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
Cardiac surgery involving cardiopulmonary bypass (CPB) is known to be associated with many major complications. A rare complication following a re-do mitral valve replacement (MVR) which turned out to be fatal is discussed.
ABSTRACT
Clonidine, a preferential alpha 2 adrenergic agonist has been reported to have perioperative effects including reduction of anaesthetic requirements, improving haemodynamic stability and providing analgesia, however its clinical usefulness in cardiac surgery is not widely studied. Thirty-four consecutive patients undergoing coronary artery bypass graft surgery (CABG) were preoperatively administered clonidine and studied for its possible desirable effects. Seventeen patients (Gr B) received 2 microg/kg clonidine orally the previous night and again one hour prior to surgery. Seventeen patients did not receive the drug and served as control (Gr A). Heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), requirement of isoflurane, requirement of nitroglycerin, sedation score, extubation score and urine output were studied throughout the perioperative period. HR was observed to be lower at all time points in the clonidine group though the difference between groups was not statistically significant (p > 0.1). MAP was higher at all time points and significantly so after intubaton in the control group (P < 0.01). Patients receiving clonidine required significantly less isoflurane and nitroglycerin (P < 0.05). sedation score was significantly higher in the clonidine group. Other aspects studied were comparable in both groups. At the doses described in this study, clonidine seems to be a safe useful adjunct to anaesthesia for CABG surgery.
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.