Abstract:Objective To explore the safety and effectiveness of extracorporeal membrane oxygenation（ECMO） in the rescue of critically ill patients with Chlamydia psittaci pneumonia. Methods The patients included in this study were 4 patients with critical Chlamydia psittaci pneumonia who received ECMO support treatment in the Emergency Department of Drum Tower Hospital from February 2018 to February 2022. General information and clinical data were collected and analyzed. Results There were three males and one female, with an average age of 61 years, had a history of close contact with birds or poultry. Metagenomic next-generation sequencing（mNGS） of alveolar lavage fluid was used to confirm Chlamydia psittaci infection. These patients had fever, progressive dyspnea and hypotension at onset. Laboratory examinations showed significant inflammatory reaction. Chest images showed lesions involving multiple lung lobes, accompanied by varying degrees of extrapulmonary organ dysfunction. All the patients met the ECMO application indications. Through artificial cardiopulmonary function support and proper drug application, the patients lung inflammation was absorbed and the function of extrapulmonary organs was recovered. Conclusion Application of ECMO in the rescue of critically ill patients with Chlamydia psittaci pneumonia is safe and effective. The role of ECMO in the treatment of multiple organ dysfunction caused by atypical pathogen infection deserves attention.