ABSTRACT
The extracorporeal circulation used during open heart surgery is associated with a significant decline in renal blood flow that can result in tubular injury. Although this complication is uncommon, it carries a poor prognosis. Although many experimental trials have highlighted the significant value of some pharmaceuticals in prevention of post ischaemic renal tubular injuries, few clinical trials are found. We aimed in this study to evaluate the efficacy of 4 drugs in the prevention of acute tubular necrosis [ATN] following open heart surgery. Patients received either diltiazem, captopreil, allopurinol or the antioxidant formula antox [n = 20 per agent], 20 control cases received placebo. Groups were matched in age, gender, type of cardiac disease, preoperative cardiac and kidney function and type of surgery. AII patients received the appointed agent for 1- week pre- and post- operative. Each group included 6 cases that underwent coronary bypass, 8 value replacements or repair and 6 total correction of congenital defects. In order to ascertain risk factors each case underwent a comprehensive history taking, clinical examination, 12 lead ECG, chest X-ray, echocardiography, arterial blood gas analysis, complete blood count, fasting and 2 hours post prandial [PP] blood sugar, coagulation profile, liver function tests, blood urea nitrogen [BUN], serum creatinine [Sc], creatinine clearance [CC], urine analysis and urine albumin/creatinine ratio [Alb/cr]. The total operation, total pump and ischaemic times were recorded for each case intra-operative as well as the use of any inotropes, vasopressors or diuretics and the occurrence of haematuria or haemoglobinuria. AII kidney function tests were repeated on the 1st, 4th and 7th post operative days. AII groups showed a postoperative significant increase in BUN, Sc, and Alb/cr and a significant decrease in CC; these changes were least with diltiazem. A highly significant correlation between preoperative Alb/cr and postoperative Sc was found for the population as whole [p<0.001]. ATN occurred only in coronary artery bypass graft, aortic valve, multiple valve and total correction of Fallot's IV patients. The incidence of ATN, duration of oliguria and need for dialysis were least with diltiazem, [P=0.05]. No single mortality was reported in either the diltiazem or allopurinol groups. In conclusion, prophylactic administration of diltiazem, to high risk patients help reduce mortality, incidence and duration of ATN, the need for dialysis and costs of hospital stay, Allopurinol is a good alternative in patients with poor left ventricular function