Hemophilia: Difference between revisions

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===Standard Calculation===
#Patient's plasma volume (50 mL/kg × weight in kg) × (Desired level of factor VIII [percent]) − (Present level of factor VIII [percent]) = Number of units for initial dose.
#In emergency therapy, the present level of factor VIII is assumed to be zero.
#One unit is the activity of the coagulation factor present in 1 mL of normal human plasma.
#Because the half-life of factor VIII is 8–12 hr, the desired level is maintained by giving half the initial dose every 8–12 hr.
#Cryoprecipitate is assumed to have 80–100 U of factor VIII:C per bag; factor VIII:C concentrates list the units per bottle on the label.


== Factor 9 ==
== Factor 9 ==

Revision as of 05:26, 12 March 2011

Factor 8

General Calculation

(weight in kg) x (50ml plasma/kg) x (desired F8 level - native F8 level) = total units^

Recommended Factor VIII Therapy 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