Bleeding and clotting disorders - investigation


These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

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To guide Emergency Department (ED) staff with the assessment and investigation of patients with possible bleeding and clotting disorders.


Common presentations of bleeding disorders are:
  • Excessive bruising and bleeding after trauma
  • Recurrent epistaxis and mucosal bleeding
  • Bleeding after operations and dental extractions
  • Spontaneous haemarthroses (only in severe factor deficiency).


History and examination

  • Try to determine whether this is an acquired or inherited bleeding problem, and whether this is a platelet disorder or a coagulation deficiency.
  • How long have symptoms been present, and is the process local or general?
  • Platelet problems usually present with mucosal and skin bleeding whereas coagulation defects present with deep muscle haematomas and haemarthroses but also have skin bruising.
  • Be alert to the possibility of non‐accidental injury, bleeding disorder associated with hepatic and renal disease and, rarely, connective tissue problems.


  • Full blood count, including platelets and blood film.
  • Standard coagulation profile, including prothrombin time, APTT and fibrinogen.
  • If there is a family history of von Willebrand’s disease (VWD) or a strong suspicion clinically, von Willebrand screen (Factor VIII-C, ristocetin cofactor and von Willebrand factor antigen) should be performed.
Diagnosis  Description  Screening tests 
Haemophilia A (Factor VIII deficiency) A sex linked condition but approximately 30% of new cases have no family history. Can be mild, moderate or severe depending on factor levels.  Prolonged APTT which corrects with 50:50 mix with normal plasma. All other tests normal.
Haemophilia B Factor IX deficiency Similar to Haemophilia A with mild, moderate, and severe cases. Prolonged APTT which completely corrects with 50:50 mix with normal plasma. All other tests normal.
von Willebrand's disease  A common mild bleeding disorder usually presenting with bruising and mucosal bleeding. Menorrhagia and post-partum haemorrhage are common problems in females. Inherited as an autosomal dominant in most cases. Most common form is Type 1 where there is a quantitative deficiency, i.e reduced factor VIII coagulant, Ristocetin cofactor, and von Willebrand factor antigen.

In Type 2 disorders there is a quantitative abnormality with reduced Ristocetin cofactor relative to a von Willebrand factor protein.

In Type 3 disorder, there is virtual absence of vWF protein production, and levels of factor VIII coagulant, and von Willebrand factor antigen are all markedly reduced.
Immune Thrombocytopaenia Purpura A common disorder in children. ITP is the most common cause of thrombocytopaenia in childhood.  Full Blood Picture

Two common causes of prolonged APTT not associated with bleeding are:

  • Factor XII deficiency
  • A lupus-like anticoagulant which is usually a transient post-viral phenomenon, prolongs the APTT and is not corrected by mixing "50:50" with normal plasma.


  1. Cameron PA, Brown G (ed), Mitra B (ed), Dalziel SR (ed) Craig S (ed). Textbook of Paediatric Emergency Medicine 3rd Edition Browne 2018, Elsevier.
  2. Kliegman RM, Stanton BMD, St Geme J, Nina F Schor NF. Nelson Textbook of Pediatrics: 20th Edition Publisher: 2016, Elsevier.

Endorsed by:  Co-Director, Surgical Services  Date: Mar 2022

 Review date:  Jan 2025

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