Kidney Replacement Therapy in COVID-19-Related Acute Kidney Injury: the Importance of Timing (preprint)

The objective of this study was to evaluate two different criteria for deciding when KRT should be initiated in patients with COVID-19-related AKI, as well as to determine the impact of the timing of KRT, as defined by each criterion, on in-hospital mortality among such patients. This was a retrospective study involving 512 adult patients admitted to the ICU. All participants had laboratory-confirmed COVID-19 and a confirmed diagnosis of AKI. The potential predictors were the determination of the timing of KRT based on a temporal criterion (days since hospital admission) and that based on a serum creatinine cutoff criterion. Covariates included age, sex, and the SOFA score, as well as the need for mechanical ventilation and vasopressors. The main outcome measure was in-hospital mortality. We evaluated 512 patients, of whom 69.1% were men. The median age was 64 years. Of the 512 patients, 76.6% required dialysis after admission. The overall in-hospital mortality rate was 72.5%. When the timing of KRT was determined by the temporal criterion, the risk of in-hospital mortality was significantly higher for delayed KRT than for timely KRT--84% higher in the univariate analysis (OR=1.84, 95%, [CI]: 1.10-3.09) and 140% higher after adjustment for age, sex, and SOFA score (OR=2.40, 95% CI: 1.36-4.24). When it was determined by the creatinine cutoff criterion, there was no such difference between high and low creatinine at KRT initiation. In patients with COVID-19-related AKI, earlier KRT appears to be associated with lower in-hospital mortality.

Early COVID-related Acute Kidney Injury Recovery May Course with Hydroelectrolytic Disorders in Patients With High Risk of Insensible Fluid Loss (preprint)

Background Acute Kidney Injury (AKI) may occur in more than 30% of COVID hospitalized patients, and renal recovery is poorly described. Aim We aimed to evaluate the renal short-term recovery profile of COVID-related AKI (COV+) compared to COVID-unrelated AKI (COV-). Design case-control retrospective single-center study Methods All patients admitted to the Hospital das Clínicas, University of São Paulo, who recovered AKI from April to June of 2020 (COV+, n=98) and from August to October of 2019 (COV-, n=50) were analyzed. Recovery was defined by spontaneous serum creatinine drop or withdrawal of dialysis. Serum electrolytes were analyzed during the first five days of recovery. Results Among 333 COV+ patients, 98 recovered from AKI (29.4%), while 50 of 177 COV-patients recovered (28.2%). The COV- group presented higher prevalence of chronic morbidities, while the COV+ group had a worse acute clinical course requiring vasoactive drugs (VAD), mechanical ventilation (MV) and dialysis. COVID-19 diagnosis was associated with need of mecxhanical ventilation, dialysis, presence of fever, and higher use of any diuretic drug during first days of recovery. The presence of fever and mechanical ventilation were the predictors associated with intravascular volume depletion surrogates (daily progressive rising in sodium levels and elevation in serum urea: creatinine ratio). Neither COVID-19 nor diuretics use seem to be independent risk factors for this. Conclusions Intravascular volume depletion surrogates are more common in short-term AKI-recovery of patients presenting fever and mechanical ventilation, commons features in SARS-CoV2 infection.

Adrenal Insufficiency in Patients with COVID-19 (preprint)

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can result in coronavirus disease 2019 (COVID-19), has caused an unprecedented global pandemic. The epicenter of that pandemic in Latin America was Brazil, where more than 500,000 deaths have been attributed to COVID-19.

Continuous Renal Replacement Therapy in COVID-19-associated AKI: Adding Heparin to Citrate to Extend Filter Life – a Retrospective Cohort (preprint)

Background: Coronavirus disease 2019 (COVID-19) may predispose patients to thrombotic events. The best anticoagulation strategy for continuous renal replacement therapy (CRRT) in such patients is still under debate. The purpose of this study was to evaluate the impact that different anticoagulation protocols have on filter clotting risk.Methods: This was a retrospective observational study comparing two different anticoagulation strategies (citrate only and citrate plus intravenous infusion of unfractionated heparin) in patients with acute kidney injury (AKI), associated or not with COVID-19 (COV+ AKI and COV− AKI, respectively), submitted to CRRT. Filter clotting risks in the first 72 hours were compared between groups.Results: Between January 2019 and July 2020, 248 patients were evaluated: 189 in the COV+ AKI group and 59 in the COV− AKI group. Filter clotting occurred during the first 72 hours of CRRT in 96 patients (38.7%). Heparin use conferred protection against filter clotting, resulting in longer filter survival. Bleeding events and the need for blood transfusion were similar between the citrate only and citrate plus unfractionated heparin strategies. In-hospital mortality was higher among the COV+ AKI patients than among the COV− AKI patients, although it was similar between the COV+ AKI patients who received heparin and those who did not. Filter clotting was more common in patients with D-dimer levels above the median (6086 ng/ml). In the multivariate analysis, the protective effect of heparin against filter clotting persisted, whereas an elevated D-dimer level, high platelet count, and high hemoglobin were found to be risk factors for circuit clotting. A diagnosis of COVID-19 was not a risk factor for filter clotting.Conclusions: In COV+ AKI patients, adding systemic heparin to standard regional citrate anticoagulation may prolong CRRT filter patency by reducing clotting risk with low risk of complications.