Endotracheal Tube Audible Leak Test

In supine position, the head will be positioned in neutral position. With fresh gas flow at 2-5L/min, and pop off valve in the anesthesia machine closed and pressure in the inspiratory circuit is slowly increased until an audible leak is heard at the mouth. That pressure will be recorded.

In the same patient position, a flexible nasal laryngoscope will be inserted and positioned superior to the laryngeal inlet by the surgeon. With fresh gas flow at 2-5L/min, and pop off valve in the anesthesia machine closed, the pressure in the inspiratory circuit will be increased slowly until a leak around the TT will be visualized by inspecting the supraglottic area for bubbles or air movement around the TT. The peak pressure at which leak is observed physically will be recorded. This is the end of the study.