Pulmonary Embolism: Test and Diagnosis

1st order laboratory parameters – obligatory laboratory tests.

• Small blood count [for basic diagnosis; if unfractionated heparin (UFH) is used, regular check of platelet count].
• CRP (C-reactive protein) or ESR (erythrocyte sedimentation rate).
• Blood gas analysis (BGA)
• D-dimer (end product of proteolysis of fibrin) – Indications: in suspected pulmonary embolismNote: The specificity (probability that actually healthy persons who do not suffer from the disease in question are also detected as healthy in the test) of the D-dimer test in suspected pulmonary embolism decreases with increasing age. Therefore, as an alternative to the fixed D-dimer threshold of 500 ng/mL, an age-adjusted cut-off value should be used, which is 500 up to 50 years of age and 10 times the age (age × 10 µg/L for patients older than 50 years) after 50 years of age.
  • (without shock) if low risk score (see also under “Physical examination” Wells score to determine clinical probability of pulmonary embolism)Note: If high score (Wells score of at least 2 points in the simplified version), immediate CTPA (computed tomography of pulmonary arteries)/V/P scintigraphy (ventilation/perfusion scintigraphy).
  • Negative predictive value 99.3%, thus suitable for screening! If positive: CTPA (computed tomography of the pulmonary arteries), V/P scintigraphy (ventilation/perfusion scintigraphy).
• High-sensitivity cardiac troponin T (hs-cTnT) or troponin I (hs-cTnI) – for suspected myocardial infarction (heart attack).
• NT-proBNP (N-terminal pro brain natriuretic peptide) – for suspected heart failure (cardiac insufficiency).
• Coagulation parameters – PTT, Quick

Additional notes

The following notes refer to the Geneva score for assessing the likelihood of pulmonary embolism (see “Physical examination” below):

• Low or intermediate clinical probability of LE: D-dimer test (preferably with high-sensitivity test) [ESC Guidelines: recommendation grade IA].
• High clinical probability of LE or D-dimer test above the cut-off value: perform CT-A to confirm the diagnosis.