PE : Signs and symptoms

Signs and symptoms
Acute dyspnoea, pleuritic chest pain, haemoptysis, and syncope.
Hypotension, tachycardia, gallop rhythm, JVP up, loud P2, right ventricular heave, pleural rub, tachypnoea, and cyanosis, AF.
Classically, PE presents 10d post-op, with collapse and sudden breathlessness while straining at stool—but PE may occur after any period of immobility, or with no predisposing factors. Breathlessness may be the only sign. Multiple small emboli may present less dramatically with pleuritic pain, haemoptysis, and gradually increasing breathlessness.
Look for a source of emboli—especially DVT (is a leg swollen?).

Investigations
U&E, FBC, baseline clotting.
ECG (commonly normal or sinus tachycardia); right ventricular strain pattern V1-3), right axis deviation, RBBB, AF, may be deep S-waves in I, Q-waves in III, inverted T-waves in III (˜SI QIII TIII).
CXR often normal; decreased vascular markings, small pleural effusion. Wedge-shaped area of infarction. Atelectasis.
ABG: hyperventilation + gas exchange: PaO2, PaCO2, pH often.
CT pulmonary angiography is sensitive and specific in determining if emboli are in pulmonary arteries. If helical CT is unavailable, a ventilation-perfusion ([V with dot above]/[Q with dot above]) scan can aid diagnosis. If [V with dot above]/[Q with dot above] scan is equivocal, pulmonary angiography or bilateral venograms may help (MRI venography or plethysmography are alternatives).
D-dimer blood test, if thrombosis present. May help in excluding a PE.