Hemophilia

Background

• Two types (clinically indistinguishable):
  • Hemophilia A: Factor VIII deficiency
  • Hemophilia B: Factor IX deficiency
• Substantial proportion of both types arise from spontaneous mutations
• ICH is most common cause of hemorrhagic death
• Never give NSAIDs or IM injections
• Consult hematology if pt has h/o inhibitors

Diagnosis

• Easy bruising or bleeding out of proportion to the history of trauma
• Recurrent bleeding into joints and muscles
• Hematuria
  • Common but typically not severe

Work-Up

• Coags
  • Only helpful for making the dx; once established unlikely to yield new information
  • PT - normal
  • PTT - abnormal (unless mild hemophilia)
• Head CT
  • If c/o HA, AMS, sig. flunt head injury
• CT A/P
  • Back, thigh, groin, or abd pain

Treatment

• FFP if dx is unknown (contains VIII and IX)
  • Each bag raises factor levels by 3-5%
• Factor replacement if dx is known
  • Factor VIII required = (Target FVIII – Baseline FVIII)/2 x wt in kg
    • If baseline is unknown assume zero
    • After the initial correction maintain via half the initial dose q 8-12hr
  • Factor IX required = (Target FIX – Baseline FIX) x wt in kg
  • Major bleeding (CNS, GI, neck, throat, large muscle, severe injury)
    • Requires factor levels between 80-100% are necessary
  • Less severe bleeding (soft tissue, muscle, joints)
    • Requires factor levels between 30-50%
  • Mild bleeding (hemophilia A)
    • May only require desmopressin (increases vWF which carries VIII in the plasma)
    • 0.3mcg/kg IV over 15-30min
• Analgesia

Factor 8 Tx for Specific Problems in Hemophilia

TYPE OF BLEEDING	INITIAL DOSAGE	DURATION	COMMENT
Skin
Abrasion	None	None	Treat with local pressure and topical thrombin
Laceration	Usually none; if necessary, treat as minor	None	Local pressure and anesthetic with epinephrine may benefit; watch 4 hours after suturing; reexamine in 24 hours
Superficial
Deep	Minor bleeding (12.5 mg/kg)	Single-dose coverage	May need hospitalization for observation; repeat may be necessary for suture removal
Nasal epistaxis
Spontaneous	Usually none; may need to be treated as mild bleeding	None	Uncommon; consider platelet inhibition; treat in usual manner
Traumatic	Moderate bleeding (25 mg/kg)	Up to 5–7 days	Trauma-related bleeding can be significant
Oral
Mucosa or tongue bites	Usually none; treat as minor if persists	Single dose	Commonly seen
Traumatic (laceration) or dental extraction	Moderate (25 U/kg) to severe (50 U/kg)	Single dose; may need more	Saliva rich in fibrin lytic activity; oral ε-aminocaproic acid (Amicar) may be given at 100 mg every 6 hr for 7 days to block fibrinolysis; check contraindications; hospitalize patients with severe bleeding
Soft tissue/muscle hematomas	Moderate (25 U/kg) to severe (50 U/kg)	2–5 days	May be complicated by local pressure on nerves or vessels (e.g., iliopsoas, forearm, calf)
Hemarthrosis
Early	Mild (12.5 U/kg)	Single dose	Treat as earliest symptom (pain); knee, elbow, ankle more common
Late or unresponsive cases of early hemarthrosis	Mild to moderate (25 U/kg)	3–4 days	Arthrocentesis rarely necessary and only with 50% level coverage; immobilization is critical point of therapy
Hematuria	Mild (12.5 U/kg)	2–3 days	Urokinase, the fibrinolytic enzyme, is in urine; with persistent hematuria an organic cause should be ruled out
Major bleeding	Major bleeding (50 U/kg)	7–10 days or 3–5 days after bleeding ceases	In head trauma, therapy should be given prophylactically; early CT scan of head recommended for all
Gastrointestinal severe bleeding
Neck/sublingual
Retroperitoneal
Intra-abdominal
Major trauma
Head injury (see text)
Central nervous system bleeding (see text)
Surgical procedure
CT, computed tomography

 Dosage of Factor VIII (Antihemophilic Factor)

BLEEDING RISK	DESIRED FACTOR VIII LEVEL (%)	INITIAL DOSE (U/KG)
Mild	5–10	12.5
Moderate	20–30	25
Severe	50 or greater	50

Factor 9 (weight in kg) x (100ml plasma/kg) x (desired F9 level - native F9 level) = total units^ ^half this dose should be readministered in 24 hours ^^DDAVP is not helpful in F9 deficiency Source DONALDSON 10/08 (From "Kaji Questions"), Rosen's