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This video refers to guidelines produced by a number of organisations (details below). Please note that the content on this channel reflects my professional interpretation/summary of the guidance and that I am in no way affiliated with, employed by or funded/sponsored by any of them.

My name is Fernando Florido and I am a General Practitioner in the United Kingdom. In this episode I cover what to do if thrombocytopenia is found, always focusing on what is relevant in Primary Care only. The information is based on Haematological guidance by Camden CCG, Manchester Foundation Trust and King’s Health Partners.

I am not giving medical advice; this video is intended for health care professionals, it is only my summary and my interpretation of the guidelines and you must use your clinical judgement.  

Disclaimer:

The Video Content on this channel is for educational purposes and not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen on this YouTube channel. The statements made throughout this video are not to be used or relied on to diagnose, treat, cure or prevent health conditions.

In addition, transmission of this Content is not intended to create, and receipt by you does not constitute, a physician-patient relationship with Dr Fernando Florido, his employees, agents, independent contractors, or anyone acting on behalf of Dr Fernando Florido.

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There is a podcast version of this and other videos that you can access here:

Primary Care guidelines podcast:

·      Redcircle: https://redcircle.com/shows/primary-care-guidelines

·      Spotify: https://open.spotify.com/show/5BmqS0Ol16oQ7Kr1WYzupK

·      Apple podcasts: https://podcasts.apple.com/gb/podcast/primary-care-guidelines/id1608821148

There is a YouTube version of this and other videos that you can access here: 

• The Practical GP YouTube Channel: 

https://youtube.com/@practicalgp?si=ecJGF5QCuMLQ6hrk

My summary of the guidance consulted can be found here:

·      https://1drv.ms/b/s!AiVFJ_Uoigq0mQ4ZjYGRH1wkGBdc?e=Zuxx84

The resources consulted can be found here:

·      Camden CCG guidance: 1456246258-2f3891e610beaa6533f2c0ad7866e776.pdf(Review) - Adobe cloud storage

·      Manchester Adult anaemia guide: https://acrobat.adobe.com/id/urn:aaid:sc:EU:f96fe528-0a47-457c-b29a-a7efb87221e0

·      Manchester Haematology GP guide: https://mft.nhs.uk/app/uploads/2021/02/MFT-Haematology-GP-Pathway-Guide-v4-11.2.21.pdf

·      King’s Health Partners: https://www.kingshealthpartners.org/assets/000/002/294/KCH_-_king_s_health_partners_-_quick_guide_to_haematology_original.pdf

Transcript

If you are listening to this podcast on YouTube, for a better experience, switch to the video version. The link is in the top right corner of the video and in the episode description.

Hello and welcome, I’m Fernando, a GP in the UK. Today we are going to cover what to do when we encounter thrombocytopenia on a full blood count, always focusing on what is relevant in Primary Care only.

I have based this episode on Haematological guidance by Camden CCG, Manchester Foundation Trust and King’s Health Partners. The links to them are in the episode description.

Right, let’s jump into it.

Thrombocytopenia is the platelet count is low, which is defined as a platelet count below 150 × 10⁹ per litre.

But before we assume a true low platelet count, we need to remember that thrombocytopenia can often be an artefact. This happens when platelets clump together in the EDTA sample tube, giving a falsely low automated count.

So, the first step is always to confirm the result with a repeat full blood count and a blood film. The blood film not only rules out platelet clumping but can also provide important clues about the underlying cause.

There are many potential causes of thrombocytopenia so, let’s have a look at them:

First, we have alcohol excess. Chronic alcohol use can directly suppress bone marrow production and shorten platelet lifespan. It is also frequently associated with chronic liver disease, where the spleen often becomes enlarged due to portal hypertension destroying more platelets than usual — a process known as hypersplenism.

Then we have recreational drugs, which can also impair platelet production or trigger immune-mediated destruction.

Then, travel history is also very important. Malaria, for example, often presents with thrombocytopenia, sometimes even before fever or parasitaemia becomes obvious.

Tuberculosis can also cause thrombocytopenia, either through bone marrow involvement or immune-mediated mechanisms.

Then we should consider liver and renal disease.

In chronic liver disease we have already explained that hypersplenism is the most common cause of thrombocytopenia in liver disease.

In renal disease, platelet lifespan is reduced because uraemia makes platelets more fragile, causing them to break down more quickly. In addition, bone marrow suppression may also occur.

Then we have medications as another common culprit.

NSAIDs, heparin, digoxin, quinine, anti-epileptics, antipsychotics and proton pump inhibitors are all recognised causes. Most drug-induced thrombocytopenia is caused by either:

• immune-mediated platelet destruction, or

• direct suppression of platelet production in the bone marrow.

Heparin is the main exception because it causes thrombocytopenia through a unique immune reaction that activates platelets, leading to their consumption and a fall in the platelet count.

Another possible cause are nutritional deficiencies, especially vitamin B12 and folate deficiency, which can impair bone marrow production and lead to thrombocytopenia, often alongside other cytopenias.

We also need to consider viral causes. For example, Epstein–Barr virus frequently causes a temporary drop in platelets, which typically resolves within a few weeks.

HIV and hepatitis B or C can cause persistent thrombocytopenia either through direct bone marrow suppression, immune-mediated destruction, or associated splenomegaly.

Then, malignancy is also on the list, because both haematological cancers and solid tumours can infiltrate or suppress the bone marrow.

Then we have bone marrow failure syndromes, such as aplastic anaemia, which will often present with thrombocytopenia together with anaemia and neutropenia.

Another cause is immune thrombocytopenic purpura, or ITP, which is an autoimmune condition that destroys platelets. In adults, ITP can be acute or chronic, and the platelet count can fall to very low levels even when the patient looks otherwise well.

Finally, autoimmune conditions such as SLE can present with thrombocytopenia as part of a broader immunological process.

Now that we have had a look at the causes, how should we manage these patients?

We have already mentioned that we should confirm thrombocytopenia with a repeat FBC and blood film. If the thrombocytopenia is confirmed, we will need to check if there are urgent criteria.

First of all, we should arrange urgent same-day hospital assessment when the platelet count is below 20 × 10⁹ per litre and any concerning clinical features are present. These include:

• Active bleeding, even if minor, because bleeding risk rises sharply at very low platelet levels.

• An abnormal blood film, such as the presence of blasts suggesting acute leukaemia, or red cell fragments suggesting microangiopathic haemolysis, as these findings indicate potentially life-threatening conditions.

• And finally an altered consciousness or confusion, which may point to serious systemic illness, intracranial bleeding, severe infection, or thrombotic microangiopathy.

We should make an urgent outpatient haematology referral if the platelet count is below 50 × 10⁹ per litre, even without symptoms. This is because at this level, the risk of spontaneous bleeding increases, and many underlying causes — such as ITP, bone marrow failure, or haematological malignancy — require urgent assessment.

Additionally, when the platelet count is below 50, it is unsafe to continue antiplatelet agents or anticoagulants, so these should be stopped unless a specialist advises otherwise.

We should also make an urgent outpatient haematology referral when the platelet count is between 50 and 100 and certain concerning features are present. These include splenomegaly, lymphadenopathy, other cytopenias, pregnancy, or planned surgery. This is because all of these situations increase the risk of serious underlying disease or increase the risk of bleeding.

However, if the platelet count is above 50 and none of the urgent referral criteria are present, we should then arrange the following baseline investigations:

Firstly, we begin with a repeat full blood count and a blood film to confirm the thrombocytopenia, rules out platelet clumping, and look for abnormal cell morphology.

Then we will check Vitamin B12 and folate levels to rule out deficiency.

Ferritin and iron studies are also helpful, given that iron deficiency can occasionally contribute to low platelets.

Inflammatory markers, such as ESR and CRP, which can suggest infection, inflammation, or an underlying autoimmune process.

An autoimmune profile to exclude autoimmune-mediated platelet destruction.

Renal, liver and thyroid function tests to identify chronic liver disease, renal failure and thyroid disease given that both hypo- and hyperthyroidism — can contribute to thrombocytopenia.

Then, viral serology for HIV, hepatitis B and hepatitis C as these viruses can be associated thrombocytopenia.

And finally, we should perform any other investigations suggested by the history or examination, for example, malaria testing after relevant travel, a TB workup, coagulation studies if there is bleeding, etc.

After the initial baseline investigations, if no obvious cause is found, the platelet count is above 50 and none of the urgent referral criteria are present, we can repeat the full blood count after 4 to 6 weeks.

If thrombocytopenia persists and remains unexplained, we should then refer the patient routinely to haematology.

So that is it, a review of the assessment and management of thrombocytopenia.

We have come to the end of this episode. Remember that this is not medical advice but only my summary and my interpretation of the guidelines. You must always use your clinical judgement.

Thank you for listening and goodbye.