Preoperative serum miR-431-5p as a predictive biomarker for perioperative respiratory adverse events in children undergoing general anesthesia.

Pediatric perioperative respiratory adverse events (PRAE) pose significant risks during general anesthesia. Reliable predictive biomarkers reflecting early airway vulnerability remain scarce. This study aimed to evaluate the predictive value of miR-431-5p for PRAE and explore its underlying cellular mechanisms. A retrospective cohort of 202 children undergoing general anesthesia with tracheal intubation was analyzed. Preoperative serum miR-431-5p levels were quantified, and correlations with clinical outcomes and inflammatory markers were evaluated. Additionally, an in vitro lipopolysaccharide (LPS)-induced alveolar epithelial cell (AEC-II) model was established to investigate the molecule's protective function. Preoperative serum miR-431-5p was significantly downregulated in PRAE-positive patients, demonstrating high diagnostic efficacy (AUC = 0.891). Reduced miR-431-5p expression emerged as an independent risk factor for PRAE and correlated negatively with peak airway pressure, postanesthesia care unit stay, and postoperative serum SP-D and IL-6 levels. In vitro, LPS stimulation suppressed miR-431-5p expression in AEC-II cells. Conversely, miR-431-5p overexpression effectively restored cellular viability and attenuated the hypersecretion of IL-6 and TNF-α. Preoperative miR-431-5p deficiency independently associated with the occurrence of PRAE in pediatric patients. The molecule appears to modulate alveolar epithelial cell viability and suppress inflammatory responses in vitro, suggesting its potential as a noninvasive. These findings are derived from a single-center cohort and in vitro experiments; multicenter validation is warranted before clinical application.