Extra corporeal membrane oxygenation to facilitate lung protective ventilation and prevent ventilator-induced lung injury in severe Pneumocystis pneumonia with pneumomediastinum: a case report and short literature review

Abstract

Background: Pulmonary infections caused by Pneumocystis jirovecii in immunocompromised host can be associated with cysts, pneumatoceles and air leaks that can progress to pneumomediastinum and pneumothoraxes. In such cases, it can be challenging to maintain adequate gas exchange by conventional mechanical ventilation and at the same time prevent further ventilator-induced lung injury. We report a young HIV positive male with poorly compliant lungs and pneumomediastinum secondary to severe Pneumocystis infection, rescued with veno-venous extra corporeal membrane oxygenation (V-V ECMO).

Case presentation: A 26 year old male with no significant past medical history was admitted with fever, cough and shortness of breath. He initially required non-invasive ventilation for respiratory failure. However, his respiratory function progressively deteriorated due to increasing pulmonary infiltrates and development of pneumomediastinum, eventually requiring endotracheal intubation and invasive ventilation. Despite attempts at optimizing gas exchange by ventilatory maneuvers, patients' pulmonary parameters worsened necessitating rescue ECMO therapy. The introduction of V-V ECMO facilitated the use of ultra-protective lung ventilation and prevented progression of pneumomediastinum, maintaining optimal gas exchange. It allowed time for the antibiotics to show effect and pulmonary parenchyma to heal. Further diagnostic workup revealed Pneumocystis jirovecii as the causative organism for pneumonia and serology confirmed Human Immunodeficiency Virus infection. Patient was successfully treated with appropriate antimicrobials and de-cannulated after six days of ECMO support.

Conclusion: ECMO was an effective salvage therapy in HIV positive patient with an otherwise fatal respiratory failure due to Pneumocystis pneumonia and air leak syndrome.

Keywords: Extra corporeal membrane oxygenation; Human immunodeficiency virus; Pneumocystis jirovecii pneumonia; Pneumomediastinum.

Fig. 1

Chest x-ray of patient. a On admission: Bilateral middle and lower zone air space opacities with air bronchograms; b After application of non-invasive ventilation: Subcutaneous emphysema around neck and axillary region, hyper-lucency around mediastinal structures suggestive of pneumomediastinum and bilateral pulmonary infiltrates. c Post endotracheal intubation and ECMO cannulation

Fig. 2

CT scan of patient. a At the level of arch of aorta. b Lung bases. Shows bilateral diffuse ground glass opacity with extensive basal consolidation. Pneumomediastinum: air in the anterior and superior mediastinum