There is no standardized protocol for workup of bleeding problems. Also, one should differentiate between workup of a patient who is actively bleeding and the use of screening tests in persons who are not bleeding. Any algorithm presented could be criticized by someone who prefers a different approach or different test procedures. Nevertheless, I will present one possible workup for persons who are actively bleeding. This includes bleeding time (to test for platelet and capillary fragility abnormalities), inspection of a peripheral blood smear for platelets and RBC morphology, APTT (to test for intrinsic pathway abnormalities), PT (to test for extrinsic pathway abnormalities), and FDP test (for DIC). If bleeding time is abnormal, a platelet count should be done. If the PT and PTT results are both abnormal, the fibrinogen level should be determined. If the APTT is the only abnormal finding, a simple correction experiment is done using the APTT and patient plasma diluted 1:1 with fresh normal plasma. If the APTT is corrected, the defect is presumed to be a factor deficiency within the intrinsic pathway. If the abnormal APTT is not corrected, or if there is time-dependent noncorrection, a circulating anticoagulant or an inhibitor should be suspected. If the PT is the only abnormal finding, liver disease or unsuspected coumarin intake should be suspected. If both the APTT and PT results are abnormal, unsuspected heparin effect (e.g., heparin flushes) are possible, as well as DIC, coumarin therapy, severe liver disease, and circulating antithrombins or fibrinolysins. The results from the FDP test should help support or rule out DIC.

If at all possible, the results of abnormal screening tests should be verified by a redrawn blood specimen, since a frequent cause of incorrect results is a nonoptimal specimen.

A frequent obstacle to correct diagnosis is transfusion of blood or blood products before a bleeding disorder is suspected, or empirical attempts at therapy before diagnostic tests are ordered or a consultation is obtained. If there is any question of abnormal bleeding, a citrate anticoagulant coagulation test tube, an EDTA-anticoagulated hematology test tube, and a nonanticoagulated serum tube should be obtained in case coagulation tests are needed later. The citrate tube should be kept in the refrigerator.