Pulmonary Embolism


* The respiratory impact is complex, often resulting to hypoxia without carbon dioxide retention. Both there is a dead space effect (broken not perfused areas) and increased physiological shunt. This is explained by the persistence of blood flow in embolized areas and the opening of latent anastomoses under the effect of PAH.

* Objective arterial blood gases usually hypoxia-hypocapnia with respiratory alkalosis. Hypoxia is corrected by oxygen therapy. PaO2> 80% in 25% of cases.

* D-Dimer: sensitivity> 95% if ELISA; positivity threshold of 500 ng / mL; if rate <this threshold can exclude the diagnosis of pulmonary embolism. A high or very high no practical interest.

* ECG usually normal. Can show a right axial deflection of the QRS axis; S1Q3 appearance; right bundle branch block; P wave “lung” (high amplitude) …

* Respiratory Call Signs: Dyspnea 80% of cases; polypnea> 16 / min in 90% of cases; rarely hemoptysis (delayed 24 hours after the pain or dyspnea, black); dry cough. Chest pain in 84% of cases. Dyspnea, pain, hemoptysis triad is evocative (25% of cases). Fever is absent at the beginning; frequent> 38 ° C in 40% and> 39 ° C in 20% of cases.

Mechanism of pulmonary embolism
Mechanism of pulmonary embolism

* Bronchospasm (differential diagnosis with asthma and can cause confusion) in 5% of cases.

* Signs of poor tolerance (massive pulmonary embolism> 50%)

– Tachycardia> 120 in the absence of fever

– Disorders circumferential repolarization ECG

– Signs of right ventricular failure

– Signs of shock or collapse or low blood pressure

– Neurological signs (syncope, convulsions …).

– Metabolic acidosis in gas analysis

* There radiological abnormalities (téléthorax) in the majority of cases (80% of cases).

* Radiological signs of massive embolism of a pulmonary artery distension with clear zone of hypovascularisation; dilation of the right heart cavities with hoof; Device hypovascularisation

* The radiological images:

– Bronchoconstriction: atelectasis (flat, horizontal); elevation of diaphragmatic

– Pulmonary infarction: triangular opacity device, systematized non retractile basal (lower lobe).

– Pleural irritation: blunting or greater effusion

* The normal scan eliminates the diagnosis of pulmonary embolism recent (within 10 days). 75% of scans are intermediate.

* Thrombolytics: indicated in the massive pulmonary embolism with shock criteria: shock or poor hemodynamic tolerance

* Interruption of IVC:

– Two formal indications pulmonary embolism or DVT with anticoagulant cons-indications; recurrent embolic proven under adequate medical treatment.

– Other information: accidents anticoagulants; after surgical embolectomy; post-embolic pulmonary heart.

* In case of massive pulmonary embolism is suspected, the diagnosis of certainty should not be delayed


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