von Willebrand Disease
OVERVIEW
- commonest inherited coagulation disorder (autosomal dominant)
- protein involved in (1) platelet adhesion and (2) carriage of factor VIII
- leads to: factor VIII deficiency, abnormal platelet adhesiveness and abnormal vascular endothelium
TYPES
1. quantitative reduction in von Willebrand factor (vWF) (90% of cases)
2. qualitative abnormality in vWF (9%) – 5 subtypes (DDAVP contraindicated in 2B)
3. similar to type 1 but a severe autosomal recessive form (1%)
CLINICAL FEATURES
Presentation
- asymptomatic
- epistaxis
- bruising
- haemarthrosis
- haematoma
- menorrhagia
Previous and/or family history of the above
INVESTIGATIONS
- normal platelet count
- prolonged bleeding time
- impaired ristocetin induced platelet aggregation
- reduced factor VIII activity
- INR normal
- APTT increased
- fibrinogen normal
- vWB factor level decreased
- increased platelet functional assay time
MANAGEMENT
- define responders and non-responders to DDAVP (0.3mcg/kg over 30min IV)
-> measurement of vWF level pre and post. - operations:
— responders should have DDAVP for prophylaxis and bleeding
— non-responders should have factor VIII concentrates or cryoprecipitate, can also use tranexamic acid 20mg/kg IV TDS - avoid antiplatelet drugs
References and Links
- PracticalHaemostasis.com — Von Willebrand Factor Assays: Introduction
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC