High incidence of acute kidney injury in COVID-19 patients
Acute kidney injury in patients hospitalized with COVID-19
Introduction and methods
Initial reports found a rate of acute kidney injury (AKI) in patients with COVID-19 ranging from 0.5% to 29% [1-10]. Little is known about AKI in COVID-19 beyond rate. This observative study took place in 13 hospitals in and around New York City and investigated the rate of AKI among patients hospitalized with COVID-19. Moreover, aspects of the phenomenology (such as descriptions of timing, laboratory findings from urine samples, and risk factors) were described for this patient population.
Data from 5449 patients who were admitted between March 1, 2020 and April 5, 2020, for COVID-19 were included in this analysis. Patients younger than 18 years old, with a kidney transplant or with end stage kidney disease were excluded. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria (stage 1: increase in serum creatinine by 0.3 mg/dl within 48 hours or a 1.5-1.9× increase in serum creatinine from baseline within 7 days, stage 2: 2.9× increase in serum creatinine within 7 days, stage 3: 3× or more increase in serum creatinine within 7 days or initiation of renal replacement therapy [RRT]).
The primary outcome was development of AKI. Other outcomes were need for RRT and hospital disposition. Patients were followed up through April 12, 2020.
- 36.3% of patients (1993 of 5449 patients) developed AKI during hospitalization. Peak stages of AKI were stage 1 in 46.5%, stage 2 in 22.4%, and stage 3 in 31.1% of patients.
- Among patients who developed AKI, 37.3% arrived with AKI or developed it within 24h of admission.
- 285 Patients required dialytic support (5.2% of all patients, 14.3% of those with AKI). 154 Patients were treated with intermittent hemodialysis (54% of patients requiring RRT), 70 were treated with continuous RRT only (24.6%) and 61 patients required both treatments at some point (21.4%).
- Among patients who required mechanical ventilation 89.7% (1068 of 1190) developed AKI, compared with 21.7% (925 of 4259) in nonventilated patients.
- RRT was required in 23.2% (276 of 1190) of patients on mechanical ventilation, compared with 0.2% (9 of 4259) in nonventilated patients.
- 52.2% Of patients who required ventilation and developed AKI had onset of AKI within 24h of intubation.
- Collected urine samples that were obtained within 24h before or 48h after development of AKI were available in up to 646 of 1993 patients with AKI. Median urine-specific gravity was 1.020 (IQR: 1.010, 1.020). By urine dipstick, 36.2% had no heme and 46.1% had 2+ to 3+ positivity. Urine protein was negative 26.0% and 42.1% had 2+ to 3+ positivity. Leukocyturia or hematuria were detected by automated microscopy in 36.5% and 40.9%, respectively. Urine sodium concentration was <35 mEq/l in 65.6% of patients.
- Independent predictors of AKI in COVID-19 by multivariate analysis included older age, black race, diabetes, hypertension, CVD, mechanical ventilation, and use of vasopressor medications.
- Among the 1993 patients who developed AKI during hospitalization, 39% were still hospitalized at the end follow-up, 26% were discharged and 35% died.
This observational study in 13 hospitals in and around New York City found that 36.6% of patients hospitalized with COVID-19 developed AKI during hospitalization. Development of AKI was linked to requirement of mechanical ventilation. Among those who required ventilation and developed AKI, onset of AKI often occurred within 24h of intubation.