MO295: Acute Kidney Injury in COVID-19 Patients: Medium-Term Evolution of Renal Function

Abstract

BACKGROUND AND AIMS Acute kidney injury (AKI) is a common complication among patients hospitalized with COVID-19. The incidence of AKI is estimated to be around 5%–80%, according to the series, but data on renal function evolution is limited. Our main objective was to describe the incidence of AKI in patients with SARS-CoV-2 infection; secondarily, we analysed the severity of AKI and medium-term renal function evolution in these patients. METHOD A retrospective observational study that included patients hospitalized a single hospital, diagnosed with SARS-CoV-2 infection, who developed AKI (March-May 2020). We register clinical and demographic characteristics, creatinine upon admission and prior to discharge, as well as creatinine and CKD-EPI glomerular filtration rate (eGFR) after at least 3 months after discharge. CKD was defined according to KDIGO stages based on the eGFR (G3-G5). The KDIGO classification was used to define and classify AKI. Recovery of kidney function was defined as difference in at discharge or post-hospitalization creatinine < 0.3 mg/dL with respect basal creatinine. The clinical follow-up ranged from admission to death or end of study. RESULTS Of 258 patients hospitalized with SARS-CoV-2 infection, AKI occurred in 73 (28.3%). 63% (n = 46) were men; the mean of age was 69 years (57–76). DRA severity: 35 (48%) KDIGO-1, 15 (21%) KDIGO-2 and 23 (31%) KDIGO-3. The mean stay was associated with the severity of AKI: 7 days (3–11) for KDIGO-1, 11 days for KDIGO-2 (5–22) and 12 days (8–35) for KDIGO-3 (P = .02). The stage of CKD established differences in the severity of AKI: 66.6% (n = 6) of the patients with CKD G4–G5 presented AKI-KDIGO 3 versus only 25.0% (n = 4) in the CKD-G3 patients (P = .02). Admission to the ICU was more frequent in KDIGO 2–3 versus KDIGO-1 [39% (n = 15) versus 9% (n = 3); P < .01]. Of the 48 patients discharged, 30 (62.5%) had recovered their baseline renal function upon discharge. Only 2 are still on RRT after 8 months (2.7% of all patients). Of the 25 patients died (34% of patients with AKI) with a median time of 3 days from DRA diagnosis (1–8). Renal function of 35 patients was monitored, which correspond to 19 (54%) KDIGO-1, 8 (23%) KDIGO-2, 8 (23%) KDIGO-3 stages. In these patients, analytical control starting 3 months after hospitalization revealed FG 66 (SD 30; 56–76) mL/min/1.73 m2. We have not found differences in renal function between pre- and post-hospitalization in related test. A total of 77% (n = 37) of discharged patients recovered their baseline renal function in the post-hospitalization control. CONCLUSION The incidence of AKI in the context of COVID-19 in our series was 28.3%, with an associated mortality of 34.2%. Most of the patients presented with AKI KDIGO 1 (47.9%). The severity of AKI is associated with a longer hospital stay, admission to the ICU and the requirement for RRT. The advanced stages of CKD pre-admission showed more severity of AKI. The maintenance in TRS in our series has been 2.7%. Patients who were discharged for recovery/improvement of COVID-19 had normalized kidney function during subsequent follow-up, regardless of the severity of the AKI developed on admission for COVID-19.

Acute Kidney Injury in Hospitalized Patients with COVID-19; evolution and mortality

“…29 patients (36.2%) of our AKI patients had prehospitalization CKD; A similar prevalence of CKD, was reported by Portolés et al [18] as they reported that 43.5% of AKI patients were well known to have chronic kidney disease (CKD), also Almenara-Tejederas et al [19] found that 34% of COVID 19 patients developed AKI, and 22% of those AKI patients had prehospitalization CKD and in these studies, CKD was associated with a higher incidence of AKI, and mortality.…”

“…In this cohort, stages of AKI were found to be distributed evenly 27(33.8%), 29(36.2%), and 24(30%), similarly; Chan et al showed that stages 1, 2, or 3 AKI occurred in 39%, 19%, and 42%, respectively 16 . Comparable results, (AKI stage 1; 48% stage 2; 21% stage 3; 31% with some predominance of AKI stage 1), were shown by Almenara-Tejederas et al [19]. Meanwhile, another group identified AKI KDIGO stage 1 as the most frequent stage, representing 70% of AKI cases [20], on the contrary; another analysis by Tejederas et al [21] who included 196 patients, showed that AKI stage 3 represented 66% of AKI patients, 17% AKI stage 2 and 15% stage 1 AKI.…”

“…Also in another study, multivariate regression analysis showed that; hypertension, diabetes mellitus, CKD stage 3-5, male gender, AKI, and malignancy were found to be significantly independent variables increasing mortality [26]. Contrary to these data, Almenara-Tejederas et al [19] could not detect any influence of the presence of CKD on mortality in their study, and they attributed this to the small number of analyzed population in their study.…”

“…After 3 months of followup, AKI recovery increased to 82% of discharged patients, 79% of AKI stage 2, and 50 % of AKI stage 3. Data regarding follow-up for renal recovery post-COVID-19 associated AKI in hospitalized patients are sparse one study reported that 65% of the survived COVID patients with AKI, recovered baseline kidney function at the time of hospital discharge; and after a mean follow-up of 21 days, this percentage increased to over 69% 16 , also Almenara-Tejederas et al [19] showed consistent data 62.5% of patients recovered baseline renal function at hospital discharge, and after 128 days of follow up, the percentage of renal recovery increased to 77.0% of the survivors. In a retrospective analysis of the 266 COVID-19-associated AKI patients, 71.8% had renal recovery (RR) at hospital discharge; however, there was no follow-up after hospital discharge [29].…”

“…24 (30%) of our patients died during hospitalization, similarly many studies reported high mortality in COVID patients who developed AKI. Almenara-Tejederas et al [19] reported 34.2 % mortality, which was especially higher in AKI stage 3(56% mortality), Hirsch et al [17] reported in-hospital mortality of 35% in COVIDassociated AKI in a Norwegian nationwide study that included COVID-19 patients admitted to ICU; Aukland et al [22] showed that in-hospital mortality was 30% whereas 90 days mortality was 38.5% in patients with COVID associated AKI, also they concluded that AKI was related to acute circulatory failure and that mortality was associated with age and AKI at ICU admission. In another study by Morieri et al [23], in-hospital mortality was 39.3% in COVID patients with AKI compared to only 4.3% in COVID patients without AKI.…”