Anaemia Flashcards
What is anaemia?
- Reduction in red cell mass
* Reduction in oxygen carrying capacity of the blood with resultant reduced oxygen delivery to tissues
What’s the aetiology of anaemia?
– Decreased production
• EPO – Increased Destruction
• haemolysis – Bleeding
What are the signs and symptoms of anaemia?
• Neurological Dizziness, fainting, lack of concentration Blurred or diminished vision Headache, tinnitus Paraesthesia in the fingers and toes Insomnia, irritability.
• CVS: Angina, dysponea, palpitation and intermittent claudication by exertion HF in severe cases or presence of other organic cardiac disease, it is high COP failure.
• Musculo skeletal: Easy fatigability.
Tiredness and lassitude.
• GI – Anorexia, Dyspepsia
• GUM – Menorrhagia
How can you measure anaemia?
• Hemoglobin = grams of hemoglobin per 100 mL of whole blood (g/dL)
• Hematocrit = percent of a sample of whole blood occupied by intact red blood cells
• RBC = millions of red blood cells per microL of whole blood
• MCV = Mean corpuscular volume – If > 100 → Macrocytic anemia
– If 80 – 100 → Normocytic anemia – If < 80 → Microcytic anemia
• RDW = Red blood cell distribution width – =(Standarddeviationofredcellvolume÷meancellvolume)×100
– Normal value is 11-15% – If elevated, suggests large variability in sizes of RBCs
What are the Laboratory Definitions of Anemia?
- Hgb: • Women: < 13.5 • Hct (haematocrit):
* Women: < 36 • Men: <41
What are the symptoms of anemia?
Decreased oxygenation – Exertional dyspnea – Dyspnea at rest – Fatigue – Bounding pulses – Lethargy, confusion Decreased volume – Fatigue – Muscle cramps – Postural dizziness – syncope
What are Special Considerations in Determining Anemia?
Acute Bleed
• Drop in Hgb or Hct may not be shown until 36 to 48 hours after
acute bleed (even though patient may be hypotensive)
Pregnancy • In third trimester, RBC and plasma volume are expanded by 25
and 50%, respectively.
• Labs will show reductions in Hgb, Hct, and RBC count, often to anemic levels, but according to RBC mass, they are actually polycythemic
Volume Depletion
• Patient’s who are severely volume depleted may not show anemia until after rehydrated
What is the RBC Life Cycle?
- In the bone marrow, erythropoietin enhances the growth of differentiation of burst forming units-erythroid (BFU- E) and colony forming units-erythroid (CFU-E) into reticulocytes.
- Reticulocyte spends three days maturing in the marrow, and then one day maturing in the peripheral blood.
- A mature Red Blood Cell circulates in the peripheral blood for 100 to 120 days.
- Under steady state conditions, the rate of RBC production equals the rate of RBC loss.
What are the Causes of Anemia?
- Erythrocyte Loss through
- Low Erythropoietin levels
- Decreased response to erythropoietin
- Iron deficiency
- Decreased marrow response (thalassemia)
- Destruction of red blood cells
What are the causes for Decreased Response to Erythropoietin? (which causes anaemia)
- Iron-Deficiency
- VitaminB12 Deficiency
- Folate Deficiency
- Anemia of Chronic Disease
What are the causes of erythrocyte loss?
• Bleeding:
- Chronic (gastrointestinal, menstrual)
- Acute/Hemodynamically significant: – Gastrointestinal – Retroperitoneal
What are the causes of Low Erythropoietin levels?
Erythropoeitin controls red blood cell production
• Kidney Disease
– Normochromic, normocytic
– Low reticulocyte count
– Frequently, peripheral smear in uremic patients show “burr cells” or echinocytes
– Target hemoglobin for patients on dialysis is 11 to 12 g/dL
• Administer erythropoietin or darbopoietin weekly • Good Iron stores must be maintained
- Iron Deficiency
– Can result from: – Pregnancy/lactation
– Normal growth – Blood loss – Intravascularhemolysis – Gastric bypass – Malabsorption
» Iron is absorbed in proximal small bowel; decreased abosrption in celiac disease, inflammatory bowel disease
– May manifest as PICA • Tendency to eat ice, clay, starch, crunchy materials
– May have pallor, koilonychia of the nails, beeturia
– Peripheral smear shows microcytic, hypochromic red cells with marked anisopoikilocytosis.
What is koilonychia?
A sign of iron deficiency anaemia. Presents as cracked nails with white lines in them.
What are the lab findings that indicate iron deficiency anaemia?
- Serum Iron
- LOW (< 60 micrograms/dL) • Total Iron Binding Capacity (TIBC)
- HIGH ( > 360 micrograms/dL) • Serum Ferritin
- LOW (< 20 nanograms/mL) • Can be “falsely”normal in inflammatory states
What are the treatments for iron deficiency anaemia?
• Oral iron salts
– Ferrous sulfate – 325 mg po Q Day • Side effects: constipation, black stools, positive
hemmoccult test – Vitamin C can facilitate iron absorption.
What’s the treatment of vit.B12 deficiency?
- Vitamin B12 – 1000 micrograms intramuscularly monthly -OR-
* Vitamin B12 – 1000-2000 micrograms po QDaily
What’s the treatment of folate deficiency?
- Folate – 1 to 5 mg po Qday
- Vit. B12 deficiency must be excluded in folate-deficient patients, because supplemental folate can improve the anemia of Vit. B12 deficiency but not the neurologic sequelae.
What is anaemia of chronic disease?
• Usually normocytic, normochromic (but can become
hypochromic, microcytic over time)
• Occurs in people with inflammatory conditions such as collage vascular disease, malignancy or chronic infection.
• Iron replacement is not necessary • May benefit from erythropoietin supplementation.
What causes destruction of red blood cells?
• Hemoglobinopathies • Sickle Cell Anemia
• Aplastic Anemia • Decrease in all lines of cells – hemoglobin, hematocrit,
WBC, platelets • Parvovirus B19, EBV, CMV • Acquired aplastic anemia
• Hemolytic Anemia
What are the results of lab analysis of Hemolytic Anemia?
- Increased indirect bilirubin
- Increased LDH
- Increased reticulocyte count • Normal reticulocyte count is 0.5 to 1.5%
- > 3% is sign of increased reticulocyte production, suggestive of hemolysis
- Reduced or absent haptoglobin • < 25 mg /dL suggests hemolysis
- Haptoglobin binds to free hemoglobin released after hemolysis
What medical problems could cause anaemia?
-Sickle cell Disease
– Thalassemia
– Renal Disease
– Hereditary Spherocytosis
How should you evaluate a patient with anemia?
Bleeding?
Any jaundice, elevated bilirubin, suspicious for hemolysis?
Any history of medical problems that could cause anemia? Are the other cell lines also low?
– If WBC and platelets are both low, consider APLASTIC ANEMIA! – Check medication list
» NSAIDS (phenylbutazone), Sulfonamides, Acyclovir, Gancyclovir, chloramphenicol, anti-epileptics (phenytoin, carbamazepine, valproic acid), nifedipine
» Check parvovirus B19 IgG, IgM » Consider hepatitis viruses, HIV
– If Platelets are low consider TTP or HUS! – Must check smear for schistocytes (for sign of microangiopathic
hemolytic anemia) – If renal failure, E. Coli O157:H7 exposure → HUS – If renal failure, neurologic changes, fever → TTP
