Can Neutrophil-to-Lymphocyte Ratio, Platelet Volume, and Platelet Distribution Width Be Used as Indicators of Delirium?

<b>Background/Objectives:</b> Postoperative delirium is a frequent complication in children undergoing general anesthesia. It has been suggested that inflammation and oxidative stress contribute to the pathophysiology of delirium. The aim of our study was to investigate the relationship between inflammatory markers and delirium. <b>Methods:</b> A total of 221 children in the ASA 1-3 risk group who underwent adenoidectomy, tonsillectomy, and/or ventilation tube application were included in our single-center, prospective, and observational study approved by the Ethics Committee, numbered E1-23-3197. Patients whose parental consent was obtained were either premedicated with oral midazolam preoperatively or taken to surgery without premedication, depending on the anesthesiologist's preference. After induction with sevoflurane, rocuronium and fentanyl were administered intravenously. Sevoflurane and infusion of remifentanil were administered for maintenance. At the end of the operation, patients were transferred to the recovery unit and followed up for 30 min. They were evaluated with the Face, Legs, Activity, Cry, and Consolability (FLACC) Scale and Pediatric Anesthesia Emergence Delirium (PAED) Scale. <b>Results:</b> Delirium was observed in 80 patients. There was no significant difference between patients with and without delirium in terms of neutrophil/lymphocyte ratio, mean platelet volume, or platelet distribution volume. Lymphocyte count, PAED score, and FLACC score were statistically higher in patients with delirium (W = 4407.5, <i>p</i>-value = 0.006997; W = 0, <i>p</i>-value < 2.2 × 10^-16; W = 9489, <i>p</i>-value < 2.2 × 10^-16, respectively). <b>Conclusions:</b> No statistically significant relationship was found between hematologic inflammatory markers and delirium. Controlled studies with larger sample sizes are needed to determine whether these markers have strong predictive value.