Evaluation of the effectiveness of glutamine in different times of administration in patients undergoing cardiopulmonary bypass during elective cardiac surgeries: randomized controlled study

Abstract

Background Although glutamine (GLN) is considered one of the pharmacological preconditioning proteins in cardiac surgeries, there is no consensus in literatures regarding the ideal time of administration. This randomized, double-blinded comparative study compared the effectiveness of GLN administration at two different time points in patients undergoing cardiopulmonary bypass.Patients and methods A total of 75 patients were randomly distributed into three equal groups: group 1 received GLN for 3 days preoperatively, group 2 received GLN at the day of surgery starting at the induction of anesthesia, whereas group 3, the control group, did not receive GLN.Primary outcome included troponin I and creatine kinase-MB measured at 30 min, 6 h, 24 h, and 48 h after cardiopulmonary bypass (CPB). Secondary outcome included postbypass heart rate, blood pressure, ejection fraction by transesophageal echocardiography, systemic vascular resistance, ventilation time, incidence of arrhythmia and inotrope use, ICU and hospital stay, and mortality rate. The data were analyzed using statistical package for the social sciences (SPSS version 17), including χ2-test for qualitative variables and analysis of variance test for quantitative variables. P value of less than 0.05 was considered statistically significant.Results There was a significant decrease in troponin I at 6, 24, and 48 h (P=0.03, 0.02, and 0.04, respectively), creatine kinase-MB at 24 and 48 h (P=0.04 and 0.04, respectively), incidence of inotrope usage (P=0.019), incidence of arrhythmias (P=0.02), and ICU stay (P=0.04), whereas significant increase in ejection fraction and blood pressure in GLN-treated groups (groups 1 and 2). The time of administration did not significantly affect the results between group 1 and group 2.Conclusion GLN enhances myocardial protection. The time of administration did not significantly affect the results, so administration at induction of anesthesia is well tolerated and feasible.