Diagnostic and Prognostic Value of Serum Procalcitonin in Pneumonia - A Prospective Observational Study

Abstract

Objectives: Community-acquired and nosocomial respiratory tract infections are public health problems of major concern and a leading cause of mortality. In the current prospective observational study, we intend to study the utility of procalcitonin (PCT) estimation in the diagnosis and prognosis of Community-acquired Pneumonia (CAP) and Ventilator-associated Pneumonia (VAP). Materials and Methods: The study was conducted over a period of two years. 40 patients with diagnosis of CAP and 40 patients of VAP were included in the study. Serum Procalcitonin levels were estimated using BRAHMS PCT Kryptor Immunofluorescent Assay (Biomerieux, France). Other routine investigations including sputum culture and endotracheal secretions cultures were done. Chi-square analysis was done to assess its prognostic and diagnostic significance. Results: PCT was positive (> 0.05ng/ml) in 68% patients with CAP and 80% patients with VAP. Higher absolute values of PCT were seen in patients with VAP compared to CAP. In VAP PCT was positive in more patients with bronchopneumonia than lobar pneumonia. Streptococcus pneumoniae was the most common bacterial etiology of CAP, and was associated with a positive PCT in 75% cases. Acinetobacter was the most common bacterial etiology of VAP, and was associated with a positive PCT in 80% cases. Mortality was more in PCT positive patients in both CAP and VAP. Maximum mortality in VAP was with PCT >10 ng/ml. Conclusion: PCT is a useful adjuvant in the diagnosis of both CAP and VAP. Positive PCT levels indicate a bacterial etiology for pneumonia. A high PCT level is a poor prognostic indicator and is associated with a higher mortality.