Serum IL-6 levels correlate with surgical stress factors in newborns with congenital diaphragmatic hernia

Abstract

Background: Peri-operative management in congenital diaphragmatic hernia (CDH) remains a significant challenge associated with mortality and morbidity. Although interleukin-6 (IL-6) reflects surgical stress in adults, its peri-operative dynamics in newborns remain unclear. This study investigated changes in IL-6 levels in CDH newborns and their association with surgical stress factors and post-operative complications.

Methods: In this single-center study, CDH newborns who underwent surgical repair between 2010 and 2022 were retrospectively studied. Changes in serum IL-6 and C-reactive protein (CRP) levels from 72-h pre-operatively to 96-h post-operatively were assessed. Correlations between peak peri-operative IL-6/CRP levels and surgical stress-related factors or early post-operative complications were also explored in this preliminary analysis.

Results: Of 49 newborns, 20 had available data to evaluate peri-operative IL-6 and CRP levels. Serum IL-6 peaked [median: 122.7 (62-1898) pg/mL] at 10-h (1-42) postoperatively, while CRP peaked [median: 2.40 (0.24-8.31) mg/dL] at 38-h (12-47). Peak IL-6 levels correlated negatively with postnatal time (r_s = -0.610) and positively with intra-operative blood loss and 24-h post-operative transfusion volumes (r_s = 0.497 and 0.510).

Conclusions: In CDH newborns, serum IL-6 levels increase during the 24-48-h post-operative period and return to baseline by the 48-72-h period. Although this is a preliminary study with a limited sample size, assessing peak IL-6 levels may provide a useful indicator of surgical stress and help optimize peri-operative management, including transfusion strategies.

Keywords: Bleeding; Cytokine; Inflammation; Surgery; Transfusion.