Influence of ketanserin pretreatment on the haemodynamic responses to sternotomy

The effect of intravenous ketanserin on the pressor response to sternotomy was studied in 36 patients undergoing coronary artery surgery. Two doses of the drug (10 mg and 20 mg) were compared with a placebo injection of saline. After induction of anaesthesia, haemodynamic variables were measured until the institution of cardiopulmonary bypass. Plasma and platelet 5-hydroxyindoles and 5-hydroxytryptamine were measured in a subset of 13 patients. Ketanserin induced a dose-dependent amelioration of the pressor response to sternotomy. Plasma 5-hydroxyindoles and platelet 5-hydroxytryptamine levels did not correlate with clinical response. The increased effectiveness of the higher dose of ketanserin may be due to an effect other than serotonin antagonism.