The role of oxygen-increased respirator in humans ascending to high altitude.
BACKGROUND
Acute mountain sickness (AMS) is common for people who live in low altitude areas ascending to the high altitude. Many instruments have been developed to treat mild cases of AMS. However, long-lasting and portable anti-hypoxia equipment for individual is not yet available.


METHODS
Oxygen-increased respirator (OIR) has been designed to reduce the risk of acute mountain sickness in acute exposure to low air pressure. It can increase the density of oxygen by increasing total atmospheric pressure in a mask. Male subjects were screened, and eighty-eight were qualified to perform the experiments. The subjects were divided into 5 groups and were involved in some of the tests at 4 different altitudes (Group 1, 2: 3700 m; Group 3,4,5: 4000 m, 4700 m, 5380 m) with and without OIR. These tests include heart rate, saturation of peripheral oxygen (SpO2), malondialdehyde (MDA), superoxide dismutase (SOD), blood lactate (BLA) and PWC (physical work capacity) -170.


RESULTS
The results showed that higher SpO2, lower heart rate (except during exercise) and better recovery of heart rate were observed from all the subjects 'with OIR' compared with 'without OIR' (P<0.05). Moreover, compared with 'without OIR', subjects 'with OIR' in Group 1 had lower concentrations of MDA and BLA, and a higher concentration of SOD (P<0.05), while subjects 'with OIR' in Group 2 showed better physical capacity (measured by the PWC-170) (P<0.05). The additional experiment conducted in a hypobaric chamber (simulating 4,000 m) showed that the partial pressure of oxygen in blood and arterial oxygen saturation were higher 'with OIR' than 'without OIR' (P<0.05).


CONCLUSIONS
We suggested that OIR may play a useful role in protecting people ascending to high altitude before acclimatization.
Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, PR China. zhangjb@mail.xjtu.edu.cn
Guanghao
G
Shen
Kangning
K
Xie
Yili
Y
Yan
Da
D
Jing
Chi
C
Tang
Xiaoming
X
Wu
Juan
J
Liu
Tao
T
Sun
Jianbao
J
Zhang
Erping
E
Luo
D000531:Altitude; D000532:Altitude Sickness / Q000097:blood / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy; D001784:Blood Gas Analysis; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D012122:Ventilators, Mechanical; D055815:Young Adult
D019344:Lactic Acid; D008315:Malondialdehyde; D013482:Superoxide Dismutase; D010100:Oxygen