Higher serum procalcitonin and IL-6 levels predict worse diagnosis for acute respiratory distress syndrome patients with multiple organ dysfunction.

Aims: To study the clinical significance and prognostic value of monitoring procalcitonin (PCT) and interleukin 6 (IL-6) levels in acute respiratory distress syndrome (ARDS) patients with multiple organ dysfunction (MODS).

Methods: We enrolled 24 ARDS patients with MODS (ARDS+MODS group), 18 patients with ARDS but without MODS (ARDS group), and 55 patients with MODS but without ARDS as controls (control group). We detected the oxygenation index, serum PCT, IL-6, C-reactive protein (CRP) and white blood cell count (WBC) values of the patients after 1, 7, 14, 21 and 28 days of hospitalization in all three groups; we also analyzed the receiver operating characteristic (ROC) curves of PCT, CRP, WBC and (or) IL-6 in the patients in the ARDS+MODS group.

Results: The serum PCT and IL-6 levels in the ARDS+MODS group were significantly higher than those in the ARDS and MODS groups (P<0.01). The PCT and IL-6 levels increased with elevated ARDS illness severity (P<0.01); the sensitivity of PCT and IL-6 was high in all groups, but the specificity was low. Moreover, the PCT and IL-6 values were closely associated with patient survival. The lower PCT and IL-6 values indicated the higher survival rate. The PCT and IL-6 combined prophetic sensitivity of MODS complicated with ARDS area under the ROC curve was 0.911; thus, the index of PCT combined with IL-6 was the highest sensitive biological marker for the predicted occurrence of MODS with ARDS.

Conclusions: The serum PCT and IL-6 levels were significant for the diagnosis of ARDS patients with MODS, and the serum levels of PCT and IL-6 were associated with the severity of MODS with ARDS. Combined monitoring of PCT and IL-6 values and their dynamic changes is helpful for detecting the incidence of early ARDS in patients with MODS, and the index can predict whether ARDS will occur. The combined assessment of PCT and IL-6 can predict the prognosis of ARDS patients with MODS.