INTRODUCTION: Renal involvement in COVID-19 is less well characterized in settings with vigilant public health surveillance, including mass screening and early hospitalization . We assessed kidney complications among COVID-19 patients in Hong Kong, including the association with risk factors, length of hospitalization, critical presentation, and mortality .
METHODS: Linked electronic records of all patients with confirmed COVID-19 from 5 major designated hospitals were extracted . Duplicated records due to interhospital transferal were removed . Primary outcome was the incidence of in-hospital acute kidney injury (AKI). Secondary outcomes were AKI-associated mortality, incident renal replacement therapy (RRT), intensive care admission, prolonged hospitalization and disease course (defined as> 90th percentile of hospitalization duration [35 days] and duration from symptom onset to discharge [43 days], respectively), and change of estimated glomerular filtration rate (GFR). Patients were further stratified into being symptomatic or asymptomatic .
RESULTS: Patients were characterized by young age (median : 38.4, IQR : 28.4-55.8 years) and short time (median : 5, IQR : 2-9 days) from symptom onset to admission . Among the 591 patients , 22 (3.72 %) developed AKI and 4 (0.68 %) required RRT . The median time from symptom onset to in-hospital AKI was 15 days . AKI increased the odds of prolonged hospitalization and disease course by 2.0- and 3.5-folds, respectively . Estimated GFR 24 weeks post-discharge reduced by 7.51 and 1.06 mL/min/1.73 m2 versus baseline (upon admission) in the AKI and non-AKI groups, respectively . The incidence of AKI was comparable between asymptomatic (4.8%, n = 3/62) and symptomatic (3.7%, n = 19/519) patients .
CONCLUSION: The overall rate of AKI among COVID-19 patients in Hong Kong is low, which could be attributable to a vigilant screening program and early hospitalization . Among patients who developed in-hospital AKI, the duration of hospitalization is prolonged and kidney function impairment can persist for up to 6 months post-discharge . Mass surveillance for COVID-19 is warranted in identifying asymptomatic subjects for earlier AKI management.
Index: Acute kidney injury, COVID-19, Cohort, Renal medicine, Risk factors