HEAM Flashcards
(33 cards)
ANAEMIA:
def
• Present when there is a decrease of haemoglobin in the blood below the reference
level for the age and sex of the individual
Red blood cell’s (RBC) lifespan is
120 days
There are three major types of aneamia:
- Hypochromic (pale) MICROCYTIC - low MCV
- Normochromic NORMOCYTIC - normal MCV
- MACROCYTIC - high MCV
MICROCYTIC ANAEMIA:
- Main causes:
- Iron deficiency anaemia - the MOST COMMON CAUSE WORLDWIDE
- Anaemia of chronic disease
- Thalassaemia (see inherited red cell disorders)
Iron deficiency anaemia Tx:
- Find and treat cause
- Oral iron e.g. FERROUS SULPHATE
• Side effects; nausea, abdominal discomfort, diarrhoea/constipation
and black stools
• FERROUS GLUCONATE if side effects are bad - Parenteral iron e.g IV iron or deep IM iron in extreme cases e.g. severe malabsorption
NORMOCYTIC ANAEMIA:
- Main causes:
• Acute blood loss • Anaemia of Chronic Disease • Endocrine disorders such as hypopituitarism, hypothyroidism and hypoadrenalism • Renal failure • Pregnancy
MACROCYTIC ANAEMIA:
Main causes:
Sub-types
• Megaloblastic: delayed nuclear maturation because of delayed DNA synthesis - these are megaloblasts, they are large (i.e. high MCV) and have no nuclei - Vitamin B12 deficiency (known as COBALAMIN) - Folate deficiency • Non-megaloblastic: erythroblasts are normal i.e. normoblastic - Alcohol - Liver disease - Hypothyroidism - Haemolysis - Bone marrow failure (aplastic anaemia) - Bone marrow infiltration - Antimetabolite therapy - Myeloma
Pernicious anaemia Tx
- If a low B12 is due to malabsorption then injections are required
- If cause is dietary then give oral B12
- Replenish B12 stores by giving IM HYDROXOCOBALAMIN
Folate deficiency:
Treat underlying cause
- Give FOLIC ACID TABLETS daily for 4 months - NEVER WITHOUT B12 as
well (unless the patient is known to have NORMAL B12) since in low B12
states it may precipitate/worsen subacute combined degeneration of the spinal cord
HAEMOLYTIC ANAEMIA:
Main causes:
RBC types (2)
• RBCs can be either NORMOCYTIC or if there are many young RBC’s (which are
larger) due to excessive destruction of old RBCs then MACROCYTIC
- RBC membrane defects:
• Hereditary spherocytosis
- Enzyme defects:
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency
- Haemoglobinopathies:
• B Thalassaemia
• A Thalassaemia
• Sickle cell disease
- Autoimmune haemolytic anaemia
HAEMOGLOBIN: • Normal Hb (HbA) = Haem +?chains • Foetal Hb (HbF) = • Hb delta (HbA2) = • In an adult: - HbA = % - HbA2 = - HbF =
• Normal Hb (HbA) = Haem + 2 alpha chains + 2 beta chains
• Foetal Hb (HbF) = Haem + 2 alpha chains + 2 gamma chains
• Hb delta (HbA2) = Haem + 2 alpha chains + 2 delta chains
• In an adult:
- HbA = 97%
- HbA2 = 2%
- HbF = 1%
THE THALASSAEMIAS - DEF + types
disorders of quantity (reduced production):
Beta Thalassaemia = Reduced B chain synthesis
• Alpha Thalassaemia = Reduced A chain synthesis
BETA THALASSAEMIA:
Tx:
Regular (every 2-4 weeks) life-long transfusions to keep Hb above 90g/L and to suppress the ineffective extramedullary haematopoiesis and to allow normal growth
- Iron-chelating agents to prevent iron overload; oral DEFERIPRONE & SC
DESDERRIOXAMINE:
• Side effects; pain, deafness, cataracts and retinal damage
• Decrease iron loading when having infusions
• Iron overload is a big problem
- Large doses of ASCORBIC ACID to increase urinary excretion of iron
SICKLE CELL ANAEMIA - DEF
Tx:
A disorder of quality (abnormal molecule or variant haemoglobins):
FOLIC ACID to all haemolysis patients
Oral HYDROXYCARBAMIDE:
- Increases HbF concentrations
APLASTIC ANAEMIA DUE TO BONE MARROW FAILURE:
Immunosuppressive therapy with ANTITHYMOCYTE GLOBULIN (ATG) and
CICLOSPORIN in those:
• Over 40
• Below 40 with severe disease who do not have a HLA identical sibling donor
• Those who are transfusion dependent
POLYCYTHAEMIA VERA (PV):
Def
+
Tx:
excess proliferation of RBCs, white blood cells and platelets which causes a raised haematocrit (packed cell volume) resulting in hyperviscosity and thrombosis
Chemotherapy:
• HYDROXYCARBAMIDE and low-dose BULSULFAN for those who do not
tolerate venesection or have poorly controlled features of the disease
e.g. thrombocytosis (too many platelets)
- Low dose ASPIRIN alongside above treatments
- RADIOACTIVE PHOSPHORUS but only in those over 70 due to increased risk
of acute leukaemia
- ALLOPURINOL to block uric acid production thereby reduce gout
THROMBOSIS: Tx: Prevention: Stoke: MI:
- Prevention:
• COX inhibitor e.g. ASPIRIN which inhibits platelet aggregation
• P2Y12 inhibitor e.g. CLOPIDOGREL which inhibits ADP from binding to the P2Y12 receptor
• DIPYRAMIDOLE inhibits phosphordiesterase-mediated breakdown of cyclic AMP which prevents platelet activation - MI:
• ASPIRIN - inhibits platelet function as COX inhibitor
• Thrombolytic therapy: - STREPTOKINASE
- TISSUE PLASMINOGEN ACTIVATOR which generates plasmin and degrades fibrin clot
- Stroke:
• ASPIRIN or CLOPIDOGREL
• TISSUE PLASMINOGEN ACTIVATOR (for brain attack, only have a narrow window)
• Treat risk factors
DVT
commonly leg
Tx:
- Low molecular weight Heparin e.g. SC ENOXAPARIN for a minimum of 5days
- ORAL WARFARIN with a target INR of 2.5 (2-3) for 6 months after
- Direct acting Oral Anti-Coagulants (DOAC) similar to warfarin eg. apixaban
IMMUNE THROMBOCYTOPENIA PURPURA (ITP):
Treatment:
- First line:
• Corticosteroids e.g. PREDNISOLONE
• IV immunoglobulin e.g. IV IgG - raises platelet count more rapidly than steroids - thus useful for surgery - Second line:
• Splenectomy
• If splenectomy fails then immunosuppression e.g. ORAL/IV
AZATHIOPRINE
THROMBOTIC THROMBOCYTOPENIC PURPURA (TTP): def + Tx:
• Widespread adhesion and aggregation of platelets leads to microvascular
thrombosis and thus consumption of platelets and thus profound
thrombocytopenia
- Plasma exchange to remove antibody to ADAMTS-13 as well as provide a source of ADAMTS-13
- IV METHYLPREDNISOLONE
- IV RITUXIMAB
THE LEUKAEMIAS
• There are 4 main subtypes:
- Acute lymphoblastic leukaemia (ALL) - Acute myeloid leukaemia (AML) - Chronic myeloid leukaemia (CML) - Chronic lymphocytic leukaemia (CLL)
rapidly proliferating immature blast blood cells (can be pre-cursors of RBCs, platelets or white cells) in the bone marrow that are non functional i.e. defective
- Acute lymphoblastic leukaemia (ALL) ACUTE MYELOID LEUKAEMIA (AML): Clx Tx:
Marrow failure:
Anaemia - low Hb:
Infection - low WCC:
Bleeding - low platelets:
ALLOPURINOL (prevents tumour lysis syndrome)
-Blood and platelet transfusions
- Neutropenia may lead to deadly infections - treat with prophylactic
antivirals, antibacterial and antifungals
- IV fluids - insert Hickman line
- Chemotherapy
- Marrow transplantation
CHRONIC MYELOID LEUKAEMIA (CML):
Tx:
chromosome?
More than 80% have the Philadelphia chromosome which forms a fusion
gene BCR/ABL on chromosome 22, which has tyrosine kinase activity -
stimulates cell division
- ORAL IMATINIB - specific BCR/ABL tyrosine kinase inhibitor
- Stem cell transplant
CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL):
Tx:
- The most common leukaemia
HUMAN IV IMMUNOGLOBULINS
