If a patient presents with pleuritic chest pain, shortness of breath and a clear chest on auscultation and xray, we obviously think of pulmonary embolism. But PEs are missed 10-30% on their initial presentations, so we should be aware of the atypical presentations. Here are a few misses/near misses based on the misdiagnosis
65yoM with cough/wheeze after returning from the Caribbean. On exam normal vitals, wheezy, normal CXR/ECG/troponin, improved on puffers and sent home. Returned a few days later more short of breath, now sats 92% on RA. On further history he had a post-op DVT. I sent him for CT chest, which confirmed PE.
65yoM two weeks left sided chest pain, occasional cough and low-grade fever so received antibiotics, but presented with increasing chest pain. CXR reported as “airspace disease compatible with pneumonia,” but he was afebrile, had a normal WBC and was worse despite antibiotics so I sent off a D-Dimer, and when it was elevated got a CT chest confirming PE.
57yoM denies any significant health problems, with one day of flank pain. On exam he had normal vital signs but appeared uncomfortable and had guarding on his left flank. Normal labs, urine. I sent him for a CT abdo to r/o AAA, which was normal except for some lung disease at the left base. On further history he had a history of Factor V Leiden and DVTs, but wasn’t taking his coumadin. CT chest confirmed acute PE.
22yoM on imuran/prednisone for ulcerative colitis, presents with shoulder/rib pain, short of breath and dizzy. Normal vitals, PERC negative. Radiologist called about CXR infiltrate, query Hampton’s Hump. Dimer positive and CT confirmed PE.
- Consider PE in all cases of shortness of breath, or chest/back/flank pain. We don’t want to CT every reactive disease or pneumonia, but you should at least consider PE, especially in bouncebacks
- Specifically ask about prior DVT and other PE risk factors as patient’s won’t necessarily volunteer this information
- PE can co-exist and be a cause for exacerbation of reactive airways/COPD, can give low grade fever and be misread as pneumonia on CXR
- Be careful applying the PERC rule to high-risk patients, eg nephrotic, coagulopathic, auto-immune, sickle cell
PERC rule: if the patient is low-pretest likelihood and has none of the PERC criteria, they have <2% chance of PE and can safely avoid the risk of PE workup and treatment (radiation, anaphylaxis, contrast nephropathy, bleed from anti-coagulation).
Here’s my mnemonic to remember PERC: if negative you can safely say “NO D-DIMER”
- North of 50 (age >50)
- Oral blood (hemoptysis)
- Double estrogen (exogenous estrogen)
- DVT in the past
- Immobilized (trauma, surgery <1 mo)
- Massive leg: unilateral leg swelling
- Elevated HR >100
- Reduced sat <95%