Anaemia

↓ production

Deficiency of
  • Iron
  • B12
  • Folate
Marrow failure
  • Malignancy
  • Drugs
  • Infection
Chronic disease

↑ loss

Bleeding
Haemolysis
- Intravascular
 - Immune
  • Immediate transfusion reaction
  • Drug induced - penicillin
  • Autoimmune
- Non-immune
  • Infection
  • Vascular - DIC, ↑↑BP, HUS, TTP
  • Mechanical - March, mech heart valve, CRRT
- Extravascular
  • Red cell defects / enzyme deficiency
  • Spherocytosis, haemoglobinopathies, G6PD
  • Autoimmune
  • Malignancy

Hypochromic, microcytic
  • Iron deficiency
  • Chronic blood loss
Normochromic, normocytic
  • Acute blood loss
  • Chronic disease
  • Haemolysis
  • Marrow failure
Macrocytic
  • B12 and folate deficiency
  • Drugs – alcohol
  • ↑ lipids – liver disease, pregnancy, hypothyroid

DIC

Activated coagulation forms small clots.
Coagulation factors and PLT are consumed causing coagulation failure and bleeding.
Clots can also obstruct organ perfusion causing organ failure.
Fibrin deposition can cause mechanical damage to RBCs.
Causes
  • Malignancy
  • Obstetric - pre-eclampsia, amniotic fluid embolism, abruption
  • Infections
  • Trauma
  • Other - liver disease, vasculitis, toxins

Precipitated by TF which activates coagulation cascade (present on endothelial cells, macrophages and monocytes and released in response to cytokines).

Bleeding, bruising, AKI
PLT ↓
PT and APTT ↑
Fibrinogen ↓
D-dimer ↑ (fibrin degradation product)
Haemolytic anaemia

Haemolytic Uraemic Syndrome (HUS)

Characterised by microangiopathic haemolytic anaemia (MAHA)
  • Haemolysis and RBC fragmentation
  • Endothelial damage triggers thrombosis. PLT consumption and fibrin strand deposition mainly in the renal microvasculature. Passing RBCs are damaged.
  • Thrombocytopenia, anaemia and ARF result
  • Clotting normal

Causes
90% from e-coli 0157 (verotoxin attacks endothelial cells) usually in children.

Treatment supportive

TTP

Fever
CNS signs - fluctuating
MAHA - often with jaundice
Thrombocytopenia
Renal failure
Haematuria/proteinuria

Deficiency of a protease that breaks down vWf causing PLT aggregation and fibrin deposition.

Caused by drugs, preg, SLE, HIV

Treatment
Plasma exchange
Steroids
Immunoglobulin
Vincristine
Splenectomy

Unexplained thrombocytopenia and anaemia should always make you think of TTP.


Leucocytosis

SIRS - Infection, stress response, trauma, burns, surgery, MI
Malignancy
Myeloproliferative disorders
Drugs - Steroids
Bleeding and haemolysis