Department of Anesthesia and Critical Care, 43963George Washington University Hospital, Washington, DC, USA.
Department of Emergency Medicine, 43963George Washington University Hospital, Washington, DC, USA.
J Intensive Care Med. 2023 Jan;38(1):27-31. doi: 10.1177/08850666221121734. Epub 2022 Sep 6.
Endotoxin is a component of Gram-negative bacteria and can be measured in blood using the endotoxin activity assay (EAA). Endotoxin exposure initiates an inflammatory cascade that may contribute to organ dysfunction. Endotoxemia has been reported in previous viral pandemics and we investigated the extent of endotoxemia and its relationship to outcomes in critically ill patients with COVID-19.
We conducted a Prospective Cohort Study of 96 critically-ill COVID-19 patients admitted to the George Washington University Hospital ICU from 25 Mar-6 Jun 2020. EAA and inflammatory markers (ferritin, d dimer, IL-6, CRP) were measured on ICU admission and at the discretion of the clinical team. Clinical outcomes (mortality, LOS, need for renal replacement therapy (RRT), intubation) were measured. Statistical analysis was conducted using descriptive statistics and effect estimates with 95% confidence intervals. Comparisons were made using chi-square tests for categorical variables, and T-tests for continuous variables.
A majority of patients (68.8%) had high EAA [≥ 0.60], levels seen in septic shock. Only 3 patients had positive bacterial cultures. EAA levels did not correlate with mortality, higher levels were associated with greater organ failure (cardiovascular, renal) and longer ICU LOS. Among 14 patients receiving RRT for severe AKI, one had EAA < 0.6 (p = 0.043). EAA levels did not directly correlate with other inflammatory markers.
High levels of endotoxin activity were found in a majority of critically-ill COVID-19 patients admitted to the ICU and were associated with greater risk for cardiovascular and renal failure. Further investigation is needed to determine if endotoxin reducing strategies are useful in treating severe COVID-19 infection.
内毒素是革兰氏阴性菌的组成部分，可以通过内毒素活性测定法（EAA）在血液中进行测量。内毒素暴露会引发炎症级联反应，从而可能导致器官功能障碍。以前的病毒大流行中已有内毒素血症的报道，我们研究了危重症 COVID-19 患者内毒素血症的程度及其与结局的关系。
我们对 2020 年 3 月 25 日至 6 月 6 日期间入住乔治华盛顿大学医院 ICU 的 96 例危重症 COVID-19 患者进行了前瞻性队列研究。在 ICU 入院时和临床团队的酌情情况下测量 EAA 和炎症标志物（铁蛋白、d 二聚体、IL-6、CRP）。测量临床结局（死亡率、 LOS、需要肾脏替代治疗（RRT）、插管）。使用描述性统计和 95%置信区间的效应估计值进行统计分析。使用卡方检验进行分类变量比较，使用 T 检验进行连续变量比较。
大多数患者（68.8%）的 EAA [≥0.60]较高，这在感染性休克中可见。仅有 3 例患者的细菌培养阳性。EAA 水平与死亡率无相关性，较高的水平与更严重的器官衰竭（心血管、肾脏）和 ICU LOS 延长相关。在 14 例因严重 AKI 接受 RRT 的患者中，有 1 例 EAA <0.6（p=0.043）。EAA 水平与其他炎症标志物无直接相关性。
大多数入住 ICU 的危重症 COVID-19 患者的内毒素活性水平较高，与心血管和肾功能衰竭的风险增加相关。需要进一步研究以确定是否使用内毒素减少策略对治疗严重 COVID-19 感染有用。
