Effects of vasodilator and esmolol-induced hemodynamic stability on early  post-operative cognitive dysfunction in elderly patients: a randomized trial.

Sheng-Hui Sun, Lin Yang, De-Feng Sun, Yue Wu, Jun Han, Ruo-Chuan Liu, Li-Jie Wang
1. Class twelve Grade two, The Middle School Attached to Liaoning Normal University, Dalian, Liaoning, China
2. Department of Nerve Electroneurophysiology, The First Affiliated Hospital of Dalian Medical University, Dalian,
Liaoning, China
3. Department of Anesthesiology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China

Abstract
Objective:To investigate the effect of continuous intravenous injection of nicardipine and/or nitroglycerin with or without  esmolol on the occurrence of early post-operative cognitive dysfunction (POCD) in elderly patients.

Methods: Elderly patients (n=340) who underwent radiofrequency ablation for atrial fibrillation were randomized into five  groups: A, nicardipine; B nicardipine+esmolol; C, (nitroglycerin) group; D nitroglycerin+esmolol; E (control) groups. The hemodynamic parameters were recorded, and Mini Mental State Examination was used to assess cognitive function.

Results: At 30 min and 60 minutes after anesthesia and at the conclusion of surgery, the rate pressure product value was  significantly lower in Groups B (10621.1±321.7, 10544.2±321.8, and 10701.3±325.5, respectively) and D (10807.4±351.1,  10784.3±360.3, and 10771.7±345.7, respectively) than in Group E (13217.1±377.6, 13203.5±357.3, and 13119.2±379.5, respectively). The heart rate was significantly higher in Groups A (104.1±10.3, 104.9±11.1, and 103.9±11.8, respectively) and C  (103.7±11.3, 105.5±10.5, and 107.7±11.7, respectively) than in Group E (89.3±12.0, 88.5±11.5, and 85.5±11.6, respectively).

The incidence of POCD was significantly lower in Groups A and B than in Groups C, D, and E. Univariate regression analysis  showed that regimens in Groups A, B, and E and doses of propofol and fentanyl were risk factors for POCD. Multivariate logistic regression analysis revealed significant associations between the incidence of POCD and interventions in Groups A and B.

Conclusion: Maintenance of stable intraoperative hemodynamics using nicardipine and nitroglycerin or their combinations  with esmolol, especially nicardipine with esmolol, reduced the incidence of POCD in the elderly with potential cardiovascular
diseases.

Keywords: Nicardipine, esmolol, nitroglycerin, hemodynamics, post-operative cognitive dysfunction.