A pulmonary embolism (also known as pulmonary embolus, PE, or P-damn-E) is an obstruction of the one of the pulmonary arteries (or its branches) by material (thrombus, air, cement, or sandwich) originating from elsewhere in the body. It is a form of venous thromboembolism.
Methods of Classifications
Timing - Based on the temporal development, PE can be characterized as chronic ("F**k!"), subacute ("Holy sh*t!"), or acute ("M**THERF**KER!!).
Hemodynamics - PE can be further classified by the presence of hemodynamic stability and right heart strain:
- Low risk - PE is present ("Darn!"), hemodynamically stable ("Woohoo!"), no right heart strain ("Score!")
- Intermediate risk - PE present ("Darn!"), hemodynamically stable ("Woohoo!"), right heart strain ("Dagnabbit!")
- High risk - PE present ("Darn!"), hemodynamically unstable ("ICU, HELP ME QUICK!!!)
Location - Classification can also be based on location: saddle (embolus took place while riding a horse), lobar (not sure what that means), segmental (woah...), and subsegmental (them's fancy radiology words!)
Symptoms - Lastly, PE can be classified on whether the patient is symptomatic ("We know why you're short of breath") or asymptomatic ("When we scanned your big toe, we did manage to catch a PE in your chest...")
Yes, it happens.
Two words: Virchow's triad. Need we say more?
In the general population, there are several well-documented risk factors for the development of PE: genetic risk factors like factor V Leiden and acquired risk factors like cancer, recent surgery, active cancer, and recent hormone therapy. There is one major risk factor that is specific to health care professionals and the development of PE: sitting at the computer for more than 90% of each work day. For this reason, it is recommended that health care professionals receive heparin prophylaxis while on service.
Patient presents and says to your face, "I think I have a PE!
Diagnosis and Treatment
Diagnosis and treatment of a PE always involves the same sequence of steps as listed below:
- Start empiric anticoagulation with heparin, enoxaparin, or a NOAC
- Order a CTPE protocol
- Cancel CTPE protocol when someone reminds you patient's creatinine is > 1.5
- Order a V/Q scan
- V/Q is inconclusive
- Hydrate or wait until Cr is < 1.5
- Reorder CTPE protocol
- CTPE is positive for PE 2-3 days later
- You and patient breathe sigh of relief that you started empiric heparin, enoxaparin, or a NOAC
- Wait for the inevitable GI bleed
- Hold anticoagulation and consult GI
- Transfuse for anemia
- Place IVC filter