A nurse is providing postoperative care for a child following an arterial cardiac catheterization. Which of the following actions should the nurse take?

A. Monitor output using an indwelling urinary catheter for the first 24 hr: Routine urinary catheterization is not indicated following cardiac catheterization and increases the risk of infection. Urine output can be monitored without an indwelling catheter unless there is a specific clinical indication. B. Remove the child's pressure dressing after the first 4 hr: Pressure dressings are typically maintained longer to prevent bleeding or hematoma formation at the arterial insertion site. Premature removal can increase the risk of hemorrhage. C. Maintain the child's NPO status for 4 to 6 hr: Oral intake is usually resumed once the child is fully awake and gag reflex has returned. Prolonged NPO status is unnecessary unless otherwise prescribed and does not address the primary postoperative concern. D. Keep the affected extremity straight for at least 6 hr: Keeping the extremity straight helps prevent bleeding and allows proper clot formation at the arterial access site. This is a key nursing intervention following arterial cardiac catheterization to reduce complications such as hematoma or hemorrhage.