LAUSR

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Spontaneous pneumothorax, pneumomediastinum, and subcutaneous emphysema have been described as rare life-threatening complications of COVID-19. Reports of pneumoperitoneum or pneumoretroperitoneum are extremely rare. We present a patient with COVID-19 pneumonia who developed spontaneous pneumomediastinum and subcutaneous emphysema with subsequent progression to pneumoretroperitoneum, without evidence of pneumothorax. CASE PRESENTATION: A 61 year old man with HIV and Addison's disease presented to the emergency department with worsening dyspnea, cough, and diarrhea. On admission, his oxygen saturation was 80% on room air, and he had diffuse bilateral lung rhonchi. Nasopharyngeal swab was positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Chest x-ray showed bilateral interstitial opacities. He was treated with dexamethasone, remdesivir, enoxaparin and supplemental oxygen. On hospital day three, he developed worsening hypoxia with pO2 of 41mmHg on 15L non-rebreather oxygen. He was transferred to the intensive care unit (ICU) and placed on non-invasive positive pressure ventilation but was quickly weaned to high-flow oxygen. On hospital day 17, he developed worsening hypoxia and reported neck swelling and tenderness. Computed tomography (CT) of the neck and chest confirmed extensive subcutaneous emphysema and pneumomediastinum and diffuse granular lung opacities without any normally aerated lung parenchyma, without evidence of pneumothorax. He was placed on mechanical ventilation after failing non-invasive positive pressure ventilation. Despite supportive care and lung protective ventilation, he remained hypoxic with worsening subcutaneous emphysema. CT of the chest, abdomen and pelvis showed development of pneumoperitoneum and pneumoretroperitoneum. Due to the patient's refractory hypoxia with progression to multi-system organ failure, his family opted for compassionate extubation and he expired on hospital day 34. DISCUSSION: Common causes of pneumoretroperitoneum include perforated viscous or iatrogenic introduction of air. As this patient had neither surgical procedures or evidence of perforation, his pneumoretroperitoneum was likely due to prolonged positive end expiratory pressure (PEEP) in setting of acute respiratory distress syndrome due to COVID-19. Mechanical ventilation likely acted as a shearing force intensifying air leak into the mediastinum which tracked inferiorly into the retroperitoneum. CONCLUSIONS: In conclusion, pneumomediastinum is a possible complication of COVID-19 pneumonia that can progress to pneumoretroperitoneum despite lung protective ventilation causing acute decompensation that can worsen patient prognosis. REFERENCE #1: Salehi, S., Abedi, A., Balakrishnan, S., & Gholamrezanezhad, A. (2020). Coronavirus Disease 2019 (COVID-19): A Systematic Review of Imaging Findings in 919 Patients. AJR. American journal of roentgenology, 215(1), 87–93. https://doi.org/10.2214/AJR.20.23034Zhou, C., Gao, C., Xie, Y., & Xu, M. (2020). COVID-19 with spontaneous pneumomediastinum. The Lancet. Infectious diseases, 20(4), 510. https://doi.org/10.1016/S1473-3099(20)30156-0 REFERENCE #2: Ahmed, A., Mohamed, M., & Ahmed, K. (2021). Severe COVID-19 Pneumonia Complicated by Pneumothorax, Pneumomediastinum, and Pneumoperitoneum. The American journal of tropical medicine and hygiene, tpmd210092. Advance online publication. https://doi.org/10.4269/ajtmh.21-0092Hillman K. M. (1983). Pneumoretroperitoneum. Anaesthesia, 38(2), 136–139. https://doi.org/10.1111/j.1365-2044.1983.tb13932. REFERENCE #3: Okamoto, A., Nakao, A., Matsuda, K., Yamada, T., Osako, T., Sakata, H., Yamaguchi, Y., Terashima, M., Iwano, J., & Kotani, J. (2014). Non-surgical pneumoperitoneum associated with mechanical ventilation. Acute medicine & surgery, 1(4), 254–255. https://doi.org/10.1002/ams2.52 DISCLOSURES: No relevant relationships by Christopher Ignatz, source=Web Response No relevant relationships by Bao Nhi Nguyen, source=Web Res onse No relevant relationships by Navitha Ramesh, source=Web Response