Extracorporeal membrane oxygenation to facilitate lung protective ventilation and prevent ventilator-induced lung injury in severe pneumocystis pneumonia with pneumomediastinum

摘要

Background: Pulmonary infections caused by Pneumocystis in immunocompromised host can be associated with cysts, pneumatoceles and air leaks that can progress to pneumomediastinum and pneumothoraces. In such cases, it can be challenging to maintain adequate gas exchange by mechanical ventilation and at the same time prevent further barotrauma or ventilator-induced lung injury (VILI). We report a young HIV positive male with poorly compliant lungs and pneumomediastinum secondary to severe Pneumocystis jirovecii infection, rescued with veno-venous extracorporeal membrane oxygenation (V-V ECMO). Case: 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 to reduce work of breathing. 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 and he developed severe type 2 respiratory failure necessitating rescue ECMO therapy. The introduction of V-V ECMO facilitated the use of ultra-lung protective 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 (HIV) infection. Patient was successfully treated with appropriate antibiotics 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.