A newborn baby has episodes of cyanosis and respiratory distress that worsen during feeding and improve while crying. Attempts to pass a size 6 French soft catheter through both nostrils fail beyond about 2 cm. What is the most appropriate next investigation to establish the diagnosis?

• A Barium swallow study
• B Lateral radiograph of the skull
• C Flexible laryngoscopy
• D Axial CT scan of the nose with thin sections ✓

Explanation

Failure to pass a catheter beyond the level of the turbinates with cyclical cyanosis relieved by crying indicates bilateral bony choanal atresia. Axial thin section CT after suctioning the nose is the diagnostic study of choice because it shows the bony plate at the level of the choanae, usually a wedge of bone between the pterygoids and the vomer, and distinguishes bony from membranous atresia. D lateral skull radiograph cannot demonstrate the choanal plate, and laryngoscopy addresses a different level of obstruction.

Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.