A 4-hour-old male newborn has perioral discoloration for the past several minutes. Oxygen by nasal cannula does not improve the cyanosis. The newborn's temperature is 37.1°C (98.8°F), pulse is 170/min, respirations are 55/min, and blood pressure is 80/60 mm Hg. Pulse oximetry shows an oxygen saturation of 85%. Cardiopulmonary examination shows a 2/6 holosystolic murmur along the lower left sternal border. The abdomen is soft and non-tender. Peripheral pulses are normal. A chest radiograph reveals clear lungs and a normal cardiac silhouette but a narrowed mediastinal shadow. Which of the following is the most likely cause of cyanosis in this patient?

Question

A 4-hour-old male newborn has perioral discoloration for the past several minutes. Oxygen by nasal cannula does not improve the cyanosis. The newborn's temperature is 37.1°C (98.8°F), pulse is 170/min, respirations are 55/min, and blood pressure is 80/60 mm Hg. Pulse oximetry shows an oxygen saturation of 85%. Cardiopulmonary examination shows a 2/6 holosystolic murmur along the lower left sternal border. The abdomen is soft and non-tender. Peripheral pulses are normal.  A chest radiograph reveals clear lungs and a normal cardiac silhouette but a narrowed mediastinal shadow.  Which of the following is the most likely cause of cyanosis in this patient?

Quizplus · Accepted Answer

Eductional Objective: Cyanotic congenital heart disease, characterized by right-to-left shunting, should be considered in neonates with severe cyanosis that does not improve with oxygen administration.  In transposition of the great arteries, deoxygenated blood from the right ventricle is delivered to the systemic circulation while oxygenated blood cycles through the pulmonary circulation.

A 4-Hour-Old Male Newborn Has Perioral Discoloration for the Past