Evaluation of the value of exhaled carbon monoxide in the differentiation of viral and bacterial pneumonia.

Aim: This study compared exhaled carbon monoxide (CO) levels in patients hospitalized for bacterial and COVID-19-related viral community-acquired pneumonia. Materials & methods: The study included a total of 150 patients: 50 patients hospitalized for COVID-19 between February 2021 and March 2022, 50 patients with bacterial community-acquired pneumonia and 50 healthy controls.

Results

In comparisons of exhaled CO levels among the groups, there was no significant difference between patients with bacterial pneumonia and controls, whereas patients with COVID-19 pneumonia had significantly higher exhaled CO levels compared with both the bacterial pneumonia and control groups (p < 0.001).

Conclusion

Viral agents can directly affect the heme oxygenase system of the lower respiratory tract, leading to greater increases in ferritin and exhaled CO levels compared with bacterial pneumonia.