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

We have measured pressure changes in a newly designed tracheal tube cuff, t he Porter Soft Seal, during nitrous oxide anaesthesia compared with a Malli nckrodt Lo-Contour tube and a Porter Profile tube. The pressure increases i n both control groups were significantly greater than those with the new de sign (P<0.0001 in each case). The mean increase in pressure in the Mallinck rodt Lo-Contour tube cuff was 9.9 (SD 3.4) mm Hg compared with 10.3 (1.8) m m Hg in the Porter Profile tube cuff and 2.1 (1.5) mm Hg in the Porter Soft Seal tube cuff. We conclude that the Porter Soft Seal cuff prevented a sig nificant increase in intracuff pressure during nitrous oxide anaesthesia.