We report the changes in blood gas tensions in a group of 17 patients
during a five-day period of anterior nasal packing after endonasal sur
gery. Significant hypocapnia was observed in the early postoperative p
eriod, which was followed by significant hypoxemia within the first 48
h after surgery, and also shortly after removal of the nasal pack. An
alyses of the changes in blood gas tensions suggested disturbances in
the ventilation-perfusion ratio. Most subjects required a period of 48
h to adapt to oral breathing.