Table 2_Impact of serum sodium trajectory on 30-day mortality in traumatic brain injury patients: insights from a retrospective cohort study using MIMIC-IV database.docx

BackgroundHypernatremia is frequently encountered in individuals with traumatic brain injury (TBI), and research has demonstrated a correlation between serum sodium levels and patient outcomes in TBI cases. This study aims to explore the temporal patterns of serum sodium concentrations and assesses their prognostic significance in TBI patients.
MethodsThis study employed data sourced from the database of Medical Information Mart for Intensive Care IV (MIMIC-IV). We applied a latent growth mixture model (LGMM) to construct the serum sodium trajectories of TBI patients within the first 96 h of their intensive care unit (ICU) stay, based on mean serum sodium measurements taken at 24-h intervals. Subsequently, Cox regression models were employed to analyze the associations among initial serum sodium levels, serum sodium trajectories, and mortality outcomes of 30 and 90 day.
ResultsA total of 852 TBI patients were included, and the LGMM model categorized serum sodium trajectories into 4 classes. Significant differences in prognosis were observed between the different grades of TBI patients, with the worst prognosis for patients with TBI in Class 2 (slow-growth type) compared to Class 1 (normal stable type) and no significant difference in mortality for the remaining grades. In addition, after adjusting for confounding factors, high first serum sodium levels were related to higher 30-day (HR = 2.14, 95% CI: 1.13–4.04, p = 0.019) and 90-day (HR = 2.22, 95% CI: 1.21–4.08, p = 0.01) mortality rates in TBI patients.
ConclusionBoth first-time serum sodium and serum sodium trajectory were independent influences on the prognosis of TBI patients. Thus, clinicians should closely monitor serum sodium in TBI patients and adjust treatment strategies based on its dynamic changes.

背景：高钠血症(Hypernatremia)在创伤性脑损伤(TBI)患者中较为常见，已有研究证实TBI患者的血清钠水平与患者预后存在关联。本研究旨在探讨血清钠浓度的动态变化模式，并评估其在TBI患者中的预后意义。
方法：本研究的数据来源于重症监护医学信息数据库IV(MIMIC-IV)。研究以每24小时采集的平均血清钠值为基础，采用潜在增长混合模型(LGMM)构建TBI患者在重症监护病房(ICU)入住前96小时内的血清钠变化轨迹。随后，采用Cox回归模型分析初始血清钠水平、血清钠变化轨迹与患者30天及90天死亡结局之间的关联。
结果：本研究共纳入852例TBI患者，LGMM模型将患者的血清钠变化轨迹划分为4个类别。不同类别的TBI患者预后存在显著差异：与第1类（正常稳定型）患者相比，第2类（缓慢升高型）TBI患者的预后最差，其余类别的患者死亡率无显著差异。此外，在调整混杂因素后，较高的初始血清钠水平与TBI患者更高的30天（风险比HR=2.14，95%置信区间CI:1.13–4.04，p=0.019）及90天（HR=2.22，95%CI:1.21–4.08，p=0.01）死亡率相关。
结论：初始血清钠水平及血清钠变化轨迹均为影响TBI患者预后的独立因素。因此，临床医师应密切监测TBI患者的血清钠水平，并根据其动态变化调整治疗策略。