Left ventricular regional wall motion and haemodynamic changes following bolus administration of pipecuronium or pancuronium to adult patients undergoing coronary artery bypass grafting

The objective of this study was to compare the haemodynamic and myocardial effects of pipecuronium and pancuronium in patients undergoing coronary artery bypass grafting (CABG) during benzodiazepine/sufentanil anaesthesia. Twenty-seven ASA III-IV patients received lorazepam (1-3 mg) po and midazolam ( < 0.1 mg.kg-1) i.v. before induction of anaesthesia with sufentanil (3-8 micrograms.kg-1) was administered to facilitate tracheal intubation. According to random allocation, each patient received either pipecuronium (150 micrograms.kg-1) or pancuronium (120 micrograms.kg-1) after sternotomy but before heparinization. Mean arterial pressure, central venous pressure (CVP), pulmonary artery pressure (PAP), ST segment position and ECG (leads III, V5, AVF) were monitored continuously throughout the procedure. Thermodilution determinations of CO in triplicate were made immediately before, and at two and five minutes after muscle relaxant administration. Multiplane transoesophageal echocardiography (TEE, midpapillary short axis views of the left ventricle) images were continuously recorded from ten minutes before until ten minutes after muscle relaxant administration and graded by two experienced echocardiographic readers. Heart rate, MAP and CO increased after administration of pancuronium (by 13.6 beats.min-1, 10.8 mmHg and 1.0 L.min-1 respectively) but not after pipecuronium (P < 0.05). Evidence of myocardial ischaemia was not detected in any patients using ECG ST segment analysis or TEE assessment of left ventricular wall motion. We conclude that pancuronium caused increases in HR, MAP and CO but that neither pancuronium nor pipecuronium caused myocardial ischaemia.