Final answer:
Pressure should be applied to the puncture site for at least 5 to 10 minutes after the removal of a radial arterial line to prevent bleeding.
Step-by-step explanation:
The nurse receives an order to discontinue a client's radial arterial line. Pressure should be applied to the site post removal for a specific duration to prevent bleeding and ensure proper clotting. Typically, the pressure is applied directly to the puncture site for at least 5 to 10 minutes if the patient has normal coagulation. For patients on anticoagulation therapy or with clotting disorders, pressure may need to be applied for a longer period, often 15-20 minutes or as advised by medical protocols or the healthcare provider.