Background: It remains uncertain as to what impact cytokine expression level has on patient outcomes. The association of serum levels of interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-10, tumor necrosis factor-α (TNF-α), and procalcitonin with critically ill patient outcomes after major abdominal surgery still need to be explored.
Methods: From January 1, 2018 to June 30, 2019, a retrospective cohort study was conducted on patients admitted to the surgical intensive care unit (SICU). Levels of IL-1β, IL-2, IL-6, IL-8, IL-10, TNF-α, and procalcitonin were assessed in 1,228 patients undergoing major abdominal surgery with blood samples drawn within 24 h after surgery.
Results: Of the 1,228 patients admitted to the SICU for the first time, 1,152 survived and 76 patients died, with a mortality rate of 6.2% (76/1,228). The results of univariate and multivariate analyses revealed that non-survivors had higher levels of IL-1β (OR =2.438, P<0.001) and IL-2 (OR =1.561, P=0.006). Of 62 (5.0%) readmitted to the SICU, the data of 59 were collected, and showed 46 patients survived and 13 died, giving a mortality rate of 22.0% (13/59), which was 3.5 times higher than the mortality rate during the first SICU admission. Serum IL-6 level associated with SICU readmission (OR =1.37, P=0.029). Furthermore, non-survivors had a longer SICU stay and higher rates of mechanical ventilation and continuous renal replacement therapy (CRRT).
Conclusions: High levels of IL-1β and IL-2 were associated with mortality, and a high level of IL-6 was a risk factor for SICU readmission in critically ill patients who underwent major abdominal surgery. The mortality rate was higher during the second SICU stay.
Keywords: Cytokine level; critically ill patients; major abdominal surgery; mortality; surgical intensive care unit readmission (SICU readmission).