Risk Factors:
Prior VTE (PE/DVT): Was the last PE/DVT unprovoked or provoked? More concerning if the last PE/DVT was unprovoked (e.g. the patient was not immobilized for a long period of time). This does not change if testing for hypercoagulability was negative. If provoked, this is less concerning.
Malignancy History: Higher risk with active cancer. This either means active treatment within the last 6 months or metastatic disease. Chemotherapy patients are also more at risk. Not all malignancies are created equal, though! Your risk is even higher with pancreatic cancer, multiple myeloma, colon cancer, glioblastoma, and melanoma.
Immobility: certain types of immobility are higher risk than others! Examples: patients in casts, hospitalized trauma patients (others not at higher risk). Surgical patients are higher risk if they were intubated, received general anesthesia, or received an epidural (e.g. knee surgery, abdominal surgery, neurological surgery). Being in a continuous seated position for > 6 hours might be a risk factor.
OCPs: estrogen of any form increases risk (e.g. OCPs, estrogen replacement, intra-vaginal estrogen). For transgendered patients, more study is needed to determine increased risk.
Pregnancy: Highest risk 2 weeks postpartum. If a patient is pregnant and symptomatic, they have a 70% risk of PE.
Increased risk at age 50: Risk of PE perpetually increases with age.
Symptoms:
Chest pain: pleuritic chest pain suggest peripheral PE (65%)
Hemoptysis: more indicative of pulmonary hemorrhage, not infarct
Exertional Dyspnea: concerning! You do not need to have chest pain to have a PE!! There is a syndrome that consists of subacute dyspnea that gets worse over days that is predictive of central PE.
Calf pain/Calf swelling: unilateral calf pain (the symptom) and calf swelling (the physical exam finding) are both concerning.
Syncope: corresponds to a large clot burden, but syncope (likely does not confer an increased likelihood of PE)
Anticoagulation: if they are compliant with anticoagulation, they are less likely to have PE. While this is definitely true with NOACs, with Coumadin, it’s less certain because levels will vary regardless of compliance with medication. Symptoms that are not significant: orthopnea, palpitations, anxiety, dizziness
Physical Exam Findings:
Abnormal pulmonary exam - decreases likelihood of PE
Clinical signs of DVT - such as calf swelling, redness, etc. increases likelihood
STEP 1 (cont): Do you, based on the information above, feel that a PE is possible? Meaning, it is ABOVE the 2% threshold for PE.
Professional recommendation: if the patient has risk factors in 2 or more of the above categories (e.g. vital sign and risk factors, or risk factors and exam findings), and there is no alternative explanation for the patient's presentation, you can say adequately that you have suspicion for PE.
If you have less than a 2% clinical suspicion for PE, STOP. You do NOT think there is a PE and you do not evaluate further. I repeat - STOP! Evaluate for other suspected pathologies). ACEP Guidelines: 2% is an acceptable cutoff recognizing limitations of testing and risk of false positives (in latest NSTEMI guidelines) Now that you truly think your differential should include PE...
STEP 2: RISK STRATIFY
It doesn't matter if you use Well's Score vs. Geneva vs. Gestalt; all have been shown to be equal. Keep in mind these decision tools SHOULD NOT used to rule out. They are only to RISK STRATIFY. Meaning that you clinically have a suspicion of said disease before you use them. This means you should NEVER document "Well's score low, not likely PE".
High risk: get a CTA! May consider empiric heparin before or after CTA.
Moderate: D-dimer.
Low: PERC
STEP 3: Further Management
Ever get a reading that said "evaluation for sub-segmental suboptimal due to motion artifact? What do you do? (Only if vital signs are stable)
Now let's go over what you do if a PE is found...
