Analysis of postoperative cognitive dysfunction and influencing factors of dexmedetomidine anesthesia in elderly patients with colorectal cancer

Effect of dexmedetomidine-assisted general anesthesia on early postoperative cognitive dysfunctions in elderly patients with colorectal cancer was explored. In total, 140 patients with radical colorectal cancer under general anesthesia from March 2012 to June 2015 were enrolled in the Guizhou Provincial People's Hospital, including 80 patients in the dexmedetomidine group and 60 patients in the saline group. Surgery conditions were recorded, and the incidence of postoperative cognitive dysfunction (POCD) and cognitive function score (MMSE score) were compared between the two groups. Serum levels of S-100 beta protein (S-100 beta) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay. The anesthesia time and intraoperative blood loss in the experiment group were significantly lower than those in the control group (P<0.05). The MMSE scores of the two groups on the 1st and 3rd day after surgery were lower than those before surgery (P<0.05). The incidence rates of the experiment group were significantly lower than that of the control group (P<0.05). The levels of serum IL-6 and S-100 beta were increased on the 1st and 3rd day after surgery compared with those before surgery (P<0.05). The levels of serum IL-6 and S-100 beta in the control group were significantly higher than those in the experiment group on the 1st and 3rd day after surgery (P<0.05). Age, duration of anesthesia, intraoperative blood loss, expression of IL-6 and S-100 beta were the influencing factors of POCD. Age >= 70 years, anesthesia duration >= 3 h, intraoperative blood loss >= 350 ml, and high expression of IL-6 and S-100 beta was an important factor related to the occurrence (P<0.05). Dexmedetomidine can significantly improve postoperative cognitive dysfunction in elderly patients with colorectal cancer, and the occurrence of cognitive dysfunction can be affected by age, duration of anesthesia, intraoperative blood loss and the high expression of IL-6 and S-100 beta.