Stress response always occurs in cardiac valve replacement patients undergoing cardiopulmonary bypass (CPB). Methods: 60 patients undergoing cardiac valve replacement were recruited and randomized into control and Dex groups. Dex group received μg·kg-1 of Dex for 10 min intravenously before anesthesia, followed by μg·kg1·h-1 of Dex, steadily administered throughout the procedure. |