Anesthesiology
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Comparative Study
Physical characteristics of and rates of nitrous oxide diffusion into tracheal tube cuffs.
Physical characteristics and time-related volume changes in air-inflated tracheal tube cuffs exposed to nitrous oxide were measured in an environmental chamber. Cuff wall diameter, thickness, residual volume, and length were also measured. Gas volumes in most air-inflated tracheal tube cuffs increased 1.7 to 7 ml within 30 min of exposure to pure nitrous oxide. ⋯ Cuff diameters ranged from 13.8 to 32 mm; thicknesses from .033 to .55 mm; residual volumes from .22 to 19.4 ml; lengths from 23.1 to 49.1 mm. Intracuff volume and pressure increase related to gas diffusion into air-inflated cuffs should be periodically adjusted or pressure automatically controlled during nitrous oxide anesthesia. Large-diameter, thin-walled cuffs are recommended.