Airway access below the vocal chords can be classified by anatomical level and technique used.
The two locations to access the airway subglottically are the cricothyroid membrane and the trachea to perform a cricothyrotomy or tracheotomy respectively. Both a cricothyrotomy and tracheotomy can be performed either surgically/ "open" or percutaneously. Consequently we have four techniques available for subglottic airway access:
The indications for each technique vary somewhat, as does the level of difficulty and skill required. Please use the links for more details.
Surgical or "open" access techniques (1. and 3.)
Using surgical access methods generally implies making a skin incision with a scalpel and some degree of tissue dissection down to the airway, after which the airway is entered under more or less direct vision.
(Dilational) percutaneous access techniques (2. and 4.)
These access methods generally involve a Seldinger technique. The airway is first located with a relatively small cannula. Correct positioning of the cannula tip is usually confirmed by aspiration of air. A thin soft-tipped wire is then advanced through the cannula into the airway. The cannula is removed after which a type of catheter is rail-roaded over the wire into the airway with varying degrees of dilation occuring depending on the size of the inserted cannula.