Background Cardiac-surgery associated acute kidney injury (CSA-AKI) remains an important and frequent complication in patients undergoing cardiac surgery and is associated with a poor short- and long-term prognosis. The incidence for CSA-AKI according to Acute Kidney Injury Network criteria (AKIN) varies between 3% and 50%. CSA-AKI requiring temporary renal replacement therapy (RRT) occurs in 5% to 20% of these patients and is associated with a high mortality rate. Objective To detect the relation between prolonged cardiopulmonary bypass time in cardiac surgery and the incidence of post-operative acute kidney injury. Patients and Methods This is an observational retrospective study conducted on (80) adult patients who underwent elective cardiac surgery at Aswan Heart Centre (Magdi Yacoub Foundation) after the approval of the Ethical Medical Committee of Aswan Heart Centre. Results Results of the statistical analysis of the present study showed that mean CPB duration was prolonged in the AKI group of patients (155 min) than the non-AKI group of patients (129 min). Conclusion Prolonged cardiopulmonary bypass duration may be an independent risk factor for acute kidney injury post cardiac surgery in adult patients.

This prospective randomized clinical study was designed to assess and compare the use of combined antegrade-retrograde cardioplegia versus antegrade cardioplegia in providing adequate myocardial preservation during coronary artery bypass graft surgery. Fifty patients undergoing elective coronary artery bypass grafting were randomly divided into 2 groups according to the route of cardioplegic delivery: group A (25 patients) received antegrade cold crystalloid cardioplegia; group B (25 patients) received combined antegrade-retrograde cold crystalloid cardioplegia. The groups were compared by clinical and electrocardiographic criteria and biochemical markers of ischemic myocardial damage. There was a highly significant statistical difference between the groups in terms of spontaneous recovery of sinus rhythm (40% of patients in group A versus 96% in group B). The use of direct current shock to restore sinus rhythm was higher in group A (60%) compared with group B (4%). Low cardiac output occurred in 20% of patients in group A and in 16% of patients in group B but this difference was not statistically significant. No bundle-branch block was found in group B whereas the incidence was 8% in group A. Significantly higher levels of biochemical markers of myocardial damage were obtained in group A at 10 minutes, 4 hours, and 12 hours after declamping. These results indicate that combined antegrade-retrograde cardioplegia is superior to antegrade cardioplegia for myocardial protection during coronary artery bypass graft surgery.

To evaluate serum troponin T as a marker of perioperative myocardial infarction, 50 patients undergoing coronary artery bypass grafting were divided into 2 groups. Group A (14 patients) had serum creatine kinase MB-isoenzyme levels above 100 U·L -1 and electrocardiographic changes indicative of infarction. Group B (36 patients) had creatine kinase MB levels below 100 U·L -1 and no electrocardiographic changes. Blood samples were obtained preoperatively, 6 hours after aortic declamping, and on postoperative day 1, 2, and 3. Following surgery, all patients had increased levels of troponin T and creatine kinase MB. Troponin T was significantly higher in group A compared to group B at 6 hours, day 1, and day 2 postoperatively. Creatine kinase MB levels were significantly higher in group A compared to group B at 6 hours and day 1 postoperatively. The increased levels of troponin T in patients without myocardial infarction suggest that some operative myocardial damage occurred. Patients with perioperative myocardial infarction had significantly higher levels of troponin T up to postoperative day 2, whereas creatine kinase MB levels were almost normal by day 2. This suggests that troponin T may be used up to 2 days postoperatively for detection of myocardial infarction.