Prevention of dexmedetomidine on postoperative delirium and early postoperative cognitive dysfunction in elderly patients undergoing hepatic lobectomy

Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common operative neurocognitive disorders, which places a heavy burden on patients, families and society. Therefore, it is very important to search for preventive drugs. Previous studies have demonstrated that perioperative use of dexmedetomidine resulted in a decrease the incidence of POD and POCD. But the specific effect of dexmedetomidine on elderly patients undergoing hepatic lobectomy and its potential mechanism are not clear. This study aims to evaluate the efficacy of intraoperative use of dexmedetomidine on preventing POD and POCD in elderly patients undergoing hepatic lobectomy and the influence on the balance between proinflammation and anti-inflammation. This trial was designed as a single-center, prospective, randomized, controlled study. One hundred and twenty hospitalized patients from January 2019 to December 2020, aged 60-80 years old with American Society of Anesthesiologists (ASA) II-III and scheduled for hepatic lobectomy, were randomly allocated into 3 groups ( =40) using a random number table: A C group, a Dex1 group, and a Dex2 group. After anesthesia induction, saline in the C group, dexmedetomidine [0.3 μg/(kg·h)] in the Dex1 group, and dexmedetomidine [0.6 μg/(kg·h)] in the Dex2 group were infused until the end of operation. The incidences of hypotension and bradycardia were compared among the 3 groups. Confusion Assessment Method (CAM) for assessing POD and Mini Mental State Examination (MMSE) for evaluating POCD were recorded and venous blood samples were obtained for the determination of neuron specific enolase (NSE), TNF-α, IL-1β, and IL-10 at the different time below: the time before anesthesia (T0), and the first day (T1), the third day (T2), the fifth day (T3), and the seventh day (T4) after operation. Compared with the C group, the incidences of bradycardia in the Dex1 group or the Dex2 group increased (both 0.05). The incidences of POD in the C group, the Dex1 group, and the Dex2 group were 22.5%, 5.0%, and 7.5%, respectively. The incidences of POD in the Dex1 group or the Dex2 group declined significantly as compared to the C group (both 0.05). The incidences of POCD in the C group, the Dex1 group, and the Dex2 group were 30.0%, 12.5%, and 10.0%