Early effects of inhalation injury on lung mechanics and pulmonary perfusion

We investigated the early effects of a rather large amount of cotton-smoke on lung mechanics and pulmonary perfusion. Under halothane anesthesia 18 ewes were intubated with a double-lumen tube. In 6 sheep the left lung was exposed to smoke, in another 6 the right lung. A sham group of 6 sheep was insufflated with air instead of smoke. Prior to and 30-45 min following the smoking- (sham-) procedure the following parameters were determined for the smoke- (sham-) exposed and the contralateral lung: static compliance, inspiratory airway resistance, and physiologic dead space ratio. In addition MAP, MPAP, WP, and CO were recorded. The data indicate that inhalation of large amounts of smoke has no major direct effects on pulmonary mechanics and perfusion in the early post-injury period. Only an increase in airway resistance of the smoke exposed lungs was found, which must be attributed to a local reflex mechanism.