Effect of dexmedetomidine-induced anesthesia on the postoperative cognitive function of elder patients after laparoscopic ovarian cystectomy

OBJECTIVE: To investigate the effect of dexmedetomidine at maintenance dose on the postoperative function of elder patients after general anesthesia for laparoscopic ovarian cystectomy. METHODS: We enrolled a total of 96 elder patients who were admitted to this hospital for laparoscopic ovarian cystectomy under general anesthesia between March 2015 and March 2017, and divided them into two groups, Group A (n = 48) and B (n = 48). Patients in both groups received the same methods for anesthesia induction and maintenance drugs. At the beginning of operation, patients in Group A received the intravenous injection of dexmedetomidine (0.8 μg/kg) followed by maintenance dose [0.5 μg/(kg h)] to the end of operation, while those in Group B underwent intravenous injection of 0.9% normal saline at the same rate, during which blood pressure, heart rate, oxyhemoglobin saturation and dosage of anesthetics at T1 (5 min after being delivered into the operation room), T2 (immediately after anesthesia induction), T3 (immediately after intubation), T4 (immediately after operation), T5 (immediately after end of operation) and T6 (immediately after extubation). Then, the levels of NSE, IL-6, CRP and HMGB1 were compared between two groups at 24 h before the operation, at the end, 24 h, 3 d and 7 d after operation. Besides, we also compared the postoperative cognitive functions and incidence of adverse reactions at 1 d before, 1, 2, 3 and 7 d after operation through MOCA scales. RESULTS: At T3, T4 and T6, comparisons of the average arterial pressure and heart rate showed that the differences between the two groups had statistical significance (p < .05). At the end of operation, and at 24 h, 3 d and 7 d after operation, we found that the levels of IL-6 and CRP in patients of two groups were all significantly elevated when compared with those before operation; at the end of operation and at 24 h and 3 d after operation, the levels of IL-6 and CRP in the Group B were higher than those in the Group A, and the differences had statistical significance (p < .05). At the end of operation and at 24 h and 3 d after operation, the levels of NSE and HMGB1 in two group were higher than those before operation, and a more significant elevation was identified in Group B with statistically significant differences (p < .05); at 7 d after operation, a decreasing trend was found in the level of HMGB1, which, however, remained higher than the preoperative level, and the level in Group B was still higher than that in Group A with statistically significant differences (p < .05). At 2 d after operation, we found that the scores of MOCA in the Group B were remarkably decreased in comparison with the scores in Group A with a statistically significant difference (p < .05). Moreover, the incidence rate of postoperative cognitive dysfunction (POCD) in the Group A was significantly lower than that in the Group B, and the difference had statistical significance (p < .05). CONCLUSION: Dexmedetomidine can ameliorate the postoperative cognitive functions of elder patients who received the laparoscopic ovarian cystectomy under general anesthesia, and effectively decrease the incidence rate of POCD without any obvious or severe adverse reaction. Thus, it can serve as a kind of adjuvant drug for general anesthesia in clinical practice.