Intraoperative clonidine modulates sympathetic tone in the early postoperative period after remifentanil. A double blind, placebo-controlled study

Abstract Aim of the study : Severe pain following major surgery can impair the control of the cardiovascular system (CVS) by causing sympathetic stimulation, possibly leading to myocardial ischaemia. In this study we examine the influence of intraoperative intravenous (i.v.) clonidine infusion on postoperative analgesia and blood concentrations of noradrenaline and adrenaline after major gynaecological surgery. Methods : All patients underwent an abdominal hysterectomy under balanced general anaesthesia using the new opioid remifentanil. The patients were randomised to receive either 5 μg kg −1 of i.v. clonidine intraoperatively ( n =20), or placebo ( n =20). Over a period of 240 minutes po…