However, it should be noted that the level of serum creatinine, traditionally used to assess renal function, does not significantly increase until a decrease of more than 50% of the glomerular filtration rate, in addition, its level depends also on some extrarenal causes. Artificial blood circulation and hemodilution leads to the preservation of the level of creatinine at sufficiently low levels up to 1-3 days postoperative period (ParkM.,CocaS.G., 2010). The level of diuresis as well as the level of creatinine is a nonspecific criterion after cardiac surgery and depends on several factors.