Gas absorption was observed in sealed frontal sinuses in cats. Gas flux rate into or out of the sinus was determined by measuring pressure change in an isovolume system or volume change in an isopressure system.
For nitrogen, oxygen, carbon dioxide, and nitrous oxide, gas flux rate showed a good correlation with the solubility of the gas in blood. Observed gas flux rates were best explained by a perfusion-limited, blood absorption mechanism. The pathogenesis of a partial vacuum which sometimes is observed in sinusitis is discussed on this basis.