Effects of different doses of dexmedetomidine in patients undergoing heart valve replacement / 中国医师进修杂志

ABSTRACT

Objective:To investigate the effects of different doses of dexmedetomidine on intestinal mucosal barrier function, cognitive function and brain protection in patients undergoing heart valve replacement.Methods:The clinical data of 135 patients with heart valve replacement from April 2019 to April 2020 in the First Affiliated Hospital of Chengdu Medical College were retrospectively analyzed. Among them, 54 patients received low-dose of dexmedetomidine after induction of anesthesia (low-dose group), 38 patients received high-dose of dexmedetomidine (high-dose group), and 43 patients did not use dexmedetomidine (control group). Before surgery (T 1), 1 h after surgery (T 2), end of surgery (T 3) and 72 h after surgery (T 4), the levels of intestinal mucosal barrier function indexes D-lactate and diamine oxidase (DAO) were detected by spectrophotometry, the levels of brain injury indexes central nervous system specific protein (S100β) and neuron-specific enolase (NSE) were detected by double antibody sandwich enzyme-linked immunosorbent assay; before surgery and 3 d after surgery, the cognitive function was assessed by the mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) scale before and 3 days after surgery. Result:There was no statistical difference in T 1, T 2 and T 4 D-lactic acid among 3 groups ( P>0.05); the T 3 D-lactic acid in low-dose group was significantly lower than that in high-dose group and the control group (7.87 ± 1.59) mg/L vs. (8.99 ± 1.82) and (9.32 ± 1.74) mg/L, the high-dose group was significantly lower than the control group, and there were statistical differences ( P<0.05). There was no statistical difference in T 1 and T 2 DAO among 3 groups ( P>0.05); the T 3 and T 4 DAO in low-dose group was significantly lower than that in high-dose group and control group (2.77 ± 0.23) kU/L vs. (3.58 ± 0.25) and (4.30 ± 0.26) kU/L, (2.08 ± 0.25) kU/L vs. (2.40 ± 0.20) and (2.71 ± 0.23) kU/L, the high-dose group was significantly lower than the control group, and there were statistical differences ( P<0.05). There were no statistical differences in MMSE score and MoCA score before surgery among 3 groups ( P>0.05); the MMSE score and MoCA score 3 d after surgery in low-dose group were significantly higher than those in high-dose group and control group (22.76 ± 0.54) scores vs. (21.41 ± 0.47) and (20.21 ± 0.43) scores, (24.90 ± 0.51) scores vs. (24.01 ± 0.48) and (23.12 ± 0.49) scores, the high-dose group was significantly higher than the control group, and there were statistical differences ( P<0.05). There was no statistical difference in T 1, T 2 and T 4 S100β among 3 groups ( P>0.05); the T 3 S100β in low-dose group was significantly lower than that in high-dose group and control group (4.09 ± 2.01) μg/L vs. (5.48 ± 1.10) and (6.10 ± 1.58) μg/L, and there were statistical differences ( P<0.05). There was no statistical difference in T 1 and T 4 NSE among 3 groups ( P>0.05); the T 2 and T 3 NSE in low-dose group was significantly lower than that in high-dose group and control group (17.20 ± 4.13) μg/L vs. (20.29 ± 3.77) and (22.35 ± 3.80) μg/L, (19.40 ± 3.92) μg/L vs. (23.46 ± 5.26) and (25.18 ± 5.32) μg/L, and there were statistical differences ( P<0.05). Conclusions:Administration of 0.5 μg/(kg·h) dexmedetomidine during heart valve replacement under cardiopulmonary bypass can reduce intestinal mucosal damage, protect brain against injury in a certain degree, and improve cognitive function.