Haematology - Anaemia & Blood dyscrasias Flashcards
(30 cards)
How do we first work up a pt w suspected anaemia?
- FBC - Hb, Serum ferritin, TIBC, MCV
- Vit B12
- Folate
- Reticulocyte count
- Peripheral smear
If pt presents with microcytic anaemia, low MCV, what are the next steps?
Investigate serum ferritin.
If low serum ferritin (Fe stores) –> IDA
If high serum ferritin, look at TIBC. If low TIBC –> Anaemia of chronic inflamm
If pt presents w macrocytic anaemia (high MCV), what are the next steps?
Work up for vit B12 and folate levels
If normal vit B12 and low folate levels –> folate def anaemia
If low vit B12 and normal folate levels –> Vit B12 def anaemia
What is the possible aetio of IDA?
Impaired absorption of Fe thru acidic env of stomach
Atrophic gastritis
Gastrectomy
Celiac disease
PPI, H2RA
Ca rich foods
H.pylori infection
Blood loss
What is the possible aetio of B12 def anaemia?
Auto Ig to intrinsic factor
Dietary def
PPI, H2RA
H.pylori infeciton
What is the possible aetio of folate def anaemia?
Dietary def
What are the possible aetio of anaemia of chronic inflammation?
CHF
CKD, ESRD
Rheumatoid arthritis
Malignancy
COPD
HIV infection
IBD
Castleman disease
What is the recommended management for IDA?
Fe supplementation. Min 1000-1500 mg elemental Fe for complete supplementation, treat for 3-6mo.
(Provided “leak” is plugged, and CKD - lifelong)
ESA
What are the % elemental Fe in common commercial preparations?
Fe polymaltose - 100%
Ferrous gluconate - 12%
Ferrous fumarate, sulfate ~33%
What is the recommended management for Vit B12 def anaemia?
Pernicious anaemia (parenteral)
- 1000 microg daily vit B12 x 1/52 f/b
- 1000 microg 1/7 vit B12 x 4/52 f/b
- 1000 microg 1/12 vit B12 for life
Other B12 suppl (PO)
- 1000 or 2000 microg daily vit B12
ESA
What are cyanocobalamin, pyridoxine, thiamine?
Cyanocobalamin = B12
Pyridoxine = B6
Thiamine = B1
What is the recommended management for folate def anaemia?
1mg daily folic acid for 1-4mo or until haematologic recovery is achieved
ESA
What is aplastic anaemia?
May affect all 3 of the cell lines (rbc, wbc, thrombocytes)
Any 2 of the three
1. WBC count <= 3500 cells/mm3 (3.5x10^9/L)
2. Platelet count <= 55000 cells/m3 (55x10^9/L)
3. Hb <= 10g/dL (100g/L, 6.21mmol/L) + reticulocyte count <= 30 000 cells/m3(30x10^9/L)
What are the drugs assoc w aplastic anaemia?
Cytotoxic, radiation chemotherapies
Chloramphenicol
ASM - CBZ, PHT, PB
Thyroid meds
Sulfonamides
Diuretics - Furosemide, Thiazides
NSAIDs
What is the recommended management of aplastic anaemia?
Infections:
If wbc count < 500 cells/mm3 (0.5x10^9/L) prophylactic abx & antifungal treatment
Febrile neutropenia: start broad spectrum abx
Immunosuppressants, glucorticoids, ciclosporine
Bleeding:
Transfusion of erythrocytes & platelets
If bone marrow failure severe:
GM-CSF or G-CSF, IL-14
Haematopoietic stem cell transplant
What is agranulocytosis/ drug induced neutropenia?
Neutropenia = ANC < 1500/microL
What are the drugs assoc w drug induced neutropenia?
Antipsychotics: clozapine & other phenothiazines
- Onset 2-15 weeks (peak onset bet 3-4weeks)
- Strict monitoring protocols
Thyroid meds: carbimazole, PTU
- Onset within 2mo
- More freq in pts >40y.o.
Betalactam abx
- Rapid onset
- Accum of drug to toxic [ ] cld be the cause
Sulfonamides
What is the recommended management for agranulocytosis/drug induced neutropenia?
NEVER restart offending agent
If neutrophil nadir <100 cells/mm3 (0.1x10^9/L): filgrastim G-CSF SQ 300 mcg/day
Routine weekly monitoring of wbc, particularly for those treated w clozapine. Shld return to normal within 2-4 weeks (frequently within 4-24d)
What are the drugs associated with megaloblastic anaemia?
Antimetabolite (chemothera) e.g. Methotrexate
Azathioprine
Cloramphenicol
Colchicine
5-Fluorouracil
OCs
ASMs: PHT, PB
Cotrimoxazole
Tetracycline
What is the recommended management of megaloblastic anaemia?
Withdrawal of causative agent
For cotrimoxazole: esp when folate/vit B12 def
- Folinic acid 5-10 mg up to QDS
For PHT, PB:
- Folic acid 1mg daily (controversial)
What is haemolytic anaemia?
Bursting of rbc
What are the drugs assoc w haemolytic anaemia?
Methyldopa
Quinine, quinidine
Abx
- Penicillins, Cephalosporins, Streptomycin
- Beta-lactamase inihb: Clavulanate, tazobactam, sulbactam
- Fluoroquinolones, Cotrimoxazole
- Chloroquine and hydroxychloroquine
ASM: PHT, PB
NSAIDs
Sulfonamides
SUs
What is drug induced thrombocytopenia?
Platelet count < 100, 000 cells/m3 or >50% from baseline
Typically presents 1-2 weeks after drug ini
May present immediately after a dose when an agent has been used intermittently in the past e.g. UFH (late onset HIT)
- Recovery begins within 1-2d of discontinuation of the offending agent and is complete at one week
- Ig to that agent may persist for years so pts shld be advised to avoid the drug indefinitely
Rapid onset may also occur w GpIIb/IIIa inhib
What are the drugs assoc w drug induced thrombocytopenia?
Heparin
GpIIb/IIIa inhib
All 1st gen ASM
Antimicrobials:
- Clarithromycin, Linezolid, Azoles, Penicillins, Cotrimoxazole, Ciprofloxacin
- All TB drugs
Sulfonamide
NSAIDs: aspirin, diclofenac, nalidixic acid, naproxen
Amiodarone, digoxin, GTN
