Acute kidney injury in critical COVID-19: a multicenter cohort analysis in seven large hospitals in Belgium

(2022) 26:225 Schaubroeck et al. Critical Care https://doi.org/10.1186/s13054-022-04086-x Open Access RESEARCH Acute kidney injury in critical COVID‑19: a multicenter cohort analysis in seven large hospitals in Belgium Hannah Schaubroeck1* , Wim Vandenberghe1 , Willem Boer2 , Eva Boonen3 , Bram Dewulf4, Camille Bourgeois4, Jasperina Dubois5 , Alexander Dumoulin6, Tom Fivez2 , Jan Gunst7,8 , Greet Hermans8,9 , Piet Lormans6, Philippe Meersseman9, Dieter Mesotten2,10 , Björn Stessel5,10 , Marc Vanhoof3, Greet De Vlieger7,8†   and Eric Hoste1,11†    Abstract Background: Acute kidney injury (AKI) has been reported as a frequent complication of critical COVID-19. We aimed to evaluate the occurrence of AKI and use of kidney replacement therapy (KRT) in critical COVID-19, to assess patient and kidney outcomes and risk factors for AKI and differences in outcome when the diagnosis of AKI is based on urine output (UO) or on serum creatinine (sCr). Methods: Multicenter, retrospective cohort analysis of patients with critical COVID-19 in seven large hospitals in Belgium. AKI was defined according to KDIGO within 21 days after ICU admission. Multivariable logistic regression analysis was used to explore the risk factors for developing AKI and to assess the association between AKI and ICU mortality. Results: Of 1286 patients, 85.1% had AKI, and KRT was used in 9.8%. Older age, obesity, a higher APACHE II score and use of mechanical ventilation at day 1 of ICU stay were associated with an increased risk for AKI. After multivariable adjustment, all AKI stages were associated with ICU mortality. AKI was based on sCr in 40.1% and UO in 81.5% of patients. All AKI stages based on sCr and AKI stage 3 based on UO were associated with ICU mortality. Persistent AKI was present in 88.6% and acute kidney disease (AKD) in 87.6%. Rapid reversal of AKI yielded a better prognosis compared to persistent AKI and AKD. Kidney recovery was observed in 47.4% of surviving AKI patients. Conclusions: Over 80% of critically ill COVID-19 patients had AKI. This was driven by the high occurrence rate of AKI defined by UO criteria. All AKI stages were associated with mortality (NCT04997915). Keywords: Acute kidney injury, Kidney replacement therapy, Renal replacement therapy, COVID-19, Intensive care unit, Epidemiology, Mortality, KDIGO, Urine output, Serum creatinine † Greet De Vlieger and Eric Hoste are joint last authors *Correspondence: 1 Department of Intensive Care Medicine, Department of Internal Medicine and Pediatrics, Ghent University Hospital, Ghent University, Corneel Heymanslaan 10, 9000 Ghent, Belgium Full list of author information is available at the end of the article Background In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) appeared for the first time in China, causing an ongoing pandemic of coronavirus disease 2019 (COVID-19). COVID-19 overwhelmed health care systems with an immense strain on intensive care units (ICU) and caused excess mortality of almost 15 million deaths worldwide [1, 2]. Acute kidney injury © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Schaubroeck et al. Critical Care (2022) 26:225 (AKI) has been reported as a complication of critical COVID-19 in 25–76%, and the use of kidney replacement therapy (KRT) in 5–44% [3–6] (Additional file 1: Table S1: Overview of studies reporting on AKI in critical COVID-19 patients). The Acute Disease Quality Initiative (ADQI) formulated in its 25th conference the need for more detailed epidemiological data [7]. The objective of this study was to evaluate the occurrence of AKI and use of KRT in critical COVID-19 in several large hospitals in Belgium and its association with mortality. We aimed to evaluate the association of baseline risk factors and therapeutic strategies in critical COVID-19 with AKI and with patient outcomes and to explore the difference in outcome when the diagnosis of AKI is based on urine output (UO) (AKI-UO) or on serum creatinine (sCr) (AKI-sCr) alone according to the 2012 KDIGO guidelines. Finally, we aimed to assess kidney outcomes, especially rapid reversal of AKI, kidney recovery and occurrence of acute kidney disease (AKD). Methods Study design, setting and participants We conducted a multicenter, retrospective cohort analysis in adult (≥ 18 y) patients with critical COVID-19 admitted to several ICU departments (medical, surgical or mixed) in seven large hospitals in Flanders between February 1, 2020, and January 31, 2021. In some of the participating hospitals, ICU capacity was increased by creating extra ICU units outside the regular ICU department, e.g., in the post-anesthesia care unit. We included patients if SARS-CoV-2 infection was confirmed by real‐time reverse‐transcriptase polymerase chain reaction (PCR) on nasopharyngeal or oropharyngeal swabs, bronchial aspirate or broncho-alveolar lavage fluid. Patients were excluded when there was a diagnosis of COVID-19 based on clinical symptoms or chest CT scan without confirmation by PCR, when patients who had a positive SARS-CoV-2 PCR were admitted to ICU for other medical reasons and when patients had endstage kidney disease on chronic KRT. The study was registered on clinicaltrials.gov (NCT04997915). The STROBE guidelines for cohort studies were applied (Additional file 1: Table S2). Data collection and management We collected patients’ baseline characteristics, comorbidities, medication at home, specific treatment for COVID-19, potentially nephrotoxic drugs, biochemical parameters, use of mechanical ventilation, P aO2/FiO2 ratio, use of veno-venous extracorporeal membrane oxygenation (VV-ECMO), use of vasoactive drugs, severity of illness and kidney and patient outcomes. All data were extracted from the electronic patient data management Page 2 of 15 systems, pseudonymized and collected by each participating center. Pseudonymized data from all centers were merged into one large database, re (...truncated)