aenmia Flashcards
lab definition of anemia
1) men Hgb < 13 g/dL
2) women Hgb < 12 g/dL
diagnosis of anemia - 3 steps
1) history taking
2) physical examination
3) lab evaluation
diagnosis of anemia - history taking
1) blood loss
2) duration of anemia, genetic/acquired
3) any clinical features? due to infection or malignancy?
- jaundice, pallor in eyelid tongue, check nail bed
4) comorbidities
5) arthritis, IBD
6) any other complaints/sypmtoms
diagnosis of anemia - lab evaluation
1) FBC: anemia, MCV
2) reticulocyte count: increase = negative feedback for anemia
3) peripheral smear
general overview of types of anemia
1) iron deficiency anemia (IDA): microcytic anemia
2) Vit B12 or folate deficiency: macrocytic anemia
3) anemia of inflammation/chronic deficiency
iron deficiency anemia (IDA)
- low MCV, low Hgb
- causes
1) decreased iron absorption -> decreased ferritin store
2) blood/iron loss - treatment: 1000 - 1500mg elemental iron for at least 3 - 6 month
Vit B12 or folate deficiency anemia - definition
high MCV, low Hgb
Vit B12 or folate deficiency anemia - causes
1) reduced absorption
2) nutritional
3) other causes that disrupt gastric mucosa so no more acidic pH thats required to absorb iron and Vit B12 (PPi, H2RA, h. pylori)
Vit B12 or folate deficiency anemia - treatment
1) Vit B12 IM/SQ
- 1000mg microgram OD 1 wk -> 1000 microgram every wk for 4 wks -> 1000 microgram every month for life
2) folate (B9)
- 1mg folate OD for 1 - 4 months or until recovery
anemia of inflammation of chronic diseases - causes
malignancy, HIV, rheumatologic disorder, IBD, HF, renal insufficiency, COPD
differentiate IDA and anemia of inflammation
1) measure ferritin
- low in IDA, normal/high in inflammation
2) measure TIBC
- high in IDA, low in inflammation
3) measure TSAT
- iron/TIBC X 100%
- low in IDA, high in inflammation
types of drug induced haematological disorders
1) aplastic anemia
2) drug induced neutropenia or agranulocytosis WBC)
3) haemolytic anaemia (RBC)
4) megaloblastic anemia (RBC)
5) thrombocytopenia
definition of aplastic anemia
- 2 or 3 types of blood cells affected
- any 2 of
1) WBC count ≤ 3500 cells/mm&3
2) platelet count ≤ 550000 cells/mm^3
3) Hgb ≤ 10 g/dL + reticulocyte count ≤ 30000 cells/mm^3
drugs associated with aplastic anemia
furosemide, NSAID, phenobaribital, sulfonamide, phenytoin, carbamazepine, thiazide, chemo, radio
treatment of asplastic anemia
- withhold offending drug
- immunosuppressant: glucocorticoid
- prevent opportunistic infection
** prophylactic Abx and antifungal when neutrophil ≤ 500
** start broad spectrum if febrile neutropenia - prevent bleeding
** blood transfusion: iron chelation if too much transfusion, G-CSF or hematopoietic stem cell transplant
definition of dug induced neutropenia or agranulocytosis (WBC)
1) neutropenia: absolute neutrophil count < 1500
2) agranulocytosis severe neutropenia, absent neutrophil count
drugs associated with drug induced neutropenia or agranulocytosis (WBC)
anti thyroid, antipsychotic (clozapine), valproic acid, penicillin
treatment of drug induced neutropenia or agranulocytosis (WBC)
- withhold offending drug and do not restart: can restart penicillin at lower dose once neutropenia resolved
- neutrophil nadir (lowest point) < 100: give filgrastim SQ 300 microgram/day
diagnosis of hemolytic anemia
Coomb’s test
causes of hemolytic anemia
1) IgM and IgG mediated RBC destruction
2) drug-induced: methyldopa, fluoroquinolones, sulfonylureas
3) G6PD deficiency
treatment of haemolytic anemia
1) withhold offending drug
2) give supplement (Vit B12 or folate) if cannot withhold
what is megaloblastic anaemia
large RBC but low number
drugs causing folate deficiency
antimetabolites, cotrimoxazole, phenytoin, phenobarbital
treatment of megaloblastic anemia
withhold offending drugs
- except cotrimoxazole give folinic acid 5 - 10mg up to 4 times a day
