The purpose of this study was to analyze the clinical characteristics of disease and the risk of death in COVID-19 patients complicated with renal failure.

A total of 1412 patients with COVID-19 in Taikang Tongji COVID-19 Hospital from February 3, 2020 to April 10, 2020 were included in the study. The patients were divided into three groups based on eGFR (mL/min/1.73 m²): normal renal function group (eGFR ≥ 90), renal insufficiency group (60 ≤ eGFR < 90), renal failure group (eGFR < 60). The clinical manifestations, laboratory indicators, complications, and prognosis were analyzed.

There were 1086 cases (76.9%) in the normal renal function group, 258 cases (18.3%) in the renal insufficiency group, and 68 cases (4.8%) in the renal failure group. The mean age of the patients was 62 years (50-70 years), and 650 cases (46.0%) were males. Compared with the normal renal function group, patients of the renal insufficiency group and the renal failure group were older, and patients of the renal failure group showed higher proportion of shortness of breath and chest tightness, but less fever and expectoration (P<0.05). The renal failure patients showed the highest proportion of hypertension, diabetes, coronary heart disease, and cerebrovascular disease. Compared with normal renal function group, the renal failure group displayed higher levels of inflammation-related indexes (C-reactive protein, interleukin-6) and coagulation function indexes (fibrinogen, D-dimer), while the lymphocyte count, platelet count, hemoglobin, and albumin were significantly decreased (P<0.05). Patients of the renal failure group were more likely to need renal support therapy (6.0%), antibiotic therapy (55.2%), and glucocorticoid therapy (18.2%), and were more prone to various serious complications, including respiratory failure, acute respiratory distress syndrome, acute heart failure, acute cardiac injury, coagulopathy, sepsis, shock, anemia, hypoproteinemia, electrolyte disorder, and acidosis (P<0.05). With the decrease of baseline renal function, the mortality rate of patients increased gradually (P<0.05), and the mortality rate of the renal failure group was up to 18.5%. Multivariate Cox regression analysis found that the risk of death in patients with renal failure was significantly increased by 7.873 times that of the normal renal function group (95%CI: 2.110-29.376, P=0.002).

COVID-19 patients complicated with renal failure had a higher incidence of cardiocerebral complications and higher mortality rate, requiring more renal support, antibiotics, and glucocorticoid therapy, etc.