Date: November 21st, 2019

Reference: Daley et al. Increased Sensitivity of Focused Cardiac Ultrasound for Pulmonary Embolism in Emergency Department Patients With Abnormal Vital Signs. AEM November 2019

Guest Skeptic: Dr. Corey Heitz is an emergency physician in Roanoke, Virginia. He is also the CME editor for Academic Emergency Medicine.

Case: You are caring for a 45-year-old male patient in the emergency department with pleuritic chest pain. You suspect he has a pulmonary embolism (PE), and the CT scanner is currently being used up by a multi-patient multiple-trauma pan-scan which promises to take hours. Your patient has a heart rate of 105 bpm and a systolic blood pressure of 95 mmHg. You pull the department’s ultrasound machine to the bedside and prepare to do a focused cardiac ultrasound to decide if you want to treat for a PE while waiting for the scanner to free up.

Background: We have covered the issue of PE many times on the SGEM. This has included outpatient management (SGEM#51 and SGEM#126), catheter directed thrombolysis (SGEM#163) and even discussed the PERC rule with its creator, Dr. Jeff Kline (SGEM#219).

We may have covered it so often because PE is commonly suspected in patients presenting the ED with chest pain, shortness of breath, or other symptoms. The current gold standard test is a CT angiogram of the pulmonary arteries (CTA), but this test cannot be performed immediately in some patients due to renal function, availability of the equipment, or contrast allergies.

There are concerns about doing CTAs in pregnant patients due to the radiation exposure to both the mother and fetus. We have a show coming up soon looking at a pregnancy adapted YEARS criteria to help minimize the number of CTAs ordered in this patient population.

In addition, patients with hemodynamic instability may not be appropriate to take out of the resuscitation bay. Focused cardiac ultrasound (FOCUS) can show findings of right ventricular strain caused by a PE, but in all patients suspected of PE, it is relatively insensitive. However, it has been suggested that in patients with hemodynamic instability, the sensitivity may be higher.

Clinical Question: In patients presenting to the ED with suspected PE, who have abnormal vital signs, what is the sensitivity of FOCUS for PE?

Reference: Daley et al. Increased Sensitivity of Focused Cardiac Ultrasound for Pulmonary Embolism in Emergency Department Patients With Abnormal Vital Signs. AEM November 2019

* Population: Adult patients (>17 years old) undergoing evaluation for PE who are tachycardic (HR >100bpm) and/or hypotensive (systolic BP <90mmHg)

* Excluded: Prisoners, wards of the state, non–English-speaking patients, and those where investigators could not obtain any ECHO data due to technical challenges.

* Intervention: Focused cardiac ultrasound (FOCUS)

* Comparison: CT angiography of the pulmonary arteries

* Outcome:

* Primary Outcomes: Sensitivity of FOCUS for PE patient with a HR ≥ 100 beats/min or sBP < 90 mm Hg (n = 136) and those with a HR ≥ 110 beats/min (n = 98).

* Secondary Outcomes: Specificity and likelihood ratios of FOCUS for PE in each population.