2026 Poster Presentations
P171: POSTOPERATIVE AMINO ACID PROFILE AND INFLAMMATORY MARKER CHANGES IN MEDULLA OBLONGATA TUMOR PATIENTS: PATTERNS AND RESPONSE TO ARGININE SUPPLEMENTATION
Liang Wang1; Ziqi Liu1; Hongyi Wang2; Guanghui Zheng1; Shuqing Yu1; Zhen Wu1; Junting Zhang1; Guojun Zhang1; Yanlin Yang1; 1Beijing Tiantan Hospital Affiliated to Capital Medical University; 2Shanghai Deji Hospital, Qingdao University
Background: Patients undergoing medulla oblongata tumor resection frequently exhibit alterations in amino acid metabolism and inflammatory activation. This study aimed to systematically characterize these changes during the 72-hour postoperative period and evaluate the influence of exogenous arginine supplementation on amino acid profiles and inflammatory markers.
Methods: 30 enrolled patients were randomly assigned to either arginine intervention (Arg) group or negative control (NC) group in a 1:1 ratio, with interventions administered at 8h and 48h after surgery. Peripheral venous blood samples at five perioperative time points (T1, after anesthesia induction; T2, immediately after surgery; T3, 8 hours after surgery; T4, 48 hours after surgery; T5, 72 hours after surgery), as well as their medical records were collected. High-performance liquid chromatography-tandem mass spectrometry was utilized to detect 20 amino acid concentrations. Enzyme-linked immunosorbent assay (ELISA) kits were used to measure three cytokines (TNF-α, IL-6, IL-2R). C-reactive protein (CRP) and systemic inflammation response index (SIRI) in peripheral blood were also calculated. One-way repeated-measures ANOVA was used to compare the concentrations at different perioperative time points.
Results: This study enrolled 30 patients with medulla oblongata tumors who underwent surgical treatment from September 2023 to November 2024. Postoperative amino acid levels exhibited a biphasic pattern (initial decline followed by recovery) in both groups. In the NC group, arginine decreased non-significantly at T3 but rose significantly at T4 (P=0.027) and T5 (P=0.010) versus T1. In contrast, the Arg group maintained stable arginine levels without postoperative decline, with T4 significantly higher than T1 (P=0.009). The overall trend of TNF-α, IL-6, IL-2R, CRP and SIRI followed the postoperative pattern of an initial increase followed by a decline in both groups, with no intergroup differences at any timepoint. The Arg group demonstrated higher area-under-the-curve (AUC) values for inflammatory marker concentrations after intervention (after T3) compared to the NC group.
Conclusions: The patterns of peripheral blood amino acid changes in patients with medulla oblongata tumors during the perioperative period (from anesthesia induction to 72 hours postoperatively) were first a decrease followed by an increase, while the inflammatory markers showed an initial rise followed by a decline. Early postoperative intravenous infusion of arginine mitigates the decline of arginine concentrations in peripheral blood during the early postoperative period in medulla oblongata tumor patients. However, this intervention may potentially exacerbate postoperative inflammatory responses, though without statistically significant severity.