HEMOPHILIA

 

Etiology:

  1. Hemophilia A - Sex-linked. factor VIII. If < 1% spontaneous bleeding occurs.
     
  2. Hemophilia B - Sex-linked. factor  IX. If < 1% spontaneous bleeding occurs.
     
  3. von Willebrand -Autosomal. VW is a factor secreted from endothelium into plasma and  helps in platelet adhesion.  It can have abnormal quantity (measured by vWF:Ag) or abnormal quality (measured with Ristocetin Pletelet Adhesion activity = vWF activity).

S & S:

  1. Spontaneous bleed, bleed s/p trauma/procedure/surgery, hemarthrosis.

DX:

  1. Hemophilia A &B have PTT and  in respective factors.
     
  2. vW has BT, PTT, vWF activity and vWF:Ag

Treatment:

Different replacement  measures for acutely bleeding pt are available. These are:

    1. FFP-has all coagulation factors but  the amount that severely  factor depleted pt may need  will cause fluid overload. Thus, this should be given in case of mild factors deficiency i.e. 5-40% of factor is present. FFP is also given when exact etiology is not known.
       
    2. Desmopressin (DDAVP)- is antidiuretic hormone that increases factor VIII and vW type I.  Used in mild cases. Not used in vW type II. Not effective in moderate (<5%) and severe (<1%) cases of factor  VIII deficiency. DDAVP has very rapid onset of action (+/-30min). Dose is 0.4mcg/kg SQ or IV.
       
    3. Cryoprecipitate - contains factor VIII and vW all types. Has significant risk for  transfusion mediated infections. Dose is 1-2 units /10kg.
       
    4. Lyophilized factor VIII (T1/2 = 12h) and Lyophilized factors II, IIV, IX, X (prothrombine factors T1/2 = 24h) - are used in treatment of moderate and severe forms of  Hemophilia A & B respectively. Also used s/p trauma, hematoma, hemarthroses, IC hemorrhage, hematuria. The dose  given depends how high one wants the level to be in units i.e. 0.3 U, 0.5 U or 1.0 U for mild, moderate or severe bleed respectively.  If available, check prior medical records for the dose used and the outcome.
       
      The dose is calculated as follows:
      (pt wgt in kg x 40) x (desired level in units).
       
      Example: (70 kg x 40) x 1 = 2800 U. If pt's desired level is 0.5 U than (70x40)x0.5=1400 U.

      It is recommended to contact  HemOnc for proper treatment.

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