Effects of altitude chamber test with inhaling different concentration oxygen mixed gas in altitude chamber on ear baric function

• DOI: 10.3760/cma.j.issn.1007-6239.2016.01.009
• Publication Date: 2016-03-15
• Authors: Dongqing Wen; Xuewen Zheng; Zhao Gu; Lihua Yu; Xiaoqin Chen; Xiaopeng Liu; Guiyou Wang; Liyong Shi; Bin Zang
• Keywords: Breathing gas; Hypobaric chamber

Objective To investigate the influence of breathing different oxygen concentration mixtures on ear baric function by altitude chamber test.

Methods For self-comparison, 5 healthy male volunteers were in 3 rounds tests with pure oxygen, 60% mixture or air breathings. The test interval was 2 wks. They breathed for 1 h and then kept same breath exposing test, that climbing to 4 000 m 20 m/s rate, stayed min descended slope. Before immediately after tests, tested subjective questionnaires, electronic otoscope acoustic immitance test. impedance index statistically analyzed.

Results Respectively (7 ears), (3 ears) (1 ear) reported pain exposures. Immediately (8 (2 respectively appeared such objective symptoms as fullness, stuffiness hearing loss. There (4 Ⅲ° congestion respectively. numbers type A tympanogram (5 (6 changes middle pressure width more significant than those before tests. After increase volunteers'acoustic reflex threshold (2.98±6.14) dB, (2.71±5.86) dB (1.17±6.85) corresponding breathing.

Conclusions Compared air, exposure brings severest symptoms, membrane most function. It is suggested would be one reasons causing barotrauma.

Key words: Oxygen; Earache; Barotrauma; Questionnaires