A 6-hour-old infant with prenatally diagnosed hypoplastic left heart syndrome is receiving PGE1. On room air, SaO₂ is 94% and femoral pulses are weak. Serum lactate is rising. Which is the single most likely explanation?
A baby born at 26 weeks' gestation is reviewed on day 9 of life. On day 3 he had a soft systolic murmur. He now has a continuous "machinery" murmur, bounding pulses, a hyperactive precordium and rising oxygen requirements. Which is the most appropriate interpretation of the change in the character of the murmur?
A 10-day-old infant with tricuspid atresia and normally related great arteries has a large ventricular septal defect, a normal pulmonary valve and unobstructed pulmonary arteries. Saturations are 92%. He is tachypnoeic, sweaty with feeds, and has hepatomegaly and faltering weight gain. What is the single most appropriate next step in management?
