#3380 ACUTE KIDNEY INJURY IN NON-CRITICALLY ILL PATIENTS: CLINICAL CHARACTERISTICS AND OUTCOMES
Authors: Fiorentino Marco , Nestola Sebastiano , Carparelli Sabrina , Gesualdo Loreto 
Published: June 2023

Abstract

Background and Aims
Acute kidney injury (AKI) still represents a major health public concern associated with worldwide growing incidence. Although many studies have been focused on critically ill patients admitted to ICUs, AKI occurs even in non-critical care settings, with similar consequences in terms of short- and long-outcomes. However, epidemiological data and characteristics of AKI outside the ICU are not well investigated. The aim of the present study was to describe main features and outcomes of AKI observed in non-critically ill patients admitted to a teaching hospital.

Method
We performed a retrospective analysis including all AKI patients referred to nephrology consultation in the period January-June 2021 at A.O.U. Policlinico, Bari, Italy. Clinical and laboratory data were collected using the hospital software to analyze the main features of AKI episodes, including their occurrence and stages, the need for renal replacement therapy (RRT), rate and factors associated to kidney function recovery (KFR) and in-hospital death. AKI was defined according to KDIGO Clinical Practice Guideline based on creatinine criteria. In addition, we further collect data on renal function after hospital discharge up to 12 months from discharge to assess the risk of AKI-to-CKD transition.

Results
Among 899 patients referred for nephrology consultation, 415 (46%) were evaluated for AKI. Pre-existing CKD was present in 204 patients (49%). Most of AKI episodes (52.5%) were classified as KDIGO Stage 3, and 54 patients (13%) required RRT (Table 1). In-hospital mortality in our study cohort was 36.9%, particularly higher in patients with pre-existing CKD (Figure 1a), in patients with stage 3 AKI (Figure 1b) and among patients who did not present KRF within 15 days (Figure 1c). Multivariate Cox regression analysis showed a higher mortality risk for advancing age (HR 1.032, 95% CI 1.012–1.053, p = 0.002) and pre- renal AKI (HR 2.823, 95%CI 1.219-6.536, p = 0.015), while KFR after AKI (HR 0.246, 95%CI 0.098-0.615, p = 0.003) was associated to a lower mortality. KFR was observed in 197 patients (47.5%), and the proportion was significantly higher among patients with AKI stage 1-2 compared to stage 3 (stage 1 62.6% vs stage 2 57.6% vs stage 3 36.8%, p&lt;0.001). Higher baseline eGFR (OR 1.025, 95%CI 1.014-1.036, p&lt;0.001) was associated with higher rate of KFR, while the development of severe AKI was independently associated with lower probability of KFR (OR 0.420, 95%CI 0.248-0.711, p = 0.001). Data on follow-up within 6 months after discharge were available in 62 patients: a further reduction of eGFR compared to the discharge was documented in 30 patients (48.4%).

Conclusion
AKI represents the main nephrologist's activity as consultants at our teaching hospital. AKI episodes referred to nephrologists are usually severe and associated with a high mortality rate even outside the ICU. A timely nephrologist consultation is important to limit the incidence and severity of AKI.