Abnormal bleeding and clotting

16.2 Abnormal bleeding and clotting



Ben Saxon, Chris Barnes


Bleeding disorders range from those that are severe and potentially life-threatening through to mild disorders that may be difficult to distinguish from normal.


Abnormal bleeding is the result of a disorder of one of the following:



• the platelets


• the coagulation mechanism


• the blood vessel or its supporting tissue.



Clinical approach to diagnosis


As a general rule, history-taking, physical examination and a small number of relatively simple laboratory tests will find most causes of abnormal bleeding. The history, with particular reference to the past and family history, will usually provide the most valuable information.



image Practical points



Bleeding disorder assessment




• History to determine normal from abnormal is the most valuable tool.


• Simple coagulation tests such as platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT/international normalized ratio (INR)) and fibrinogen will confirm the majority of diagnoses.


• Mucosal bleeding needs assessment for von Willebrand disorder.


• Assessment of other family members is often required.



History



What is abnormal?


The main question to answer in the history is whether the bleeding symptoms are within or outside normal limits. Isolated bruises over the shins are common, whereas spontaneous petechiae are abnormal. Finger-induced epistaxis is common and not indicative of a bleeding disorder; however, recurrent nose bleeds lasting for more than 10 minutes or leading to anaemia are often related to a bleeding disorder. Table 16.2.1 gives some clinical guidance.



Table 16.2.1 What symptoms and signs may be related to a bleeding disorder?

image


When did the bleeding start?



Prenatal and neonatal




• Congenital infection may result in a bleeding disorder.


• Mucosal bleeding occurs with haemorrhagic disease of the newborn.


• Umbilical stump bleeding is associated with factor XIII deficiency and dysfibrinogenaemias.


• Intracranial haemorrhage may occur with factor deficiencies and with neonatal alloimmune thrombocytopenia.


• Prolonged bleeding following circumcision is suggestive of haemophilia and may be the presenting feature of haemorrhagic disease of the newborn.



Early childhood




• Bleeding often implies a congenital defect.


• Bruising, muscle and joint bleeding is strongly suggestive of haemophilia.


• Petechiae and mucosal bleeding suggests a platelet problem or von Willebrand disorder.



Sudden onset




• Usually indicates an acute problem such as immune thrombocytopenic purpura.


• Non-accidental injury may have a haemorrhagic presentation with inadequate explanations for each specific bruise, which may have an unusual distribution (see Chapter 3.9). Skeletal trauma and other stigmata of non-accidental injury may be present.



Where is the bleeding?


Specific bleeding sites have characteristic associations:



• Joint bleeding: haemophilia A and B


• Nasal mucosa: local irritation; von Willebrand disorder and platelet dysfunction


• Gums, periosteum, skin: scurvy


• Gastrointestinal: haemorrhagic disease of the newborn in babies; liver disease in older children


• Retro-orbital: haematological malignancy or disseminated solid tumour.



What is the context of bleeding?



Family history


Haemophilia A and B are X-linked; most von Willebrand disorder subtypes and haemorrhagic hereditary telangiectasia are recessive and several platelet function disorders are dominantly inherited. Clinical penetrance in haemophilia carriers and von Willebrand disorder may be variable. It is important to review whether the family has a history of bleeding complicating surgical challenges and it may be helpful to explore any history of menorrhagia in family members.



Other aspects of history


Easy bruising, bruising at abnormal sites, prolonged bleeding following trivial trauma or bleeding following surgery and dental extractions are all indications for investigation. Bleeding may also occur in the presence of disorders such as systemic lupus erythematosus, liver disease, extrahepatic portal hypertension, gross splenomegaly, giant haemangiomas, reticuloendothelial malignancies and leukaemia.



Drug ingestion


Drugs may produce abnormal bleeding through:



• depression of clotting factors: anticoagulants, liver toxins


• bone marrow depression: chloramphenicol, cytotoxic agents, radiation


• antigen–antibody reactions with platelet membranes: quinine group of drugs


• direct inhibition of enzymes in platelets: aspirin effects on platelet cyclo-oxygenase.



Physical examination


The following should be noted on physical examination.



The type of skin bleeding


Petechiae alone strongly suggest a platelet or vessel problem, whereas ecchymoses alone suggest a factor deficiency. Combined petechiae and ecchymoses suggest a severe disorder, often of platelet origin.



The site of the bleeding


Confirmation of history, defining the number of all different bleeding sites, and assessment of severity of bleed and functional implications are all important aspects for both diagnosis and management.



Splenomegaly


Hypersplenism occurs when a large spleen removes platelets from the circulation, leading to bleeding. The problem is the underlying cause of the splenomegaly. Hepatomegaly, splenomegaly, lymphadenopathy and/or anaemia, in association with bleeding, strongly suggest leukaemia.



Miscellaneous


Bleeding in association with eczema is a feature of Wiskott–Aldrich syndrome; telangiectasia and mucosal bleeding are typical of hereditary haemorrhagic telangiectasia. Hyperelastic skin, hyperextensible joints and bruising are associated with Ehlers–Danlos syndrome.



Investigation of bleeding in childhood


The tests in Table 16.2.2 are the most important.



Table 16.2.2 Interpretation of initial blood tests in children with abnormal bleeding

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Other tests


Measurement of von Willebrand factor level (antigen), activity (ristocetin co-factor and/or collagen binding assay) and factor VIII level are required to diagnose von Willebrand disorder. The bleeding time has lost favour because of its scarring potential but is characteristically prolonged in thrombocytopenia (normal 2–7 min), von Willebrand disorder and platelet function disorders, and is normal in other coagulation disorders.



Bleeding due to platelet disorders


Bleeding disorders resulting from platelet abnormalities are usually due to thrombocytopenia but may be due to qualitative platelet defects. The various types of inherited and acquired thrombocytopenia are listed in Table 16.2.3.


Table 16.2.3 Inherited and acquired thrombocytopenias














































  Disorder Key Information
Acquired    
Neonatal Immune thrombocytopenia Neonatal alloimmune or maternal autoimmune
Intrauterine infection TORCH
Pre-eclampsia  
Birth asphyxia  
Giant haemangioma ‘Kasabach–Merritt syndrome’ features platelet consumption
Any age Immune thrombocytopenia (ITP) The most common acquired thrombocytopenia
Inherited    
With platelet dysfunction Examples include Bernard–Soulier syndrome and Wiskott–Aldrich syndrome Rare
Without platelet dysfunction Examples include Fanconi anaemia and Alport syndrome Rare
Mediterranean macrothrombocytopenia Large platelets, autosomal dominant

TORCH, toxoplasmosis, other (e.g. HIV and parvovirus B19), rubella, cytomegalovirus, herpes simplex.



Immune thrombocytopenic purpura


Immune thrombocytopenic purpura is the most common acquired bleeding disorder in children. It may be acute or chronic (defined as lasting longer than 12 months), episodic or continuous. Common to all clinical variations is the marked reduction in platelet life span due to immune-mediated splenic sequestration.


Features of typical acute immune thrombocytopenic purpura:



• 80–90% of paediatric immune thrombocytopenic purpura cases


• preceding viral illness is common


• peak age 2–5 years


• abrupt onset of bleeding


• mucosal and skin bleeding


• petechiae common


• otherwise normal examination – no lymphadenopathy or hepatosplenomegaly


• platelet count usually < 20 × 109/L


• normal red cell and white cell parameters.

Related posts:

  1. Sudden unexpected death in infancy
  2. Birth defects, prenatal diagnosis and teratogens
  3. Neural tube defects, large heads and hydrocephalus
  4. Surgical conditions in the newborn

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Aug 4, 2016 | Posted by in PEDIATRICS | Comments Off on Abnormal bleeding and clotting

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