Procalcitonin is a valuable prognostic marker in ARDS caused by community-acquired pneumonia

Background and objective: ARDS is life-threatening acute respiratory failure, and pneumonia is one of the most common causes of direct ARDS. Procalcitonin (PCT) has been evaluated for its utility in determining the aetiology of community-acquired pneumonia (CAP), choice of antibiotics and prediction of outcome. This study evaluated the role of PCT in predicting the outcome of patients with ARDS caused by severe CAP. Methods: This was a prospective observational study conducted from September 2002 to December 2003. The plasma PCT was analysed at baseline, 24 and 72 h after enrolment and measured by ELISA. Results: Of the 22 patients with ARDS caused by CAP and enrolled in the study, 17 (77.3%) were alive 14 days after admission and five (22.7%) had died. The survivors had lower APACHE II scores (22.2 +/- 4.6 vs 30.6 +/- 9.6, P = 0.031), pneumonia severity index (141.9 +/- 2.2 vs 195.6 +/- 23.8, P = 0.005) and lower plasma PCT at baseline (9.83 +/- 3.54 vs 106.70 +/- 67.86, P = 0.004), at 24 h (10.51 +/- 5.39 vs 81.32 +/- 57.68, P = 0.014) and at 72 h (2.03 +/- 0.76 vs 19.57 +/- 6.67, P = 0.005). Conclusion: PCT analysed within 72 h of the onset of ARDS predicted mortality of patients with ARDS caused by severe CAP.