Ventilation-perfusion balance.
D000368:Aged; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009730:Nursing Assessment; D012128:Respiratory Distress Syndrome / Q000503:physiopathology*; D014692:Ventilation-Perfusion Ratio