Acute kidney injury in patients with COVID-19 in the intensive care unit: evaluation of risk factors and mortality in a national cohort

Abstract

ObjectivesAcute kidney injury (AKI) is a frequent complication among critical ill patients with COVID-19, but the actual incidence is unknown as AKI-incidence varies from 25% to 89% in intensive care unit (ICU) populations. We aimed to describe the prevalence and risk factors of AKI in patients with COVID-19 admitted to ICU in Norway.DesignNation-wide observational study with data sampled from the Norwegian Intensive Care and Pandemic Registry (NIPaR) for the period between 10 March until 31 December 2020.SettingICU patients with COVID-19 in Norway. NIPaR collects data on intensive care stays covering more than 90% of Norwegian ICU and 98% of ICU stays.ParticipantsAdult patients with COVID-19 admitted to Norwegian ICU were included in the study. Patients with chronic kidney disease (CKD) were excluded in order to avoid bias from CKD on the incidence of AKI.Primary and secondary outcome measuresPrimary outcome was AKI at ICU admission as defined by renal Simplified Acute Physiology Score in NIPaR. Secondary outcome measures included survival at 30 and 90 days after admission to hospital.ResultsA total number of 361 patients with COVID-19 were included in the analysis. AKI was present in 32.0% of the patients at ICU admission. The risk for AKI at ICU admission was related to acute circulatory failure at admission to hospital. Survival for the study population at 30 and 90 days was 82.5% and 77.6%, respectively. Cancer was a predictor of 30-day mortality. Age, acute circulatory failure at hospital admission and AKI at ICU admission were predictors of both 30-day and 90-day mortality.ConclusionsA high number of patients with COVID-19 had AKI at ICU admission. The study indicates that AKI at ICU admission was related to acute circulatory failure at hospital admission. Age, acute circulatory failure at hospital admission and AKI at ICU admission were associated with mortality.

Prognostic significance of early acute kidney injury in COVID-19 patients requiring mechanical ventilation: a single-center retrospective analysis

“…High mortality of critically ill COVID-19 patients with advanced AKI or the need for RRT was also found in other studies. RRT was used in 10-31% of patients, with an ICU mortality of patients requiring RRT of 50-70% [ 14 , 27–29 ], which is comparable with our results. Numerous studies have also shown the association between AKI on ICU admission and mortality in critically ill COVID-19 patients [ 14–19 ], although they differed substantially in the patient population included and in the outcome.…”

“…RRT was used in 10-31% of patients, with an ICU mortality of patients requiring RRT of 50-70% [ 14 , 27–29 ], which is comparable with our results. Numerous studies have also shown the association between AKI on ICU admission and mortality in critically ill COVID-19 patients [ 14–19 ], although they differed substantially in the patient population included and in the outcome. For instance, 90-day mortality in patients without AKI on admission was reported to be 7–15% versus 44% in our study, but only 70-81% of that study’s patients were ventilated, compared with the 100% in our study.…”

“…First, we used a modified definition of AKI. The aforementioned studies [ 14–19 ] used the standard KDIGO definition [ 20 ], defining AKI as a proportional increase in creatinine compared to the baseline value or an absolute increase in creatinine or low diuresis within 48 h of admission. However, such a definition does not allow us to assess the impact of the early development of renal dysfunction within the first 48 h, which was the primary objective of our study, because we can only determine whether a patient has AKI on admission after the patient has been admitted for 48 h. In addition, we did not have available prehospital baseline creatinine values in most patients.…”

“…We specifically aimed to determine if AKI and its early progression during the first 48 h after ICU admission are predictive of outcome and use of renal replacement therapy (RRT). Although numerous studies have shown the association between AKI on ICU admission and mortality in critically ill COVID-19 patients [ 14–19 ], none of them focused explicitly on the prognostic significance of the very early development of renal impairment after ICU admission.…”

The Effect of Estimated Glomerular Filtration Rate on Mortality in the Elderly COVID-19 Patients in the Intensive Care Unit

“…Age, acute circulatory failure during admission to hospital and AKI during admission to ICU were reported as determinants of both 30-day and 90-day mortality. [16] In systematic review and meta-analysis of 54 studies, AKI occurred in about 30% of the patients who were hospitalized with COVID-19, the course of >45% of patients who needed intensive care became complicated and 1 out of 5 patients who were admitted to the intensive care unit received kidney replacement therapy. [17] In a study by Fisher et al, the incidence of acute kidney injury was compared in patients who were hospitalized with COVID-19 and without COVID-19 and the incidence of acute kidney injury was found higher in COVID-19 patients compared to the control group (56.9% vs. 25.1% respectively).…”