Acute kidney injury in patients hospitalized with COVID-19 from the ISARIC WHO CCP-UK Study: a prospective, multicentre cohort study

Abstract

Background: Acute kidney injury (AKI) is common in coronavirus disease 2019 (COVID-19). This study investigated adults hospitalized with COVID-19 and hypothesized that risk factors for AKI would include comorbidities and non-White race.

Methods: A prospective multicentre cohort study was performed using patients admitted to 254 UK hospitals with COVID-19 between 17 January 2020 and 5 December 2020.

Results: Of 85 687 patients, 2198 (2.6%) received acute kidney replacement therapy (KRT). Of 41 294 patients with biochemistry data, 13 000 (31.5%) had biochemical AKI: 8562 stage 1 (65.9%), 2609 stage 2 (20.1%) and 1829 stage 3 (14.1%). The main risk factors for KRT were chronic kidney disease (CKD) [adjusted odds ratio (aOR) 3.41: 95% confidence interval 3.06-3.81], male sex (aOR 2.43: 2.18-2.71) and Black race (aOR 2.17: 1.79-2.63). The main risk factors for biochemical AKI were admission respiratory rate >30 breaths per minute (aOR 1.68: 1.56-1.81), CKD (aOR 1.66: 1.57-1.76) and Black race (aOR 1.44: 1.28-1.61). There was a gradated rise in the risk of 28-day mortality by increasing severity of AKI: stage 1 aOR 1.58 (1.49-1.67), stage 2 aOR 2.41 (2.20-2.64), stage 3 aOR 3.50 (3.14-3.91) and KRT aOR 3.06 (2.75-3.39). AKI rates peaked in April 2020 and the subsequent fall in rates could not be explained by the use of dexamethasone or remdesivir.

Conclusions: AKI is common in adults hospitalized with COVID-19 and it is associated with a heightened risk of mortality. Although the rates of AKI have fallen from the early months of the pandemic, high-risk patients should have their kidney function and fluid status monitored closely.

Keywords: COVID-19; SARS-CoV-2; acute kidney injury; dialysis; renal failure.

Graphical Abstract

Figure 1:

Associations between risk factors and acute kidney replacement therapy. *Adjusted for age, sex, race, deprivation quintile, chronic kidney disease, heart disease, diabetes, admission oxygen saturations on air and admission respiratory rate. HIV, human immunodeficiency virus; RR, respiratory rate; SpO2, oxygen saturations. Error bars are 95% confidence intervals (CI).

Figure 2:

Associations between risk factors and biochemical acute kidney injury. *Adjusted for age, sex, race, deprivation quintile, chronic kidney disease, heart disease, diabetes, admission oxygen saturations on air and admission respiratory rate. HIV, human immunodeficiency virus; RR, respiratory rate; SpO2, oxygen saturations. Error bars are 95% confidence intervals (CI).

Figure 3:

Kaplan–Meier plot of 28-day mortality by biochemical acute kidney injury status. Time is after symptom onset. Shaded area represents 95% confidence intervals.

Figure 4:

Associations between acute kidney injury and 28-day mortality. P-values for all groups <0.001. *Adjusted for age, sex, race, deprivation quintile, chronic kidney disease, heart disease, diabetes, admission oxygen saturations on air and admission respiratory rate. Error bars are 95% confidence intervals (CI).

Figure 5:

Acute kidney injury rates and 4C scores by month in 2020. Error bars represent 95% confidence intervals for KRT and biochemical AKI rates and interquartile ranges for illness severity.