R.B. asks, “When a patient is on the ventilator, what causes a leak in the cuff?”

Answer: There are many causes to a cuff leak. First, to clarify, it is rare that a leak within the cuff actually happens. What happens most often is a leak around the cuff.  This leak around the cuff is usually caused by a tube that is too small, or by an overinflated cuff.

When a tube is too small for the airway, most clinicians attempt to compensate by overinflating the cuff.  This may solve the problem temporarily; however,  the problem is that overinflation of the cuff changes a low-pressure cuff into a high-pressure cuff, creating many more problems later on.  A small tube should be changed to one of proper size in order to ensure an adequate seal.

Chronic overinflation of the cuff, even in a tube of proper size, can cause the tracheal tissue to stretch in the area of the cuff.  This is called tracheomalacia.  In this case, the tube should be changed to a longer one to extend past the area of tracheomalacia.