Expansion
Thrombus, fat, air, amniotic fluid, tumour, septic and foreign body
Expansion
- Thromboembolism: over 95 per cent. Venous emboli lodge in the lung; arterial emboli, often from the left atrium in atrial fibrillation or from a mural thrombus, travel to brain, gut, kidney or limb
- Fat embolism: 24 to 72 hours after long bone fracture or orthopaedic surgery. Triad of respiratory distress, neurological signs and a petechial rash
- Air embolism: neck vein injury, central line insertion or removal, diving barotrauma, laparoscopy. Requires a large volume, of the order of 100 ml
- Amniotic fluid embolism: during or just after labour. Sudden dyspnoea, collapse, seizures and disseminated intravascular coagulation. High mortality
- Septic: infective endocarditis, causing infarcts that become abscesses
- Tumour: the route of haematogenous metastasis
- Foreign body: talc in intravenous drug users, catheter fragments
- Cholesterol: after vascular instrumentation, causing livedo and renal failure
Paradoxical embolism occurs when a venous embolus crosses a patent foramen ovale to the systemic circulation, and should be considered in a young patient with stroke and no other cause.