After arterial switch surgery, an infant shows ST elevation, low oxygen saturation, and frothy secretions.

ST segment elevationindicatesmyocardial ischemia, andfrothy secretions + desaturationsuggestpulmonary edemaor shunting. Aresidual ventricular septal defect (VSD)post-surgery can lead toright-to-left shunting, bypassing the lungs and resulting inhypoxemiadespite adequate ventilation.

“Residual intracardiac shunts, especially VSDs, can lead to desaturation and heart failure symptoms post arterial switch. ST changes suggest myocardial ischemia secondary to hypoxia.”

(Referenced from CCRN Pediatric – Direct Care: Cardiovascular, Postoperative Congenital Heart Disease Complications)