Certified Registered Nurse Anesthetist (CRNA) Practice Exam

Why does a newborn with bilateral choanal atresia present with severe respiratory distress?

1. The newborn is a mouth breather

2. Obligatory nose breathing

3. Inability to cry effectively

4. Infection in the nasal passages

The correct answer is: Obligatory nose breathing

A newborn with bilateral choanal atresia presents with severe respiratory distress primarily due to the condition's impact on breathing patterns. In infants, normal respiration is predominantly nasal, as they are obligate nasal breathers. When choanal atresia occurs, this anatomical obstruction prevents air from flowing through the nasal passages to the lungs during inhalation. As a result, the newborn cannot get adequate oxygen through the nasal route, leading to significant respiratory distress. The fact that newborns are obligate nasal breathers means that, unlike older children and adults who can compensate for nasal obstruction by breathing through their mouths, these infants cannot effectively do so. They rely entirely on the patency of their nasal passages to breathe. When both passages are obstructed, as in bilateral choanal atresia, the lack of airflow can quickly lead to life-threatening hypoxia and respiratory distress. In this scenario, while mouth breathing may seem like a possible adaptation, it is not an option for newborns until they learn and develop the ability to breathe through the mouth effectively. Additionally, characteristics such as ineffective crying or infection in the nasal passages do not directly contribute to the primary issue at hand, which is the inability to ventilate adequately due to the obstruction. Therefore, the