Respiratory exercises during high altitude (HA) exposure help to maintain a better oxygen saturation (SpO2) counteracting the effects of hypoxia

Background: Accurate detection of cerebral oxygen saturation (rSO2) may be useful for neonatal brain injury prevention, and the normal range of rSO2 of neonates at high altitude remained unclear. Objective: To compare cerebral rSO2 and cerebral fractional tissue oxygen extraction (cFTOE) at high-altitude and low-altitude areas in healthy neonates and neonates with underlying diseases. Methods: 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 rSO2 in neonates within 24 h after admission. The differences of rSO2, pulse oxygen saturation (SpO2), and cFTOE levels were compared between neonates from low- and high-altitude areas. Results: (1) The mean rSO2 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 (p < 0.05). (2) At high altitude, neonates with HIE, pneumonia (p < 0.05), anemia, and congenital heart disease (p < 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 (p < 0.05), while neonates with heart disease in plateau areas had higher cFTOE than those in plain areas (p < 0.05). Conclusions: The rSO2 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.

Download Full-text

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

Revista Brasileira de Medicina do Esporte ◽

10.1590/1517-8692202127042021_0119 ◽

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.

Download Full-text

The Effect of Homeopathic Coca on High Altitude Mountain Sickness: Mt. Everest Base Camp

Complementary health practice review ◽

10.1177/153321010000600107 ◽

2000 ◽

Vol 6 (1) ◽

pp. 45-55 ◽

Cited By ~ 6

Author(s):

Mary F. Shackelton ◽

Christina M. Tondora ◽

Susan Whiting ◽

Michael Whitney

Keyword(s):

Oxygen Saturation ◽

High Altitude ◽

Statistical Significance ◽

Randomized Study ◽

Base Camp ◽

Group Oxygen ◽

Difficulty Breathing ◽

Mountain Sickness ◽

Study Participants ◽

Experimental Group

Homeopathic coca was tested among high altitude trekkers en route to the Mt. Everest base camp to determine its effect on mountain sickness symptoms. Study participants ( n = 24) took homeopathic coca while ascending from 8,000 ft. to 17,600 ft. Measurements included: heart rate, oxygen saturation, and a question naire detailing the occurrence and severity of symptoms. Questionnaire items regarding nausea, headaches, difficulty breathing while asleep all demonstrated statistical significance in the experimental group. Oxygen saturation in the exper imental group was significantly higher. In this placebo-controlled, single-blinded, non-randomized study, homeopathic coca significantly reduced the effects of altitude on trekkers in the experimental group when compared with placebo.

Download Full-text

THE ROLE OF HIGH ALTITUDE SIMULATION TEST (HAST) IN PATIENTS WITH PULMONARY DISEASE AND NORMAL OXYGEN SATURATION AT BASELINE

Respirology ◽

10.1111/resp.13420_394 ◽

2018 ◽

Vol 23 ◽

pp. 232-232

Keyword(s):

Oxygen Saturation ◽

High Altitude ◽

Pulmonary Disease ◽

Simulation Test

Download Full-text

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

AJP Renal Physiology ◽

10.1152/ajprenal.00333.2019 ◽

2019 ◽

Vol 317 (4) ◽

pp. F1081-F1086 ◽

Cited By ~ 3

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.

Download Full-text

Singing Improves Oxygen Saturation in Simulated High-Altitude Environment

Journal of Voice ◽

10.1016/j.jvoice.2020.06.031 ◽

2020 ◽

Author(s):

Alzamani Mohammad Idrose ◽

Norsham Juliana ◽

Sahar Azmani ◽

Noor Anisah Abu Yazit ◽

Munawarah Silam Abu Muslim ◽

...

Keyword(s):

Oxygen Saturation ◽

High Altitude ◽

Simulated High Altitude

Download Full-text

Response to Limper et al. re: “Positional Changes in Arterial Oxygen Saturation and End-Tidal Carbon Dioxide at High Altitude: Medex 2015”

High Altitude Medicine & Biology ◽

10.1089/ham.2020.0041 ◽

2020 ◽

Vol 21 (3) ◽

pp. 307-307

Author(s):

James D. Anholm ◽

Arlena Kuenzel

Keyword(s):

Carbon Dioxide ◽

Oxygen Saturation ◽

High Altitude ◽

Arterial Oxygen Saturation ◽

Arterial Oxygen ◽

End Tidal Carbon Dioxide ◽

End Tidal

Download Full-text

Oxygen Saturation of Hemoglobin in Healthy Children of 2- 14 Years at High Altitude in Nepal

Kathmandu University Medical Journal ◽

10.3126/kumj.v10i1.6912 ◽

2012 ◽

Vol 10 (1) ◽

pp. 30-33

Author(s):

S Shrestha ◽

L Shrestha ◽

N Bhandary

Keyword(s):

Oxygen Saturation ◽

High Altitude ◽

Healthy Children ◽

Older Children ◽

Contributing Factors ◽

Lower Altitude ◽

Value Of Children ◽

The Mean ◽

The Difference ◽

Different Altitudes

Background Individuals residing at higher altitude may have oxygen saturation of hemoglobin different to those living at lower altitude. # Objectives To find out the baseline value of SpO2 in healthy Nepali children (2-14 years) living permanently at high altitude using pulse oximeter and also to study the relation of SpO2 with age, sex and ethnicity. Methods A descriptive observational study was conducted at 4 different altitudes ranging from 2700 to 3800 m in Mustang district. The mean pulse oximery values at different altitudes were calculated and compared. Results One hundred six children were enrolled with the median age of 10 years. The mean SpO2 value of children permanently residing at altitude 2700m was 95.18%, at 2800m was 94.82%, at 3550m was 94.1% and 3800m was 93.1%.The difference in the SpO2 values at different altitude was statistically significant. No sex or age wise differences were noted on the mean SpO2 values in the study group. Conclusions The mean SpO2 values were higher than several other studies done in the altitude above 2500 meters. Enrollment of older children and the different ethnic background could be the contributing factors for the differences. KATHMANDU UNIVERSITY MEDICAL JOURNAL VOL.10 | NO. 1 | ISSUE 37 | JAN - MAR 2012 | 40-43 DOI: http://dx.doi.org/10.3126/kumj.v10i1.6912

Download Full-text

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

European Heart Journal ◽

10.1093/eurheartj/ehz746.1071 ◽

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

Download Full-text