Case-Based Approach to Dyspnea Evaluation

This educational session introduces medical students to a systematic approach for evaluating dyspnea in adult internal medicine patients. Through a detailed case study of a 65-year-old male with multiple comorbidities, participants learn to generate a multi-systemic differential diagnosis, identify appropriate diagnostic studies, and correlate pathophysiology with patient presentation and treatment options for common causes of shortness of breath.

Session Overview and Educational Goals: This session is designed to introduce medical students to a structured approach for evaluating dyspnea in adult internal medicine patients. The key objectives include enabling students to create a multi-systemic differential diagnosis, identify relevant diagnostic studies, and correlate the underlying pathophysiology with clinical presentation and treatment options for common causes of dyspnea. The format is an in-person, large-group case discussion, requiring no prior preparation and allowing participants to use open resources.

Patient Presentation - Part 1: The case centers on a 65-year-old male who presents to the emergency room with acute, rapid-onset shortness of breath, beginning the previous night. His significant medical history includes hypertension, hyperlipidemia, coronary artery disease, type 2 diabetes, and chronic kidney disease stage 3a. He reports severe dyspnea on exertion (unable to walk more than 20 feet), orthopnea requiring him to sleep in a recliner, and nocturnal awakenings due to shortness of breath. Other symptoms include worsening bilateral leg swelling and a frequent cough. He denies chest pain, palpitations, fevers, or chills. He reports feeling tired for some time but attributes the current symptoms to acute onset. His home medications include Aspirin, Lisinopril, Hydrochlorothiazide, Amlodipine, Atorvastatin, and Metformin. Social history notes he is a retired construction manager, a former smoker with a 30 pack-year history, and lives alone, maintaining independence in activities of daily living.

Physical Examination Findings: Upon physical examination, the patient presents in atrial fibrillation with a heart rate of 95 bpm, severe hypertension (BP 195/110 mmHg), tachypnea (RR 25), and hypoxemia (Sat 85% on room air). He is obese (BMI 38) and his dyspnea limits his ability to speak in full sentences. His neck examination reveals a significantly elevated jugular venous pressure (JVP) of 15 cm. Cardiovascular assessment shows a regular rate and rhythm, normal S1 and S2 heart sounds, a present S4 gallop, and no murmurs or rubs. Peripheral pulses are equal bilaterally. Respiratory examination reveals dullness to percussion at the bases with crackles extending up to the mid-lung fields bilaterally, without wheezes or rhonchi. Extremities are warm and well-perfused, with 2+ pitting edema extending to the shins bilaterally.

Laboratory Workup and Interpretation - Part 2: The initial laboratory results provide crucial insights. His complete blood count is largely normal with a WBC of 5, RBC of 9, and platelets of 300. Basic metabolic panel shows normal electrolytes (Na 141, K 4.3, Cl 100, CO2 25), but his renal function is elevated with BUN of 25 and Creatinine of 1.7, consistent with his known CKD. Cardiac biomarkers are significantly abnormal: Troponin levels are elevated and show a rising trend (150 -> 180 -> 175), indicating acute myocardial injury. NT-ProBNP is markedly elevated at 1350, strongly suggesting significant cardiac strain and heart failure. A D-Dimer level of 200 is low, making acute pulmonary embolism less likely to be the primary cause of his dyspnea.

Clinical Questions and Learning Points: The case prompts several critical thinking questions for medical students. These include identifying the general organ systems capable of causing acute dyspnea and outlining the initial diagnostic workup. Students are tasked with formulating a comprehensive problem list for the patient based on his history, comorbidities, and acute presentation. A key step involves developing a top differential diagnosis for his dyspnea. Furthermore, the discussion focuses on interpreting the presented laboratory data in context, determining the most likely diagnosis, defining the acute treatment goals for this condition, and strategizing long-term prevention methods to mitigate future occurrences.

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