Plasma interleukin-6 is a potential predictive biomarker for postoperative delirium among acute type a aortic dissection patients treated with open surgical repair

Objectives The relationship between inflammatory cytokines and postoperative delirium (POD) remains to be further investigated, especially in patients undergoing acute type A aortic dissection (AAD). Interleukin-6 (IL-6) is involved in the inflammatory process and has recently been identified as a biomarker of cerebral dysfunction. We explored the hypothesis that IL-6 was one of the critical causes of POD after surgical repair of AAD. Methods Plasma IL-6 was measured using electrochemiluminescence technology in patients preoperatively and 24 h, 48 h, and 72 h after surgical repair of acute type A aortic dissection. After the first three postoperative days, delirium was evaluated twice daily using the Confusion Assessment Method. ROC curves were used to evaluate the ability of IL-6 measurements to distinguish POD. Results The incidence of POD was 14.03% (31 of 221 patients). The patients in the POD group were significantly older than the patients in the non-POD group (56.48 [+ or -] 11.68 years vs 52.22 [+ or -] 10.50 years, P = 0.040). Plasma IL-6 concentrations were significantly higher in the POD group than in the non-POD group at three time points: preoperatively, after 24 h, and after 48 h. The AUC values corresponding to IL-6 preoperatively and 24 h after surgery were 0.73 and 0.72, respectively. Conclusions Cerebral dysfunction after the surgical repair of AAD shows elevated stress levels and inflammatory responses. Plasma IL-6 is a potential biomarker to predict the onset of POD in acute type A aortic dissection patients following surgical repair. Keywords: Aortic dissection, Postoperative delirium, Interleukin-6, Inflammatory cytokines