Studies of the gas exchange and pressure in the maxillary sinuses in normal and infected humans.

The total gas pressure in experimentally occluded maxillary sinus was continuously recorded during 90 minutes on 7 healthy human subjects. PO2 and PCO2 were measured before and after the total pressure recording. In 3 cases the volume changes in the sinus were measured. The total gas pressure after an initial increase to about 35 mm H2O decreased to a steady state of about 70 mm H2O below atmospheric pressure. The volume changes in sinus showed a corresponding alteration. The gas measurements showed a decrease of PO2 of 25 mm Hg and a rise of PCO2 of 21 mm Hg. In 3 patients with acute purulent sinusitis there was seen a pressure of about 10 cm H2O above the atmospheric pressure.