Abstract and Introduction
Abstract
Graphical Abstract
Background: Patients suffering from acute kidney injury(AKI) in the intensive care unit (ICU) can have various renal trajectories and outcomes. Aims were to assess the various clinical trajectories after AKI in the ICU and to determine risk factors for developing chronic kidney disease (CKD).
Methods: We conducted a prospective 5-year follow-up study in a medical ICU at Bordeaux University Hospital (France). The patients who received invasive mechanical ventilation, catecholamine infusion or both and developed an AKI from September 2013 to May 2015 were included. In the Cox analysis, the violation of the proportional hazard assumption for AKD was handled using appropriate interaction terms with time, resulting in a time-dependent hazard ratio (HR).
Results: A total of 232 patients were enrolled, with an age of 62 ± 16 years and a median follow-up of 52 days (interquartile range 6–1553). On day 7, 109/232 (47%) patients progressed to acute kidney disease (AKD) and 66/232 (28%) recovered. A linear trajectory (AKI, AKD to CKD) was followed by 44/63 (70%) of the CKD patients. The cumulative incidence of CKD was 30% [95% confidence interval (CI) 24–36] at the 5-year follow-up. In a multivariable Cox model, in the 6 months following AKI, the HR for CKD was higher in AKD patients [HR 29.2 (95% CI 8.5–100.7); P < 0.0001). After 6 months, the HR for CKD was 2.2 (95% CI 0.6–7.9; P = 0.21; n = 172 patients).
Conclusion: There were several clinical trajectories of kidney disease after ICU-acquired AKI. CKD risk was higher in AKD patients only in the first 6 months. Lack of renal recovery rather than AKD per se was associated with the risk of CKD.
Introduction
Acute kidney injury (AKI) is observed in >50% of patients admitted to intensive care units (ICUs) and >10% of them require renal replacement therapy (RRT).[1–3] Sepsis is the most common aetiology of AKI in this context.[4] The short-term consequences of AKI are well described: increased mortality,[4] longer hospital stays[5] and deterioration in the quality of life.[6] The long-term implications have been more recently addressed. AKI is a significant risk factor for developing chronic kidney disease (CKD),[7–9] which in turn increases cardiovascular (CV)[10] and mortality risks,[11] decreases the quality of life[12] and is a substantial burden for health systems.[13] The concept of acute kidney disease (AKD) has been recently proposed to describe a highly vulnerable period following AKI during which the patient could experience a decline in glomerular filtration and finally develop CKD.[14]
Patients with AKI could have various clinical trajectories and outcomes (early or late recovery, relapse after recovery, AKD or CKD). However, to our knowledge, no cohort study has accurately described these trajectories.[14,15] According to recommendations, a post-intensive care clinic has been proposed within 3–6 months after ICU discharge.[16] Without detailed data on the clinical trajectories of patients, it is difficult to know whether the 3–6 months time frame is relevant to detect the long-term consequences of an AKI.
Using a prospective 5-year follow-up cohort, our primary objective was to assess the various clinical trajectories after AKI in ICU. Our secondary objectives were to evaluate the long-term incidence of CKD and to determine risk factors for developing CKD that specifically take into account these trajectories, and particularly AKD.
Nephrol Dial Transplant. 2023;38(1):167-176. © 2023 Oxford University Press
