Profile soft-seal cuff, a new endotracheal tube, effectively inhibits an increase in the cuff pressure through high compliance rather than low diffusion of nitrous oxide.

We assessed the nitrous oxide (N(2)O) gas-barrier properties of a new endotracheal tube cuff, the Profile Soft-Seal Cuff (PSSC) (Sims Portex, Kent, UK). The tracheas of randomly selected patients were intubated with the Trachelon (Terumo, Tokyo, Japan), Profile Cuff (PC) (Sims Portex), or PSSC (n = 15 for each) endotracheal tube. Cuffs were inflated with air, and intracuff pressure was measured during anesthesia with 67% N(2)O. The concentration of N(2)O in cuffs was measured at the end of anesthesia. Postoperative sore throat was assessed. The volume-pressure relationship and thickness of the cuff were also measured. Cuff pressure, which increased gradually during anesthesia, was significantly less in the PSSC and PC groups than in the Trachelon group. The PSSC had smaller pressure than the PC 120 min after the start of anesthesia (P < 0.05). There were no significant differences in the N(2)O concentration in cuffs among the groups, although the PSSC had the thinnest cuff with the highest compliance. The incidence of postoperative sore throat in the Trachelon group was significantly higher than in the other two groups. In summary, the PSSC effectively inhibits an increase in cuff pressure during anesthesia with N(2)O. The underlying mechanism is probably the higher compliance of the thinner cuff, rather than a reduction in N(2)O diffusion into the cuff.