# Interleukin-6 to identify mildly injured patients in the trauma resuscitation room – a clinical feasibility study

## TL;DR

This study explores using interleukin-6 (IL-6) to distinguish between mildly and moderately injured trauma patients early in treatment, aiming to improve triage accuracy and resource use.

## Contribution

The study demonstrates that IL-6 can differentiate mild from moderate trauma patients early after admission.

## Key findings

- IL-6 levels significantly correlate with injury severity scores (ISS) in trauma patients.
- Moderately injured patients had higher IL-6 levels than mildly injured patients within the first 6 hours.
- An IL-6 cut-off of 2.9 pg/ml predicted moderate injuries with high sensitivity and negative predictive value.

## Abstract

Overtriage in the trauma resuscitation room (TRR) is often a consequence of admission based solely on trauma mechanism criteria. As interleukin-6 (IL-6) can assess injury severity in critically injured patients, the hypothesis of this study was that IL-6 can differentiate upon admission between mild (Injury Severity Score (ISS) 0–8) and moderate (ISS 9–15) trauma and that the parameter correlates with injury severity in lower injury severity groups (ISS < 16) during the first 24 h. Subsequently, we evaluated the ability to define IL-6 cut-off values with an adequate sensitivity, specificity, and negative predictive value to distinguish between moderate and mild injuries.

Fifty patients admitted to the TRR solely based on trauma mechanism criteria and with an ISS < 16 were included in the study. IL-6 was measured at admission, 1, 6, 12 and 24 h later.

Thirty-one patients were mildly injured (ISS 0–8), while nineteen patients sustained moderate injuries (ISS 9–15). IL-6 correlated significantly with ISS at all time points. Moderately injured patients showed significantly higher IL-6 levels than mildly injured patients during the first 6 h. IL-6 levels at admission predicted moderate injuries for the IL-6 cut-off value of 2.9pg/ml with a sensitivity of 0.933, specificity of 0.370 and a negative predictive value of 0.970 resulting in undertriage rates of 6.6% and overtriage rates of 54.8%.

The data of this feasibility study indicates that IL-6 has the potential to be employed in clinical workflows for early determination between patients with mild and moderate injuries, who are admitted to TRR based on trauma mechanism criteria to abort as early as possible TRR treatment and therefore free resources immediately while preserving patients’ safety.

The online version contains supplementary material available at 10.1007/s00068-026-03160-1.