Final answer:
After applying pressure to the antecubital space post-phlebotomy, the medical assistant should bandage the site, dispose of the needle correctly, and ensure the patient's wellbeing, using Type O negative blood in emergencies when the patient's blood type is unknown.
Step-by-step explanation:
Following a phlebotomy procedure where pressure is applied after needle removal, the medical assistant should next bandage the injection site. This action helps to ensure hemostasis and protect the puncture site from infection. Once the site is secure, disposing of the needle in the appropriate sharps container should be completed to maintain safety and hygiene standards. It is crucial to ensure that the patient is feeling well, although this step might often be performed simultaneously or immediately after the bandage is placed, depending on the situation and protocol in place. In an emergency, if a patient's blood type is unknown and they require an immediate blood transfusion, Type O negative blood is used because it is considered the universal donor type and the safest option to prevent adverse transfusion reactions.