#5703 COVID-19, RENAL DAMAGE AND ITS EVOLUTION IN HOSPITALISED PATIENTS IN THE FIRST WAVE OF THE PANDEMIC: EXPERIENCE OF ONE CENTRE
Authors: Garijo Celia , Bengoa Guillermo Pereda , Najera Esther , Ruiz Aránzazu Pardo , Hernandez Hermann , Larrañaga Marta Artamendi , Bello Elisa , Paraiso Antonio Gil , Catalinas Fernando Gil , Huarte Emma 
Published: June 2023

Abstract

Background and Aims
The damage that SARS Cov2 virus exerts at the renal level has been the subject of analysis in many studies. We analysed the extent of Acute Kidney Injury (AKI), possible factors involved and mortality in patients hospitalised with Covid-19 during the first wave of the pandemic. We reassessed renal function, as well as inflammatory and nutritional status of patients 18 months after admission, together with the capacity for recovery of renal function.

Method
Observational and retrospective study of patients admitted to the ward or intensive care unit (ICU) for Covid-19 during the month of March 2020. We defined the stage of renal damage according to the KDIGO guidelines. Among the possible risk factors associated with AKI and mortality, we analysed haematological analytical parameters (lymphopenia and plateletopenia), inflammatory markers such as CRP and ferritin, and nutritional status, vitamin D and cholesterol, among others. We evaluated ICU mortality using the Odin scale and the life expectancy at 10 years using the Charlson scale. We used the Chi-square test and Fisher's test, considering significant values p&lt;0.05.

Results
A total of 576 patients were admitted during the study period, of whom 10.6% were admitted to the ICU (n 61). A total of 45.9% (n 28) had some degree of AKI, the most frequent being grade 2 (22.9%), followed by grade 3 (18%) and grade 1 (4.9%).
Of all patients requiring admission to the ICU, 78.6% of those with AKI died. The Odin scale was significantly associated with AKI and mortality, but the Charlson scale was not. The maximum dose of Cisatracurium was significantly associated with AKI. Among the patients admitted to inpatient areas (n 515), 9.9% (n 51) had AKI and 31.4% of these patients died. In most cases the degree of renal damage was mild (82.4% grade 1 vs. 13.7% grade 2 and 3.9% grade 3). When we studied the patients who presented with AKI (n 79), we observed that CK and LDH values were significantly higher, indicating a more inflammatory state. Of the 79 patients, 48.1% (n 38) died, with significant differences in serum CRP and D-dimer levels. Of the 41 patients who survived, we conducted an 18-month follow-up study that only 36.6% (n 15) completed, with a mean age of 69.7 years, 73.3% being male and 20% with previous chronic kidney disease (CKD). At the end of follow-up 86% of them recovered renal function, according to pre-admission figures, including those patients with baseline CKD. Only 13% of the patients who completed follow-up showed a slight worsening of renal function with respect to their baseline situation. We observed differences in the values of calcium, vitamin B12 and vitamin D in the group of patients who recovered renal function compared to those who showed deterioration with respect to their situation prior to admission (p&lt;0.02).

Conclusion
The incidence of AKI in COVID patients requiring admission to the ICU was four times higher than in patients admitted to the ward. The severity of renal damage was greater in the ICU, predominantly AKI 2-3 vs AKI 1, with mortality 2.5 times higher than in the ward. The group of patients who develop AKI have an elevation of inflammatory markers, which increases in the group of deceased patients. In ICU, the Odin scale was significantly related to AKI and mortality. - The mortality rate in the group of patients with AKI was high. Most of the patients have recovered pre-admission renal function after 18 months of follow-up, with differences in nutritional parameters such as calcium, vitamin B12 and vitamin D.