Effects of preoperative intravenous glutamine administration on cardiac and renal functions in patients undergoing mitral valve replacement surgeries: A randomized double-blind controlled trial

Background Preoperative poor nutrition greatly raises the risk of complications and increases length of stay (LOS). Glutamine deficiency may impair immune functions, reduce myocardial adenosine triphosphate-adenosine diphosphate (ATP-ADP) substrate and decrease myocardial glutathione level. We evaluated the effects of preoperative glutamine administration in patients undergoing mitral valve replacement surgery upon cardiac and renal outcomes or hospital/ICU LOS. Methods This prospective randomized double-blinded study included 60 patients above 18 up to 60 years undergoing mitral valve replacement. For 3 days preoperatively, Group N patients received glutamine intravenously 0.4 g/kg/day while Group C patients received intravenous normal saline as placebo. The primary outcome was to assess the effects of glutamine on cardiac function as reflected on proBNP (brain natriuretic peptide) during 4 postoperative days. Secondary outcomes included renal function, vasoactive inotropic score, duration of mechanical ventilation, and hospital/ICU stays. Results Postoperative proBNP was significantly lower in Group N during the entire period. It was significantly decreased on the first postoperative day in both groups in comparison to the preoperative values. No significant changes were recorded regarding renal functions, and duration of mechanical ventilation between groups. Also, there was signifiacant difference between the two studied groups regarding the vasoactive inotropic score at the 12th, 18th, 24th and 48th hours with lower scores in Group N. ICU and hospital stays were significantly lower in Group N than Group C. Conclusion Short term of preoperative intravenous glutamine 0.4 g/kg/day decreased the postoperative proBNP level and hospital/ICU stays in mitral valve replacement surgery. No significant implication was reported upon postoperative human NGAL level or kidney functions.