Abstract
Summary
Several biomarkers have been studied as diagnostic tools in patients with ventilator-associated pneumonia (VAP) to assess prognosis, antimicrobial treatment response and duration.
Promising results for the diagnosis of VAP have been reported. However, these results need further validation by independent cohorts. Procalcitonin (PCT) appears to be of limited value, although most data have not been sufficiently controlled for potential confounders. Soluble triggering receptor, expressed on myeloid cells-1, could not be confirmed as a useful diagnostic tool. Overall, diagnostic data for biomarkers are impaired by the same limitations as all data on quantitative cultures of respiratory samples are, i.e. the lack of a gold standard for validation.
All investigated biomarkers differentiated survivors and nonsurvivors; however, predictions were limited by restricted patient numbers and unvalidated results.
Intervention studies using biomarker-based algorithms (particularly PCT) have been shown to safely and effectively reduce the duration of antimicrobial treatment. However, data are affected by obvious overtreatment practices in the control groups. Thus, the role of biomarkers, within simple and inexpensive clinical rules and algorithms, to shorten antimicrobial treatment needs defining.