Impacto da injúria renal aguda na taxa de filtração glomerular em idosos a longo prazo

Abstract

Introduction: Patients who developed Acute Kidney Injury (AKI) are at a higher risk of developing chronic kidney disease (CKD), especially in the most severe cases. It is essential to evaluate over time the glomerular filtration rate (GFR) in patients who have had AKI, especially in the elderly population. Studies evaluating the reduction of the filtration rate in elderly patients after an ARF episode are still scarce. Aim: The present study aim to analyze the impact of AKI on glomerular filtration rate in the elderly after at least 1 year according to AKI severity. Methodology: This study is a retrospective cohort conducted in a tertiary care hospital. We collected data from patients with acute kidney injury aged 65 years or older who were evaluated by the nephrology service during the period from January 1, 2012 to December 31, 2018. Only those who had at least one serum creatinine measurement after a period of at least one year from the development of AKI were included. GFR was calculated by the CKD-EPI formula in ml/min/1.73m2 . Patients diagnosed with stage 5 chronic kidney disease (estimated GFR less than 15 ml/min/1.73m2 ), kidney transplant recipients, and those who died during hospitalization were excluded. All data were collected through electronic medical record review. We analyzed the mean GFR at time zero (T0) and after 365 days (T1). They were assessed according to the KDIGO classification for AKI. Results: 145 patients were analyzed, 54.5% were male with a mean age of 77.6 ±7.7 years and 45.5% had CKD. Using the KDIGO criteria: 62 patients were classified with stage 1 (42.75%), 38 with stage 2 (26.2%) and 45 with stage 3 (31.03%). Patients who had stage 1 had a median reduction in GFR of -11.8 ml/min/1.73m2 (-24.4; -6.5), (p<0.001), stage 2 of -18.7 ml/min/1.73m2 (-33.2; -10.7) (p<0.001) and stage 3 of -21 ml/min/1.73m2 (-35.1; -7.21) (p<0.001) between T0 and T1. However, comparing these groups, the median GFR reduction was not significant (p>0.05). Patients who had prior CKD had a decline in GFR of -11.8 ml/min/1.73m2 (-19.9; -5.9), and patients who did not have prior CKD had a decline in GFR of -26.1 ml/min/1.73m2 (-43.7; -7.9) (p<0.001). Male patients had a decrease in GFR of -21.1 ml/min/1.73m2 (-38.0; -8.79), and female patients had a decrease in GFR of -13.2 ml/min/1.73m2 (-25.50 -5.5) (p=0.027). Patients younger than 80 years reduced GFR by -17.6 ml/min/1.73m2 (-30.6; -7.2) and those older than 80 years decreased by 16.7 ml/min/1.73m2 (-32.6; -6.7) (p>0.05). The patients who had oliguria had decreased GFR of -19.3 ml/min/1.73m2 , (-30.1; -9.3) and the group without oliguria of -17 ml/min/1.73m2 (-31.7; 6.9), (p>0.05). The hemodialysis patients had reduced GFR by -26.7 ml/min/1.73m2 (-34.6; - 18.5), and the non-dialysis group by -15.5 ml/min/1.73m2 (30.8; - 6.6) (p=0.033). In relation to causes of AKI, the decline of GFR for sepsis were -22.3 ml/min/1.73m2 (-33.8; -12.1), for dehydration/hypovolemia were -10.8 ml/min/1.73m2 (-26.8; -5.2), and for heart failure were - 14.6 ml/min/1.73m2 (-23.0; -6.5) (p=0.037). Conclusion: The study suggests that there is a reduction in GFR for each KDIGO stage between T0 and T1, however we found no statistically significant difference in reduction between these groups. The reduction was statistically significant in male patients, without CKD, with sepsis and who underwent hemodialysis. Chest CT findings in COVID-19 and association with temporal evolutionary stages