ABSTRACT
We compared the effects of continuous intravenous infusions of nicorandil and diltiazem on left ventricular function, haemodynamics and as anti-ischaemic and anti-arrhythmic agents in 50 patients undergoing off pump coronary artery bypass surgery using arterial conduits. The patients were randomized into two equal groups to receive diltiazem or nicorandil. Both the drugs were given as a continuous infusion in the dose of 1microg/kg/min starting at induction and continued for 24 hours postoperatively. Haemodynamic parameters, cardiac enzyme levels and use of vasoactive agents were studied and compared using ANOVA, unpaired "t" and Fisher's exact tests. The two groups did not differ with respect to preoperative and operative data. Diltiazem group showed lower cardiac index (2.66+/-0.8 and 2.27+/-0.89 L/min/m2) as compared with nicorandil group (3.16+/-0.79 and 2.97+/-1.01 L/min/m2) during revascularisation of anterior (P=0.03) and inferior (P=0.01) circulation respectively. The systemic vascular resistance index was higher (2290+/-699 and 2545+/-911 dync.sec.cm-5.m2) in diltiazem group as compared with nicorandil group (1822+/-532 and 1877+/-548 dyne. sec.cm-5.m2) during revascularization of anterior (P=0.01) and inferior (P=0.002) circulation respectively. The mean pulmonary artery pressure was significantly higher in nicorandil group as compared with diltiazem group during revascularisation of anterior circulation (22.5+/-4.9 and 18.1+/-6.8 mmHg, P=0.01). The patients in the diltiazem group maintained a lower heart rate throughout the study period, but the difference was not statistically significant. None of the patients exhibited any arrhythmia except one in nicorandil group, who developed supraventricular arrhythmia 24 hours postoperatively. Cardiac enzyme levels were found to be similar in the two groups. The present study demonstrates that the anti-ischemic and antiarrythmic effects of diltiazem and nicorandil are comparable, but diltiazem causes a decrease in cardiac index and increase in systemic vascular resistance index during revascularization of anterior and inferior circulation.
ABSTRACT
The inflammatory response to major surgery, especially cardiac surgery using cardiopulmonary bypass (CPB) is now a well established entity. A whole body inflammatory response can lead to severe organ dysfunction, postoperative bleeding disorders, respiratory distress syndrome and sometimes death. There is, however, controversy over various methods and their efficacy towards suppression of this response. We studied forty consecutive patients undergoing coronary artery bypass grafting (CABG) using CPB. Ten patients in group A served as control while ten patients in group B received piroxicam, a non steroidal anti-inflammatory drug (NSAID). Ten patients in group C received aprotinin, a kallikrein inhibitor and ten patients in group D underwent haemofiltration during CPB. Inflammatory response by way of increase in total white blood cell (WBC) count (p<0.007), decrease in lymphocyte count (p<0.005), increase in C-reactive protein (CRP, p <0.005) was observed in all four groups at 24 hour after CPB. A decrease in complement C3 and C4 (p<0.01) was observed in groups A and C at 24 hours after CPB. The response observed was not severe enough to cause any organ damage in any group. None of the methods studied could effectively suppress the inflammatory response to CPB but the response was altered in some way by each method.