Effect of dexmedetomidine on development of perioperative cardiovascular events in elderly patients

Objective To evaluate the effects of dexmedetomidine on the development of perioperative cardiovascular events in elderly patients. Methods Forty-eight patients of both sexes, aged 65-85 yr, with body mass index of 19.5-25.3 kg/m2, of American Society Anesthesiologists physical status Ⅱ or Ⅲ, scheduled for elective abdominal or lower limb surgery under general anesthesia, were divided into 2 groups(n=24 each)using a random number table: general anesthesia group(group G)and dexmedetomidine plus general anesthesia group(group D). In group D, dexmedetomidine was intravenously infused in a loading dose of 0.25 μg/kg over 10 min and then continuously infused at 0.2 μg·kg-1·h-1 until 30 min before the end of surgery.The equal volume of normal saline was intravenously infused instead in group G. At 1 day before surgery and 1 and 2 days after surgery, dynamic electrocardiogram was used to monitor heart rate variability including standard deviation of normal-to-normal intervals, standard deviation of the average 5-min normal-to-normal intervals, and root of the mean of the sum of the squares of differences between adjacent normal-to-normal intervals.The development of intraoperative cardiovascular events and requirement for vasoactive drugs were recorded, and the development of cardiovascular events within 2 days after surgery was also recorded. Results Compared with group G, standard deviation of normal-to-normal intervals and standard deviation of the average 5-min normal-to-normal intervals at 1 and 2 days after surgery and root of the mean of the sum of the squares of differences between adjacent normal-to-normal intervals at 2 days after surgery were significantly increased, the total incidence of intraoperative cardiovascular events and requirement for vasoactive drugs were decreased, and the total incidence of cardiovascular events within 2 days after surgery was decreased in group D(P <0.05). Conclusion Dexmedetomidine can reduce the development of perioperative cardiovascular events in elderly patients. Key words: Dexmedetomidine; Aged; Intraoperative complications; Postoperative complications