[A study on the mechanism of severe hypoxemia associated with acute unilateral atelectasis in dogs].
OBJECTIVE
To study the mechanism of severe hypoxemia associated with acute unilateral atelectasis (AUA).


METHODS
Six dogs with acute left side atelectasis were studied during the period of rest and exercise. The pulmonary shunt and PaO2 were measured at different levels of ventilation of right lung.


RESULTS
After the left side ateloctasis during resting condition, the right lung could compensate to produce only mild hypoxemia (PaO2 9 kPa). But with further increased ventilation by exercise the shunt increased (from 19% to 29%) and led to severe hypoxemia (PaO2 8 kPa). When an artificial pneumothorax was instituted on the left lung, the shunt decreased (from 29% to 18%) and PaO2 increased (from 8 kPa to 9 kPa).


CONCLUSIONS
After AUA, whether severe hypoxemia would occur is determined by the volume of ventilation of the normal side lung. The excess increase of ventilation of the normal side lung by any reason may result in severe hypoxemia.
Deng
X
X
Department of Respiratory Medicine, 2nd Hospital, Beijing Medical University.
Ding
D
D
Li
M
M
D000818:Animals; D001785:Blood Gas Monitoring, Transcutaneous; D004285:Dogs; D005260:Female; D000860:Hypoxia / Q000097:blood / Q000209:etiology*; D008297:Male; D001261:Pulmonary Atelectasis / Q000150:complications*; D012123:Pulmonary Ventilation