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A6678 - Spontaneous Pneumomediastinum (Hamman’s Syndrome): A Case Report
Author Block: Y. Eslaamizaad, M. Berrou, P. Almalouf; Pulmonary and Critical Care, University of South Alabama, Mobile, AL, United States.
Introduction:
Spontaneous pneumomediastinum is a rare condition defined by the presence of mediastinal free air in the absence of a precipitating cause. When presented with subcutaneous emphysema, it is known as Hamman’s syndrome. This condition was first described in a postpartum case and is most often reported as a result of excessive Valsalva maneuvers, persistent retching, coughing, straining and inhalational drug abuse. Although benign and self-limiting, due to its rarity and infrequent discussion within the literature, the diagnosis of Hamman’s syndrome can lead to unnecessary and expensive diagnostic and surgical procedures.
Case Report:
28-year-old Caucasian female presented to the emergency department with a two week history of chest pain exacerbated by deep inspiration and movement. Past medical history was significant for bipolar disorder, anxiety and migraines and patient had never had any history of asthma, tobacco abuse or alcohol. She denied any history of trau­ma, vomiting, foreign body ingestion, recreational drug use, smoke inhalation or prior history of similar episodes. Vital signs were only significant for a heart rate of 125 beats/minute and otherwise within normal limits. On physical examination she was found to have palpable subcu­taneous emphysema over the left upper extremity, and the rest of the exam was unremarkable. Routine laboratory evaluations including troponins were unremarkable. Drug screen was negative. Electrocardiogram demonstrated normal sinus tachycardia without any findings. A chest radiograph showed subcutaneous and intramuscular emphysema over the chest with no associated pneumothoroax. The chest CT scan confirmed extensive sub­cutaneous emphysema primarily involving the right pectoralis muscles and extending into bilateral arms and pneumomediastinum extending superiorly into the soft tissues of the neck. Bronchoscopy was performed for airway inspection and demonstrated no abnormal findings. Due to hemodynamic stability, patient was observed for 48 hours and discharged home. On clinic follow-up subsequent imaging demonstrated decrease in subcutaneous emphysema and decreased crepitus on exam.
Discussion:
Hamman’s syndrome is a rare condition known to be associated with transiently elevated intra-alveolar pressure. Our patient exhibited classic clinical and radiographic presentation. All possible causes were investigated and ruled out. It is possible that presentation is associated with anxiety disorder and primary hyperventilation syndrome. The majority of cases are typically benign, non-recurrent and managed with observation alone. Chest X-ray is the most important diagnostic test and the inclusion of Hamman’s syndrome as part of the differential of chest pain and subcutaneous emphysema avoids unnecessary procedures and treatment.