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A TEXTBOOK OF POSTPARTUM HEMORRHAGE - PART 6

Việc chẩn đoán có thể không đơn giản, như một hoặc nhiều hơn của các hoạt động của FVIII và vWF có thể được biên giới và thậm chí bình thường. Nó là thường cần thiết để lặp lại các ước tính ít nhất ba lần. Căng thẳng, tập thể dục thể chất, phẫu thuật gần đây và mang thai của tất cả các tăng nồng độ trong huyết tương vWF và FVIII mức, và chẩn đoán có thể gặp khó khăn trong circumstances64 này | Acquired and congenital hemostatic disorders vWF RCo and collagen-binding assay vWF CB accompanied by variable reductions in vWF antigen vWF Ag and FVIII. Several further tests that aid in classification include analysis of ristocetin-induced platelet aggregation RIPA vWF multimer and assay of FVIII binding to vWF63. The diagnosis may not be straightforward as one or more of the activities of FVIII and vWF may be borderline and even normal. It is often necessary to repeat the estimations on at least three occasions. Stress physical exercise recent surgery and pregnancy all increase plasma vWF levels and FVIII levels and diagnosis may be difficult in these circum-stances64. When investigating patients with borderline results it should be taken into account that FVIII and vWF levels are 15-20 lower in individuals with blood group O compared to individuals with blood group A64. The aim of therapy for vWD is to correct the impaired primary hemostasis and impaired coagulation. Treatment choice depends on the severity and the type of disease and on the clinical setting. Treatment options usually include DDAVP and vWF-containing blood products65. DDAVP a synthetic vasopressin analogue releases vWF from endothelial stores there is also an increase in the plasma FVIII level. It is usually given by slow intravenous infusion of 0.3 Jg kg over 20 min which can be repeated every 4-6 h on two or three occasions. The drug can also be given subcutaneously or as a nasal spray. Side-effects include hypotension facial flushing fluid retention for up to 24 h and consequent hyponatremia. DDAVP can safely be used during pregnancy66 and after delivery. It is effective in securing in many situations in type 1 vWD with a 3-5-fold increase in the plasma vWF and FVIII levels. It is of no therapeutic benefit in type 3 vWD because of the very low basal levels of vWF and FVIII. The response in types 2 is less predictable. DDAVP is contraindicated in patients with type 2B because it may .