Originally published on June 4, 2011
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.