A combined parameter of changes in procalcitonin and C-reactive protein (CRP) in predicting the clinical outcome of severe pneumonia.

Background: Pneumonia is an infectious disease with high mortality rates despite early diagnosis and adequate treatment. Therefore, the use of biological infection parameters is expected to improve patients' clinical outcome prognostic accuracy. In this study, we proposed a combination of decreased procalcitonin (PCT) and C-reactive protein (CRP) to predict the clinical outcome of severe pneumonia. Methods: This was a prospective cohort study of severe pneumonia patients treated in the single-center Intensive Care Unit (ICU) of Dr. Soetomo General Hospital from December 2023 to February 2024. Subjects who met the inclusion and exclusion criteria were examined for PCT and CRP within the first 24 hours of admission and repeated 96 hours later (day five). Clinical outcomes, including acute respiratory distress syndrome (ARDS), acute kidney injury (AKI), septic shock, and 30-day mortality, were observed. Results: Thirty-five patients were enrolled for this study. Five subjects did not survive until the fifth day, and 30 subjects were eligible for analysis. A decrease of PCT >50% within five days was associated with a reduction of 30-day mortality (p=0.013) and septic shock incidence (p=0.005), whereas the decrease in CRP alone did not show any significant relationship towards any clinical outcome. The combination of a decreased PCT >50% and decreased CRP within five days could increase the prognostic specificity up to 88.9% in predicting 30-day mortality. Conclusion: Decreased PCT by more than 50% within 96 hours may predict the 30-day mortality rate and septic shock incidence in patients with severe pneumonia, while combining it with a decreased CRP expression would elevate prognostic specificity for severe pneumonia. [ABSTRACT FROM AUTHOR]