Markers of Inflammation


Plasma IL-6 concentrations have been directly correlated with risk of death in intra-abdominal sepsis, and measurements of this single variable predicted outcome in these cases with remarkable (82.9%) accuracy [Br J Surg 81: 1306, 1994]. Plasma IL-6 concentrations have been found to be 69% (95% confidence interval 30–108%) higher in nonsurvivors compared with survivors with sepsis [Ann Intern Med 119: 771, 1993]. Numerous studies have shown an association between mean plasma IL-6 concentrations over time and mortality rate [Crit Care Med 23: 376, 1995]

C-Reactive Protein


Initially much enthusiasm surrounded use of procalcitonin, which was thought to help clinicians discriminate between infectious and non-infectious sources of inflammation / SIRS. This enthusiasm was tempered by the Procalcitonin And Survival Study (PASS) Group, who conducted by far the largest study on the topic. The results of this randomized controlled trial (conducted in nine ICUs including 1200 patients) suggested that incorporation of procalcitonin into antimicrobial escalation strategies as associated with increased ICU length of stay as well as significant increases in morbidity [Jensen JU et al. Crit Care Med 39: 2048, 2011]