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Tetralogy of Fallot hypercyanotic spell — RACP Paediatrics MCQ

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HardCardiologyTetralogy of Fallot hypercyanotic spellRACP Paediatrics

A 9-month-old with known tetralogy of Fallot becomes deeply cyanosed after crying. He is tachypnoeic, has reduced intensity of his systolic murmur and oxygen saturation is 58%. What is the most appropriate management?

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Correct answer: C — Knee-chest positioning with oxygen, morphine and urgent cardiac support

This is a hypercyanotic spell from dynamic right ventricular outflow obstruction; knee-chest positioning, oxygen, calming, fluids and morphine are appropriate while urgent cardiac help is obtained. Furosemide can worsen preload and the spell. The pearl is that a softer murmur during cyanosis suggests reduced right ventricular outflow, not improvement.

Reference: RCH Clinical Practice Guidelines: Cyanotic episodes; Therapeutic Guidelines (eTG)