HAPH. SDMA concentration decreases during CIH and shows no association with HAPH. Our data support a role of impaired NO-mediated pulmonary vasodilation in the pathogenesis of high altitude pulmonary hypertension. Acknowledgement/Funding CONICYT/FONDEF/FONIS Sa 09I20007; FIC Tarapaca BIP 30477541-0; BMBF grant 01DN17046 (DECIPHER); Georg & Jürgen Rickertsen Foundation, Hamburg

scholarly journals Effect of Lepidium meyenii (Maca) on spermatogenesis in male rats acutely exposed to high altitude (4340 m)

2004 ◽  
Vol 180 (1) ◽  
pp. 87-95 ◽  
Author(s):  
GF Gonzales ◽  
M Gasco ◽  
A Cordova ◽  
A Chung ◽  
J Rubio ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Sperm Count ◽  
Treated Group ◽  
Stage I ◽  
Male Rats ◽  
Dependent Manner ◽  
Epididymal Sperm ◽  
Lepidium Meyenii ◽  
Stage Viii

Lepidium meyenii (Maca) is a Peruvian hypocotyl that grows exclusively between 4000 and 4500 m in the central Andes. Maca is traditionally employed in the Andean region for its supposed fertility-enhancing properties.The aim of this study was to test the hypothesis that Maca can prevent high altitude-induced testicular disturbances. Adult male rats were exposed for 21 days to an altitude of 4340 m and treated with vehicle or aqueous extract of Maca (666.6 mg/day). The lengths of the stages of the seminiferous epithelium and epididymal sperm counts were obtained at 0, 7, 14 and 21 days of exposure. The stages of the seminiferous tubules were assessed by transillumination. A dose-response study was also performed at sea level to determine the effect of Maca given to male rats at doses of 0, 6.6, 66.6 and 666.6 mg/day for 7 days on body weight, seminiferous tubule stages and epididymal sperm count. The length of stage VIII and the epididymal sperm count were increased in a dose-dependent manner in Maca-treated rats but treatment reduced the length of stage I. At the highest dose, sperm count increased 1.58 times, the length of stage VIII increased 2.4 times and the length of stage I was reduced 0.48 times compared with the value at dose 0. Exposure to high altitude resulted in a reduction in epididymal sperm count after 7 days and lower values were maintained up to 21 days. Altitude reduced spermiation (stage VIII) to half and the onset of spermatogenesis (stages IX-XI) to a quarter on days 7 and 14 but treatment with Maca (666.6 mg/day) prevented these changes. Data on transillumination and epididymal sperm count in the Maca-treated group exposed to high altitude were similar to those obtained at sea level. Maca increased the sperm count on day 21 of exposure to high altitude to values similar (1095.25 +/- 20.41x10(6) sperm, means +/- S.E.M.) to those obtained in the Maca-treated group at sea level (1132.30 +/- 172.95x10(6) sperm). Furthermore, in the Maca-treated group exposed for 21 days to high altitude, epididymal sperm count was higher than in the non-treated group at sea level (690.49 +/- 43.67x10(6) sperm). In conclusion, treatment of rats with Maca at high altitude prevented high altitude-induced spermatogenic disruption.

Sign in / Sign up

Export Citation Format

Share Document