A Volatilomics Approach for the Identification of Volatile Organic Compounds as Biomarkers of Ventilator-Associated Pneumonia Using GC–MS

Ventilator-associated pneumonia (VAP) is a common and serious complication of patients at intensive care units (ICUs), contributing to increased morbidity and mortality. Current diagnostic approaches for VAP rely on clinical, radiological, and invasive methods, which are time-consuming, carry risks, and may result in delayed or inconclusive findings. The need for rapid, reliable, and non-invasive diagnostic tools is critical. Biomarkers and specifically volatile organic compounds (VOCs) in exhaled breath have emerged as promising candidates for this purpose. In this study, we applied gas chromatography-mass spectrometry (GC-MS) with solid-phase microextraction (SPME) to analyze breath VOC profiles in critically ill children and explore their potential as early indicators of VAP. Results reveal significant challenges in breath volatilomics, including batch effects and variability in VOC detection. However, normalization strategies allowed for meaningful comparisons across multiple time points, revealing subtle trends in VOC profiles that could differentiate patients with high and low suspicion of VAP. Notably, VOCs such as octanol and benzyl alcohol showed reduced levels in patients with higher suspicion of VAP at Day 6, suggesting potential associations with respiratory infection severity. While preliminary, these findings support further investigation into breath-based VOC signatures as a non-invasive, early diagnostic tool for VAP in pediatric ICUs. This approach could enhance diagnostic accuracy and inform timely clinical decisions, improving patient outcomes.