The effect of resolution time of acute kidney injury on clinical outcomes

Acute kidney injury (AKI) is a frequent and complex disease. It is not clearly defined whether its duration is related to adverse outcomes. We determined the effect of AKI resolution time on patient's clinical outcomes. A prospective cohort of hospitalized patients with AKI by AKI network (AKIN) creatinine criteria was included. Variables for prognosis and follow-up were analyzed. One hundred and thirteen patients were included in the study. Seventy-seven (68.1%) were males, mean age 55 years (range, 16-76 years), and 48 (42.5%) were diabetic. The most common cause of AKI was sepsis (31%). AKI resolution time ≤2 days and >2 days was seen in 47 (41.6%) and 66 (58.4%) of the cases, respectively. AKI resolution time >2 days was common in older patients (66.24 ± 17.6 year vs. 47.16 ± 12.32 year, P = 0.004), with the use of mechanical ventilation (27% vs. 4%, P = 0.02) and vasopressors (41% vs. 11%, P ≤ 0.01); it was associated with increased mortality (47% vs. 4%, P ≤ 0.01), and a discharge estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² (52% vs. 2%, P = 0.01), than in patients with resolution time ≤2 days. Survival rate was significantly worse in patients with a resolution time >2 days. By multivariate logistic step-wise regression analysis, AKI >2days, vasopressor use, and AKIN stage 2-3 were independently associated with higher mortality. AKI >2 days and vasopressor utilization were independently associated to an eGFR <60 ml/min/1.73 m² at the time of discharge. We conclude that AKI resolution time >2 days is linked to adverse clinical outcomes.