[The assessment of the risk of altitude decompression sickness during simulation of repeated (with 12 hour interval) exits into open space].
Purpose of the investigation was to assess contribution of repeated (with a 12-hr interval) decompression to the risk of altitude decompression sickness (ADS) by simulation of 6-hr extravehicular activities (EVA) of space crewmembers in altitude chamber. The protocol included "ascents" of 6 essentially healthy male subjects at the age of 24 to 51 to the altitude of 7,600 m (37 kPa) following 30-min prebreathing (elimination of nitrogen from the body by breathing pure oxygen through a mask at the ambient pressure of 73 kPa = 2,600 m). Each subject participated in 2 experimental exposures: first initial and then repeated decompression. None of 24 "ascents" produced clinical signs of ADS. Comparison of the data concerning frequency and time points of detection by ultrasonic Doppler equipment of gas bubbles (GB) in the venous bed during decompression with initial, maximal and mean values of US signal intensity failed to state a significant difference between them. Data of the investigation were confronted with anticipated length of GB dispersion in body tissues.
Katuntsev
V P
VP
Chadov
V I
VI
Filipenkov
S N
SN
Iseev
L R
LR
Vorob'ev
G F
GF
Poliakov
V N
VN
Kazakova
R T
RT
Skedina
M A
MA
D000328:Adult; D003665:Decompression Sickness / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D011651:Pulmonary Artery / Q000000981:diagnostic imaging; D012307:Risk Factors; D012720:Severity of Illness Index; D013026:Space Flight; D013997:Time Factors; D018608:Ultrasonography, Doppler