An 8 year old female is brought in by her mother after falling off her scooter one hour ago. She was not wearing a helmet, and hit her head on the ground. Patient and mother deny LOC. On exam, she is well-appearing, playing with her mother’s cell phone. She has a mild hematoma over her right parietal region with a normal neuro exam and no active external bleeding appreciated. Medical history is significant for hemophila A.
How would you manage this patient?
Head trauma can be life-threatening in hemophilia patients and CNS bleeds are a major cause of complications. In these injuries, treatment consists of replacement therapy to at least 50% before the child is sent for CT. If bleeding is diagnosed on CT, 100% activity should be achieved, giving 50 units/kg of Factor VIII (in emergency therapy, assume 0% activity at baseline and treat accordingly).
Hemophilia A is an X-linked recessive disorder, causing a variation in Factor VIII which diminishes clot promotion in the clotting cascade.
Infusion of 1 unit of Factor VIII/kg will increase the level by approximately 2%.
Depending on the site of the bleeding, different levels of activity are needed. In hemarthrosis, aim for 30-50% activity. In GI or CNS bleeds, 100% activity is needed.
Hospitalization is likely in a patient with hemophilia A after a head injury. After the initial factor replacement, efforts should be made to get in touch with the patient’s hematologist, who can guide further therapy. Several doses of factor therapy will be needed over days to control bleeding, as the half-life of the factor is only 12-24 hours.
Pearl courtesy of a combination of PEER VIII questions/answers.