The effect of dexmedetomidine on the perioperative hemodynamics and postoperative cognitive function of elderly patients with hypertension: Study protocol for a randomized controlled trial

INTRODUCTION: Cognitive dysfunction after surgery, a common clinical manifestation of postoperative psychonosema. It usually occurs after heart surgery, hip replacement, mandibular fractures, and other major operations. Dexmedetomidine can exert sedative, analgesic, anxiolytic effect, inhibits the sympathetic activity, maintains hemodynamic balance, helps reduce the amount of anesthetic agents, and relatively slightly depresses respiration. Preoperative administration of dexmedetomidine for sedation has been reported to reduce the incidence of acute postoperative delirium. But currently there is no study on the effect of dexmedetomidine on the postoperative cognitive function of elderly patients with essential hypertension. METHODS/DESIGN: This study is a prospective, single-center, double-blind controlled clinical trial. Elderly patients aged between 60 and 80 years old, diagnosed with primary hypertension for 1 year or longer will be included, and randomized into 2 groups. Patients in observational group will be given a loading dose of dexmedetomidine at 0.8 μg/kg, pumped for over 10 minutes. Although patients in control group will be pumped of the same volume of normal saline within 10 minutes, before the induction of anesthesia. Minimental state examination and levels of interleukin-6, tumor necrosis factor alpha, and C-reactive protein will be set as primary endpoints. Baseline characteristics of patients will be summarized by groups and compared using Chi-square or Fisher exact tests for categorical variables and 2-sample t tests or Wilcoxon rank sum test for the continuous variables. Repeated measurement analysis of covariance model will also be used for the comparison of endpoints between 2 groups. CONCLUSION: The present study is designed to investigate the effect of the application of dexmedetomidine on postoperative myocardial injury and postoperative cognitive dysfunction, also to explore the association between inflammatory factors and postoperative cognitive function. With this study, we are expecting to find out an appropriate anesthesia method for elderly people with hypertension to alleviate the postoperative adverse effects caused by medical treatments. Trials registration: This study was registered on Chinese Clinical Trial Registry (http://www.chictr.org.cn/) with the ID ChiCTR-IPR-16009156.