C-reactive protein as a marker of ventilator-associated pneumonia resolution: a pilot study

Abstract

The aim of this study was to evaluate C-reactive protein (CRP) levels, body temperature and white cell count (WCC) after prescription of antibiotics in order to describe the clinical resolution of ventilator-associated pneumonia (VAP). A cohort of 47 VAP patients with microbiological confirmation of disease was assessed. CRP levels, body temperature and WCC were monitored daily. On day 4 of the antibiotic therapy, the CRP level of survivors was 0.62 times the initial value, whereas, in nonsurvivors, it was 0.98. Body temperature and WCC remained almost unchanged. By day 4, a CRP of >0.6 times the initial level was a marker of poor outcome (sensitivity 0.92; specificity 0.59). Patients were divided according to their CRP patterns of response to antibiotics: fast response, slow response, nonresponse, and biphasic response. All patients with fast and slow response patterns survived, whereas those showing nonresponse and a biphasic response pattern exhibited a mortality of 78 and 75%, respectively. The adequacy of the initial antibiotic therapy had a marked influence on the rate of CRP decrease, as well as on mortality. In conclusion, daily C-reactive protein measurements after antibiotic prescription were useful in the identification, as early as day 4, of ventilator-associated pneumonia patients with poor outcome. The identification of the pattern of C-reactive protein response to antibiotics was useful in the recognition of individual clinical course, improving or worsening, as well as of the rate of improvement.