Approach to anaemia Flashcards
What is the clinical definition of anaemia?
Hemoglobin below normal reference range for age and sex
What are some general symptoms and signs of anaemia?
Symptoms:
1) Fatigue, weakness
2) Dyspnea
3) Palpitations, worsening CHF
4) Tinnitus
5) Headache, presyncope, cognitive impairment, dizziness, apathy
Signs:
1) Pallor
2) Tachycardia
3) Bounding pulse
4) Hemic murmur
5) Cardiac failure
What are 3 diagnostic tests used for suspected anaemia?
1) Full blood count
2) Reticulocyte count
3) Peripheral blood film
4) BM aspirate
5) Bilirubin (Liver panel)
6) Ferritin levels
Pallor in the conjunctiva and not skin creases is indicative (more/less) severe anaemia?
Less
Conjunctival: Hb<9
Skin creases: : Hb<7
What are the 3 main cells lines in an FBC and how are the differentiated?
1) Hb (RBC lysed)
- measured by photometry
2) WBC (any cell w nucleus)
- differentiated by granule content
3) Platelets (any cell w/o nucleus)
- differentiated by size
What is pancytopenia?
A condition where all 3 cell lines (Hb, WBC, and platelets) are reduced
What is bicytosis?
A condition where any 2 of the 3 cell lines (Hb, WBC, and platelets) are increased
What are the 4 main red cell indices?
1) MCV (size)
2) MCH (avg. Hb/cell)
3) RDW (RBC width distribution: ↑% → < irregular/anicytosis)
4) Red cell count
What are some possible findings in a peripheral blood film?
1) Sizes
- Macro/microcytosis
- Anisocytosis
2) Appearances
- Hyper/hypochromic
- Target cells
- Inclusion bodies
3) Shapes
- Spherocytes
- Cell fragments
- Poikilocytosis
4) Maturity
- Reticulocytes
- Erythroblasts
- Megaloblasts
If an anemic px has low MCV, they are said to have ______ anemia. Further investigations on their _____ levels would narrow diagnostic possibilities into: ________________.
Microcytotic → Ferritin levels (Iron panel)
1) Low ferritin
- Fe deficiency
2) High/normal ferritin
- Thalassemia
- Inflammation anemia
- Sideroblastic anemia
If an anemic px has normal MCV, they are said to have ______ anemia. Further investigations on their _____ levels would narrow diagnostic possibilities into: ________________.
Normocytic → Reticulocyte count
1) High reticulocyte (↑prod.)
- acute bleeding
- haemolysis
2) Low reticulocyte (↓ prod.)
- Renal anemia
- inflammatory anemia
- marrow disease
If an anemic px has high MCV, they are said to have ______ anemia. Further investigations on their _____ levels would narrow diagnostic possibilities into: ________________.
Macrocytic → B12/Folate levels/FBP
1) Megaloblastic anemia
- B12/Folate deficiency
2) Non-megaloblastic anemia
- Reticulocytosis
- Alcohol
- Liver disease
What are some possible causes of anemia in a px with reduced reticulocytes?
↓ production:
1) Hematinic deficiencies (Fe, B12, Folate)
2) Reduced globin chain (Thalassemia)
3) Bone marrow failure (inflammation, suppression, defect)
4) Insufficient EPO
5) Inability to utilise Fe
What are some possible causes of anemia in a px with increased reticulocytes?
↑ loss/destruction:
1) Bleeding (surgery, trauma, menorrhagia, GI/GUT)
2) Immune-mediated hemolysis (AIHA, CHAD, PCH)
3) Non-immune hemolysis (hemoglobinopathies, infections, enzymes, mechanical)
How does a px with iron deficiency typically present biochemically?
1) Ferritin <30ug/L
2) Microcytic, hypochromic anemia
What are some possible underlying causes of iron deficiency?
1) Increased iron loss
- Bleeding
- Menstruation
- Drugs (eg. NSAIDS, blood thinners)
- elite athletes (fe loss thru sweat)
2) Increased iron requirement
- Pregnancy
- 0-5y/o
- adolescent girls
- women of child bearing age
3) Decrease intake/absorption
- diet
- antacids
- infections/Gi ulcers
- Foods (eg. tea, coffee, calcium, etc.)
How is iron deficiency normally treated?
Oral Fe supplements
(↑Hb ~3g/dL in 3 wks; 3-6 months post-Hb normalisation for Fe store restoration)
What are things to suspect/think of in px with iron deficiency but not responding to oral supplementation?
1) ensure compliance
2) Ix ongoing loss
3) Try IV iron
How can a px with suspected hemoglobinopathies be screened?
Thalasseaemia screen:
1) Hb electrophoresis
2) HbH stain (moderate α thalassemia)
3) HPLC
Why would a px with megaloblastic anemia have raised bilirubin and LDH?
Intra-medullary hemolysis of megaloblasts
How is B12/folate deficiency treated?
B12 replacement:
1) IM B12
2) Oral B12 (if Hb normalised)
Folate replacement:
1) Oral
What test(s) can you do to confirm hemolysis?
1) Reticulocyte count (high)
2) Liver f(x) test (↑ LDH, unconj. bilirubin)
3) Haptoglobin test (low)
4) PBF:
- Spherocytes (immune)
- Bite/blister cells (oxidative)
- Fragments (MAHA/mechanical)
What test(s) can you do to confirm immune-mediated hemolysis?
Direct Coombs test
(polyspecific IgM, IgG or C3 reagent binds to Ab/complement coated RBCs)
What is the first line treatment for autoimmune hemolytic anaemia?
Steroids
What are 4 possible causes of secondary autoimmune hemolytic anemia?
1) Malignancy
(CLL, lymphomas, solid organ)
2) Infection
(Hep C, HIV, CMV, TB, pneumococcus)
3) Immune
(SLE, Sjogren’s, post-transplant, ulcerative colitis, scleroderma)
4) Drugs
(penicillin, cephalosporins, fludarabine, interferon)
What are some indicators of blood loss in anemia?
1) Sudden ↓Hb
2) negative hemolytic markers (Haptoglobin, bilirubin)
What do Schistocytes on a PBF indicate in a px?
MAHA (Microangiopathic Haemolytic Anaemia)
What do Target cells on a PBF indicate in a px?
Thalassemia
What are Spherocytes on a PBF indicate in a px?
AIHA (Autoimmune-mediated Haemolytic Anaemia)
What do bite cells on a PBF indicate in a px?
G6PD Deficiency
