Talk:Pulmonary Embolization

Pulmonary Embolism

A pulmonary embolism (PE) is the blockage of blood flow in the lungs caused by a blood clot, tissue fragments, fat or air (McCance, Huether, Brashers & Rote, 2010). Most commonly, they occur from the dislodgement of a venous thromboembolism in the pelvis or thigh. Virchow triad is the categories of risks that increase the likelihood of a PE. They include venous stasis, or a slowing or pooling of blood in veins, hypercoagulability and injuries to the blood vessels (McCance, Huether, Brashers & Rote, 2010). Prolonged bed rest, sitting during travel, advanced age, pregnancy, obesity, CHF are the most common causes of venous stasis. Hypercoagulability is most commonly caused by genetic inheritance. Damage to vessels can occur from trauma, surgery, IV catheters and medications that are irritating to veins.

Pathophysiology

PE are categorized into four types. Embolus with infarction are those that cause tissue death in the lung. Embolus without infarction do not cause tissue death. Massive occlusions block a large area of circulation. Multiple PE are those that are frequent or chronic.

Clinical Presentation

PE are difficult to diagnose due the non-specific symptoms that may be present. In order to accurately and efficiently diagnose a PE, thorough history is crucial. Presence of a DVT may increase the possibility, but lack of DVT does not rule out PE. Common symptoms include difficulty breathing, rapid pulse, anxiety, coughing up blood and chest pain that is pleuritic in nature. Symptoms come on suddenly. Objective symptom elevated white count, pleural friction rub, fever and pleural effusion. Massive occlusions result in shock, pulmonary hypertension, and chest pain in addition to above symptoms (McCance, Huether, Brashers & Rote, 2010).

Diagnosis and Treatment

After ROS and PMH, if PE is suspected EKG, ABG and chest x-ray should be obtained rapidly. A D-dimer is a blood test that measures degradation of the fibrinolytic system, but is non-specific and often falsely elevated due to other causes. It is elevated, an CT angiogram can determine the specific location of a PE if present.

Treatment can be surgical or with medication (Mayo clinic Staff, 2014). Surgical options include removal of the clot via catheter or the placement of a filter to prevent the clot from traveling to the lung. Medications can be used to treat current clots and prevent future clots. Preventive medications include warfarin, low-molecular-weight heparin, fondaparinux (McCance, Huether, Brashers & Rote, 2010) and enoxaparin. Heparin is generally started immediately after diagnosis, if not contraindicated. Prophylactic therapy may only be necessary for a short period of time if risk factors are short in nature. These include pregnancy and bed rest post-operatively. If risks factors are not modifiable, the patient may be on medication indefinitely.

Prevention

Prevention of PE include medications and limiting inactivity. Post-operative patients should ambulate as soon as possible or assisted to move while in bed until able to ambulate. The key to prevention is identification of those at risk.

Reference McCance, K. L., Huether, S. E., Brashers, V. L., & Rote, N. S. (2010). Pathophysiology: The biologic basis for disease in adults and children. (6 ed.). Maryland Heights: Mosby Elsevier.

Mayo Clinic Staff. (2014, January 2). Pulmonary embolism. Retrieved from http://www.mayoclinic.org/diseases-conditions/pulmonary-embolism/basics/treatment/con-20022849