Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, School of Medicine, Zhongda Hospital, Southeast University, Nanjing, Jiangsu, 210009, China.
Department of Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215000, China.
BMC Pulm Med. 2023 Apr 19;23(1):129. doi: 10.1186/s12890-023-02431-6.
Recent studies have shown an association between baseline arterial carbon dioxide pressure (PaCO) and outcomes in patients with acute respiratory distress syndrome (ARDS). However, PaCO probably varies throughout the disease, and few studies have assessed the effect of longitudinal PaCO on prognosis. We thus aimed to investigate the association between time-varying PaCO and 28-day mortality in mechanically ventilated ARDS patients.
In this retrospective study, we included all adult (≥ 18 years) patients diagnosed with ARDS who received mechanical ventilation for at least 24 h at a tertiary teaching hospital between January 2014 and March 2021. Patients were excluded if they received extracorporeal membrane oxygenation (ECMO). Demographic data, respiratory variables, and daily PaCO were extracted. The primary outcome was 28-day mortality. Time-varying Cox models were used to estimate the association between longitudinal PaCO measurements and 28-day mortality.
A total of 709 patients were eligible for inclusion in the final cohort, with an average age of 65 years, of whom 70.7% were male, and the overall 28-day mortality was 35.5%. After adjustment for baseline confounders, including age and severity of disease, a significant increase in the hazard of death was found to be associated with both time-varying PaCO (HR 1.07, 95% CI 1.03-1.11, p<0.001) and the time-varying coefficient of variation for PaCO (HR 1.24 per 10% increase, 95% CI 1.10-1.40, p<0.001) during the first five days of invasive mechanical ventilation. The cumulative proportion of exposure to normal PaCO (HR 0.72 per 10% increase, 95% CI 0.58-0.89, p = 0.002) was associated with 28-day mortality.
PaCO should be closely monitored in mechanically ventilated ARDS patients. The association between PaCO and 28-day mortality persisted over time. Increased cumulative exposure to normal PaCO was associated with a decreased risk of death.
最近的研究表明，动脉血二氧化碳分压（PaCO）基线与急性呼吸窘迫综合征（ARDS）患者的结局之间存在关联。然而，PaCO 可能在整个疾病过程中发生变化，很少有研究评估纵向 PaCO 对预后的影响。因此，我们旨在研究机械通气的 ARDS 患者中时变 PaCO 与 28 天死亡率之间的关系。
在这项回顾性研究中，我们纳入了 2014 年 1 月至 2021 年 3 月期间在一家三级教学医院接受至少 24 小时机械通气治疗的所有成人（≥18 岁）ARDS 患者。如果患者接受体外膜氧合（ECMO），则将其排除在外。提取人口统计学数据、呼吸变量和每日 PaCO。主要结局为 28 天死亡率。使用时变 Cox 模型估计纵向 PaCO 测量值与 28 天死亡率之间的关系。
共有 709 名患者符合最终队列的入选标准，平均年龄为 65 岁，其中 70.7%为男性，总 28 天死亡率为 35.5%。在调整了年龄和疾病严重程度等基线混杂因素后，发现死亡风险的显著增加与时变 PaCO（HR 1.07，95%CI 1.03-1.11，p<0.001）和 PaCO 时变变异系数（HR 1.24/每增加 10%，95%CI 1.10-1.40，p<0.001）在机械通气的前五天内呈正相关。接触正常 PaCO 的累积比例（HR 每增加 10%，0.58-0.89，p=0.002）与 28 天死亡率相关。
机械通气的 ARDS 患者应密切监测 PaCO。PaCO 与 28 天死亡率之间的关联随着时间的推移而持续存在。累积接触正常 PaCO 的增加与死亡风险降低相关。
