Editing Pulmonary embolus (section)

== Diagnosis ==

* High index of suspicion required
* Clinical impression has a sensitivity and specificity of 85% and 51% respectively
* Blood tests are non-specific
** D-dimer <10microg/L * age has good sensitivity
** Troponin and BNP are recommended for stratification of patients with confirmed PE
* ECG changes are unreliable
** Similar to all other causes of pulmonary hypertension
** S1Q3T3 (prominent S wave in lead I, Q wave and inverted T wave in lead III) reflects RV strain, but is seen in less than 20% of diagnosed PEs
* CXR is not sensitive or specific and all signs are rare
** Generally normal CXR
** Fleischner sign - enlarged pulmonary artery
** Hampton hump - peripheral wedge of airspace opacity - lung infarction
** Westermarck sign - regional oligaemia
** Knuckle sign - abrupt tapering or cut-off of a pulmonary artery
* CTPA
** Sensitivity 83% specificity 96%
* Echocardiogram
** Can diagnose RV dysfunction but not PE
** Not recommended routinely, but can be used to justify emergency reperfusion treatment for PA
* V/Q scan
** Primarily used in renal failure and pregnancy
** Highly sensitive but non-specific