A nurse is caring for an infant experiencing a hypercyanotic, or "tet spell.”. Which interventions are appropriate for this condition?

Choice A rationale

Epiglottitis is a rapidly progressive, life-threatening bacterial infection causing severe swelling of the epiglottis, potentially leading to acute, complete upper airway obstruction. The most critical initial nursing action is to minimize distress and be immediately prepared for definitive airway management (intubation or tracheostomy) by the appropriate team, as the airway can close suddenly.

Choice B rationale

Racemic epinephrine is an α-adrenergic agonist used to cause vasoconstriction and reduce subglottic edema, primarily indicated for croup. Epiglottitis involves supraglottic swelling, and while it may theoretically reduce edema, the primary risk is mechanical obstruction, making preparation for airway management the priority.

Choice C rationale

While prompt intravenous antibiotic administration is essential to treat the causative bacterium, usually Haemophilus influenzae type b, this action is secondary to securing a patent airway. A patient can die from asphyxiation much faster than from bacteremia, thus airway security must be addressed first.

Choice D rationale

Attempting to obtain a throat culture in a child with suspected epiglottitis is contraindicated. Any manipulation of the posterior pharynx or epiglottis, such as using a tongue blade or swab, can trigger laryngospasm and cause immediate, complete airway obstruction, which is a catastrophic complication.

Choice A rationale

Hypercyanotic spells, or "tet spells," result from a sudden decrease in pulmonary blood flow and increased right-to-left shunting, leading to profound hypoxemia. Administering oxygen helps by slightly increasing arterial oxygen tension, which acts as a mild pulmonary vasodilator, potentially reducing pulmonary vascular resistance and improving oxygen delivery to tissues. This aims to counteract the immediate hypoxemia.

Choice C rationale

Morphine administration is appropriate because of its central nervous system depressant effects. It helps to calm the infant, decreasing systemic oxygen demands and reducing the hyperpnea (rapid, deep breathing) that often accompanies the spell. Furthermore, morphine mildly vasodilates, which increases systemic vascular resistance, decreasing the right-to-left shunt flow.

Choice E rationale

Placing the infant in the knee-chest position significantly increases systemic vascular resistance (SVR) by compressing the major arteries in the lower extremities. The increased SVR reduces the pressure gradient driving the right-to-left shunt through the ventricular septal defect, thereby increasing pulmonary blood flow and improving oxygen saturation during the hypercyanotic event.