Flovent Inhaler

- High-volume, Low-pressure Cuffs (9)

High-volume, Low-pressure Cuffs (9)The 7.0 LO cuff has the same shape as the 8.0 LO cuff, but is slightly smaller in diameter than the tracheal model. Consequently, the 7.0 LO cuff had to be stretched in order to occlude the trachea, leading to high intracuff pressures and alteration of normal tracheal contour. The marked difference in 7.0 and 8.0 LO intracuff pressures results from slight differences in cuff vs tracheal diameter. This example shows that the relationship of CT diameter has been the key principle to the reduction of intracuff (hence CT) pressures in the change from low-volume, small-diameter cuffs to high-volume, large-diameter cuffs.
The Effect ofAirway Pressure on Cuff Inflation Pressure
Regardless of cuff design, raising the PIP by reducing Cl necessitated additional cuff inflation and resulted in higher intracuff pressure to maintain the same level of ventilation. This in turn increases CT pressure that interferes with tracheal wall blood flow and predisposes to ischemic necrosis. The magnitude of the increase in cuff inflation pressure varied with the cuff design. In the less compliant lung (Fig 2B), the MED cuff design consistently required higher pressures than the HI cuff, and both designs required pressures bordering on or exceeding the upper limit of “safe” cuff pressure. In no case did the 7.0 LO design function within the range of “safe” pressure (the 8.0 LO is considered to be a unique example of ideal CT diameter, as discussed previously).

June 16, 2013 Cardiac function
Tags: airway pressure ischemic tracheal complications tracheal stenosis