7 An increase in alveolar to arterial on differenc

[Editor]

7 An increase in alveolar to arterial on difference occurs with
a. a decrease in alveolar dead space
b. Breathing 100% O²
c. Pulmonary oedema
d. low cardiac output
e. Venous admixture

mark wrote:

7 An increase in alveolar to arterial on difference occurs with
a. a decrease in alveolar dead space
b. Breathing 100% O²
c. Pulmonary oedema
d. low cardiac output
e. Venous admixture

TTTTT

Increase in alveolar dead space will reduce PaO2 and increase A-a difference. Breathing high concentrations of O2 will increase difference as shunted fraction is not corrected by increased FiO2. Pulmonary oedema will reduce alveolar gas transfer. Transfer of oxygen is also partially perfusion limited so a fall in cardic output will reduce PaO2. (West, pg 27) Venous admixture will increase A-a diffence due to increased shunt