Question Of The Day #87

Shortness of breath, also known as dyspnea, is a common reason for patients to visit the Emergency Department.  Dyspnea is often caused by a pulmonary or cardiovascular condition, but it is important to remember that dyspnea can be due to endocrine conditions, toxicologic conditions, neurologic conditions, hematologic conditions, musculoskeletal conditions, and psychiatric conditions. 

The initial approach to all patients with shortness of breath involves the primary survey, or “ABCs” (Airway, Breathing, Circulation).  This first involves checking the patient for a patent airway.  A simple method to assess the airway is to ask the patient to speak and listen for the voice.  A muffled voice, the presence of stridor, hematemesis, or a lethargic patient are clues that a patent airway may not be present.  Problems with the airway, such as an obstructing foreign body, inflammation (i.e., epiglottitis, anaphylactic shock), or vocal cord dysfunction can certainly cause shortness of breath.  Endotracheal intubation may need to be performed before moving forward.  Breathing is assessed by evaluating the function of the lungs.  Steps include looking at how the patient is breathing (fast or slow), measurement of an SpO2 level, and auscultation of both lungs for wheezing, crackles, rhonchi, or distant or absent sounds.  A low oxygen level should be immediately addressed with supplemental oxygen before moving forward.  The patient’s breathing rate and lung sounds can be very helpful in discovering the diagnosis and guiding treatment.  Lastly, circulation should be assessed.  Check the heart rate, blood pressure, peripheral pulses, skin color and temperature, and evaluate for any sites of hemorrhage.  The presence of hypotension or tachycardia should be addressed appropriately based on the presumed cause.  After the primary assessment (“ABCs”) and initial treatment actions, a more detailed history and physical exam should be conducted. 

Pertinent causes of shortness of breath for the emergency practitioner to know are outlined in the chart below. 

This patient arrives to the Emergency department with shortness of breath with deceased exercise tolerance or 5 days.  Her vital signs are normal and lungs are clear, but she appears pale.  The laboratory test provided shows normal kidney function, a negative serum pregnancy test, and a markedly low hemoglobin level.  A ruptured ectopic pregnancy (Choice B) can cause shortness of breath due to anemia and hemorrhagic shock, but this patient has a negative pregnancy test.  Asthma (Choice A) is unlikely given the patient’s normal lung exam without wheezing and no mention of cough.  A pulmonary embolism (Choice D) is possible due to the tachycardia, but the patient lacks other risk factors as stated in the question stem.  A D-Dimer test could help further evaluate if this patient has a pulmonary embolism, but the low hemoglobin likely explains the patient’s symptoms.  The patient’s history of menorrhagia, also known as heavy menses (Choice C), is a common cause of anemia in women of childbearing age.  Even though this patient is not currently menstruating, her heavy menses are the most likely cause for her shortness of breath.  Choice C is the best answer.