A 6-month-old infant with hypoplastic left heart syndrome is admitted with signs of heart failure. The infant is receiving digoxin 0.01 mg/kg/day divided into two doses. Which nursing intervention is the priority when caring for this infant?

Assessing apical heart rate before each digoxin dose is the priority to prevent life-threatening bradycardia or arrhythmias from toxicity. Other interventions like monitoring weight, oxygen therapy, or positioning are important but less time-critical.

Core Nursing Explanation Key Concept Analysis: This question integrates pediatric cardiac care with high-risk medication administration. The core theme is identifying the priority nursing intervention for an infant with Hypoplastic Left Heart Syndrome (HLHS) who is receiving Digoxin. HLHS is a severe congenital heart defect where the left side of the heart is underdeveloped, leading to single-ventricle physiology and chronic Heart failure (HF). Digoxin is a positive inotrope used to improve cardiac contractility, but it has a Key Point! narrow therapeutic index, meaning the difference between a therapeutic dose and a toxic dose is very small. Infants are particularly vulnerable to toxicity.

Answer Rationale: The correct answer is Key Point! Assess apical heart rate before each digoxin dose. This is a non-negotiable safety action. Digoxin toxicity can cause severe bradycardia and life-threatening arrhythmias. For infants, the apical pulse must be auscultated for a full minute to ensure accuracy. If the heart rate is below the established safe limit (often 90-110 bpm for an infant, but facility/physician specific), the nurse must withhold the dose and notify the provider. This intervention directly prevents patient harm and is time-critical with each scheduled dose.

Distractor Analysis:
Watch out for confusion! While all options are important aspects of heart failure management, they are not the immediate priority related to the specific risk of digoxin administration.
① Monitor daily weight and strict intake and output (I&O): This is a core intervention for managing fluid balance in heart failure. A sudden weight gain is a key indicator of worsening failure. However, it is not the most immediate, time-sensitive action required before administering a high-risk medication.
② Administer oxygen therapy to maintain oxygen saturation above 95%: In HLHS, maintaining adequate oxygenation is complex. These infants often have mixing lesions, and excessively high oxygen saturations can actually decrease pulmonary vascular resistance and cause pulmonary overcirculation at the expense of systemic perfusion. The target saturation is often balanced (e.g., 75-85%) to promote balanced circulation. Therefore, a blanket goal of "above 95%" is incorrect and potentially harmful for this specific condition.
③ Position the infant in semi-Fowler's position to reduce cardiac workload: This is a supportive measure to ease breathing by reducing pressure from abdominal contents on the diaphragm. It is a standard comfort measure for respiratory distress but does not address the acute, drug-specific safety check required.

Related Concepts: The principle of "assessment before administration" for narrow therapeutic index drugs is paramount. Other drugs requiring similar checks include insulin (check blood glucose) and anticoagulants like heparin (check aPTT). In pediatric cardiac nursing, understanding the unique pathophysiology of defects like HLHS (e.g., ductal-dependent systemic circulation) is crucial for providing appropriate, non-harmful care.

Nursing Clinical Practice Guide Clinical Scenario: You are the nurse for "Baby Liam," a 6-month-old with HLHS status post Norwood procedure, now admitted with tachypnea, poor feeding, and diaphoresis. He is on digoxin, furosemide, and captopril. His morning vital signs are: HR 115, RR 55, SpO2 80% on room air.

Nursing Intervention Strategy: 1. Assessment: Before the 9 AM digoxin dose, perform a full one-minute apical heart rate assessment. Also assess for other signs of digoxin toxicity: vomiting, poor feeding, lethargy, and visual disturbances (in older children). Monitor for signs of worsening HF: increased work of breathing, crackles (though less common in infants), hepatomegaly, and periorbital edema. 2. Care & Medication: If HR is within safe parameters, administer digoxin precisely using an oral syringe. Do not mix with formula in case the infant does not finish the bottle, leading to an underdose. Administer other cardiac medications (diuretics, ACE inhibitors) as scheduled, monitoring for hypotension and electrolyte imbalances. 3. Patient Safety & Precautions: Contraindication: Never administer digoxin if significant bradycardia or new arrhythmias are present. Key Monitoring: Obtain daily weights at the same time, with the same scale, and wearing the same amount of clothing. Strict I&O includes weighing diapers. Understand that in single-ventricle physiology, oxygen saturation targets are not normal; follow the cardiology team's specific goal (e.g., SpO2 75-85%).

Nursing Procedure & Medication Flow Digoxin Administration for an Infant: 1. Verify order and calculate dose with a second nurse. 2. Gather equipment: stethoscope, medication, oral syringe. 3. Auscultate apical pulse for one full minute. If HR < safe limit (e.g., 90-110 bpm for infant), WITHHOLD drug and notify provider. 4. Draw up exact dose. Administer slowly into the side of the infant's mouth, toward the cheek. 5. Offer a small amount of water or milk to ensure swallowing. 6. Document HR, dose given (or withheld), and patient response. A Word from Your Senior Nurse "In the fast-paced world of pediatrics, it's easy to get caught up in the multitude of tasks. But with medications like digoxin, there is zero room for error. That one-minute you spend listening to that tiny heartbeat isn't just a task—it's a lifeline. You are the final safety checkpoint. Always remember: No HR check, no digoxin. This mindset protects your most vulnerable patients and builds the unshakable clinical judgment the NCLEX tests for."