Haematology Flashcards
What is polycythaemia rubra vera?
Polycythaemia vera is a neoplasm of the bone marrow which results in the production of excessive red blood cells.
How does polycythaemia rubra vera present?
The classic symptom of this condition is intense itching which usually occurs after exposure to hot water or hot and humid weather. It is believed that this is due to abnormal histamine or prostaglandin production.
Due to the excess of red cells, patients who suffer from polycythaemia vera are predisposed to blood clots which could explain the deep vein thrombosis this patient had. Also in polycythaemia vera, roughly 20% of patients will also suffer from gouty arthritis.
How does DIC present on blood film?
The combination of low platelets, increased clotting time and raised fibrin degradation products (FDPs) in this setting make DIC the most likely diagnosis.
Describe the pathophysiology of DIC in sepsis
One critical mediator of DIC is the release of a transmembrane glycoprotein known as tissue factor. Tissue factor (TF) is present on the surface of many cell types and is not normally in contact with the general circulation, but is exposed to the circulation after vascular damage. For example, TF is released in response to exposure to cytokines (particularly interleukin 1), tumour necrosis factor, and endotoxin. This plays a major role in the development of DIC in septic conditions.
How does acute chest syndrome present?
This condition is a severe complication of sickle cell anaemia, characterised by the presence of new pulmonary infiltrates on chest x-ray, accompanied by symptoms such as fever, cough, sputum production, dyspnoea or hypoxia. The patient’s history of sickle cell anaemia, presenting symptoms and radiological findings are all indicative of this diagnosis.
How does DIC present on FBC and coag screen?
↓ platelets
↓ fibrinogen
↑ PT & APTT
↑ fibrinogen degradation products
How can we lower the risk of tumour lysis syndrome?
Giving allopurinol or rasburicase prior to chemotherapy is a way to reduce the risk of developing tumour lysis syndrome, as they stop/reduce uric acid from crystalising which is released from cancer cells
How does polycythaemia rubra vera present?
Pruritis (worst after taking showers or hot baths).
Tingling, burning, and numbness in arms, hands, and feet.
Headaches and lethargy.
Splenomegaly.
Elevated haemoglobin on full blood count.
What is the initial tx for polycythaemia rubra vera?
Phlebotomy or venesection is performed to remove a patient’s blood in order to reduce the haemoglobin levels in patients. Initially, patients may need this procedure every week; however when the condition is under control, most patients require venesection every 6 to 12 weeks.
What is a sequestrian crisis?
Sequestration crises
sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
associated with an increased reticulocyte count
How do we treat post-thrombotic syndrome?
However, once post-thrombotic syndrome has developed compression stockings are a recommended treatment. Other recommendations including keeping the leg elevated.
What must we counsel patients on when starting tamoxifen
Tamoxifen increases the risk of VTE + endometrial cancer
How do we manage sickle cell crisis?
The main components for managing sickle cell crisis should be analgesia, oxygen, and IV fluids. You can also consider antibiotics if you suspect an infection, and transfusion if the Hb is low
What mode of inheritance produces sickle cell anaemia?
Autosomal recessive
What is the reversing agent for dabigatran?
Idarucizumab
What do we use to reverse heparin?
Protamine is used to reverse the heparin effect in those on heparin who are bleeding or need an urgent operation, however, it is ineffective in reversing DOAC effect.
How does multiple myeloma present?
‘CRAB’ features of multiple myeloma = hyperCalcaemia, Renal failure, Anaemia (and thrombocytopenia) and Bone fractures/lytic lesions
What do you see on blood film in multiple myeloma?
Rouleaux formation
Why may you see a raised reticulocyte count in sickle cell?
Sickle cell disease causes a normocytic anaemia with raised reticulocyte count - due to haemolysis
What does a high TIBC reflect?
Low iron stores
(Total iron binding capacity)
What does cryoprecipitate contain?
factor VIII, fibrinogen, von Willebrand factor and factor XIII
Where do we use cryoprecipitate?
Patients with haemophilia A are genetically deficient in factor VIII, which is what the cryoprecipitate would be used to replace when actively haemorrhaging
Where do you see Auer rods on blood film?
Auer rods on blood film strongly suggests acute promyelocytic leukaemia