The effect of a single intravenous dose of metamizol 2 g, ketorolac 30 mg and propacetamol 1 g on haemodynamic parameters and postoperative pain after heart surgery

Although nonopiate analgesics may be particularly useful in the immediate p ostoperative period after major surgery, their use has been associated with haemodynamic adverse effects during postoperative pain treatment and in cr itically ill patients in intensive care. The effect of a single intravenous dose of metamizol (dipyrone) 2 g, ketorolac 30 mg and propacetamol 1 g on haemodynamic variables and pain control in the immediate postoperative peri od after heart surgery is compared. Seventy-two patients undergoing electiv e coronary and/or heart valve surgery, were included in a cohort study of 1 -years duration (1998). After weaning from mechanical ventilation and extub ation, haemodynamic variables and a 4-point verbal rating pain scale were a sseseed at base-line and 60 min after the administration of a single doses of metamizol, ketorolac or propacetamol. The Student's t-test for paired sa mples was used to compare changes produced by the study medications. A sign ificant, but small, decrease in radial artery blood pressure was observed i n all treatment groups which had little clinical relevance; no vasodilator effects were observed and ventricular function showed only minor changes: p ropacetamol decreased cardiac index by 10% and a 15% decrease in right vent ricular work was also observed. Metamizol and ketorolac produced a 10% decr ease in the left ventricular work index. Pain scores showed a statistically significant decrease in all treatment groups. The analgesic effects of met amizol, ketorolac and propacetamol were not associated with a clinically si gnificant impairment in haemodynamic function when administered to haemodyn amically stable patients.