Clinical experience with fluoroquinolones for treatment of severe Chlamydia psittaci pneumonia with invasive mechanical ventilation in ICU: a retrospective study

Background In this study, we sought to investigate the clinical manifestations, laboratory findings and radiographic features of severe Chlamydia psittaci pneumonia requiring invasive mechanical ventilation in the intensive care unit (ICU), as well as evaluate the role of fluoroquinolones in its treatment. Methods We retrospectively reviewed the clinical data of 14 patients diagnosed with severe C. psittaci pneumonia at Zhejiang University School of Medicine, Sir Run Run Shaw Hospital from December 2018 to November 2022. We collected the clinical characteristics, laboratory examination results, imaging features, treatment and prognosis. We used the SPSS 26.0 software to perform statistical analysis. Results Most patients presented high fever (≥39 °C), shortness of breath and cough, as well as extrapulmonary symptoms such as fatigue, dizziness, muscle pain and headache. There were also significant increases in white blood cells, C-reactive protein (CRP), procalcitonin (PCT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and D-dimer, while lymphocytes decreased significantly. Primary chest imaging features included consolidation, exudation and pleural effusion. All 14 patients received fluoroquinolones-based treatment and recovered. Conclusion The clinical manifestations of severe C. psittaci pneumonia are nonspecific. Fluoroquinolones-based treatment may be effective in severe C. psittaci pneumonia with invasive mechanical ventilation in ICU. For severe cases of C. psittaci pneumonia, the treatment regimen may require an intravenous fluoroquinolone-based approach.