Associations Between Complete Blood Count-Derived Inflammation Indices and Emergence Delirium in Children Undergoing Adenotonsillectomy

Background: Emergence delirium (ED) is a common postoperative complication in the pediatric population. Although the pathophysiology of ED has not been fully elucidated, an association has been suggested between inflammation and the development of the condition. Aims: The aim of this study was to investigate the associations between the development of ED and preoperative inflammatory indices, primarily the systemic immune inflammation index (SII) and the pan-immune inflammation value (PIV) calculated from complete blood count parameters in pediatric patients undergoing adenoidectomy or adenotonsillectomy. Methods: This prospective study was conducted with children aged 3–12 years who underwent adenoidectomy or adenotonsillectomy at our hospital. Preoperative inflammatory indices were calculated from complete blood count parameters, including the SII (platelet × neutrophil/lymphocyte), PIV (platelet × neutrophil × monocyte/lymphocyte), neutrophil-to-lymphocyte ratio (NLR), neutrophil-to-monocyte ratio (NMR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and platelet-to-monocyte ratio (PMR). ED was assessed using the Pediatric Anesthesia Emergence Delirium (PAED) scale, while the Face, Legs, Activity, Cry, Consolability (FLACC) scale was used to minimize confounding by postoperative pain. Statistical analyses included receiver operating characteristic (ROC) curve analysis and multivariable logistic regression to assess the association between inflammatory indices and emergence delirium. Results: ED occurred in 32 out of 99 patients (32.3%). SII exhibited an AUC of 0.850 with a cut-off value of 412 (sensitivity 81.3%; specificity 86.6%). PIV exhibited an area under the curve of 0.883, with a cut-off value of 289 (sensitivity 75.0%; specificity 92.5%). In the univariable analysis, operative time, SII, and PIV were significantly associated with ED. In the multivariable analysis, operative time, SII and PIV were significantly associated with ED. Conclusions: SII and PIV values derived from routine complete blood count parameters were observed to be associated with the development of ED in pediatric patients undergoing adenotonsillectomy and may provide useful insights into the potential role of systemic inflammation in the pathophysiology of such delirium. © 2026 John Wiley & Sons Ltd.