Symptoms

• Mucocutaneous bleeding

• Oral cavity bleeding

• Menorrhagia

• Joint and deep tissue bleeding

• Postoperative bleeding Laboratory Testing

• Low or normal von Willebrand's factor antigen concentration in plasma (vWF:Ag)

• Low or normal factor VIII coagulation assay (FVIII:C)a

• Low ristocetin cofactor activity (vWF:RCo)b a Factor VIII coagulation assay measures the ability of vWF to ind factor and maintain adequate levels of factor VIII.

b Ristocetin cofactor activity (vWF:RCo) assay measures the ability of vWF to interact with intact platelets (normal 50-200 IU/dL).

• To stop spontaneous bleeding as necessary

• To prevent surgical and postpartum bleeding

Nonpharmacologic Therapy

Local measures, including pressure and ice, may be used to control superficial bleeding.

Pharmacologic Therapy

Systemic therapy is used to prevent bleeding associated with surgery, childbirth, and dental extractions and to treat bleeding that cannot be controlled with local measures. The two systemic approaches involve using desmopressin, which stimulates the release of endogenous vWF, or administering products that contain vWF. The general approach to the treatment of vWD is depicted in Figure 67-3. In 2008, The National Heart, Lung, and Blood Institute issued a comprehensive evidence-based guidelines for the diagnosis and management of vWD.16

DDAVP

Most patients with type 1 vWD (functionally normal vWF) and a minor bleeding episode can be treated successfully with desmopressin, which induces release of factor VIII and vWF from endothelial cells through interaction with vasopressin V2 receptors. The recommended dose is the same as that used to treat mild factor VIII deficiency (0.3 mcg/kg IV in 50 mL of normal saline infused over 15-30 min). This therapy is generally ineffective in type 2A patients, who secrete abnormal vWF, and is controversial in type 2B patients because it may increase the risk of postinfusion thrombocytopenia. Type 3 vWD patients who lack releasable stores of vWF do not respond to DDAVP therapy.17

The individual responsiveness to desmopressin is consistent, and a test dose administered at the time of diagnosis or prior to therapy is the best predictor of response. Generally, DDAVP is more effective in vWD than in hemophilia patients, with an average two-to five-fold increase in vWF and factor VIII levels over baseline. In patients with an adequate response, desmopressin is first-line therapy because it allows for once-daily administration (elevates plasma levels for 8-10 hours), does not pose a threat in terms of viral transmission, and costs substantially less than that of the plasma-derived products.

Clinically relevant von Wiflebrand disease (vWD)

Type t vWD

1

r

Desmopressin test infusion

f

No

Response

w

1

Ves t

Desmopressin" first-line therapy

Intermediate or high purity vi rus-inactivated factor vi Ii concentrates

1

r

Monitor factor Vlll level, symptoms, ristocetin oof actor, and bfeeding time

1

r

Transfusion of platelets could be required in special circumstances

FIGURE 67-3. Guidelines for the treatment of vWD. a Use factor VIII concentrate for life-threatening bleeding. b Some patients with type 2 or 3 vWD may respond to desmopressin.

Table 67-5 Replacement Therapy in vWD

Condition Thejapy

Becominentted Do-nqe

4í¡-eo wHVWsr badina doit, foik^YCd by 20-40 uniti/ty every S--J4 hitHirs DDAvP may be added ¡tter a few dayi

Major sji^try Mü™¡nvW«iU*jr¿<:iú<vtiiievefci¡n lean lWHJftJi WlOwPd by iOIUAil far M4iU^ To minimira list of throrobovs; vWF.HCo Icvríí should not PuTVd Ml LI/i1L. ,Sih1 f^KK VIII li-i^K ihOukl my íai'rtVj

250IUUL

Mino iuiLXTï rtotiiylsms-mslnwiii vW lïCO and f* Wf VI" liMtti íCMit 50 30-60 irtSflïj loaín^ CJOMt faftowcd by 30-40 Uflfti/bfl

ILIvdl (pvpfoiíiHy >ÍÜ lUUti J every 1Í-4Bhüuri

MirOt 8IH)«y; rnd¡iHi|iilv\VF:flCti iir*J fjtlw VIII WlrtHs ill Si'.Ht DOM/P rnJ¥ bt iKWed JÍU'i .ifewtldW SCHUWJl (prtfflatdy >50IUfldL) for t-idays

Ai'M fonceruriteî aie dowtl l»wd on irriirs coricenriition in die |Xi|iiriiii*i W at hifr^ ltie <íeí¡i«J líWf-flto le^Tî,

Antifibrinolytic Therapy

Fibrinolysis inhibitors and oral contraceptives are used successfully in the management of epistaxis and menorrhagia or as adjuvant treatments. Fibrinolysis inhibitors include aminocaproic acid (25-60 mg/kg orally or IV every 4-6 hours, to a maximum dose of 24 g/day) and tranexamic acid (10 mg/kg IV every 8 hours). Tranex aminic acid is not FDA-approved for oral administration; however, IV form given as swish and swallow or spit every 6 to 8 hours has been used as bleeding prophylaxis in dental surgery. Both aminocaproic acid and tranexaminic acid are dose adjusted with renal insufficiency.

Replacement Therapy Type 1 „ » des„,„, Pa„e„,s with types 2 and 3 vWD, and major surgery patients require replacement therapy with plasma-derived, intermediate- and high-purity factor VIII virus-inactivated factor VIII concentrates containing vWF 18 Table 67-5 provides typical dosing guidelines and target levels of replacement therapy-concentrates to control various types of hemorrhage. Ultra-high-purity (monoclonal) plasma-derived and recombinant factor VIII concentrates do not contain vWF and should not be used in the treatment of vWD. Cryoprecipitate contains considerable amounts of both factor VIII and vWF. However, this product is not a first-line treatment option because it does not undergo viral inac-tivation.

How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book


Post a comment