Blood gases, hematology, and renal blood flow during prolonged mountain sojourns at 3500 and 5800 m.
BACKGROUND
This study mainly focused on renal blood flow, hematological parameters, blood gases, and blood pH, which are affected on exposure to moderate (3500 m) and extreme altitudes (5800 m) in sea level residents.


OBJECTIVE
Acute and prolonged exposure to high or extreme altitude may cause pathophysiological changes in kidney and renal plasma/blood flow, leading to retention of fluids in the tissues. Combined with the decreased availability of oxygen to the tissues, these may be responsible for high altitude maladies.


METHODS
Fifteen male sea level (SL) volunteers, 22-25 yr old, were studied for blood gases, blood viscosity, hematocrit, hemoglobin concentration, and effective renal blood/plasma flow at Delhi (260 m), 3500 m (60 d stay), 5800 m (70 d stay), and 7 d after return to SL.


RESULTS
Compared with SL, a significant increase from 7.34 to 7.43 (p < 0.01) in blood pH was observed at 3500 m that remained significantly increased at 5800 m. PO2 was about 39% less at 5800 m than at SL. PCO2 reduced significantly from 42.07 to 28.05 mm Hg on return from 5800 m to SL. The blood viscosity increased significantly (38%) at 5800 m and decreased significantly by 38% (p < 0.01) after return to SL. The effective renal plasma flow reduced significantly (p < 0.01) from 615.6 at SL to 381.5 ml x min(-1) x 1.73 m(-2) at 5800 m.


CONCLUSIONS
The study suggests a crucial role of renal function in the acclimatization process; renal function also appears to be one factor by which the body protects itself against severe hypoxia.
Singh
M V
MV
Department of Radio-Tracers and Laser Biology, Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi, India.
Salhan
A K
AK
Rawal
S B
SB
Tyagi
A K
AK
Kumar
N
N
Verma
S S
SS
Selvamurthy
W
W
D000064:Acclimatization / Q000502:physiology*; D000328:Adult; D000531:Altitude; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D001809:Blood Viscosity; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D012079:Renal Circulation / Q000502:physiology*; D018709:Statistics, Nonparametric
D006454:Hemoglobins