Acute Kidney Injury in Children After Cardiopulmonary Bypass

Acute kidney injury (AKI) is a common complication in patients with congenital heart defects after cardiopulmonary bypass. The death rate from AKI in critically ill children remains high and reaches 60%.

The basic criteria for diagnosing and assessing the severity of kidney injury until recently were the level of serum creatinine and the amount of urine released. 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. The level of diuresis as well as the level of creatinine is a nonspecific criterion after cardiac surgery and depends on several factors.

Currently, in the field of acute renal injury studies, progress has been made in the emergence of new biomarkers such as the tissue inhibitor metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding globulin-7 (IGFBP7), which are early markers of acute renal damage. In a study in adult patients, it was shown that the levels of TIMP-2 and IGFBP7 increased In the first 24-48 before the diagnosis of IR-associated renal damage.

Among pediatric patients with congenital heart defects, such studies are single and only present for the age group 3 and older, which also demonstrated the high specificity and prognostic significance of these biomarkers in the early diagnosis of acute renal damage.

It should also be noted that, in spite of the high specificity of the markers described, it is also necessary to note their considerable cost.

Thus, taking into account the above, it is planned to compare and identify the relationship of these indicators with such parameter as the index of renal vascular resistance, the increase of which in the pre- and postoperative period may serve as a sign of the beginning acute renal injury.