Tracheal tube cuff pressure. Changes during nitrous oxide anaesthesia following inflation of cuffs with air and saline.

The volume and pressure of a tracheal tube cuff inflated with air increases during nitrous oxide anaesthesia. The study was designed to investigate the changes of tracheal tube cuff pressure during nitrous oxide anaesthesia following inflation of the cuff with air or saline in 10 mongrel dogs who were anaesthetised with nitrous oxide and their lungs artificially ventilated. At the end of 6 hours there was no change in cuff pressure when saline had been used for inflation, but was six times the initial pressure when air had been used. On microscopic examination of the trachea, only the air group had glandular inflammation, dilatation and destruction. Therefore, it appears that if saline is used to inflate tracheal tube cuffs, there will not be an increase in cuff volume and pressure during nitrous oxide anaesthesia.