**Question:** A mid tracheostomy is done over

A. Cricoid cartilage
B. Right thyroid cartilage
C. Left thyroid cartilage
D. Right cricoid cartilage

**Correct Answer:** A mid tracheostomy is done over C. Left thyroid cartilage.

**Core Concept:** Tracheostomy refers to the surgical creation of an opening in the trachea to provide a direct airway access. The trachea is a tube-like structure that carries air from the mouth and nose to the lungs. In adults, it is divided into three parts: true trachea, false trachea, and subglottis.

**Why the Correct Answer is Right:** A mid tracheostomy, also known as a modified tracheostomy, is performed at the level of the true trachea, specifically at the cartilaginous rings of the trachea. The trachea is divided into six true rings and two false rings. The correct position for a mid tracheostomy is at the level of the second or third true tracheal ring, which corresponds to the left thyroid cartilage.

**Why Each Wrong Option is Incorrect:**

A. Cricoid cartilage: This is the wrong choice because cricoid cartilage is the first ring of the trachea, located just below the vocal cords. A mid tracheostomy should be placed above the cricoid cartilage.

B. Right thyroid cartilage: The thyroid cartilage is the second cartilage ring in the trachea, which is too far superior to the correct position for a mid tracheostomy.

C. Left thyroid cartilage: This option is also incorrect as the left thyroid cartilage is too inferior to the correct position for a mid tracheostomy.

D. Right cricoid cartilage: Similar to option B, the right cricoid cartilage is located too superior to the correct position for a mid tracheostomy.

**Clinical Pearl:**

A mid tracheostomy provides a stable and secure airway access compared to a lower level tracheostomy. It is often performed when a higher level tracheostomy is not feasible, such as in cases with a large oropharynx mass or narrow pharynx. The position of the tracheostomy site helps to prevent complications, such as tracheal injury or pneumothorax, which can occur if the tracheostomy is placed too low.

**Why the Correct Answer is Right:** Placing the mid tracheostomy at the level of the second or third true tracheal ring ensures a stable airway access while avoiding complications. This position allows for the tracheostomy tube to be placed in the midline, providing an equal division of the tracheal rings and preventing injury to the trachea.

**Why Each Wrong Option is Incorrect:**

A. Cricoid cartilage: This cartilage lies too superior to the correct position for a mid tracheostomy.

B. Right cricoid cartilage: Similar to option A, the right cricoid cartilage is located too superior to the correct position for