Han Junli, Wang Lianghe, Jin Lingling, Liu Mingzhu
Department of Critical Care Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, P.R. China.
Department of Critical Care Medicine, Ngari Prefecture People's Hospital, Ngari Prefecture, P.R. China.
PLoS One. 2025 Jun 10;20(6):e0325498. doi: 10.1371/journal.pone.0325498. eCollection 2025.
This study explored the association between serum bicarbonate levels and mortality risk among patients with acute respiratory distress syndrome (ARDS) admitted to the intensive care unit (ICU).
This was a retrospective cohort study utilizing data extracted from the Medical Information Mart for Intensive Care (MIMIC)-IV database. Cox proportional hazards models and restricted cubic splines (RCS) were deployed for elucidating the association between the baseline bicarbonate levels and the risk of 28-day mortality while utilizing the Kaplan-Meier method to estimate survival curves, with hazard ratio (HR) and 95% confidence interval (CI). Subgroup analyses were conducted based on age, gender, Charlson Comorbidity Index (CCI) score, ARDS severity and bicarbonate administration.
Totally, 6,377 patients (15.38% deaths) were included. Baseline bicarbonate was significantly associated with 28-day mortality (HR: 0.98, 95% CI: 0.97-1.00, P = 0.011) in patients with ARDS. This association was particularly evident in female patients (HR: 1.16, 95% CI: 1.14-1.87, P = 0.003), those with a CCI of 2 or higher (HR: 1.27, 95% CI: 1.05-1.53, P = 0.013), among those with a PaO2/FiO2 ratio ranging from 200 to 300 mmHg (HR: 1.39, 95% CI: 1.08-1.78, P = 0.011), and those without bicarbonate administration (HR = 1.26, 95%CI: 1.07-1.48, P = 0.004), where bicarbonate levels falling below 23 mEq/L were linked to a heightened risk of not surviving the first 28 days in ARDS patients. RCS analysis revealed that the bicarbonate levels were non-linear associated with the 28-day mortality in ARDS patients (P for non-linear <0.001).
Lower serum bicarbonate levels are significantly associated with an increased 28-day mortality risk in ARDS patients, with particular emphasis on female patients, those with higher CCI scores, and those with milder ARDS. Baseline bicarbonate levels of ARDS patients in ICU have certain clinical reference value for the development of clinical management and the assessment of prognostic risk during the ICU admission.
本研究探讨了入住重症监护病房（ICU）的急性呼吸窘迫综合征（ARDS）患者血清碳酸氢盐水平与死亡风险之间的关联。
这是一项回顾性队列研究，利用从重症监护医学信息数据库（MIMIC）-IV中提取的数据。采用Cox比例风险模型和受限立方样条（RCS）来阐明基线碳酸氢盐水平与28天死亡风险之间的关联，同时利用Kaplan-Meier方法估计生存曲线，并计算风险比（HR）和95%置信区间（CI）。基于年龄、性别、Charlson合并症指数（CCI）评分、ARDS严重程度和碳酸氢盐使用情况进行亚组分析。
共纳入6377例患者（15.38%死亡）。ARDS患者中，基线碳酸氢盐水平与28天死亡率显著相关（HR：0.98，95%CI：0.97 - 1.00，P = 0.011）。这种关联在女性患者（HR：1.16，95%CI：1.14 - 1.87，P = 0.003）、CCI为2或更高的患者（HR：1.27，95%CI：1.05 - 1.53，P = 0.013）、动脉血氧分压/吸入氧分数（PaO2/FiO2）比值在200至300 mmHg之间的患者（HR：1.39，95%CI：1.08 - 1.78，P = 0.011）以及未使用碳酸氢盐的患者（HR = 1.26，95%CI：1.07 - 1.48，P = 0.004）中尤为明显，其中ARDS患者碳酸氢盐水平低于23 mEq/L与前28天内死亡风险增加相关。RCS分析显示，碳酸氢盐水平与ARDS患者28天死亡率呈非线性关联（非线性P<0.001）。
较低的血清碳酸氢盐水平与ARDS患者28天死亡风险增加显著相关，尤其在女性患者、CCI评分较高的患者以及病情较轻的ARDS患者中。ICU中ARDS患者的基线碳酸氢盐水平对临床管理的制定以及ICU住院期间预后风险的评估具有一定的临床参考价值。
