What Do I Do When Laboratory Results Are Not Consistent With the Patient's Physical Presentation?
A 74-year-old woman arrived in the emergency department with bruising over most of her extremities.
She gave no family or personal history of bleeding but did indicate that she had delivered eight children. Her bleeding time was slightly abnormal at 9 minutes (reference < 8 minutes), but her PT and aPTT were within normal range. Factor assays of factors VIII and IX were normal, and platelet aggregation studies were normal. What are the possibilities for the incongruities in this patient workup?
This patient presented a diagnostic dilemma. Quality control was verified at all levels on all pieces of equipment used. A repeat bleeding time, PT, and aPTT were performed and fell within ranges similar to the original. Factor assays were not repeated. These results stumped the coagulation staff. After careful consideration of exactly what was being tested for, the possibility of a factor XIII deficiency was considered. Factor XIII is necessary for clot stabilization and would healing. A 5 mol/L urea test was performed, and the results were abnormal. An inherited deficiency of factor XIII is the rarest of all of the bleeding disorders, presenting as autosomal recessive. Our patient has a history of multiple pregnancies and successful deliveries; therefore an inherited coagulation deficiency was not considered. A thorough medication check revealed that the patient was on cardiac medication, which potentially could have caused an inhibitory effect on factor XIII, because all other factor-related assays were normal. Cryopre-cipitate was infused to prevent any future bleeding complication. The patient's cardiac medication was discontinued, and the patient was given an appropriate alternative medication for her cardiac condition.
(Many thanks to D. Castellone for the resource material for this case.)
Was this article helpful?