Clinical Characteristics and Short-Term Outcomes of Acute Kidney Injury Missed Diagnosis in Older Patients with Severe COVID-19 in Intensive Care Unit

OBJECTIVES: Patients with severe or critical COVID-19 are at higher risk for developing acute kidney injury (AKI). However, whether AKI is diagnosed in all the patients and the correlation between the outcomes of COVID-19 are not well understood. PATIENTS AND METHODS: This cohort study was conducted from February 4, 2020 to April 16, 2020 in Wuhan, China. All consecutive inpatients with laboratory-confirmed COVID-19 were included in this study. AKI was defined according to the KDIGO 2012 criteria. The outcomes of patients with and without AKI and whether AKI was or was not recognized were compared. RESULTS: A total of 107 elderly patients were included in the final analysis. The median age was 70 (64–78) years, and 69 (64.5%) were men. Overall, 48 of 107 patients (44.9%) developed AKI during hospitalization. Meanwhile, 22 (45.8%) cases with AKI was not recognized (missed diagnosis) in this cohort. The Kaplan-Meier curves showed that survival was better in the non-AKI group than in the AKI group (log-rank, all P < 0.001); in the subgroups of the patients with AKI, the hospital survival rate decreased when AKI was not recognized. The survival of patients with recognized AKI was better than that of patients with unrecognized AKI (log-rank, all P < 0.001). According to the multivariate regression analysis, the independent risk factors for in-hospital mortality were AKI (recognized AKI vs non-AKI: HR = 2.413; 95% CI = 1.092–5.333; P = 0.030 and unrecognized AKI vs non-AKI: HR = 4.590; 95% CI = 2.070–10.175; P <0.001), C-reactive protein level (HR = 1.004; 95% CI = 1.000–1.008; P = 0.030), lactate level (HR = 1.236; 95% CI = 1.098–1.391; P < 0.001), and disease classification (critical vs severe: HR = 0.019; 95% CI = 1.347–26.396; P = 5.963). CONCLUSIONS: AKI is not an uncommon complication in elderly patients with COVID-19 who admitted to ICU. Extremely high rates of underdiagnosis and undertreatment of AKI have resulted in an elevated in-hospital mortality rate. Kidney protection is an important issue that cannot be ignored, and intensive care kidney specialists should take responsibility for leading the battle against AKI.