Evolution and significance of circulating procalcitonin levels compared with IL-6, TNFα and endotoxin levels early after thermal injury

To determine the evolution and significance of circulating procalcitonin (ProCT), IL-6, TNFα and endotoxin levels early after thermal injury, we performed a prospective, single unit, longitudinal study. Forty burn patients with total body surface area (TBSA) >30 per cent were studied, of whom 33 suffered an inhalation injury. Blood samples were taken on the day of admission, every 4 h during the first day and daily during the first week. All patients had increased ProCT and IL-6 levels without any proven infection. Endotoxin and TNFα levels remained very low or undetectable. ProCT and IL-6 levels correlated well with the severity of skin burn injury (respectively, p<0.006 and p<0.028, using the non-parametric Kruskal-Wallis test). ProCT levels are not associated with smoke inhalation. ProCT and IL6 are prognostic factors of mortality at the time of admission but less reliable than the clinical UBS (unit burn standard) score. Endotoxin and TNFα were undetectable, suggesting that the problem of the early gut bacterial translocation remains to be proven.