Effect of renal support therapy on 5-year survival in patients discharged from the intensive care unit

BACKGROUND: Between 30 and 70% of patients admitted to the intensive care unit (ICU) have acute kidney injury (AKI), and 10% of these patients will require renal replacement therapy (RRT). A significant number of studies have compared the mortality of patients who require RRT versus those who do not require it, finding an increase in mortality rates in the short and medium term; however, few studies have evaluated the long-term survival in a mixture of patients admitted to the ICU. OBJECTIVE: To evaluate the impact of RRT on 5-year survival in patients with AKI admitted to the ICU METHODS: Using administrative databases of insurers of the Colombian health system, a cohort of patients admitted to the ICU between 1 January 2012 and 31 December 2013 was followed until 31 December 2018. ICD-10 diagnoses, procedure codes, and prescribed medications were used to establish the frequencies of the comorbidities included in the Charlson index. Patients were followed for at least 5 years to evaluate survival and establish the adjusted risks by propensity score matching. RESULTS: Of the 150,230 patients admitted to the ICU, 4366 (2.9%) required RRT in the ICU. Mortality rates for patients with RRT vs no RRT evaluated at ICU discharge, 1 year, and 5 years were 35%, 57.4%, and 67.9% vs 7.4%, 17.6%, and 30.1%, respectively. After propensity score matching, the hazard ratio was calculated for patients who received RRT and those who did not (HR, 2.46; 95% CI 2.37 to 2.56; p < 0.001), with a lower difference in years of survival for patients with RRT (mean effect in the treated) of − 1.86 (95% CI − 2.01 to to1.65; p < 0.001). CONCLUSIONS: The impact of acute renal failure with the consequent need for RRT in patients admitted to the ICU is reflected in a decrease of approximately one quarter in 5-year survival, regardless of the different comorbidities.