Supplementary Material for: Epidemiology and Outcomes of Acute Kidney Injury in COVID-19 Patients with Acute Respiratory Distress Syndrome: A Multicenter Retrospective Study

<b><i>Background:</i></b> Acute kidney injury (AKI) is associated with increased mortality in patients with acute respiratory distress syndrome (ARDS). However, the epidemiological features and outcomes of AKI among COVID-19 patients with ARDS are unknown. <b><i>Methods:</i></b> We retrospectively recruited consecutive adult COVID-19 patients who were diagnosed with ARDS according to Berlin definition from 13 designated intensive care units in the city of Wuhan, China. Potential risk factors of AKI as well as the relation between AKI and in-hospital mortality were investigated. <b><i>Results:</i></b> A total of 275 COVID-19 patients with ARDS were included in the study, and 49.5% of them developed AKI during their hospital stay. In comparison with patients without AKI, patients who developed AKI were older, tended to have chronic kidney disease, had higher Sepsis-Related Organ Failure Assessment score on day 1, and were more likely to receive invasive ventilation and develop acute organ dysfunction. Multivariate analysis showed that age, history of chronic kidney disease, neutrophil-to-lymphocyte ratio, and albumin level were independently associated with the occurrence of AKI. Importantly, increasing AKI severity was associated with increased in-hospital mortality when adjusted for other potential variables: odds ratio of stage 1 = 5.374 (95% CI: 2.147–13.452; <i>p</i> &lt; 0.001), stage 2 = 6.216 (95% CI: 2.011–19.210; <i>p</i> = 0.002), and stage 3 = 34.033 (95% CI: 9.723–119.129; <i>p</i> &lt; 0.001). <b><i>Conclusion:</i></b> In this multicenter retrospective study, we found that nearly half of COVID-19 patients with ARDS experienced AKI during their hospital stay. The coexistence of AKI significantly increased the mortality of these patients.

<b><i>背景：</i></b> 急性肾损伤（Acute kidney injury, AKI）与急性呼吸窘迫综合征（Acute respiratory distress syndrome, ARDS）患者的死亡率升高相关。然而，合并急性呼吸窘迫综合征的新型冠状病毒肺炎（COVID-19）患者中急性肾损伤的流行病学特征及预后尚不明确。<b><i>方法：</i></b> 本研究回顾性纳入了中国武汉市13家定点重症监护病房（intensive care units, ICU）中符合柏林定义（Berlin definition）的连续性成年COVID-19合并ARDS患者，探讨了AKI的潜在危险因素，以及AKI与住院死亡率之间的关联。<b><i>结果：</i></b> 本研究共纳入275例COVID-19合并ARDS患者，其中49.5%的患者在住院期间发生了AKI。与未发生AKI的患者相比，发生AKI的患者年龄更大，更易合并慢性肾脏疾病，入院首日的脓毒症相关器官功能衰竭评估（Sepsis-Related Organ Failure Assessment, SOFA）评分更高，且更倾向于接受有创通气治疗，更易发生急性器官功能障碍。多因素分析显示，年龄、慢性肾脏疾病病史、中性粒细胞与淋巴细胞比值以及白蛋白水平与AKI的发生独立相关。值得注意的是，在校正其他潜在混杂变量后，AKI的严重程度升高与住院死亡率增加显著相关：1期AKI的比值比（odds ratio, OR）为5.374（95%置信区间：2.147–13.452；p < 0.001），2期为6.216（95%置信区间：2.011–19.210；p = 0.002），3期为34.033（95%置信区间：9.723–119.129；p < 0.001）。<b><i>结论：</i></b> 本项多中心回顾性研究发现，近半数COVID-19合并ARDS患者在住院期间发生了AKI。AKI的合并显著升高了此类患者的死亡率。