Abstract Shortness of breath comprises approximately 5-9% of emergency department complaints and can represent a broad range of differential diagnoses, commonly including infections, asthma, COPD, and heart failure. However, rare neuromuscular causes, such as diaphragmatic paralysis, are often overlooked, posing a diagnostic challenge. Diaphragmatic paralysis impairs respiratory mechanics and can lead to significant dyspnea or respiratory failure. It may result from phrenic nerve injury, trauma, surgical complications, or post-infectious states. Here we report a case of unilateral diaphragmatic paralysis in a young, otherwise healthy patient with worsening dyspnea. The case highlights the importance of considering diaphragmatic dysfunction in unexplained dyspnea. A 35-year-old previously healthy male presented to the emergency department with progressively worsening dyspnea and associated right subscapular pain. He had initially been treated with azithromycin and corticosteroids in the outpatient setting. On arrival, he was hypoxic, requiring 3 L/min of supplemental oxygen. Laboratory studies showed a mildly elevated D-dimer of 0.95 mg/L and mild leukocytosis. Initial chest x-ray showed no focal consolidations but noted an elevated right hemidiaphragm. CT angiography of the chest showed no pulmonary embolism. Cardiac evaluation, including echocardiogram and cardiac MRI, was unremarkable for pathology explaining the patient’s symptoms. Due to his persistent respiratory symptoms requiring supplemental oxygen, an otherwise negative workup, and no evidence of infection, fluoroscopic sniff testing was performed, which revealed right-sided diaphragmatic paralysis. The patient was initiated on a 5-day course of prednisone and discharged on 4 L/min supplemental oxygen therapy. Outpatient pulmonary function tests (PFTs) demonstrated a restrictive pattern consistent with diaphragmatic paralysis. Diaphragmatic paralysis is a rare cause of respiratory dysfunction, with a reported incidence of less than 0.05%. Unlike bilateral paralysis, unilateral diaphragmatic paralysis often has subtle symptoms, posing a diagnostic challenge despite its potential to significantly impair quality of life. While a chest x-ray may be suggestive of the diagnosis, confirmatory testing with fluoroscopic sniff testing is essential. This case underscores the importance of maintaining a broad differential diagnosis for dyspnea, particularly in young, otherwise healthy patients with nonspecific respiratory complaints. Early recognition of diaphragmatic paralysis can prevent unnecessary testing, expedite appropriate management, and improve patient outcomes. This abstract is funded by: None
Jamal et al. (Fri,) studied this question.