Risk stratification 
The new guidelines do not classify PE as massive or non-massive. PE is now classified according to estimated early death rate: high risk and non-high risk (intermediate and low risk). The parameters for stratification are clinical criteria (shock or hypotension), RV dysfunction markers (RV dilatation assessment through echocardiography or CT, high BNP or pro-BNP, or high RV pressures measured through a catheterisation procedure), and myocardial injury markers (high tropononin T or I levels). Shock or hypotension are suggested as markers of high risk. Other markers are useful for further risk sub-stratification.
Diagnostic
The clinical presentation is unspecific. Tachypnoea-dyspnoea and thoracic pain, however, appear in 90% of the cases. The diagnostic algorithm is based on an evaluation of the clinical probability of PE, with validated prediction rules (Geneva Score or Wells). The resulting clinical probability categories would be high, intermediate and low. Risk factors, symptoms and clinical signs are also considered.
- Ultrasound with compression of inferior limbs has become more important than phlebography and has a sensitivity higher than 90% and specificity of 95% for TVP.
- Ventilation-perfusion lung scans use macroaggregated albumin particles marked with Tc-99m. Results are categorised as normal, almost normal, low probability, intermediate and high probability of PE (PIOPED 1990).
- CT allows visualization at the obstruction level. Its interpretation depends on the number of equipment detectors and on the pre-test probability.
- Pulmonary angiography is rarely used today, as improvement in most of the non-invasive methods, such as CT, have taken its place. In these Guidelines, pulmonary angiography is considered as a last step test.
- Echocardiography allows evaluation of some parameters with hemodynamic repercussion as follows: speed of tricuspid insufficiency jet, acceleration time of the pulmonary artery flow, RV diameters, existence of thrombus and RV wall motility abnormalities. It is indicated in the immediate evaluation of patients with a high-risk suspicion of PE, in order to rule out other etiologies of shock and provide risk stratification.
Diagnostic strategies
The diagnostic algorithm proposed in these Guidelines, is to establish in the first place the risk of early death in the suspected patient with PE.
A CT should initially be performed in those suspected patients at high risk of PE, and/or an echocardiogram if necessary to assess indirect signs of severe pulmonary hypertension and RV overload. The treatment can be decided afterwards. A highly suspicious echocardiogram, if CT is not available, can establish the indication of an initial strategy based on thrombolytic therapy.
Treatment
Norepinephrine is indicated in patients with PE who remain hypotense. Dobutamine and/or dopamine should be indicated in normotensive patients but with a low cardiac index. In case of shock, epinephrine can be an effective option. Vasodilators have not yet an established role. Mechanical ventilation is rarely indicated in case of hypoxemia.
Thrombolysis is indicated in patients at high-risk of PE associated with cardiogenic shock and/or persistent hypotension.
Surgical pulmonary embolectomy is reserved for those at high-risk with contraindications or inadequate response to thrombolysis, besides those with permeable oval foramen and with intracardiac thrombus. Percutaneal treatment has a low level of evidence and is indicated when thrombolysis is contraindicated or has failed, or as an alternative to surgery in high-risk patients.
Anticoagulant treatment has two phases: initial and long-term. Initial anticoagulation is intended to diminish early mortality ratio and recurring events.
Venous filters have a precise indication when there is an absolute contraindication to anticoagulation, or there is high risk for recurrence of TVP in the long term.
There are special situations to consider. PE associated with pregnancy is more frequent during the post-partum period, and practically follows the same diagnostic algorithm.
In intracardiac thrombus, therapy strategies remain controversial. Thrombolysis is recommended, or even surgery if there is a concomitant permeable oval foramen.