A 2- year old boy fell from a backyard gym set. His shoulder and upper arm became very swollen shortly after the fall. The boy's mother took him to the emergency room a few hours after the incident because he was complaining of pain. On physical examination, the emergency room physician noted that a large hematoma had formed in the upper part of the boy's right arm. There was no history of surgery, illness or injury. The boy was receiving no medication.
Emergency room treatment consisted of aspirating the hematoma. Subsequent to this treatment, the boy began to bleed extensively. He was admitted to the hospital. Additional information from the mother revealed that the boy's cousin had a "bleeding problem"
* International normalized ratio (INR) therapeutic values: anticoagulant therapy = 2.0-3.0; Prosthetic heart valve = 2.5-3.5
2. One of the largest lab abnormalities is the aPTT (partial thromboplastin time). What does the aPTT measure? What diseases/disorders could this abnormal test result indicate? (4)
3. What is factor VIII? Why would having a decreased/absent amount of factor VIII be problematic? (4)
4. What can an abnormal factor VIII test result mean? Does any of these conditions overlap with the possible outcomes from the aPTT test? Based on the combined results, what is the most likely diagnosis? (6)
Use the information provided by the National Hemophilia Foundation (http://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeding-Disorders to answer the following question
5. What are the three severity levels of hemophilia A? What are the differences and criteria for diagnosis? (4)