A client is diagnosed with a herpes infection. Which drug is considered the first-line treatment?

A. The right arm: Measuring blood pressure in only one arm can miss important pressure discrepancies that occur with certain congenital heart defects, particularly those involving obstruction of systemic blood flow. Upper-extremity readings alone do not provide a complete hemodynamic picture.

B. The left arm: While the left arm may reflect systemic circulation, isolated measurement does not allow comparison between upper and lower extremities, which is essential for detecting defects such as coarctation of the aorta. A single-site reading limits diagnostic value.

C. All four extremities: Congenital heart defects, especially coarctation of the aorta, often cause higher blood pressure in the arms and lower pressure in the legs due to narrowing of the aorta distal to the subclavian arteries. Measuring all four extremities allows detection of pressure gradients that strongly suggest CHDs.

D. Both arms while the child is crying: Crying can falsely elevate blood pressure due to sympathetic stimulation and does not provide reliable or comparative data. Additionally, measuring only the arms fails to assess lower-extremity perfusion differences critical in CHD evaluation.

A. Place the infant in the knee-chest position: In a hypercyanotic (“Tet”) spell, placing the infant in a knee-chest position increases systemic vascular resistance, reduces right-to-left shunting, and improves pulmonary blood flow and oxygenation. Immediate positioning is a first-line emergency intervention.

B. Start an IV for fluids: Establishing IV access is important for administering medications and fluids, but it is secondary to immediate measures to relieve cyanosis and improve oxygenation during a Tet spell.

C. Prepare the infant for surgery: Surgical repair is definitive treatment for tetralogy of Fallot, but emergent stabilization takes priority before operative intervention can occur.

D. Raise the head of the bed: Elevating the head may aid comfort and respiratory mechanics in some conditions, but it does not address the acute pathophysiology of right-to-left shunting causing cyanosis during a Tet spell.