右美托咪定对老年人髋部手术后认知功能障碍的影响.

Objective To observe the effect of a variety dosage of dexmedetomidine on circulatory and cognitive functions in elderly patients who underwent hip orthopedic surgery. Methods A total of 120 patients who underwent hip orthopedic surgery, with age over 65 years old were recruited from 06/2013 to 09/2014 and were administered intravenously dexmedetomidine after epidural anesthesia. Based on the dosage of dexmedetomidine, patients were randomly divided into 3 groups with 40 cases in each group: Group A were given 0.2 μg·h-1·kg-1 dexmedetomidine; Group B were given dexmedetomidine 0.4 μg·h-1·kg-1, and group C were given 0.6 μg·h-1·kg-1. The heart rate (HR)，mean arterial pressure (MAP), and pulse oxygen saturation (SpO2) were recorded at 6 time points, including the time entering operating room (T0), 10 min (T1), 20 min (T2) after drug administration, the time of drug withdrawal (T3), 10 min after drug withdrawal (T4) and the terminal time of surgery (T5) respectively. Cognitive function was evaluated by mini-mental state examination (MMSE) at the time points of 24 hours before surgery (t1), 12 hours (t2), 24 hours (t3), and 72 hours (t4) after surgery. Results All 3 groups of patients show no significant differenceof MAP, HR and SpO2 at T0 (P > 0. 05)．A significant decrease in MAP and HR were observed in Group C at T2 and T3 time points compared to those in Group A or Group B (P < 0.05). There was no significant difference in MMSE at time point T1 among all three groups (P > 0.05). However, compared to that in group A or group C, MMSE increased significantly at time point T2, T3 in group B (P < 0.05). In addition, compared to group A or group C, the patients in group B exhibited lower incidence of postoperative cognitive function disorder (P < 0.05). Conclusion Continuous intravenous infusion of Dexmedetomidine can be used in elderly patient who underwent hip orthopedic surgery at the dose of 0.4 μg·h-1·kg-1 safely with little interference to circulatory and cognitive function in perioperative period. [ABSTRACT FROM AUTHOR]