Supplementary Material for: Acute Kidney Injury and Renal Replacement Therapy in Critically Ill COVID-19 Patients: Risk Factors and Outcomes: A Single-Center Experience in Brazil

<b><i>Background:</i></b> Critically ill patients with COVID-19 may develop multiple organ dysfunction syndrome, including acute kidney injury (AKI). We report the incidence, risk factors, associations, and outcomes of AKI and renal replacement therapy (RRT) in critically ill COVID-19 patients. <b><i>Methods:</i></b> We performed a retrospective cohort study of adult patients with COVID-19 diagnosis admitted to the intensive care unit (ICU) between March 2020 and May 2020. Multivariable logistic regression analysis was applied to identify risk factors for the development of AKI and use of RRT. The primary outcome was 60-day mortality after ICU admission. <b><i>Results:</i></b> 101 (50.2%) patients developed AKI (72% on the first day of invasive mechanical ventilation [IMV]), and thirty-four (17%) required RRT. Risk factors for AKI included higher baseline Cr (OR 2.50 [1.33–4.69], <i>p</i> = 0.005), diuretic use (OR 4.14 [1.27–13.49], <i>p</i> = 0.019), and IMV (OR 7.60 [1.37–42.05], <i>p</i> = 0.020). A higher C-reactive protein level was an additional risk factor for RRT (OR 2.12 [1.16–4.33], <i>p</i> = 0.023). Overall 60-day mortality was 14.4% {23.8% (<i>n</i> = 24) in the AKI group versus 5% (<i>n</i> = 5) in the non-AKI group (HR 2.79 [1.04–7.49], <i>p</i> = 0.040); and 35.3% (<i>n</i> = 12) in the RRT group versus 10.2% (<i>n</i> = 17) in the non-RRT group, respectively (HR 2.21 [1.01–4.85], <i>p</i> = 0.047)}. <b><i>Conclusions:</i></b> AKI was common among critically ill COVID-19 patients and occurred early in association with IMV. One in 6 AKI patients received RRT and 1 in 3 patients treated with RRT died in hospital. These findings provide important prognostic information for clinicians caring for these patients.

**背景**：新冠重症患者可并发多器官功能障碍综合征，其中包括急性肾损伤（acute kidney injury, AKI）。本研究报道了重症新冠患者中AKI与肾脏替代治疗（renal replacement therapy, RRT）的发生率、危险因素、相关关联及预后结局。
**方法**：本研究为回顾性队列研究，纳入2020年3月至2020年5月期间收治于重症监护病房（intensive care unit, ICU）且确诊新冠感染的成年患者。采用多变量logistic回归分析，明确AKI发生与RRT使用的危险因素。本研究的主要结局为ICU入院后60天死亡率。
**结果**：共计101例（50.2%）患者发生AKI，其中72%的患者在有创机械通气（invasive mechanical ventilation, IMV）首日即出现AKI；34例（17%）患者需接受RRT。AKI的危险因素包括基线血肌酐水平升高（比值比[odds ratio, OR] 2.50，95%置信区间1.33–4.69，*p*=0.005）、利尿剂使用史（OR 4.14，95%置信区间1.27–13.49，*p*=0.019）以及有创机械通气（OR 7.60，95%置信区间1.37–42.05，*p*=0.020）。C反应蛋白水平升高是RRT使用的额外危险因素（OR 2.12，95%置信区间1.16–4.33，*p*=0.023）。总体60天死亡率为14.4%：AKI组23.8%（*n*=24），非AKI组仅5%（*n*=5），风险比（hazard ratio, HR）2.79，95%置信区间1.04–7.49，*p*=0.040；RRT组35.3%（*n*=12），非RRT组10.2%（*n*=17），HR 2.21，95%置信区间1.01–4.85，*p*=0.047。
**结论**：AKI在新冠重症患者中较为常见，且多与有创机械通气同时早期发生。每6名AKI患者中即有1例接受RRT治疗，而接受RRT的患者中每3例便有1例在住院期间死亡。本研究结果为临床医护人员管理此类患者提供了重要的预后参考信息。