In experimental endotoxemia in healthy volunteers, IL-6 and IL-8 concentrations increased steeply within 1 to 2 h, resembling our findings.29,30 In a murine model of caecal ligation and puncture, IL-6 and IL- 8 increased more steadily and peaked at 16 h.31 We detected higher plasma IL-6 and IL-8 concentrations in the subgroup of patients presenting with the first OD median of 4 h before ICU admission than in patients with onset of OD on ICU admission. Here, IL6 is linked to serum lipopolysaccharide activity.