Serum levels of interleukin-6, interleukin-8, interleukin-10, and tumor necrosis factor-α, renal function biochemical parameters and clinical outcomes in pediatric cardiopulmonary bypass surgery

Abstract

Background: Cardiopulmonary bypass causes detrimental effects on remote organs due to inflammatory response. One of these organs is kidney that is frequently affected by cardiac surgery. Acute kidney injury is a post-cardiopulmonary bypass complication, which may result in increased post-operative morbidity and mortality. Post-cardiopulmonary bypass inflammatory response may contribute to remote organ dysfunction. In the present study, we investigated the relation between cytokines including interleukin-6, interleukin-8, interleukin-10, and tumor necrosis factor-α, and renal function tests such as creatinine and blood urea nitrogen (BUN).

Methods: In total, 91 patients between the ages of 4 and 60 months were enrolled for elective cardiac surgery with cardiopulmonary bypass after informed consent. Data regarding renal function tests and clinical outcomes were carefully recorded until 24 hours after admission to intensive care unit and analyzed.

Results: Our findings support that there is a direct correlation between cytokines including interleukin-6, interleukin-8, interleukin-10, and tumor necrosis factor-α and cardiopulmonary bypass time, duration of operation, and intensive care unit stay. Longer cardiopulmonary bypass time was associated with higher interleukin-8 at cross-clamp removal and 24 hours post- intensive care unit as well as higher interleukin-10 at declamp time. Higher interleukin-6 at declamp time was directly correlated with higher post-operative BUN. Interleukin-8 level after anesthesia induction was directly correlated with intensive care unit stay duration. Higher blood interleukin-6 and tumor necrosis factor-α levels following 24 hours of admission to intensive care unit were associated with longer mechanical ventilation time.

Conclusion: Higher circulatory pro-inflammatory cytokine level is associated with adverse outcomes such as increased intensive care unit stay and longer mechanical ventilation time in pediatric patients. It is also correlated with unfavorable biochemical parameter of renal function, BUN. Findings hint that proper control of the inflammatory response is vital for the control of unfavorable clinical and pathological outcomes.

Keywords: acute kidney injury; cardiac surgery with cardiopulmonary bypass; inflammatory cytokines; outcomes.