Haematology Flashcards
ANAEMIA: List the typical symptoms of patients with anaemia
- Fatigue
- Lethargy
- Pallor
- Dyspnoea
- Palpitations
- Chest pain
ANAEMIA: Classify anaemia in terms of red cell indices and list common causes of each type of anaemia.
ANAEMIA: Discuss the common causes of confirm iron deficiency anaemia.
- Dietary
- Blood loss (menstruation)
- Duodenum or proximal jejunum pathology that reduced absorption
- Pregnancy
ANAEMIA: Outline the clinical features and laboratory diagnosis of sickle cell anaemia
Clinical features:
- Sickle cell crisis1: Severe pain lasting up to 7/7
- Recurrent infections
- Anaemia (normocytic)
- Failure to thrive
Laboratory findings:
- High rectiulocyte count
- Howell-Jolly bodies (a nucleated cell which provide evidence of functional asplenia, due to the sickled cells becoming stuck in the spleen) and target cells on blood smear
- Iron levels are normal
- Abnormal haemoglobin forms on electrophoresis - HgS and HgSC
- Pathological basis: Defect in the beta chain of haemoglobin. Autosomal recessive condition
1: Symptoms arise due to the abnormally shaped cells blocking small blood vessels, reducing perfusion to distal sites which can in turn cause organ damage and increased vulnerabilty to infections (due to splenic damage)
ANAEMIA: Outline the clinical management of sickle cell crisis and the importance of sickle cell
Management of sickle cell crisis
- Analgesia: Paracetamol, NSAIDS or opioids as appropriate for pain level
- Supportive care and correction of cause:
- Oxygen if hypoxic, fluids and antibiotics if required
- Correct cause e.g. warming if hypothermic
- Blood transfusion for life-threatening vaso-occlusive events
ANAEMIA: Describe the laboratory features of haemolysis. Outline the causes of haemolytic anaemia and their treatment.
Laboratory findings:
- Normocytic anaemia
- MCHC elevated (due to lysed RBCs releasing haemoglobin)
- Increased reticulocyte count (as the body tries to increase RBC number)
- Abnormal forms on peripheral smear (schistocytes)
- Elevated LDH and unconjugated bilirubin due to increased RBC breakdown
- Low haptoglobin (becomes depleted in the presence of high concentrations of haemoglobin, as acts to bind free haem)
- Coomb’s test: Positive suggests an immune mediated cause (tests for IgG bound to the surface of RBCs)
Causes of haemolytic anaemia:
- Rhesus incompatibility
- ABO incompatibility
- Hereditary causes:
- RBC defects, enzymatic deficiencies, abnormal Hb (sickle cell), thalassaemia
- Acquired haemolytic anaemia:
- Immune mediated:
- Autoimmune antibodies in conditions such as SLE, RA and scleroderma
- Haemolytic disease of the newborn
- Non-immune mediated:
- Medication induced
- Infection
- HUS, DIC, TTP, HELLP syndrome
- Immune mediated:
Management of haemolytic anaemia
Coomb’s positive (immune mediated)
- Treat causes plus steroids
- Splenectomy1 plus rituximab (Monoclonal Ig against B cells)
- Whole obody plasmaphoresis
Coomb’s negative (not immune mediated) e.g. prosthetic valve haemlysis, TPP, hypersplenism
Congenital
1: Splenectomy is helpful as the spleen is the major site of RBC destruction
ANAEMIA: Outline the laboratory features of microangiopathic anaemia and list the common causes.
Microangiopathic haemolytic anaemia (MAHA) is where the small blood vessels have structural abnormalities that cause haemolysis of the blood cells travelling through them. Imagine a mesh inside the small blood vessels shredding the red blood cells. This is usually secondary to an underlying condition:
- Haemolytic Uraemic Syndrome (HUS)
- Disseminated Intravascular Coagulation (DIC)
- Thrombotic Thrombocytopenia Purpura (TTP)
- Systemic Lupus Erythematosus (SLE)
- Cancer
Laboratory findings:
- Schistocytes (products of RBC breakdown)
- ?Thrombocytopenia (platelet aggregation in vessels leads to haemolysis of RBCs)
ANAEMIA: Outline the features and causes of inherited red cell membrane defects and of red cell enzymopathies.
Features:
- Anaemia (haemolytic)
- Jaundice
- Gallstones (pigmented - due to the increased production of bilirubin)
- Splenomegaly (due to the increased breakdown of RBCs)
Causes:
- Hereditary Spherocytosis: Autosomal dominant. Sphere shaped, fragile RBCs which break easily when passing through the spleen.
- Hereditary Elliptocytosis: As above but oval shaped RBCs
- Thalassaemia: Defect in the alpha or beta chain of haemoglobin
- Sickle Cell Anaemia
- G6PD Deficiency: X-linked recessive. It causes crises that are triggered by infection, medications (antimalarials) or broad beans. Heinz bodies on blood film (can see bits of damaged haem attached to the sides of the RBCs)
ANAEMIA: Outline the clinical features and laboratory diagnosis of thalassaemia
Clinical features
- Microcytic anaemia
- Fatigue
- Pallor
- Jaundice
- Gallstones
- Splenomegaly
- Poor growth and development
- Pronounced forehead and prominent cheekbones
Laboratory diagnosis
- FBC - microcytic anaemia
- Haemoglobin electrophoresis reveals abnormal globin structure
- Elevated ferritin (iron overload can be seen in patients with thalassaemia)
THE WHITE CELL: Interpret a blood count showing a leucocytosis and list common causes for neutrophilia and neutropaenia, lymphocytosis and lymphopaenia.
THE WHITE CELL: Describe the clinical features of acute leukaemia and discuss the laboratory diagnosis.
THE WHITE CELL: Outline the general principles of treatment of acute leukaemias
Primarily treated with chemotherapy and steroids.
Bone marrow transplant if prognosis is poor or relapse. Bone marrow transplant is necessary for those with the philadelphia chromosome in ALL.
Supportive care:
- Hickman line for venous access
- High calorie diet
- Allopurinol to prevent chemo induced tumour lysis syndrome (reduces urate acid levels)
- Monitor potassium and phosphate levels
- Monitoring for neutropenic sepsis - temperature >38 degrees on 2 occasions more than an hour apart → start abx (cephalosporin plus gentamicin)
THE WHITE CELL: Describe the clinical features and laboratory diagnosis of chronic leukaemias and outline the principles of management.
THE WHITE CELL: Outline the clinical presentation of leukaemias and key ddx
THE WHITE CELL: Describe the clinical features and laboratory diagnosis of multiple myeloma. Outline the associated laboratory abnormalities
Clinical features: C.R.A.B.
- Calcium: Hypercalcaemia
- Renal: Impaired renal function due to light chain deposition
- Anaemia: Due to bone marrow failure. Other consequences of bone marrow failure include recurrent infections and increased bleeding/bruising
- Bone: Osteolytic bone lesions due to osteoclast activation (backache, pathological fractures)
- Increased viscosity of blood
Laboratory diagnosis:
- Monoclonal band/paraprotein (representative of excessive production of a single Ig)
- Urine Bence-Jones protein postive
- FBC: Normocytic normochromic anaemia, leukopenia
- Blood film: Rouleaux formation (stacks of RBCs)
- Raised ESR and calcium
- Deranged U&Es
- ‘Pepper pot’ skull on skeletal XR