A 3-year-old child with known Tetralogy of Fallot is found squatting in the garden after exertion. His mother reports episodic deep cyanosis and unconsciousness lasting a few minutes, especially in the mornings. What is the immediate management of one of these acute cyanotic spells?
- A Place in knee-chest position and give IV morphine and propranolol ✓
- B Administer IV digoxin to improve cardiac contractility
- C Perform immediate surgical repair of VSD and pulmonary stenosis
- D Administer IV furosemide to reduce pulmonary edema
Correct answer: A. Place in knee-chest position and give IV morphine and propranolol
Explanation
Hypercyanotic (Tet) spells in Tetralogy of Fallot are caused by dynamic infundibular spasm worsening right ventricular outflow obstruction, increasing right-to-left shunt. The knee-chest (squatting) position increases systemic vascular resistance, reducing right-to-left shunting. Morphine relieves infundibular spasm and reduces hyperpnea; propranolol reduces heart rate and infundibular spasm. Oxygen, IV fluid bolus, and sodium bicarbonate for acidosis are also part of management. Squatting spontaneously mimics this position and is characteristic of ToF.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.