Evaluation of pressure changes in a new design tracheal tube cuff, the Portex Soft Seal, during nitrous oxide anaesthesia.

We have measured pressure changes in a newly designed tracheal tube cuff, the Portex Soft Seal, during nitrous oxide anaesthesia compared with a Mallinckrodt Lo-Contour tube and a Portex Profile tube. The pressure increases in both control groups were significantly greater than those with the new design (P < 0.0001 in each case). The mean increase in pressure in the Mallinckrodt Lo-Contour tube cuff was 9.9 (SD 3.4) mm Hg compared with 10.3 (1.8) mm Hg in the Portex Profile tube cuff and 2.1 (1.5) mm Hg in the Portex Soft Seal tube cuff. We conclude that the Portex Soft Seal cuff prevented a significant increase in intracuff pressure during nitrous oxide anaesthesia.