Obligatory medical device diagnostics.
- Electrocardiogram (ECG; recording of the electrical activities of the myocardium)* – as an emergency baseline diagnostic[excessive P wave (P pulmonale), a right deviation of position type, right heart strain sign (new onset right bundle branch block), S-I Q-III type, T negatives in V1-V4 (5), ST depressions; atrial arrhythmias]
- Blood pressure measurement [Right ventricular dysfunction (RVD) or right heart strain is detected by a blood pressure index (BPI) ≤ 1.7 with a sensitivity of 92.8% (percentage of diseased patients in whom the disease is detected by use of the procedure, ie, a positive finding occurs) and a specificity (probability that actually healthy individuals who do not have the disease in question are also detected as healthy by the test) of 100%. The positive predictive value thus reached 100%. Note: pulmonary embolism with right heart involvement is more likely to be fatal (9.5% of patients died, compared with 1.4% without RVD)
- X-ray of the chest (X-ray thorax/chest), in two planes* – as an emergency baseline diagnostic.
- Blood gas analysis (ABG)*
- Pulse oximetry* – procedure that is used for continuous non-invasive measurement of oxygen saturation of arterial blood and pulse rate.
- Computed tomography (CT) with thoracic angiography (imaging of blood vessels; CT angiography) of the pulmonary arteries (computed tomography pulmonary angiography; CTPA) – as a basic diagnostic test in suspected pulmonary embolism or in patients with a Wells score of at least 2 points in the simplified version (see under physical examination) [gold standard]Note: If CTPA detects isolated subsegmental LE, ask for a second opinion to avoid unnecessary and potentially dangerous anticoagulation [guidelines: 2019 ESC Guidelines].Alternative procedures:
- Pulmonary scintigraphy: V/P scintigraphy (ventilation/perfusion scintigraphy) (sensitivity (percentage of diseased patients in whom disease is detected by use of the test, i.e., a positive test result occurs): Approx. 78 %; Specificity (probability that actually healthy persons who do not suffer from the disease in question are also detected as healthy by the procedure): 98%)The procedure results in a radiation exposure of only two mSv (milli-Sievert; two mSv is the radiation dose to which every human being is exposed by natural radiation) and, according to the German guideline on “Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism,” is suitable for pregnant women and patients with renal insufficiency.Other indications include:
- Patients who have previously suffered a pulmonary embolism.
- Patients who had no abnormalities on chest x-ray/chest x-ray
- Patients in whom leg vein thrombosis was detected by sonography (ultrasound examination).
- All patients in whom the CT has not provided a clear result.
A normal finding on scintigraphy allows a safe decision not to initiate anticoagulation.
- Magnetic resonance angiography (MRA): fewer major adverse PE-related event (MAPE) complications occurred within six months in the MRA group than in the CTA group (5.4% versus 13.6%).
- Pulmonary scintigraphy: V/P scintigraphy (ventilation/perfusion scintigraphy) (sensitivity (percentage of diseased patients in whom disease is detected by use of the test, i.e., a positive test result occurs): Approx. 78 %; Specificity (probability that actually healthy persons who do not suffer from the disease in question are also detected as healthy by the procedure): 98%)The procedure results in a radiation exposure of only two mSv (milli-Sievert; two mSv is the radiation dose to which every human being is exposed by natural radiation) and, according to the German guideline on “Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism,” is suitable for pregnant women and patients with renal insufficiency.Other indications include:
- Echocardiography (echo) if necessary transesophageal echocardiography – in the clinically unstable patient, echo is the crucial diagnostic step to estimate right ventricular pressure load and dysfunction [parameters indicative of hemodynamically relevant PE:
- Impaired wall motion of the right ventricle.
- Right ventricular dilatation
- Impaired (paradoxical) movement of the interventricular septum.
- Tricuspid regurgitation]
- Compression ultrasonography – in cases of suspected deep vein thrombosis (TBVT); detection of venous thrombosis is possible with high sensitivity (percentage of diseased patients in whom the disease is detected by the use of the test, ie, a positive test result occurs) and specificity (probability that actually healthy people who do not have the disease in question are also detected as healthy in the test).
- Phlebography (imaging of veins by contrast medium in an X-ray examination) – to look for deep vein thrombosis (DVT) if compression ultrasonography remains without clear findings
- Magnetic resonance imaging/angiography of the thorax (thoracic MRI/thoracic MRA) – as an alternative in contraindications (contraindications) for CTPA or pulmonary scintigraphy; only in centers with a high level of expertise
* These examination procedures are unsuitable to confirm or exclude a pulmonary embolism with sufficient certainty!
PERC criteria (“pulmonary embolism rule-out”)
Accordingly, immediate CT pulmonary angiography (CTPA) should be performed only if one of the following 8 PERC criteria is present:
- Medical history (history)
- Patient age > 50 years
- History of pulmonary embolism or deep vein thrombosis
- Hormone use (oral contraceptives, hormone replacement therapy, or intake of estrogens in male or female patients).
- Recent trauma or recent surgery
- Clinical findings/laboratory diagnostics.
- Unilateral leg swelling
- Hemoptysis (coughing up blood)
- Arterial oxygen saturation (SpO2): ≤ 94%.
- Pulse rate: ≥ 100 beats/minute.
- Medical history
- Patient age > 50 years
- History of pulmonary embolism or deep vein thrombosis
- Hormone use (oral contraceptives, hormone replacement therapy, or intake of estrogens in male or female patients).
- Recent trauma or recent surgery
- Clinical findings/laboratory diagnostics.
- Unilateral leg swelling
- Hemoptysis (coughing up blood)
- Arterial oxygen saturation (SpO2): ≤ 94%.
- Pulse rate: ≥ 100 beats/minute.
- Medical history
Note: Use of PERC criteria results in less than 2% missed pulmonary emboli in the United States.
YEARS algorithm for deciding for or against immediate CT pulmonary angiography (CTPA)
| D-dimer test | Clinical criteria | Interpretation |
| > 500 ng/ml |
|
If any of the 3 clinical criteria are met, a definitive diagnosis should be sought with CT. |
| > 1,000 ng/ml | Even if none of the previously mentioned criteria are present, a definitive diagnosis should be sought with a CT scan |
* In pregnant women, perform compression ultrasound on the affected leg to start treatment with anticoagulants in any case if the findings are positive. In adult patients, the algorithm avoids approximately half of all CT examinations; in pregnant women, one third are spared an unnecessary CT examination.
Prognostic factors
The ratio of right and left ventricular diameters (RV/LV quotient) determined by transverse computed tomography (CT), as a quantitative measure of right ventricular failure, has the strongest predictive value for mortality after acute pulmonary embolism. Pathologically high ratios were associated with a mortality risk of 2.5-fold within a six-month period. In terms of embolism-related mortality risk (mortality risk), high RV/LV quotients were associated with a mortality risk increased to fivefold.
