A 6-month-old infant with tetralogy of Fallot is admitted to the pediatric unit with signs of cyanosis and hypercyanotic spells. Which nursing assessment finding should receive the highest priority?

A 6-month-old infant with known Tetralogy of Fallot presents with acute cyanosis and hypercyanotic spell. The nurse’s immediate priority is to recognize and intervene for severe hypoxemia.

Key Assessment Finding: Respiratory distress with tachypnea, nasal flaring, and grunting indicates the infant is in a hypercyanotic spell and actively compensating for profound hypoxemia. This takes precedence over other findings.

Immediate Nursing Actions:

• Place the infant in a knee-to-chest position to increase systemic vascular resistance and decrease right-to-left shunting.
• Administer 100% oxygen via face mask to maximize oxygen saturation.
• Administer prescribed morphine sulfate to reduce respiratory drive and decrease infundibular spasm.
• Provide calm, quiet environment to minimize metabolic oxygen demand.
• Notify the healthcare provider immediately for potential escalation to IV propranolol or emergent surgery.

Rationale for Priority: Untreated severe hypoxemia leads to metabolic acidosis, loss of consciousness, and cardiac arrest. Respiratory distress signs are the most direct clinical indicator of this life-threatening state, requiring immediate action before secondary signs like decreased urine output develop.