Coags
Factor IX Deficiency
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Factor IX Deficiency
, Christmas Disease, Hemophilia B, Plasma thromboplastin component deficiency
Epidemiology
Accounts for 15% of
Hemophilia
cases (remainder are
Hemophilia A
which is a
Factor VIII Deficiency
)
Pathophysiology
Inherited sex linked trait
Factor IX Deficiency
Clinically indistinguishable from
Hemophilia A
(which is the much more common
Factor VIII Deficiency
)
Symptoms
Chronic history of
Bleeding Diathesis
since childhood
Spontaneous bleeding
Excessive
Hemorrhage
follows:
Dental procedures
Surgery
Signs
Joint deformities
Muscle contractures
Labs
Partial Thromboplastin Time
(PTT) prolonged
Corrects with Factor IX supplementation
Corrects with Normal serum
Management
Recombinant Factor IX replacement
Indications
Acute Bleeding
Preoperative prophylaxis
Dosing basic regimen
Initial dose
Factor IX 100 units/kg every 8-12 hours OR
Factor IX (desired concentration - current concentration) * wtKg every 8-12 hours
Factor IX Infusion
Load: 100 units/kg
Infusion: 4-5 units/hour (directed by Factor IX levels)
Dosing in major bleeding (directed by involved region and target Factor IX levels)
Major injury with active bleeding or preoperative and perioperative prophylaxis and management
Target: 100% initially, then 80-100% until wound healed, then 30% of normal Factor IX Level until
Suture
removal
Recombinant Factor IX 100 units/kg initially and then 50 units/kg daily (adjusted for healing)
Joint bleeding (hemarthrosis)
Target: 80% in acute period, then 40% every other day of normal Factor IX Level
Recombinant Factor IX 80 units/kg initially, then 40 units/kg every other day (or every third day) until healed
Gastrointestinal Bleeding
Target: 100% initially, then 50% of normal Factor IX Level until healed
Recombinant Factor IX 100 units/kg initially, then 30-40 units/kg daily
Genitourinary bleeding
Target: 100% initially, then 30% of normal Factor IX Level until healed
Recombinant Factor IX 100 units/kg initially, then 30-40 units/kg daily
CNS Bleeding
Target: 80-100% initially, then 50-100% of normal Factor IX Level for 14 days
Recombinant Factor IX 100 units/kg initially, then 50 units/kg daily
Oral Bleeding
Target: 100% of normal Factor IX Level
Recombinant Factor IX 100 units/kg
Consider topical fibrinolytic agents
Epistaxis
Target: 80-100% initially, then 30% of normal Factor IX Level until healed
Recombinant Factor IX 80-100 units/kg then 35-40 units/kg daily
Muscle bleeding
Target: 50% of normal Factor IX Level
Recombinant Factor IX 40-60 units/kg daily then 20-30 units/kg every other day until healed
Alternative agents when Factor IX is not available
Fresh Frozen Plasma
(FFP) 4 units
Increases Factor IX to only 5%
Prothrombin Complex Concentrate
(PCC) 100 units
Risk of thrombosis (reserve only for very serious bleeding such as CNS
Hemorrhage
)
References
Deloughery and Orman in Majoewsky (2013) EM:Rap 13(9): 1-4
DiMichele (1996) Pediatr Clin North Am 43(3): 709-36 [PubMed]
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