SPONTANEOUS PNEUMOMEDIASTINUM IN AN ADULT ASTHMATIC MALE

Abstract

SESSION TITLE: Medical Student/Resident Disorders of the Mediastinum Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pneumomediastinum is a condition usually caused by trauma where air escapes from the lung, airway, or bowel into the chest cavity. CASE PRESENTATION: A 29-year-old male with a history of asthma, active marijuana use, and prior incarceration presented with 4 days of productive cough, wheezing, and pleuritic chest pain. Prior to arrival, he had several consecutive episodes of clear emesis. He was febrile to 101°F and was breathing at 22 breaths/minute with mild accessory muscle usage. Bilateral diffuse rhonchi were noted on auscultation and palpation of his supraclavicular neck revealed crepitus. He had no preceding trauma. CXR displayed subcutaneous gas in the right supraclavicular region. Contrast CT imaging revealed extensive pneumomediastinum in the anterior neck (right>left) without any extravasation of oral contrast or esophageal perforation. There were findings of aspiration in the bilateral lower lobes. He was treated for aspiration pneumonia, asthma exacerbation, and spontaneous pneumomediastinum. An oral challenge was recommended by Thoracic Surgery. His respiratory status improved after antibiotics and nebulizer treatments. Though his crepitus persisted on exam, he tolerated a full diet well. He was discharged home with amoxicillin-clavulanic acid and nebulizers. A repeat CXR 5 days later revealed complete resolution of the pneumomediastinum and subcutaneous gas seen on the previous study. DISCUSSION: Spontaneous pneumomediastinum (SPM) is defined by the presence of air or gas in the mediastinum occurring without a traumatic cause. It is usually seen in young adolescent males, and is rarely seen in adults or children. Air from ruptured alveoli moves towards the mediastinum via the bronchovascular sheath. The most common causes are asthma exacerbation and lower respiratory tract infections, followed by Valsalva maneuvers and vomiting. A clinical triad of chest pain, dyspnea, and subcutaneous emphysema (present in this case) may be seen. Diagnosis is confirmed by chest radiography, and contrast esophagography is indicated when suspicion for esophageal rupture is present; it was necessary here given the patient’s clinical status and vomiting prior to arrival. The disease process is usually self-limited, and treatment aims at addressing underlying causes. The most likely triggers for this patient were asthma exacerbation, vomiting, and pneumonia; his marijuana use (found to be an underappreciated risk factor for developing SPM) may have also played a role. Rare, severe complications include tension pneumothorax/pneumomediastinum or pneumopericardium. CONCLUSIONS: SPM is a rare occurrence of air or gas in the mediastinum without a traumatic cause. The most common triggers are asthma exacerbation and pneumonia; marijuana use is an underappreciated risk factor. Treatment aims at addressing underlying causes. Reference #1: Johnson JN, Jones R, Wills BK. Spontaneous pneumomediastinum. West J Emerg Med 2008;9:217–8 Reference #2: Cicak B, Verona E, Mihatov-Stefanovic I, Vrsalovic R. Spontaneous pneumomediastinum in a healthy adolescent. Acta Clin Croat 2009;48:461–467 Reference #3: Weiss ZF, Gore S, Foderaro A. Pneumomediastinum in marijuana users: a retrospective review of 14 cases. BMJ Open Respir Res 2019 DISCLOSURES: No relevant relationships by Christopher Chu, source=Web Response no disclosure on file for MARUTI KUMARAN; No relevant relationships by Ali Noory, source=Web Response