Epidemiology and Outcomes of Acute Kidney Injury in COVID-19 Patients with Acute Respiratory Distress Syndrome: A Multicenter Retrospective Study

Research on the global trends of COVID-19 associated acute kidney injury: a bibliometric analysis

Critically ill COVID-19 patients may exhibit various clinical symptoms of renal dysfunction including severe Acute Kidney Injury (AKI). Currently, there is a lack of bibliometric analyses on COVID-19-related AKI. The aim of this study is to provide an overview of the current research status and hot topics regarding COVID-19 AKI. The literature was retrieved from the Web of Science Core Collection (WoSCC) database. Subsequently, we utilized Microsoft Excel, VOSviewer, Citespace, and Pajek software to revealed the current research status, emerging topics, and developmental trends pertaining to COVID-19 AKI. This study encompassed a total of 1507 studies on COVID-19 AKI. The United States, China, and Italy emerged as the leading three countries in terms of publication numbers, contributing 498 (33.05%), 229 (15.20%), and 140 (9.29%) studies, respectively. The three most active and influential institutions include Huazhong University of Science and Technology, Wuhan University and Harvard Medical School. Ronco C from Italy, holds the record for the highest number of publications, with a total of 15 papers authored. Cheng YC's work from China has garnered the highest number of citations, totaling 470 citations. The co-occurrence analysis of author keywords reveals that 'mortality', 'intensive care units', 'chronic kidney disease', 'nephrology', 'renal transplantation', 'acute respiratory distress syndrome', and 'risk factors' emerge as the primary areas of focus within the realm of COVID-19 AKI. In summary, this study analyzes the research trends in the field of COVID-19 AKI, providing a reference for further exploration and research on COVID-19 AKI mechanisms and treatment.

Tocilizumab Associated With Survival in Patients Hospitalized for COVID-19 Acute Respiratory Distress Syndrome and Low Urine Output

BACKGROUND

Acute respiratory distress syndrome (ARDS) with oliguria is associated with increased mortality. Interleukin-6 (IL-6) plays an integral role in the pathophysiology of both disease processes. Patients who experience severe COVID-19 have demonstrated higher IL-6 levels compared to baseline, and use of tocilizumab has demonstrated efficacy in such cohorts. We set out to investigate the relationship between tocilizumab use, COVID-19 ARDS, low urine output, and mortality.

METHODS

Retrospective cohort review of adult patients aged ≥ 18 years with COVID-19 and moderate or severe ARDS, admitted to the intensive care unit (ICU) of a tertiary referral center in metropolitan Detroit. Patients were analyzed based on presence of oliguria (defined as ≤ 0.7 mL/kg/h) on the day of intubation and exposure to tocilizumab while inpatient. The primary outcome was inpatient mortality.

RESULTS

One hundred and twenty-eight patients were analyzed, 103 (80%) with low urine output, of whom 30 (29%) received tocilizumab. In patients with low urine output, risk factors associated with mortality on univariate analysis included Black race (P  =  .028), lower static compliance (P  =  .015), and tocilizumab administration (P  =  .002). Tocilizumab (odds ratio 0.245, 95% confidence interval 0.079-0.764, P  =  .015) was the only risk factor independently associated with survival on multivariate logistic regression analysis.

CONCLUSION

In this retrospective cohort review of patients hospitalized with COVID-19 and moderate or severe ARDS, tocilizumab administration was independently associated with survival in patients with low urine output ≤ 0.7 mL/kg/h on the day of intubation. Prospective studies are needed to investigate the impact of urine output on efficacy of interleukin-targeted therapies in the management of ARDS.

AKI in Adults with COVID-19 Infection: Mechanisms of Development and Role of Blood Filtration Devices in Treatment

During the coronavirus disease 2019 (COVID-19) pandemic, acute kidney injury (AKI) was a common sequela of COVID-19 infection and predicted disease severity and mortality. Extracorporeal blood purification techniques involving blood filtration devices are an emerging treatment for AKI in the setting of severe COVID-19 infections. In this review, we discuss potential mechanisms for the development of AKI in COVID-19 patients as well as the various available blood filtration devices and the role they may play in managing the AKI in COVID-19 patients. A total of seven blood filters currently available were compared based on their potential in treating AKI in COVID-19 patients. Blood filtration devices show potential as an emerging treatment modality for COVID-19-induced AKI, but further clinical trials are necessary before their widespread adoption and usage.

The interface between SARS-CoV-2 and non-communicable diseases (NCDs) in a high HIV/TB burden district level hospital setting, Cape Town, South Africa

BACKGROUND

COVID-19 experiences on noncommunicable diseases (NCDs) from district-level hospital settings during waves I and II are scarcely documented. The aim of this study is to investigate the NCDs associated with COVID-19 severity and mortality in a district-level hospital with a high HIV/TB burden.

METHODS

This was a retrospective observational study that compared COVID-19 waves I and II at Khayelitsha District Hospital in Cape Town, South Africa. COVID-19 adult patients with a confirmed SARS-CoV-2 polymerase chain reaction (PCR) or positive antigen test were included. In order to compare the inter wave period, clinical and laboratory parameters on hospital admission of noncommunicable diseases, the Student t-test or Mann-Whitney U for continuous data and the X2 test or Fishers' Exact test for categorical data were used. The role of the NCD subpopulation on COVID-19 mortality was determined using latent class analysis (LCA).

FINDINGS

Among 560 patients admitted with COVID-19, patients admitted during wave II were significantly older than those admitted during wave I. The most prevalent comorbidity patterns were hypertension (87%), diabetes mellitus (65%), HIV/AIDS (30%), obesity (19%), Chronic Kidney Disease (CKD) (13%), Congestive Cardiac Failure (CCF) (8.8%), Chronic Obstructive Pulmonary Disease (COPD) (3%), cerebrovascular accidents (CVA)/stroke (3%), with similar prevalence in both waves except HIV status [(23% vs 34% waves II and I, respectively), p = 0.022], obesity [(52% vs 2.5%, waves II and I, respectively), p <0.001], previous stroke [(1% vs 4.1%, waves II and I, respectively), p = 0.046]. In terms of clinical and laboratory findings, our study found that wave I patients had higher haemoglobin and HIV viral loads. Wave II, on the other hand, had statistically significant higher chest radiography abnormalities, fraction of inspired oxygen (FiO2), and uraemia. The adjusted odds ratio for death vs discharge between waves I and II was similar (0.94, 95%CI: 0.84-1.05). Wave I had a longer average survival time (8.0 vs 6.1 days) and a shorter average length of stay among patients discharged alive (9.2 vs 10.7 days). LCA revealed that the cardiovascular phenotype had the highest mortality, followed by diabetes and CKD phenotypes. Only Diabetes and hypertension phenotypes had the lowest mortality.

CONCLUSION

Even though clinical and laboratory characteristics differed significantly between the two waves, mortality remained constant. According to LCA, the cardiovascular, diabetes, and CKD phenotypes had the highest death probability.

Machine learning-based prediction model of acute kidney injury in patients with acute respiratory distress syndrome

BACKGROUND

Acute kidney injury (AKI) can make cases of acute respiratory distress syndrome (ARDS) more complex, and the combination of the two can significantly worsen the prognosis. Our objective is to utilize machine learning (ML) techniques to construct models that can promptly identify the risk of AKI in ARDS patients.

METHOD

We obtained data regarding ARDS patients from the Medical Information Mart for Intensive Care III (MIMIC-III) and MIMIC-IV databases. Within the MIMIC-III dataset, we developed 11 ML prediction models. By evaluating various metrics, we visualized the importance of its features using Shapley additive explanations (SHAP). We then created a more concise model using fewer variables, and optimized it using hyperparameter optimization (HPO). The model was validated using the MIMIC-IV dataset.

RESULT

A total of 928 ARDS patients without AKI were included in the analysis from the MIMIC-III dataset, and among them, 179 (19.3%) developed AKI after admission to the intensive care unit (ICU). In the MIMIC-IV dataset, there were 653 ARDS patients included in the analysis, and among them, 237 (36.3%) developed AKI. A total of 43 features were used to build the model. Among all models, eXtreme gradient boosting (XGBoost) performed the best. We used the top 10 features to build a compact model with an area under the curve (AUC) of 0.850, which improved to an AUC of 0.865 after the HPO. In extra validation set, XGBoost_HPO achieved an AUC of 0.854. The accuracy, sensitivity, specificity, positive prediction value (PPV), negative prediction value (NPV), and F1 score of the XGBoost_HPO model on the test set are 0.865, 0.813, 0.877, 0.578, 0.957 and 0.675, respectively. On extra validation set, they are 0.724, 0.789, 0.688, 0.590, 0.851, and 0.675, respectively.

CONCLUSION

ML algorithms, especially XGBoost, are reliable for predicting AKI in ARDS patients. The compact model maintains excellent predictive ability, and the web-based calculator improves clinical convenience. This provides valuable guidance in identifying AKI in ARDS, leading to improved patient outcomes.

Acute Kidney Injury Associated with Severe SARS-CoV-2 Infection: Risk Factors for Morbidity and Mortality and a Potential Benefit of Combined Therapy with Tocilizumab and Corticosteroids

Background: Acute kidney injury (AKI) is a common complication in patients with severe COVID-19. Methods: We retrospectively reviewed 249 patients admitted to an intensive care unit (ICU) during the first wave of the pandemic to determine risk factors for AKI. Demographics, comorbidities, and clinical and outcome variables were obtained from electronic medical records. Results: Univariate analysis revealed older age, higher admission serum creatinine, elevated Sequential Organ Failure Assessment (SOFA) score, elevated admission D-Dimer, elevated CRP on day 2, mechanical ventilation, vasopressor requirement, and azithromycin usage as significant risk factors for AKI. Multivariate analysis demonstrated that higher admission creatinine (p = 0.0001, OR = 2.41, 95% CI = 1.56–3.70), vasopressor requirement (p = 0.0001, OR = 3.20, 95% CI = 1.69–5.98), elevated admission D-Dimer (p = 0.008, OR = 1.0001, 95% CI = 1.000–1.001), and elevated C-reactive protein (CRP) on day 2 (p = 0.033, OR = 1.0001, 95% CI = 1.004–1.009) were independent risk factors. Conversely, the combined use of Tocilizumab and corticosteroids was independently associated with reduced AKI risk (p = 0.0009, OR = 0.437, 95% CI = 0.23–0.81). Conclusion: This study confirms the high rate of AKI and associated mortality among COVID-19 patients admitted to ICUs and suggests a role for inflammation and/or coagulopathy in AKI development. One should consider the possibility that early administration of anti-inflammatory agents, as is now routinely conducted in the management of COVID-19-associated acute respiratory distress syndrome, may improve clinical outcomes in patients with AKI.

Acute kidney injury in critical COVID-19: a multicenter cohort analysis in seven large hospitals in Belgium

Background

Acute kidney injury (AKI) has been reported as a frequent complication of critical COVID-19. We aimed to evaluate the occurrence of AKI and use of kidney replacement therapy (KRT) in critical COVID-19, to assess patient and kidney outcomes and risk factors for AKI and differences in outcome when the diagnosis of AKI is based on urine output (UO) or on serum creatinine (sCr).

Methods

Multicenter, retrospective cohort analysis of patients with critical COVID-19 in seven large hospitals in Belgium. AKI was defined according to KDIGO within 21 days after ICU admission. Multivariable logistic regression analysis was used to explore the risk factors for developing AKI and to assess the association between AKI and ICU mortality.

Results

Of 1286 patients, 85.1% had AKI, and KRT was used in 9.8%. Older age, obesity, a higher APACHE II score and use of mechanical ventilation at day 1 of ICU stay were associated with an increased risk for AKI. After multivariable adjustment, all AKI stages were associated with ICU mortality. AKI was based on sCr in 40.1% and UO in 81.5% of patients. All AKI stages based on sCr and AKI stage 3 based on UO were associated with ICU mortality. Persistent AKI was present in 88.6% and acute kidney disease (AKD) in 87.6%. Rapid reversal of AKI yielded a better prognosis compared to persistent AKI and AKD. Kidney recovery was observed in 47.4% of surviving AKI patients.

Conclusions

Over 80% of critically ill COVID-19 patients had AKI. This was driven by the high occurrence rate of AKI defined by UO criteria. All AKI stages were associated with mortality (NCT04997915).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04086-x.

Acute kidney injury in critically ill COVID-19 infected patients requiring dialysis: experience from India and Pakistan

Background

Acute kidney injury (AKI) was common in the first two waves of the SARS-COV-2 pandemic in critically ill patients. A high percentage of these patients required renal replacement therapy and died in the hospital.

Methods

The present study examines the clinical presentation, laboratory parameters and therapeutic interventions in critically ill patients with AKI admitted to the ICU in two centres, one each in India and Pakistan. Patient and outcome details of all critically ill COVID 19 patients admitted to the ICU requiring renal replacement therapy were collected. Data was analysed to detect patient variables associated with mortality.

Results

A total of 1,714 critically ill patients were admitted to the ICUs of the two centres. Of these 393 (22.9%) had severe acute kidney injury (AKIN stage 3) requiring dialysis. Of them, 60.5% were men and the mean (± SD) age was 58.78 (± 14.4) years. At the time of initiation of dialysis, 346 patients (88%) were oligo-anuric. The most frequent dialysis modality in these patients was intermittent hemodialysis (48.1%) followed by slow low efficiency dialysis (44.5%). Two hundred and six (52.4%) patients died. The mortality was higher among the Indian cohort (68.1%) than the Pakistani cohort (43.4%). Older age (age > 50 years), low serum albumin altered sensorium, need for slower forms of renal replacement therapy and ventilatory support were independently associated with mortality.

Conclusion

There was a very high mortality in patients with COVID-19 associated AKI undergoing RRT in the ICUs in this cohort from the Indian sub-continent.

Development and validation of the MMCD score to predict kidney replacement therapy in COVID-19 patients

BACKGROUND

Acute kidney injury (AKI) is frequently associated with COVID-19, and the need for kidney replacement therapy (KRT) is considered an indicator of disease severity. This study aimed to develop a prognostic score for predicting the need for KRT in hospitalised COVID-19 patients, and to assess the incidence of AKI and KRT requirement.

METHODS

This study is part of a multicentre cohort, the Brazilian COVID-19 Registry. A total of 5212 adult COVID-19 patients were included between March/2020 and September/2020. Variable selection was performed using generalised additive models (GAM), and least absolute shrinkage and selection operator (LASSO) regression was used for score derivation. Accuracy was assessed using the area under the receiver operating characteristic curve (AUC-ROC).

RESULTS

The median age of the model-derivation cohort was 59 (IQR 47-70) years, 54.5% were men, 34.3% required ICU admission, 20.9% evolved with AKI, 9.3% required KRT, and 15.1% died during hospitalisation. The temporal validation cohort had similar age, sex, ICU admission, AKI, required KRT distribution and in-hospital mortality. The geographic validation cohort had similar age and sex; however, this cohort had higher rates of ICU admission, AKI, need for KRT and in-hospital mortality. Four predictors of the need for KRT were identified using GAM: need for mechanical ventilation, male sex, higher creatinine at hospital presentation and diabetes. The MMCD score had excellent discrimination in derivation (AUROC 0.929, 95% CI 0.918-0.939) and validation (temporal AUROC 0.927, 95% CI 0.911-0.941; geographic AUROC 0.819, 95% CI 0.792-0.845) cohorts and good overall performance (Brier score: 0.057, 0.056 and 0.122, respectively). The score is implemented in a freely available online risk calculator ( https://www.mmcdscore.com/ ).

CONCLUSIONS

The use of the MMCD score to predict the need for KRT may assist healthcare workers in identifying hospitalised COVID-19 patients who may require more intensive monitoring, and can be useful for resource allocation.

Multi-omic comparative analysis of COVID-19 and bacterial sepsis-induced ARDS

BACKGROUND

Acute respiratory distress syndrome (ARDS), a life-threatening condition characterized by hypoxemia and poor lung compliance, is associated with high mortality. ARDS induced by COVID-19 has similar clinical presentations and pathological manifestations as non-COVID-19 ARDS. However, COVID-19 ARDS is associated with a more protracted inflammatory respiratory failure compared to traditional ARDS. Therefore, a comprehensive molecular comparison of ARDS of different etiologies groups may pave the way for more specific clinical interventions.

METHODS AND FINDINGS

In this study, we compared COVID-19 ARDS (n = 43) and bacterial sepsis-induced (non-COVID-19) ARDS (n = 24) using multi-omic plasma profiles covering 663 metabolites, 1,051 lipids, and 266 proteins. To address both between- and within- ARDS group variabilities we followed two approaches. First, we identified 706 molecules differently abundant between the two ARDS etiologies, revealing more than 40 biological processes differently regulated between the two groups. From these processes, we assembled a cascade of therapeutically relevant pathways downstream of sphingosine metabolism. The analysis suggests a possible overactivation of arginine metabolism involved in long-term sequelae of ARDS and highlights the potential of JAK inhibitors to improve outcomes in bacterial sepsis-induced ARDS. The second part of our study involved the comparison of the two ARDS groups with respect to clinical manifestations. Using a data-driven multi-omic network, we identified signatures of acute kidney injury (AKI) and thrombocytosis within each ARDS group. The AKI-associated network implicated mitochondrial dysregulation which might lead to post-ARDS renal-sequalae. The thrombocytosis-associated network hinted at a synergy between prothrombotic processes, namely IL-17, MAPK, TNF signaling pathways, and cell adhesion molecules. Thus, we speculate that combination therapy targeting two or more of these processes may ameliorate thrombocytosis-mediated hypercoagulation.

CONCLUSION

We present a first comprehensive molecular characterization of differences between two ARDS etiologies-COVID-19 and bacterial sepsis. Further investigation into the identified pathways will lead to a better understanding of the pathophysiological processes, potentially enabling novel therapeutic interventions.

Multi-omic comparative analysis of COVID-19 and bacterial sepsis-induced ARDS

Background

Acute respiratory distress syndrome (ARDS), a life-threatening condition characterized by hypoxemia and poor lung compliance, is associated with high mortality. ARDS induced by COVID-19 has similar clinical presentations and pathological manifestations as non-COVID-19 ARDS. However, COVID-19 ARDS is associated with a more protracted inflammatory respiratory failure compared to traditional ARDS. Therefore, a comprehensive molecular comparison of ARDS of different etiologies groups may pave the way for more specific clinical interventions.

Methods and Findings

In this study, we compared COVID-19 ARDS (n=43) and bacterial sepsis-induced (non-COVID-19) ARDS (n=24) using multi-omic plasma profiles covering 663 metabolites, 1,051 lipids, and 266 proteins. To address both between- and within-ARDS group variabilities we followed two approaches. First, we identified 706 molecules differently abundant between the two ARDS etiologies, revealing more than 40 biological processes differently regulated between the two groups. From these processes, we assembled a cascade of therapeutically relevant pathways downstream of sphingosine metabolism. The analysis suggests a possible overactivation of arginine metabolism involved in long-term sequelae of ARDS and highlights the potential of JAK inhibitors to improve outcomes in bacterial sepsis-induced ARDS. The second part of our study involved the comparison of the two ARDS groups with respect to clinical manifestations. Using a data-driven multi-omic network, we identified signatures of acute kidney injury (AKI) and thrombocytosis within each ARDS group. The AKI-associated network implicated mitochondrial dysregulation which might lead to post-ARDS renal-sequalae. The thrombocytosis-associated network hinted at a synergy between prothrombotic processes, namely IL-17, MAPK, TNF signaling pathways, and cell adhesion molecules. Thus, we speculate that combination therapy targeting two or more of these processes may ameliorate thrombocytosis-mediated hypercoagulation.

Conclusion

We present a first comprehensive molecular characterization of differences between two ARDS etiologies - COVID-19 and bacterial sepsis. Further investigation into the identified pathways will lead to a better understanding of the pathophysiological processes, potentially enabling novel therapeutic interventions.

Integration of sustained low-efficiency dialysis into extracorporeal membrane oxygenation circuit in critically ill COVID-19 patients - a feasibility study

Background

Severe COVID‐19 can necessitate multiple organ support including veno‐venous extracorporeal membrane oxygenation (vvECMO) and renal replacement therapy. The therapy can be complicated by venous thromboembolism due to COVID‐19‐related hypercoagulability, thus restricting vascular access beyond the vvECMO cannula. Although continuous renal replacement therapy can be performed via a vvECMO circuit, studies addressing sustained low‐efficiency dialysis (SLED) integration into vvECMO circuits are scarce. Here we address the lack of evidence by evaluating feasibility of SLED integration into vvECMO circuits.

Methods

Retrospective cohort study on nine critically ill COVID‐19 patients, treated with integrated ECMO‐SLED on a single intensive care unit at a tertiary healthcare facility between December 2020 and November 2021. The SLED circuits were established between the accessory arterial oxygenator outlets of a double‐oxygenator vvECMO setup. Data on filter survival, quality of dialysis, and volume management were collected and compared with an internal control group receiving single SLED.

Results

This study demonstrates general feasibility of SLED integration into existing vvECMO circuits. Filter lifespans of ECMO‐SLED compared with single SLED are significantly prolonged (median 18.3 h vs. 10.3 h, p < 0.01). ECMO‐SLED treatment is furthermore able to sufficiently normalize creatinine, blood urea nitrogen, and serum sodium, and allows for adequate ultrafiltration rates.

Conclusions

We can show that ECMO‐SLED is practical, safe, results in adequate dialysis quality and enables sufficient electrolyte and volume management. Our data indicate that SLED devices can serve as potential alternative to continuous‐veno‐venous‐hemodialysis for integration in vvECMO circuits.

Latin American registry of renal involvement in COVID-19 disease. The relevance of assessing proteinuria throughout the clinical course

The Latin American Society of Nephrology and Hypertension conducted a prospective cohort, multinational registry of Latin American patients with kidney impairment associated to COVID-19 infection with the objective to describe the characteristics of acute kidney disease under these circumstances. The study was carried out through open invitation in order to describe the characteristics of the disease in the region. Eight-hundred and seventy patients from 12 countries were included. Median age was 63 years (54-74), most of patients were male (68.4%) and with diverse comorbidities (87.2%). Acute kidney injury (AKI) was hospital-acquired in 64.7% and non-oliguric in 59.9%. Multiorgan dysfunction syndrome (MODS) due to COVID-19 and volume depletion were the main factors contributing to AKI (59.2% and 35.7% respectively). Kidney replacement therapy was started in 46.2%. Non-recovery of renal function was observed in 65.3%. 71.5% of patients were admitted to ICU and 72.2% underwent mechanical ventilation. Proteinuria at admission was present in 62.4% of patients and proteinuria during hospital-stay occurred in 37.5%. Those patients with proteinuria at admission had higher burden of comorbidities, higher baseline sCr, and MODS was severe. On the other hand, patients with de novo proteinuria had lower incidence of comorbidities and near normal sCr at admission, but showed adverse course of disease. COVID-19 MODS was the main cause of AKI in both groups. All-cause mortality of the general population was 57.4%, and it was associated to age, sepsis as cause of AKI, severity of condition at admission, oliguria, mechanical ventilation, non-recovery of renal function, in-hospital complications and hospital stay. In conclusion, our study contributes to a better knowledge of this condition and highlights the relevance of the detection of proteinuria throughout the clinical course.

Blood Filters in Children with COVID-19 and AKI: A Review

COVID-19 has challenged the global healthcare system through rapid proliferation and lack of existing treatment resulting in over 180 million cases and 3.8 million deaths since December 2019. Although pediatric patients only comprise 1-2% of diagnosed cases, their incidence of acute kidney injury ranges from 8.2% to 18.2% compared to 49% in adults. Severe infection, initiated by dysregulated host response, can lead to multiorgan failure. In this review, we focus on the use of various blood filters approved for use in pediatric kidney replacement therapy to mitigate adverse effects of severe illness. Therapeutic effects of these blood filters range from cytokine removal (CytoSorb, HA330, HCO/MCO), endotoxin removal (Toraymyxin, CPFA), both cytokine and endotoxin removal (oXiris), and non-specific removal of proteins (PMMA) that have already been established and can be used to mitigate the various effects of the cytokine storm syndrome in COVID-19.

Risk Factors for Acute Kidney Injury in Adult Patients With COVID-19: A Systematic Review and Meta-Analysis

Background and Objective: Since December 2019, coronavirus disease 2019 (COVID-19) has spread rapidly around the world. Studies found that the incidence of acute kidney injury (AKI) in COVID-19 patients was more than double the incidence of AKI in non-COVID-19 patients. Some findings confirmed that AKI is a strong independent risk factor for mortality in patients with COVID-19 and is associated with a three-fold increase in the odds of in-hospital mortality. However, little information is available about AKI in COVID-19 patients. This study aimed to analyse the risk factors for AKI in adult patients with COVID-19.

Methods: A systematic literature search was conducted in PubMed, EMBASE, Web of Science, the Cochrane Library, CNKI, VIP and WanFang Data from 1 December 2019 to 30 January 2021. We extracted data from eligible studies to compare the effects of age, sex, chronic diseases and potential risk factors for AKI on the prognosis of adult patients with COVID-19.

Results: In total, 38 studies with 42,779 patients were included in this analysis. The meta-analysis showed that male sex (OR = 1.37), older age (MD = 5.63), smoking (OR = 1.23), obesity (OR = 1.12), hypertension (OR=1.85), diabetes (OR=1.71), pneumopathy (OR = 1.36), cardiovascular disease (OR = 1.98), cancer (OR = 1.26), chronic kidney disease (CKD) (OR = 4.56), mechanical ventilation (OR = 8.61) and the use of vasopressors (OR = 8.33) were significant risk factors for AKI (P < 0.05).

Conclusions: AKI is a common and serious complication of COVID-19. Overall, male sex, age, smoking, obesity, hypertension, diabetes, pneumopathy, cardiovascular disease, cancer, CKD, mechanical ventilation and the use of vasopressors were independent risk factors for AKI in adult patients with COVID-19. Clinicians need to be aware of these risk factors to reduce the incidence of AKI.

System Review Registration: PROSPERO, identifier [CRD42021282233].

Acute Kidney Disease and Mortality in Acute Kidney Injury Patients with COVID-19

Background: The incidence of AKI in coronavirus disease 2019 (COVID-19) patients is variable and has been associated with worse prognosis. A significant number of patients develop persistent kidney damage defined as Acute Kidney Disease (AKD). There is a lack of evidence on the real impact of AKD on COVID-19 patients. We aim to identify risk factors for the development of AKD and its impact on mortality in COVID-19 patients. Methods: Retrospective analysis of COVID-19 patients with AKI admitted at the Centro Hospitalar Universitário Lisboa Norte between March and August of 2020. The Kidney Disease Improving Global Outcomes (KDIGO) classification was used to define AKI. AKD was defined by presenting at least KDIGO Stage 1 criteria for >7 days after an AKI initiating event. Results: In 339 COVID-19 patients with AKI, 25.7% patients developed AKD (n = 87). The mean age was 71.7 ± 17.0 years, baseline SCr was 1.03 ± 0.44 mg/dL, and the majority of patients were classified as KDIGO stage 3 AKI (54.3%). The in-hospital mortality was 18.0% (n = 61). Presence of hypertension (p = 0.006), CKD (p < 0.001), lower hemoglobin (p = 0.034) and lower CRP (p = 0.004) at the hospital admission and nephrotoxin exposure (p < 0.001) were independent risk factors for the development of AKD. Older age (p = 0.003), higher serum ferritin at admission (p = 0.008) and development of AKD (p = 0.029) were independent predictors of in-hospital mortality in COVID-19-AKI patients. Conclusions: AKD was significantly associated with in-hospital mortality in this population of COVID-19-AKI patients. Considering the significant risk of mortality in AKI patients, it is of paramount importance to identify the subset of higher risk patients.

Overview of acute kidney manifestations and management of patients with COVID-19

Since the start of the COVID-19 pandemic, several manifestations of kidney involvement associated with infection of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus have been described, including proteinuria, hematuria, and acute kidney injury. A growing body of literature has explored the risk factors and pathogenesis of COVID-19-associated acute kidney injury (AKI), including direct and indirect mechanisms, as well as early postdischarge outcomes that may result from various manifestations of kidney involvement. In this review, we explore the current state of knowledge of the epidemiology of COVID-19-associated AKI, potential mechanisms and pathogenesis of AKI, and various management strategies for patients in the acute setting. We highlight how kidney replacement therapy for patients with COVID-19-associated AKI has been affected by the increasing demand for dialysis and how the postacute management of patients, including outpatient follow-up, is vitally important. We also review what is presently known about long-term kidney outcomes after the initial recovery from COVID-19. We provide some guidance as to the management of patients hospitalized with COVID-19 who are at risk for AKI as well as for future clinical research in the setting of COVID-19 and the significance of early identification of patients at highest risk for adverse kidney outcomes.

Acute kidney injury prevalence, progression and long-term outcomes in critically ill patients with COVID-19: a cohort study

BACKGROUND

There are limited data on acute kidney injury (AKI) progression and long-term outcomes in critically ill patients with coronavirus disease-19 (COVID-19). We aimed to describe the prevalence and risk factors for development of AKI, its subsequent clinical course and AKI progression, as well as renal recovery or dialysis dependence and survival in this group of patients.

METHODS

This was a retrospective observational study in an expanded tertiary care intensive care unit in London, United Kingdom. Critically ill patients admitted to ICU between 1st March 2020 and 31st July 2020 with confirmed SARS-COV2 infection were included. Analysis of baseline characteristics, organ support, COVID-19 associated therapies and their association with mortality and outcomes at 90 days was performed.

RESULTS

Of 313 patients (70% male, mean age 54.5 ± 13.9 years), 240 (76.7%) developed AKI within 14 days after ICU admission: 63 (20.1%) stage 1, 41 (13.1%) stage 2, 136 (43.5%) stage 3. 113 (36.1%) patients presented with AKI on ICU admission. Progression to AKI stage 2/3 occurred in 36%. Risk factors for AKI progression were mechanical ventilation [HR (hazard ratio) 4.11; 95% confidence interval (CI) 1.61-10.49] and positive fluid balance [HR 1.21 (95% CI 1.11-1.31)], while steroid therapy was associated with a reduction in AKI progression (HR 0.73 [95% CI 0.55-0.97]). Kidney replacement therapy (KRT) was initiated in 31.9%. AKI patients had a higher 90-day mortality than non-AKI patients (34% vs. 14%; p < 0.001). Dialysis dependence was 5% at hospital discharge and 4% at 90 days. Renal recovery was identified in 81.6% of survivors at discharge and in 90.9% at 90 days. At 3 months, 16% of all AKI survivors had chronic kidney disease (CKD); among those without renal recovery, the CKD incidence was 44%.

CONCLUSIONS

During the first COVID-19 wave, AKI was highly prevalent among severely ill COVID-19 patients with a third progressing to severe AKI requiring KRT. The risk of developing CKD was high. This study identifies factors modifying AKI progression, including a potentially protective effect of steroid therapy. Recognition of risk factors and monitoring of renal function post-discharge might help guide future practice and follow-up management strategies. Trial registration NCT04445259.

Current treatment of COVID-19 in renal patients: hope or hype?

To date the severe acute respiratory syndrome coronavirus 2 (SARS- CoV-2), known as COVID-19, is for clinicians the most difficult global therapeutic problem. In this landscape, the management of patients with chronic kidney disease, acute kidney injury or patients undergoing immunosuppressant therapies for kidney transplant or glomerular diseases, represent a clinical challenge for nephrologists, especially in patients with severe acute lung involvement. Therefore in this setting, due to the lack of anti-COVID treatment schedules, tailored management is mandatory to reduce the side effects, as consequence of impaired renal function and drugs interactions. We report the main treatment actually used against SARS-CoV-2, underlining its possible use in the nephropatic patients and the central role of nephrologists to improve the clinical outcome.