The Macklin Effect in Recurrent Spontaneous Pneumomediastinum in Systemic Lupus Erythematosus & COVID19

S. Soniwala^a (Dr), C. Fernandez^a (Dr), Y. Perry^a (Dr), J. Lang^b (Dr), S. Saha*^a (Dr)

^a University of Buffalo: School of Medicine, Buffalo, UNITED STATES ; ^b Buffalo General Hospital, Buffalo, UNITED STATES

* sandipsa@buffalo.edu

Background

Spontaneous pneumomediastinum (SPM) is defined as the presence of free air in the mediastinum, with no clear traumatic etiology. Interestingly found in 1% of Covid related cases (Chen et al 2020). The Macklin effect, described in 1939, refers to centripetal alveolar rupture causing free air to track along the bronchovascular sheaths towards the hilum of the lung and into the mediastinum (Murayama 2014). With SPM seen in the setting of COVID, there are a few case reports correlated to immunosuppression. We describe the first case of the Macklin effect in a patient with systemic lupus erythematosus (SLE) and prior COVID.

Case report

A 38 year-old male with a history of SLE and COVID-19 was admitted for respiratory failure. CT imaging showed pneumomediastinum with subcutaneous emphysema tracking up to the orbital regions. The patient was discharged on steroids and antibiotics, and improved briefly. After 1 month, he returned with worsening dyspnea, cough, and pneumomediastinum. EGD was unremarkable for an esophageal perforation. Bronchoscopy revealed severe tracheomalacia, but no airway defects. Bronchoscopic cultures were positive for MSSA, and he was started on broad spectrum antibiotics given the dense bilateral pulmonary infiltrates. Repeat CT imaging was significant for developing bilateral pneumothoraces and air migrating along the broncho-vascular bundles around both hila, with air tracking into the mediastinum. The patient eventually developed a large left pneumothorax, requiring chest tube placement, and eventual intubation with low tidal volume, low PEEP, and high FiO2.

Conclusion

This case illustrates the importance of being aware of complications such as SPM in post covid patients, who are immunocompromised, particularly with SLE. Complications can range from benign, such as pneumorrhachis, to severe respiratory failure (Murayama 2014). As the Macklin effect is not commonly identified, this is a case to bring to the forefront of our clinical minds.

Disclosure of funding source(s): none