MP323 - HAEMATOLOGICAL DISORDERS Flashcards
erythropoiesis
RBC production, stimulated by hypoxia, controlled by erythropoietin (hormone synthesised in kidney)
Haemolysis
- destruction of RBCs
- releases bilirubin into bloodstream
- normal lifespan of RBC = 120 days
anticoagulation
- elements that interfere with blood clotting
- aspirin
- clopidogrel
- warfarin
- heparin
Leukopenia
decreased WBCs
neutropenia
decreased neutrophil count
RBC count for women and men
women = 4.5 - 5.5 x10^6
men = 4.0 - 5.0 x10^6
Haematocrit (Hct)
percentage of whole blood that is composed of red blood cells
measures the number the RBCs and the size of red blood cells
normal platelet count
150,000 - 400,000
spontaneous haemorrhage likely when <20,000
thrombocytopenia
decreased platelet count
pancytopenia
decreased number of RBCs, WBCs and platelets
anaemia
- reduction in RBCs, the quantity of haemoglobin, or the volume of RBCs
- main function of RBCs is oxygenation, anaemia results in varying degrees of hypoxia
- drives ischaemic pathologies
prevalent conditions in anaemia
- blood loss
- decreased production of erythrocytes
- increased destruction of erythorcyes
symptoms of anaemia
- PALLOR
- fatigue, weakness
- dyspnoea
- palpitations, tachycardia
- headache, dizziness and restlessness
- slowing of thought
- paraesthesia
aetiology of iron-deficiency anaemia
DECREASED ERYTHROCYTE PRODUCTION
- inadequate dietary intake
- malabsorption
- blood loss
- haemolysis
common symptoms of iron-deficiency anaemia
- pallor and glossitis (inflamed tongue)
- cheilitis
- sensitivity to clod
- weakness and datigue
diagnostic studies for iron-deficiency anaemia
- FBC
- iron levels: total iron-binding capacity (TIBC) and serum ferritin
- endoscopy/colonoscopy
iron replacement for iron-deficiency anaemia
- oral iron
- ferrous sulphate
- absorbed best in acidic environment
side effects of oral ferrous sulphate for iron-deficiency anaemia
- constipation/diarrhoea
- GI discomfort
- nausea
can be taken after food to reduce GI side-effects but best absorbed on empty stomach
megaloblastic anaemias
- characterised by large RBCs which are fragile and easily destroyed
common forms: cobalamin deficiency, folic acid deficiency
causes of cobalamin (vitamin B12) deficiency
- gastric mucosa not secreting intrinsic factor
- long-term use of H2 histamine receptor blockers cause atrophy or loss of gastric mucosa
- nutritional deficiency
- hereditary defects
common symptoms of cobalamin deficiency anaemia
- general symptoms of anaemia
- sore tongue
- anorexia
- weakness
- paraesthesia
- altered thought processes
diagnostic studies of B12 deficiency anaemia
- RBCs appear large
- abnormal shapes
- structure contributes to erythrocyte destruction
treatment for B12 pernicious anaemia
- oral cyanocobalamin
- parental cobalamin
- dietary intake is important
characteristics of folic acid deficiency
- RBCs that are large and fewer in number
- folic acid required for RBC formation and maturation
causes of folic acid deficiency
- poor dietary intake
- malabsorption syndromes
- drugs that inhibit absorption
- alcohol abuse
- haemodialysis
characteristics of anaemia of chronic disease
- underproduction of RBCs, shortening of RBC survival
- 2nd most common cause of anaemia
- generally develops after 1-2 months of sustained disease
causes of anaemia of chronic disease
- impaired renal function
- chronic, inflammatory, infectious or malignant disease
- chronic liver disease
- folic acid deficiencies
- splenomegaly
- hepatitis
anaemia caused by acute blood loss
result of sudden haemorrhage (trauma, surgery, vascular disruption)
care for anaemia caused by acute blood loss
- replacing blood volume
- identifying source of haemorrhage
- stopping blood loss
chronic blood loss sources/symptoms
- similar to iron-deficiency anaemia
- GI bleeding, haemorrhoids, menstrual blood loss
care for chronic blood loss
supplemental iron administration
types of anaemia caused by increased erythrocyte destruction
- haemolytic anaemia
- sickle cell anaemia
- haemochromatosis
- polycythemia
haemolytic anaemia characteristics
- destruction or haemolytic of RBCs at a rate that exceeds production
- third major cause of anaemia
intrinsic haemolytic anaemia
- abnormal haemoglobin
- enzyme deficiencies
- RBC membrane abnormalities
extrinsic haemolytic anaemia
- normal RBCs
- damaged by external factors (liver, spleen, toxins, mechanical injury)
