Apnoea of prematurity — structured oral (viva)

Branch 1 — Definition and classification

Examiner: "What is apnoea of prematurity, and how do you define an event?" Candidate: Apnoea of prematurity is a developmental disorder of respiratory control in infants born before 37 weeks, presenting after the first 24 hours. An event is defined as a cessation of breathing for 20 seconds or longer, or a shorter pause with bradycardia below 80 beats per minute, central cyanosis, or desaturation below 80 to 85 percent. ^[2]

Examiner: "Name the three types. Which is most common?" Candidate: Central apnoea is absent effort and airflow from loss of neural drive; obstructive apnoea preserves effort but loses airflow through upper-airway collapse; and mixed apnoea is a central pause followed by obstruction. Mixed is the most common type, which is why continuous positive airway pressure is often required alongside caffeine. ^[2]