Case Scenario

S.M. is a 32 y/o Female with past medical history  of mild asthma who presents to the ED with acute onset shortness of breath, pleuritic chest pain, palpitations, and right calf pain and swelling for the past 1 day after a recent long car ride.

History Elements

• Symptoms started yesterday evening after returning from a 7 hour car ride.
• Sudden onset SOB and right-sided chest pain.
• Chest pain is 7/10, sharp, and worse with deep inspiration.
• Reports palpitations and lightheadedness when walking.
• Right calf pain and swelling started earlier that day.
• Has mild asthma, but states this does not feel like her usual asthma because chest pain is new and albuterol did not help.
• Used albuterol inhaler twice with minimal relief.
• Takes combined oral contraceptive pills.
• Denies fever, chills, productive cough, hemoptysis, syncope, wheezing, trauma, recent surgery, recent hospitalization, known cancer, prior DVT/PE, leg injury, crushing chest pressure, radiation to arm/jaw, diaphoresis, nausea/vomiting, or cardiac history.
• PMHx: mild intermittent asthma.
• PSHx: no prior surgeries.
• Medications: albuterol inhaler PRN, combined OCP.
• Allergies: NKDA.
• FHx: mother with HTN. No known clotting disorders or sudden cardiac death.
• SHx: works as a teacher. Denies tobacco, vaping, or illicit drug use. Drinks alcohol socially. Recent 7-hour car trip.

Physical Exam

• Vitals: BP 124/78, P 118, RR 24, T 98.7°F, O2 sat 93% RA, BMI 29
• General: A&Ox3, Patient appears stated age, Anxious, mildly dyspneic, speaking in full sentences
• Skin: Warm and dry, no cyanosis
• HEENT: Normocephalic, atraumatic, moist mucous membranes
• Neck: Supple, no JVD
• Cardiac: Tachycardic, regular rhythm, no murmurs, no rubs, no gallops, no reproducible chest wall tenderness
• Lungs: Mild tachypnea. Clear to auscultation bilaterally, no wheezes and no rales
• Abdomen: Soft, nontender, nondistended
• Extremities: Right calf mildly swollen and tender compared to left. No erythema. Distal pulses intact bilaterally.

Labs/Tests

• EKG: Sinus tachycardia, HR 116
• CXR: No acute cardiopulmonary disease
• CBC: WBC 8.9, Hgb 13.1, Plt 265
• BMP: WNL, creatinine normal
• Troponin: Negative
• BNP: WNL
• D-dimer: Elevated
• Urine hCG: Negative
• CTA chest: Filling defect in segmental branches of the right lower lobe pulmonary artery, consistent with acute PE. No saddle PE. No RV enlargement.
• RLE venous Doppler: Noncompressible right popliteal vein consistent with right popliteal DVT.

DDx

1. Pulmonary embolism: Most likely diagnosis. Patient has acute SOB, pleuritic chest pain, tachycardia, mild hypoxia, recent prolonged immobility from a 7-hour car ride, combined OCP use, and unilateral calf swelling. CTA confirms segmental PE.
2. DVT: Likely source of the PE. Patient has unilateral right calf swelling and tenderness after prolonged travel, and RLE Doppler confirms right popliteal DVT.
3. Asthma exacerbation: Considered because patient has asthma and SOB. Less likely because lungs are clear, no wheezing, albuterol did not help, and she has pleuritic chest pain with unilateral calf swelling.
4. ACS: Considered because patient has chest pain, SOB, and tachycardia. Less likely because pain is pleuritic, EKG shows no ischemic changes, troponin is negative, and she is young without major cardiac risk factors.
5. Pneumothorax: Considered because sudden SOB and pleuritic chest pain can occur with pneumothorax. Less likely because breath sounds are equal bilaterally and CXR is negative.
6. Pneumonia : Considered because SOB and chest pain can be infectious. Less likely because she is afebrile, has no productive cough, normal WBC, and negative CXR.

Treatment

• Start supplemental O2 and monitor vitals/cardiac status in the ED.
• Place IV access and keep patient on observation to make sure tachycardia and O2 sat improve.
• Since patient is stable with no hypotension, no RV strain, negative troponin, and normal BNP, start apixaban 10 mg PO BID x 7 days, then 5 mg PO BID.
• Give acetaminophen PRN for chest discomfort. 
• Discontinue combined OCP due to increased clot risk.
• Admit if persistent hypoxia, worsening tachycardia, worsening chest pain/SOB, high bleeding risk, or unreliable follow-up.
• If patient becomes unstable, start heparin and consider thrombolysis/thrombectomy.
• Continue albuterol PRN for asthma

Patient Counseling

• Explain diagnosis in simple terms: “You have a blood clot in your lung, called a pulmonary embolism. It most likely came from the clot in your right leg.”
• Explain that the blood thinner does not instantly dissolve the clot, but prevents it from getting bigger and prevents new clots while the body breaks it down.
• Review apixaban instructions: take exactly as prescribed, 10 mg twice daily for 7 days, then 5 mg twice daily. Do not skip doses or stop without talking to a provider.
• Review bleeding risks: easy bruising, nosebleeds, bleeding gums, heavy periods, black/bloody stool, blood in urine, vomiting blood, or severe headache after head injury.
• Return precautions: come back for worsening SOB, worsening chest pain, coughing blood, fainting, severe dizziness, new/worsening leg swelling, signs of bleeding, or any head injury.
• Counsel to stop estrogen-containing birth control and follow up with OBGYN for safer options like progestin-only pill, implant, IUD, or copper IUD.
• For long trips, take walking breaks, stay hydrated, and do calf exercises.
• Use teach-back: “Can you tell me how you will take the blood thinner and what symptoms would make you come back to the ER?”