Biomarkers in critical illness: have we made progress?

Biomarkers have emerged as exemplary key players in translational medicine. Many have been assessed for timely recognition, early treatment, and adequate follow-up for a variety of pathologies. Biomarker sensitivity has improved considerably over the last years but specificity remains poor, in particular when two "marker-sensitive" conditions overlap in one patient. Biomarker research holds an enormous potential for diagnostic and prognostic purposes in postoperative and critically ill patients who present varying degrees of inflammation, infection, and concomitant (sub)acute organ dysfunction or failure. Despite a remarkable progress in development and testing, biomarkers are not yet ready for routine use at the bedside.