Thrombocytopaenia/thrombocytosis Flashcards
Why would someone with splenomegaly likely have thrombocytopaenia?
storage of platelets in spleen causing reduction in platelets in peripheral circulation
Which hormone stimulates production of plts and where is it produced?
TPO= thrombopoetin, produced in liver
Someone has an isolated platelet count of 100. Are you worried?
Not necessarily, clinical picture is important. Plt <50 is very concerning, speak to haematology team immediately
A patient has a history of epistaxis and fatigue. Their platelet count is normal. Could there still be a platelet issue?
Yes, it could be a qualitative issue e.g. non functioning platelets due to mutations in receptors etc
What are the clinical signs of thrombocytopaenia?
skin signs: non-blanching rash (purpura, petechiae)
Mucosal bleeding: epistaxis, gum bleeding, menorrhagia
How can your differential diagnosis be divided for thrombocytopaenia?
productive (BM issue) versus consumptive (peripheral destruction)
What are examples of underproduction causes of thrombocytopaenia?
B12, folate, drug-induced, aplastic anaemia, fanconi syndrome, sepsis, leukaemia, liver failure (thrombopoietin produced in the liver!!!!)
Examples of overdestruction causes of thrombocytopaenia?
DIC, ITP, TTP, haemolytic uraemic syndrome. alcohol, drugs
A patient has pancytopaenia. Is the cause of thrombocytopaenia likely to be productive or consumptive in origin?
productive- BM
What are causes of DIC?
sepsis, cancer, trauma, OBG
Is the risk of clotting or bleeding higher in DIC?
imbalance between both, therefore risk of both
What is TTP?
thrombotic thrombocytic purpura, results in blood clots forming throughout the body. This is a medical emergency
What is the pathophysiology of TTP?
autoantibody targets ADAMTS-13 which is an enzyme that breaks down clots
Which feature would see you on blood film in TTP?
schistocytes due to fragmentation of RBCs through narrowed vessels due to blockage with clots
Should you give platelets in TTP?
No!!
What is the main difference between in DIC and TTP that will become apparent during your investigations
TTP has normal coag screen (PT/PTT, fibrinogen) while DIC shows increased PT/PTT and decreased fibrinogen. D-dimer is normal in TTP and raised in DIC
Which hematological condition can arise from heparin usage?
HIT= heparin induced thrombocytopaenia
What is the management of HIT?
switch anticoag therapy
Which scoring is available for HIT?
4T’s- medcalc (stratifies risk of patient having HIT)
Which principles should you follow before speaking to haematologist?
- Acute/chronic
- Evidence of bleeding, pregnant, clot
- Med hx- alcohol, liver disease
- DH- heparin, anticoag?
- Tests: FBC, LFTs, U+E, CRP, coag
- Blood film results
What is the management of DIC?
treat underlying cause
What is the treatment of ITP?
steroids, TPO agonists, IV immunoglobulins
What is the treatment of TTP?
plasma exchange
How can differential for thrombocytosis be divided?
reactive vs BM
What are reactive causes of thrombocytosis?
infection, inflammation, malignancy, iron deficiency
What is a BM cause of thrombocytosis?
myeloproliferative neoplasm
What is the pentad of TTP?
renal failure, neuro symptoms, microangiopathic haemolytic anaemia, thrombocytopenia, fever
Two differentials for abnormal or prolonged bleeding?
Thrombocytopenia- ITP, TTP
Haemophilia A and B
Von Willebrand disease
DIC
Deficiency in factor VIII is associated with which condition?
Haemophilia A
Haemophilia B is associated with a deficiency in which factor?
factor IX
Which sex is affected in haemophilia?
men- x-linked recessive disorder
Name two features of haemophilia
sponatneous bleeding into joints and muscles
abnormal bleeding in gums, GI tract, urinary tract, following procedures…anywhere in the body, spontaneous haemorrhage without trauma
How is diagnosis made for von willebrand disease and haemophilia?
family history
genetic testing
coag factor assays
bleeding scores
Why is desmopressin given to manage von willebrand disease and haemophilia?
stimulates release of von willebrand factor
