Effect of dexmedetomidine on postoperative cognitive function in patients with mild hyperbilirubinemia caused by choledocholithiasis

Abstract

Objective To evaluate the effect of dexmedetomidine on postoperative cognitive function in the patients with mild hyperbilirubinemia caused by choledocholithiasis. Methods One hundred and twenty patients of both sexes with mild hyperbilirubinemia (serum total bilirubin levels 21-170 μmol/L) caused by choledocholithiasis, aged 51-63 yr, with body mass index of 20-28 kg/m2, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, with preoperative Mini-Mental State Examination (MMSE) scores≥20, scheduled for elective cholecystectomy and choledocholithotomy, were divided into 3 groups (n=40 each) using a random number table method: control group (C group) and dexmedetomindine 0.4 μg·kg-1·h-1 group (D1 group) and dexmedetomindine 0.6 μg·kg-1·h-1 group (D2 group). After induction of anesthesia, dexmedetomidine was intravenously infused for 10 min in a loading dose of 0.5 μg/kg, followed by an infusion of 0.4 and 0.6 μg·kg-1·h-1 until the end of operation in D1 and D2 groups, respectively.The equal volume of normal saline was given instead in group C. with preoperative scores≥20, MMSE and Montreal Cognitive Assessment (MoCA) were used to assess the cognitive function at 1 day before operation (T0) and 1, 3, 5 and 7 days after operation (T1-4). The occurrence of cognitive dysfunction within 7 days after operation was recorded.Venous blood samples were collected at the time points mentioned above, and the plasma concentrations of β-amyloid (Aβ) 42 were determined by enzyme-linked immunosorbent assay. Results Compared with group C, MoCA scores were significantly increased at T1 in group D1, and MMSE scores at T1 and MoCA scores at T1 and T2 were significantly increased, and the plasma concentrations of Aβ42 were decreased at T2-4 in group D2, and the incidence of cognitive dysfunction was significantly decreased in D1 and D2 groups (P<0.05). Compared with group D1, MoCA scores were significantly increased at T1, and the plasma concentrations of Aβ42 were decreased at T2-4 in group D2 (P<0.05). Conclusion Dexmedetomidine can improve postoperative cognitive function, and intravenous infusion at a rate of 0.6 μg·kg-1 · h-1 provides better efficacy for the patients with mild hyperbilirubinemia caused by choledocholithiasis. Key words: Dexmedetomidine; Cognition disorders; Postoperative complications; Hyperbilirubinemia; Cholelithiasis