Assessing for signs of infection or bleeding at the surgical site.

Choice A rationale:

Administering herbal supplements to aid in healing is not a key nursing intervention in post-operative care for a child who has undergone heart surgery.

The use of herbal supplements should be carefully considered and discussed with the healthcare team, as they may interact with medications or affect the child's recovery.

However, it's not a primary nursing intervention.

Choice B rationale:

Monitoring the child's growth and development is an important aspect of pediatric care, but it is not the key nursing intervention during the immediate post-operative period.

The primary focus in this phase is on assessing for immediate post-surgical complications and ensuring the child's stability and recovery.

Choice C rationale:

Ensuring the child maintains complete bed rest is not a recommended intervention in the post-operative care of a child who has undergone heart surgery.

While some restrictions on physical activity may be necessary, complete bed rest is generally not advisable.

Mobilization, as appropriate, is essential to prevent complications such as deep vein thrombosis and to promote recovery.

Choice D rationale:

Assessing for signs of infection or bleeding at the surgical site is a key nursing intervention during the post-operative period.

Infection and bleeding are immediate post-operative complications that can have serious consequences.

Early detection and prompt intervention are crucial to ensure the child's safety and well-being.

Nursing assessments focus on monitoring vital signs, wound appearance, and any signs of infection or bleeding.