Cyanotic newborn and critical congenital heart disease screening — formative SAQs

SAQ 1 (10)

A term infant born after an uncomplicated pregnancy is noted on the postnatal ward at thirty hours of age to be dusky during a feed but otherwise comfortable, with no respiratory distress. The midwife records a pulse oximetry of 86 per cent in the right hand and 84 per cent in the foot in air. There is no murmur. ^{[2] [3]}

a) Interpret these pulse-oximetry findings against the screening thresholds, and state the immediate next step. (2 marks) ^[2]

b) The baby is alert and looks well. Justify why this appearance does not lower your concern, and name the bedside examination findings that would localise a cardiac lesion. (3 marks) ^[2]

c) Outline your immediate management, naming the drug, the dose and the airway consideration, and explain why it precedes the echocardiogram. (3 marks) ^{[8] [9]}

d) The team asks whether to give 100 per cent oxygen while awaiting the team. Explain the principle that governs oxygen use in a suspected duct-dependent mixing lesion. (2 marks) ^[2]