scholarly journals Oxygen concentrators for the delivery of supplemental oxygen in remote high-altitude areas

2000 ◽  
Vol 11 (3) ◽  
pp. 189-191 ◽  
Author(s):  
James A. Litch ◽  
Rachel A. Bishop
Keyword(s):  
High Altitude ◽  
Supplemental Oxygen

Acute hypoxia in a simulated high-altitude airdrop scenario due to oxygen system failure

2017 ◽  
Vol 123 (6) ◽  
pp. 1443-1450 ◽  
Author(s):  
William Ottestad ◽  
Tor Are Hansen ◽  
Gaurav Pradhan ◽  
Jan Stepanek ◽  
Lars Øivind Høiseth ◽  
...  
Keyword(s):  
High Altitude ◽  
Acute Hypoxia ◽  
Supplemental Oxygen ◽  
Cerebral Oximetry ◽  
Arterial Oxygen ◽  
Hypoxic Exposure ◽  
System Failure ◽  
Oxygen System ◽  
Simulated High Altitude ◽  
Oxygen Tensions

High-Altitude High Opening (HAHO) is a military operational procedure in which parachute jumps are performed at high altitude requiring supplemental oxygen, putting personnel at risk of acute hypoxia in the event of oxygen equipment failure. This study was initiated by the Norwegian Army to evaluate potential outcomes during failure of oxygen supply, and to explore physiology during acute severe hypobaric hypoxia. A simulated HAHO without supplemental oxygen was carried out in a hypobaric chamber with decompression to 30,000 ft (9,144 m) and then recompression to ground level with a descent rate of 1,000 ft/min (305 m/min). Nine subjects were studied. Repeated arterial blood gas samples were drawn throughout the entire hypoxic exposure. Additionally, pulse oximetry, cerebral oximetry, and hemodynamic variables were monitored. Desaturation evolved rapidly and the arterial oxygen tensions are among the lowest ever reported in volunteers during acute hypoxia. PaO2 decreased from baseline 18.4 (17.3–19.1) kPa, 138.0 (133.5–143.3) mmHg, to a minimum value of 3.3 (2.9–3.7) kPa, 24.8 (21.6–27.8) mmHg, after 180 (60–210) s, [median (range)], N = 9. Hyperventilation with ensuing hypocapnia was associated with both increased arterial oxygen saturation and cerebral oximetry values, and potentially improved tolerance to severe hypoxia. One subject had a sharp drop in heart rate and cardiac index and lost consciousness 4 min into the hypoxic exposure. A simulated high-altitude airdrop scenario without supplemental oxygen results in extreme hypoxemia and may result in loss of consciousness in some individuals. NEW & NOTEWORTHY This is the first study to investigate physiology and clinical outcome of oxygen system failure in a simulated HAHO scenario. The acquired knowledge is of great value to make valid risk-benefit analyses during HAHO training or operations. The arterial oxygen tensions reported in this hypobaric chamber study are among the lowest ever reported during acute hypoxia.

scholarly journals High-altitude Pulmonary Edema in Emergency Department: A Review

2021 ◽  
pp. 113-118
Author(s):  
Hisham Mohammed Sonbul ◽  
Abdu Saleh Alwadani ◽  
Bader Aziz Alharbi ◽  
D. Almaymuni, Saleh Mohammed ◽  
Abdulrazaq Abdulmohsen Alkhalaf ◽  
...  
Keyword(s):  
Pulmonary Edema ◽  
High Altitude ◽  
Supplemental Oxygen ◽  
Severe Form ◽  
Physical Effort ◽  
Disease Etiology ◽  
Salt Consumption ◽  
Pulmonary Vasodilator ◽  
High Altitude Pulmonary Edema ◽  
High Altitude Disease

High altitude pulmonary Edema (HAPE) is a severe form of high-altitude disease that, if left untreated, can result in death in up to half of those who are affected. Lowlanders who rapidly go to elevations more than 2500-3000 m are more likely to develop high altitude pulmonary Edema (HAPE). Individual sensitivity owing to a low hypoxic ventilatory response (HVR), quick pace of climb, male sex, usage of sleep medicine, high salt consumption, chilly ambient temperature, and intense physical effort are all risk factors. HAPE may be totally and quickly reversed if caught early and correctly treated. Slow climb is the most effective technique of prevention. A fall of at least 1000 meters, is the best and most certain treatment choice in HAPE. Supplemental oxygen, portable hyperbaric chambers, and pulmonary vasodilator medications (nifedipine and phosphodiesterase-5 inhibitors) may be beneficial. In this article we’ll be looking at the disease etiology, epidemiology, diagnosis and management.

scholarly journals The Effect of Ambient Temperature on the Use of Supplemental Oxygen at High Altitude

2008 ◽  
Vol 19 (2) ◽  
pp. 143-144
Author(s):  
Jeremy S. Windsor ◽  
James S. Milledge ◽  
George W. Rodway
Keyword(s):  
Ambient Temperature ◽  
High Altitude ◽  
Supplemental Oxygen

scholarly journals Isolated psychosis during exposure to very high and extreme altitude – characterisation of a new medical entity

2017 ◽  
Vol 48 (11) ◽  
pp. 1872-1879 ◽  
Author(s):  
Katharina Hüfner ◽  
Hermann Brugger ◽  
Eva Kuster ◽  
Franziska Dünsser ◽  
Agnieszka E. Stawinoga ◽  
...  
Keyword(s):  
High Altitude ◽  
Acute Mountain Sickness ◽  
Supplemental Oxygen ◽  
Status Change ◽  
Statistical Manual ◽  
Medical Diagnoses ◽  
Diagnostic And Statistical Manual ◽  
Extreme Altitude ◽  
Medical Entity ◽  
Very High

BackgroundPsychotic episodes during exposure to very high or extreme altitude have been frequently reported in mountain literature, but not systematically analysed and acknowledged as a distinct clinical entity.MethodsEpisodes reported above 3500 m altitude with possible psychosis were collected from the lay literature and provide the basis for this observational study. Dimensional criteria of the Diagnostic and Statistical Manual of Mental Disorders were used for psychosis, and the Lake Louise Scoring criteria for acute mountain sickness and high-altitude cerebral oedema (HACE). Eighty-three of the episodes collected underwent a cluster analysis to identify similar groups. Ratings were done by two independent, trained researchers (κ values 0.6–1).FindingsCluster 1 included 51% (42/83) episodes without psychosis; cluster 2 22% (18/83) cases with psychosis, plus symptoms of HACE or mental status change from other origins; and cluster 3 28% (23/83) episodes with isolated psychosis. Possible risk factors of psychosis and associated somatic symptoms were analysed between the three clusters and revealed differences regarding the factors ‘starvation’ (χ2 test, p = 0.002), ‘frostbite’ (p = 0.024) and ‘supplemental oxygen’ (p = 0.046). Episodes with psychosis were reversible but associated with near accidents and accidents (p = 0.007, odds ratio 4.44).ConclusionsEpisodes of psychosis during exposure to high altitude are frequently reported, but have not been specifically examined or assigned to medical diagnoses. In addition to the risk of suffering from somatic mountain illnesses, climbers and workers at high altitude should be aware of the potential occurrence of psychotic episodes, the associated risks and respective coping strategies.

scholarly journals Cognitive function and mood at high altitude following acclimatization and use of supplemental oxygen and adaptive servoventilation sleep treatments

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0217089 ◽  
Author(s):  
Erica C. Heinrich ◽  
Matea A. Djokic ◽  
Dillon Gilbertson ◽  
Pamela N. DeYoung ◽  
Naa-Oye Bosompra ◽  
...  
Keyword(s):  
Cognitive Function ◽  
High Altitude ◽  
Supplemental Oxygen ◽  
Adaptive Servoventilation

scholarly journals Autonomic cardiovascular function in high-altitude Andean natives with chronic mountain sickness

2003 ◽  
Vol 94 (1) ◽  
pp. 213-219 ◽  
Author(s):  
C. Keyl ◽  
A. Schneider ◽  
A. Gamboa ◽  
L. Spicuzza ◽  
N. Casiraghi ◽  
...  
Keyword(s):  
Beneficial Effect ◽  
High Altitude ◽  
Baroreflex Sensitivity ◽  
Cardiovascular Function ◽  
Supplemental Oxygen ◽  
Arterial Oxygen ◽  
Control Group ◽  
Chronic Mountain Sickness ◽  
Mountain Sickness ◽  
Spontaneous Baroreflex

We evaluated autonomic cardiovascular regulation in subjects with polycythemia and chronic mountain sickness (CMS) and tested the hypothesis that an increase in arterial oxygen saturation has a beneficial effect on arterial baroreflex sensitivity in these subjects. Ten Andean natives with a Hct >65% and 10 natives with a Hct <60%, all living permanently at an altitude of 4,300 m, were included in the study. Cardiovascular autonomic regulation was evaluated by spectral analysis of hemodynamic parameters, while subjects breathed spontaneously or frequency controlled at 0.1 and 0.25 Hz, respectively. The recordings were repeated after a 1-h administration of supplemental oxygen and after frequency-controlled breathing at 6 breaths/min for 1 h, respectively. Subjects with Hct >65% showed an increased incidence of CMS compared with subjects with Hct <60%. Spontaneous baroreflex sensitivity was significantly lower in subjects with high Hct compared with the control group. The effects of supplemental oxygen or modification of the breathing pattern on autonomic function were as follows: 1) heart rate decreased significantly after both maneuvers in both groups, and 2) spontaneous baroreflex sensitivity increased significantly in subjects with high Hct and did not differ from subjects with low Hct. Temporary slow-frequency breathing may provide a beneficial effect on the autonomic cardiovascular function in high-altitude natives with CMS.

Pathophysiology and management of altitude-related disorders

2016 ◽  
Author(s):  
Daniel S. Martin ◽  
Michael P. W. Grocott
Keyword(s):  
High Altitude ◽  
Acute Mountain Sickness ◽  
Specific Treatment ◽  
Symptomatic Treatment ◽  
Supplemental Oxygen ◽  
Poor Sleep ◽  
Effective Prophylaxis ◽  
Life Threatening ◽  
Medical Emergencies ◽  
Limiting Condition

Acute high-altitude related illnesses include acute mountain sickness (AMS), high altitude pulmonary oedema (HAPO) and high altitude cerebral oedema (HACO). AMS is characterized by headache, lack of appetite, poor sleep, lethargy, and fatigue. AMS is a common, generally benign, self-limiting condition if managed with rest, no ascent, and symptomatic treatment. Descent is indicated in severe cases. HACO and HAPO are rare, but serious conditions that should be considered life-threatening medical emergencies. HACO is characterized by the presence of neurological signs (including confusion) at altitude, commonly in the presence of headache. HAPO is characterized by breathlessness and signs of respiratory distress at altitude, particularly accompanying exercise. Management of HACO and HAPO involves urgent descent, supplemental oxygen (cylinder, concentrator, or portable hyperbaric chamber) if available, and specific treatment with dexamethasone (HACO) or nifedipine (HAPO). Slow controlled ascent (adequate acclimatization) is the best prophylaxis against the acute high-altitude-related illnesses. Acetazolamide is an effective prophylaxis against AMS.

scholarly journals Residence at moderately high altitude and its relationship with WHO Group 1 pulmonary arterial hypertension symptom severity and clinical characteristics: the Pulmonary Hypertension Association Registry

2020 ◽  
Vol 10 (4) ◽  
pp. 204589402096434
Author(s):  
Shoaib Fakhri ◽  
Kelly Hannon ◽  
Kelly Moulden ◽  
Ryan Peterson ◽  
Peter Hountras ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
High Altitude ◽  
Clinical Characteristics ◽  
Supplemental Oxygen ◽  
Walk Distance ◽  
Pulmonary Arterial ◽  
Low Altitude ◽  
Group 1

Background WHO Group 1 pulmonary arterial hypertension is a progressive and potentially fatal disease. Individuals living at higher altitude are exposed to lower barometric pressure and hypobaric hypoxemia. This may result in pulmonary vasoconstriction and contribute to disease progression. We sought to examine the relationship between living at moderately high altitude and pulmonary arterial hypertension characteristics. Methods Forty-two US centers participating in the Pulmonary Hypertension Association Registry enrolled patients who met the definition of WHO Group 1 pulmonary arterial hypertension. We utilized baseline data and patient questionnaire responses. Patients were divided into two groups: moderately high altitude residence (home ≥4000 ft) and low altitude residence (home <4000 ft) based on zip-code. Clinical characteristics, hemodynamic data, patient demographics, and patient reported quality of life metrics were compared. Results Controlling for potential confounders (age, sex at birth, body mass index, supplemental oxygen use, race, 100-day cigarette use, alcohol use, and pulmonary arterial hypertension medication use), subjects residing at moderately high altitude had a 6-min walk distance 32 m greater than those at low altitude, despite having a pulmonary vascular resistance that was 2.2 Wood units higher. Additionally, those residing at moderately high altitude had 3.7 times greater odds of using supplemental oxygen. Conclusion Patients with pulmonary arterial hypertension who live at moderately high altitude have a higher pulmonary vascular resistance and are more likely to need supplemental oxygen. Despite these findings, moderately high altitude Pulmonary Hypertension Association Registry patients have better functional tolerance as measured by 6-min walk distance. It is possible that a “high-altitude phenotype” of pulmonary arterial hypertension may exist. These findings warrant further study.

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