Haemolytic Anaemias
Anaemia due to erythrocyte destruction, causes of which can be classified on a number of axes:
- Intracorpuscular vs. Extracorpuscular haemolysis
- Intracorpuscular
Abnormal haemoglobin, membrane, or cytoplasmic composition and function.- Majority are inherited
- Extracorpuscular
Destruction due to mechanical, immunologic, infectious, or metabolic pathology.
- Intracorpuscular
- Immune vs. non-immune
Immune indicates destruction by antibody or complement, and is indicated by a positive Coombs test. - Intravascular vs. Extravascular haemolysis
- Intravascular
Results in free haemoglobin, urinary haemoglobin, and ↓ haptoglobin. - Extravascular
Destruction by macrophages of the reticuloendothelial system.
- Intravascular
Epidemiology and Risk Factors
Pathophysiology
Aetiology
| Intravascular | Extravascular | |
|---|---|---|
| Intracorpuscular |
|
Haemoglobinopathies:
Membrane abnormalities:
Metabolic:
|
| Extracorpuscular | Antibody-mediated:
Mechanical:
Other:
|
Hypersplenism:
|
March and bongo-players haemolysis both occur through repeated mechanical trauma to the tissue bed.
Clinical Features
Assessment
History:
Exam:
Investigations
Bedside:
Laboratory:
Imaging:
Other:
Diagnostic Approach and DDx
Management
- Treat cause
- Minimise AKI
Resuscitation:
Specific therapy:
- Pharmacological
- Immunosuppression
For autoimmune haemolytic anaemias.
- Immunosuppression
- Procedural
- Splenectomy
For warm haemolytic anaemias, to ↓ extravascular haemolysis.
- Splenectomy
- Physical
Supportive care:
- F
- Fluid resuscitation
Minimise free haemoglobin-associated AKI.
- Fluid resuscitation
Disposition:
Preventative: