Emergency Medicine In-Training Examination (EM-ITE) Practice Test 2026 - Free EM-ITE Practice Questions and Study Guide

Monophonic inspiratory stridor is characterized by a singular, uniform sound during inspiration, which is indicative of an obstructive process located in the upper airway or extra thoracic trachea. This type of stridor occurs when there is a collapse of the airway structures during the negative pressure phase of inspiration, leading to a narrowed or obstructed airway. Conditions such as laryngeal edema, croup, or a mass effect in the upper airway can cause this type of sound.

When the extra thoracic trachea collapses during inspiration, the audible stridor reflects the turbulent airflow as it moves through a narrowed segment of the airway. This is particularly notable with inspiratory stridor, which suggests that the obstruction is at or above the level of the vocal cords.

Other choices—such as expiratory stridor, which would indicate obstruction located in the intrathoracic airway, or continuous stridor, which does not specifically localize the obstruction, and multi-phased stridor, which can suggest a more variable condition—do not apply in this specific scenario of extra thoracic collapse during inspiration. Hence, the answer focuses on monophonic inspiratory stridor, clearly aligning with the described dynamics of airway obstruction.