Does carotid sinus baroreceptor dysfunction increase vasopressor drug requirements after combined carotid and coronary artery surgery?

Abstract

undergoing combined carotid and coronary artery surgery (group I) were matched according to sex, age, left ventricle ejection fraction, and number of grafted coronary artery vessels with 25 patients undergoing elective coronary artery surgery (group II). Anesthesia management, surgical and cardiopulmonary bypass techniques, and postoperative care protocols were identical in all patients. Medical records were reviewed for demographic characteristics, risk factors, preoperative medical treatments, and surgical data. Hemodynamic parameters and vasopressor drug requirements during the first 24 hours in the intensive care unit also were assessed. Patients who presented with postoperative acute ventricular failure, cardiac tamponade, or major surgical bleeding were excluded. Student’st-test and Fisher’s exact test were used for statistical analysis; p 0.05 was considered to be significant. Demographic, medical, and surgical characteristics were identical in the 2 groups of patients. The lowest cardiac index, heart rate, mean arterial pressure, and systemic vascular resistance recorded in the intensive care unit and the frequency of vasopressor drug use are presented in Table 1. There was no statistically significant difference between the 2 groups regarding postoperative vasopressor drug requirements and hemodynamic parameters. In conclusion, vasopressor drug requirements were not increased after concomitant carotid and coronary artery surgery compared with isolated coronary artery surgery. Excessive carotid sinus responses may have been blunted by the increased arterial vasoconstriction after coronary artery bypass graft surgery. 2 This vasoconstriction is multifactorial, including responses to decreasing anesthetic levels increases in endogenous catecholamines, activation of the renin-angiotensin system, neural coronary and great vessel reflexes, and hypothermia. 3 Prospective studies are needed to assess the impact of carotid baroreceptor impairment on blood pressure autoregulation after combined carotid and coronary artery surgery.