Influence of the method of re-expansion of atelectatic lung upon the development of pulmonary edema in dogs.

An endobronchial tube was used to separately ventilate each lung in anesthetized dogs, and absorption atelectasis was then induced in the left lung and maintained for 3 1/2 h. The left lung was partially re-expanded by ventilation at normal tidal volumes for 10 min, and then completely re-expanded by manual hyperinflation. This delayed re-expansion was associated with an extravascular water content significantly greater than that of the right lung. A previous study demonstrated no increase in the ratio of left to right lung water content after 3 h of atelectasis alone and a significant increase after immediate hyperinflation. Delayed re-expansion produces significantly different results, and it is therefore concluded that the method of lung re-expansion influences the development of pulmonary edema after atelectasis.