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118 Cards in this Set
- Front
- Back
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Describe the WHO definition of anaemia |
Anaemia is a condition in which the number of RBCs and therefore their oxygen carrying capacity is insufficient to meet the bodies physiological needs |
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What will cause number of circulating RBCs to vary? |
1) Age 2) Gender 3) Altitude 4)Smoking behaviour 5) Pregnancy and stage of pregnancy |
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Describe the normal ranges for weight parameters |
Hb - 115-155 g/L
RBC - 3.8-5.3 x10^12/L
Haematocrit - 0.37-0.45 L/L
MCV - 83-96 fL
Mean cell Haemoglobin - 27-32 pg
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By which of the RBC parameters is anaemia defined? |
Mean cell volume |
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What are the three basic classifications of anaemia, as well as the MCV that they contain? |
Microcytic - <83fL
Normocytic - 83-96 fL
Macrocytic - >96fL |
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Microcytic anaemia is caused by which two things |
Iron deficiency Thalassaemia |
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What is normal body iron (serum ferritin) |
4g (3g Hb and 1g reticulo-epithelial cells) |
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Where is iron absorbed and in what quantity? |
In the duodenum at 1mg/day |
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Causes of deficiency (four)? |
1) Dietary (lack of meat/green veg)
2) Physiological (infancy, adolescence, pregnancy)
3) Blood loss (menstruation)
4) Malabsorption (Coeliac) |
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Name four clinical features seen in severe iron deficiency anaemia |
Angular stomatitis
Glossitis
Koilonychia
Pharyngeal and Oesophageal webbing |
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Why is ferritin better to measure in blood than iron? |
Because ferritin is the bioavailable form of iron |
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If iron deficiency is physiological in cause what is the next stage of action? |
Treat with oral iron |
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If iron deficiency is found in pre-menopausal women what is the next stage of action? |
Look for localising GI symptoms and signs:
No, treat with oral iron
Yes, barium Enema/Colonoscopy |
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if iron deficiency is found in males or post-menopausal women? |
Barium enema/colonoscopy |
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Normocytic anaemias describe an anaeamia with an MCV of? |
83-96fl |
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Normocytic anaemia is an anaemia of...... |
Chronic disease |
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4 common causes? |
1) Acute blood loss
2) Bone marrow infiltration
3) Combined haemitinic deficiency
4) Haemolysis |
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Two causes of anaemia |
Low red cell mass Increased plasma volume |
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What is a low Hb for men? |
<13.5 g/dL |
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Causes of anaemia of chronic disease? Five |
1) chronic infection (TB, Osteomyelitis) 2) Malignancy 3) Vasculitis 4) Rheumatoid arthritis 5) Renal failure |
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Treatment of anaemia of chronic disease? |
Treat the underlying cause
Recombinant EPO can help raise the Hb level (side effects can include: flu-like symptoms, hypertension, mild rise in platelet count) |
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Haemolytic anaemia occurs due to what process? |
Premature breakdown of RBCs (<120 days) |
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Occurs in which two areas |
Intravascular
Extravascular |
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The intravascular pathophysiology is due to what? |
Red cells are lysed in circulation and release Hb into the plasma |
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Extravascular pathophysiology is due to what? |
Red cells are phagocytosed by macrophages in liver and spleen and bone marrow. Reticuloendothelial system |
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How much can the erythropoietic system increase its rbc production to compensate for anaemia? |
7 fold by recruiting long bones, humerus, spleen, liver |
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When a microcytic anaemia is not responding to iron, what may be the cause? |
Sideroblastic anaemia (present in 20% of elderly with a low MCV) |
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Three tests for sideroblastic anaemia |
Ferritin Blood film Marrow film |
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The marrow slide will show what in sideroblastic anaemia? |
Ring sideroblasts surrounded by a grey ring of iron granules |
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What is a low Hb for women? |
<11.5 g/dL |
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What is the pathophysiology behind sideroblastic anaemia? |
Ineffective erythropoiesis leading to increased iron absorption leading to increased iron loading in the marrow and possible haemosiderosis (liver and heart) |
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Causes of sideroblastic anaemia? |
Congenital
Acquired - myeloproliferative disorders/chemo/tb drugs/alcohol excess/lead excess |
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Treatment for sideroblastic anaemia |
Remove the cause
Pyridoxine and transfuse if severe |
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Iron deficiency anaemia is seen in what percentage of menstruating women? |
14% |
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Iron deficiency anaemia should be treated with..... |
Ferrous sulphate 200mg/8h PO |
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How long do you continue therapy for? And how fast should Hb rise? |
Hb should rise by around 1g/dL/week 3 months |
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When would IV iron be needed? |
When there is a functional iron deficiency in chronic renal disease |
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What blood tests will be decreased in iron deficiency anaemia? |
MCV MCH MCHC |
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Anaemia of chronic disease caused by |
Depression of erythropoiesis of multifactorial aetiology |
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What will be shown on bloods for anaemia of chronic disease? |
Mild to moderate anaemia 90-110 Normocytic normochromic Serum ferritin normal or increased |
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What is the pathophysiology behind anaemia of chronic disease? |
Failure of transport of iron from RE system to developing red cells |
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Signs of Extravascular haemolysis |
Splenic hypertrophy
Splenomegaly |
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Autoimmune haemolytic anaemia can be of which two types? |
Warm AIHA
Cold AIHA |
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AIHA causes mainly what signs |
Extravascular haemolysis and spherocytosis |
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Warm AIHA mediated by what and treated by? |
IgG and autoantibodies bind at 37c Treat with steroids and immunosuppressants |
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Cold AIHA mediated by what and treated with what? |
IgM mediated and autoantibodies bind at <4 degrees which activates cell surface complement
Keep warm and may give chlorambucil
May follow infections such as mycoplasma or AI conditions such as SLE |
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Paroxysmal cold haemoglobulinuria is seen with what and involves what? |
Viruses and syphilis
Donath-Landsteiner antibodies sticking to RBCs in the cold and causing haemolysis when warmed |
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Two causes of isoimmune acquired haemolytic anaemias? |
Acute transfusion reaction
Haemolytic disease of the newborn |
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Negative Coombs test seen in what percentage of AIHA? |
2% |
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Coombs negative AIHA seen in what conditions? |
Autoimmune hepatitis Post flu Post use of pipe piperacillin and ritixumab |
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A mechanical disruption of RBCs in circulation causing harmolytic anaemia is called |
Microangiopathic haemolytic anaemia (think of mech heart valves slicing up the red cells) |
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Microangiopathic haemolytic anaemia can be caused by |
DIC PET Eclampsia Haemolytic uraemia syndrome |
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Five features of intravascular haemolysis |
1) increased free plasma haemoglobin 2) methaemalbuminaemia: broken down haem combines with albumin to make methaemalbumin 3) decreased plasma haptoglobin as mops up free plasma Hb 4) Haemoglobinuria causes red-brown urine 5) Haemosiderinuria due to haptoglobin binding capacity being exceeded. |
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Which infection cause haemolytic anaemia? |
Malaria due to red cell lysis |
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Hereditary causes of haemolytic anaemia can be split into which groups? Three |
Enzyme defects Membrane defects Haemoglobinopathies |
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Name the chief RBC enzyme defect causing haemolytic anaemia? |
G6PD deficiency |
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How do you test for haemosiderinuria? |
Using Prussian blue staining roughly ~1 week after onset |
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On examination what may be four signs seen? |
Jaundice
Hepatosplenomegaly
Gallstones of the pigmented variety (bilirubin due to haemolysis)
Leg ulcers (poor blood flow) |
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Six investigations for haemolytic anaemia |
1) FBC 2) Reticulocytes 3) Bilirubin 4) LDH 5) Haptoglobin 6) Urinary urinobilinogen |
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If someone has anaemia and a history of travel what Ix should be included? |
Thick and thin films |
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Direct antiglobulin test AKA |
Coombs test |
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How does a Coombs test work? |
Identifies red cells coated with anti-body or complement and a positive result shows an immune cause of haemolysis |
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Two main causes of haemolytic anaemia? |
Congenital
Acquired |
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Acquired causes of haemolytic anaemia are divided into which two groups? |
Immune
Non-immune |
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G6PD affects how many people and where mainly? |
Roughly 100 million and in africa and the med |
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Most are asymptomatic but may get symptoms when? |
May get oxidative crisis due to decreased glutathione production caused by:
Drugs such as aspirin and sulfonamides
Fava beans |
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During an attack of G6PD deficiency what haematological cells may be observed? |
Bite cells
Blister cells |
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Work up involves what for G6PD deficiency? |
Enzyme assay following 8 weeks after the crisis so that young RBCs cannot trick you into a normal result |
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Treatment for G6PD deficency? |
Avoid precipitants
Transfuse if severe |
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Name a less common cause of membrane defect congenital haemolytic anaemia? |
Pyruvate Kinase deficiency |
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The pathophys behind Pyruvate kinase deficiency? |
Decreased ATP production therefore decreased RBC survival. Will present with neonatal jaundice and later splenomegaly and adult jaundice |
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Name two membrane defects causing a congenital haemolytic anaemia? |
Hereditary spherocytosis - trapped in spleen therefore splenomegaly
Hereditary Elliptocytosis - Usually ok supp with folate |
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Name the two major haemoglobinopathies causing congenital/hereditary anaemia? |
Thalassaemia
Sickle cell disease |
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What factor will exacerbate anaemia? |
Infection especially parvovirus which can cause an aplastic anaemia therefore shutting off reticulocyte formation |
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Sickle cell anaemia is what kind of anaemia? |
A haemoglobinopathy causing acquired haemolytic anaemia |
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Is sickle cell disease an autosomal dominant or recessive condition? An biochemically what occurs? |
Recessive and the creation of abnormal beta globin chains occurs due to a switch from glutamine to valine at position six |
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The sickle cell trait is common in which group of people? |
Africans at 1 in 700 |
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What differences do homozygous and heterozygous sickle cell sufferers present with? |
Homozygous get HbSS and therefore sickle cell anaemia Heterozygous get HbAS and sickle cell trait with no disability* |
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Why is it necessary to check all those of african descent for sickle cell trait? |
Heterozygous sickle cell trait carriers will become symptomatic in hypoxic conditions such as aircraft or anaesthetic |
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Desrcibe the pathogenesis of HbS |
HbS polymerises when it is deoxygenated causing RBCs to deform and become sickle shaped they therefore become trapped in small vessels |
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Initial work up for sickle cell anaemia |
Hb - low at between 6-9g/dl
Reticulocytes increased by 10-20%
Blood film showing target cells and sickle cells |
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What is the definitve test to diagnose sickle cell anaemia? When should diagnosis be aimed for? |
Hb electrophoresis
At birth from cord blood so that pneumococcal vaccine can be given |
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Micro vascular occlusion in sickle cell anaemia can cause what? |
Vaso-occlusive 'painful' crisis |
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Vaso-occlusive crisis is often triggered by what? |
Cold Infection Dehydration Hypoxia |
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If under 3 years old what symptom can occur during a vaso-occlusive crisis? |
Dactylitis due to attacking of the hand and feet |
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List five other complications that may occur as a result of a vaso-occlusive crisis? |
Mesenteric ischaemia
CNS infarction in 10% children (reduce by transcranial doppler)
Avascular necrosis of femoral head
Leg ulcers
Low-flow priapism (phenylephrine and cavernosus-spongiosum shunting) |
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Parvovirus B19 causes what in sickle cell anaemia |
Aplastic crisis due to reduction in marrow production of RBCs (usually self-limiting and transfuse if necessary) |
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Sequestration crisis in sickle cell anaemia usually affects who? What is it? |
Children Because the spleen has not yet undergone atrophy there is pooling of blood there and in the liver causing organomegaly, failure and shock Transfuse urgently |
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Name a complication of sickle cell anaemia that occurs before 2 years old? What supplement may help it? |
Splenic infarction due to microvascular occlusion leading to high risk of infection (40% of paeds deaths from HbS are due to this) Zinc supplements |
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Name six other complications of HbS |
Poor growth Chronic renal failure Iron overload Lung damage due to fibrosis (max exp will help) Retinal disease Gallstones |
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How do you manage a sickle cell crisis? |
1) Call for help 2) Generous analgesia IV opiates 3)Crossmatch blood and do FBC, RE, cultures 4) Rehydrate and keep warm and 02 via mask 5) ABx if temp or chest signs 6) Measure PCV, RE, liver and spleen size twice daily 7) Give transfusion if Hb or RE fall sharply |
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Acute chest syndrome in HbS occurs due to what? |
Pulmonary infiltrates blocking off entire segments |
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Macrocytic anaemia involves an MCV of.... |
>96g/fL |
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Macrocytosis alone is often caused by what? |
Alcohol excess |
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Pernicious anaemia also known as |
B12 deficiency anaemia |
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How do you classify macrocytic anaemia's? |
1) Megaloblastic anaemia 2) Non-megaloblastic anaemia 3) Other haematological disease |
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Three examples of megaloblastic anaemia |
1) B12 deficiency 2) Folate deficiency 3) Cytotoxic drugs |
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Five examples of non-megaloblastic anaemia |
1) Alcohol 2) Reticulocytosis 3) Liver disease 4) Hypothyroidsim 5) Pregnancy |
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What is a megaloblast? |
A cell in which nuclear maturation is delayed compared with the cytoplasm, B12 and folate deficiencies cause this as they are both inolved with DNA synthesis |
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On blood film megaloblastic anaemia will show what? |
Hypersegmented neutrophils (>5 segments) |
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What other work-up can be included to diagnose macrocytic anaemia? |
LFTs (gamma GT) TFTs Serum B12 Serum folate |
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Folate can be deficient in which four ways |
1) Increased requirement i.e. pregnancy or cell turnover increase 2) Decreased intake due to poor diet 3) Decreased absorption in the gut from coeliac 4) Drugs: AEDs, alcohol, methotrexate, trimethoprim |
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Where is folate absorbed? |
In the duodenum and proximal jejunum |
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Rx of folate deficiency? |
Treat underlying cause Folic acid 5mg/day PO for 4 months with B12 |
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If the patient has low B12 and you give them folate only without checking what could be made worse? |
Subacute combined degeneration of the cord |
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Vitamin B12 is given how and in what dosage with folate? |
Hydroxocobalamin 1mg/48h IM |
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Vitamin B12 deficiency cause anaemia how? |
B12 helps synthesis thymidine which in turn is essential in DNA synthesis, therefore RBC production is reduced |
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How is B12 absorbed? |
It is orginally protein bound, then in the stomach it binds to intrinsic factor which is produced by gastic parietal cells and forms a complex which is absorbed in the terminal ileum |
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What is pernicious anaemia? |
An autoimmune atrophic gastritis leading to achlorhydria and subsequent lack of gastric intrinsic factor secretion |
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Three general symptoms specific to B12 deficiency anaemia? |
1) Angular stomatitis 2) Glossitis (a beefy sore and red tongue) 3) Lemon tinge due to a combination of pallor from anaemia and mild jaundice from haemolysis
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Subacute combined degeneration of the cord will present with a triad of..... |
1) Extensor plantar reflexes
2) Absent knee jerk
3) Absent ankle jerk |
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SCDC affects which two tracts? |
Symmetrical dorsal column loss (sensory and LMN)
Symmetrical corticospinal tract loss (motor and UMN)
Nut spinothalamic saved therefore often temperature and pain are spared |
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What condition is 3 x more common in those with pernicious anaemia? |
Carcinoma of the stomach |
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Rx regimen for low B12 anaemia? |
Hydroxocobalamin 1mg IM alternate days for 2 weeks then same dose once/3 months for life |
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Initial improvement when treated for B12 deficiency should be seen when? |
4-5 days with a marked reticulocytosis |
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PA usually occurs in what age group and what is it likely to be in those under this age? |
>40 years old
Malabsorption |
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In treating B12 deficiency what is it important to watch out for? |
Hypokalaemia |
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A rise of what in Hb should be aimed for when treating anaemia? |
1g/dL/week |
