Haematology Investigations in Suspected Physical Abuse in Children

Clinical history

• Where is the injury?
• What is the mechanism of injury?
• Is the injury consistent with the child’s developmental stage?
• Is the child taking any prescribed or non-prescribed medications? (to consider medication-related coagulopathy)

Bleeding history

This is very important and cannot be left at asking broadly about any known history. Questions need to be asked specifically about:

• Site or sites of bleeding; this should include specifically asking about skin, mucous membranes (mouth or gums, epistaxis or menorrhagia).
• Whether any bleeding or bruising seen is spontaneous vs traumatic
• Lifelong or acute; is there a history of bruising from a young age?
• Previous haemostatic challenges (e.g. previous surgery or dental work)
  • The absence of significant bleeding after surgical procedures largely excludes a clinically significant inherited bleeding disorder²
• Umbilical stump bleeding or bleeding post circumcision
• Previous transfusions
• Current medication
• If an infant, did they receive Vit K? (IM or oral, also ask about feeding method)

Family bleeding History

This is important and can help guide investigations but even children with, for example, severe haemophilia will only have a positive family history in 50% of cases.

• Significant bleeding symptoms (as above, including grandparents)
• Inherited bleeding disorders
• Parental consanguinity
• Propensity to bruising
• Medical conditions

Thorough top-to-toe examination should be completed, with careful documentation and photographs of injuries.

Note any findings which may be consistent with a collagen disorder – blue sclera, abnormal dentition, short stature, dysmorphic faces, atrophic scars and increased skin/joint laxity.

Not all children presenting with injuries suspicious of inflicted injuries require blood tests. The British Society of Haematology consensus paper recommendations have been adopted by the RCPCH.

Box 1, below, shows situations where blood tests are unlikely to be required. Box 2 illustrates situations when tests are likely to be required.  If any uncertainty then please seek advice from the child protection team (86657) or the non-malignant haematology team (85645).

Children fitting into one of the categories in Box 2 should be considered for First line Investigations (Box 3). Second line investigations are divided in part one and part two investigations (Box 4). See the flow chart below to help guide whether to do second line part one investigation simultaneously with first line investigations.

Second line part two investigations should only be done after discussion with paediatric haematology. This can be with the registrar who would be expected to discuss all child protection cases with the on-call consultant.  In cases of high suspicion of a bleeding disorder, it may be appropriate to do all second line tests simultaneously with first line tests after discussion with a haematologist, to avoid multiple sampling attempts. Dect phone at RHC is 85645 for the non-malignant haematology registrar.

Second line tests often have additional sampling requirements (specific bottles/day test is run etc) so need careful planning so as not to unnecessarily bleed a child repeatedly and waste laboratory resources. Repeated sampling due to inappropriately ordered and handled tests can cause unnecessary pain and stress for the child and their family.

Please see next section for important information around logistics around ordering and handling samples for second line tests. Several of the tests have similar names so it is important the correct test is ordered for the correct patient.

Chart 1: Pathway to guide haematological investigations

If clinically you feel this child may have a bleeding disorder, please discuss with the non- malignant haematology team for further advice.

Platelet membrane glycoproteins

• Request as ‘cell markers’ on Trakcare
• Sample is sent in a large blue bottle (not the EDTA bottle suggested on printed request form).
• Best days to send are Mon/Tues/Wed
• Suggest calling the flow cytometry lab the day before to let them know sample coming if possible (57707)
• This test requires a control sample- fresh coagulation bottle from an individual with no known clotting disorders.

Chromogenic factor VIII levels

• These can be requested via Trakcare

Von Willebrand screen

• Important to remember this test can give a falsely high reading if a patient is particularly unwell or in a heightened emotional state/upset, if there is a high clinical suspicion of this, a second sample is always recommended
• If two normal results and high clinical suspicion of vWD, suggest further discussion with haematology

Platelet nucleotides

• This can be requested on Trakcare
• Sample bottles are two large blue bottles (needs to be 7ml in total).
• Contact lab the day before to let them know sample coming (89097) and let them know who from haematology team it has been discussed with.
• Best days to send these are Mon/Tues/Wed
• Samples are run in Edinburgh, the haematology team can liaise with the Edinburgh lab in terms of results if urgent or high clinical suspicion

Platelet function tests

• This test should only be undertaken by the haematology team as there are a significant number of pre-analytic and analytic variables that can give rise to both false positives and negatives.
• While this test can pick up severe bleeding disorders (Bernard Soullier and Glanzmann's), these should hopefully be identified via platelet membrane glycoproteins.
• The vast majority of bleeding disorders picked up via platelet function tests or platelet nucleotides would be classed as mild bleeding disorders and you might see e.g. aspirin-like platelet defects.
• We do not routinely perform these in patients under two years old
• If there is a situation arising that a patient requires platelet function tests, the haematology team will organise this within the non-malignant haematology team.

If there are concerns or any questions about the practicalities of undertaking these investigations or results please contact the non-malignant haematology team on 85645.