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

Monitor output using an indwelling urinary catheter for the first 24 hr.

Remove the child's pressure dressing after the first 4 hr.

Maintain the child's NPO status for 4 to 6 hr.

Keep the affected extremity straight for at least 6 hr.