What should be the next step when a patient types as O positive with agglutination in both screen and red cells?

When encountering a patient who types as O positive and shows agglutination reactions in both the antibody screen and red cells, the next appropriate step is to conduct an autocontrol and a direct antiglobulin test (DAT) on the patient. This step is crucial for evaluating whether the agglutination is due to the presence of antibodies in the patient's serum that are reacting with their own red blood cells (which could indicate an autoimmune condition) or if the result is due to other factors, such as the presence of a reaction in the screen cells that doesn't involve the patient's own cells.

The autocontrol checks for the presence of antibodies against the patient's own red blood cells, and a positive result can suggest an underlying issue such as an autoantibody. Meanwhile, the direct antiglobulin test helps to determine if there are antibodies bound to the patient’s red blood cells, indicating hemolysis or potential transfusion reaction. This testing is essential before proceeding with any transfusion or further crossmatching to ensure patient safety and to better define the cause of the observed agglutination.

Other options, such as performing an enzyme panel or an elution, are more advanced steps that may be warranted based on further results, but they are not the immediate