Acute Kidney Injury in Patients with the Coronavirus Disease 2019: A Multicenter Study

Proximal tubular dysfunction as a predictor of AKI in Hospitalized COVID-19 patients

BACKGROUND

High concentration of Angiotensin converting enzyme receptors in the proximal tubules make kidneys an early target in COVID-19. Proximal tubular dysfunction (PTD) may act as an early predictor of acute kidney injury (AKI) and more severe disease.

METHODS

This prospective observational study was conducted in the COVID unit, Bangabandhu Sheikh Mujib Medical University. 87 COVID-19 patients without known kidney disease were screened for 6 markers of PTD on admission-hyperuricosuria, normoglycemic glycosuria, proteinuria, renal phosphate leak, sodium leak and potassium leak. Positivity of 2 of the first 4 markers was considered as PTD. 35 patients with PTD and 35 without PTD were followed up throughout their hospital stay.

RESULTS

52.9% had PTD on admission. The most prevalent markers were renal sodium leak (67%), followed by proteinuria (66.7%), hyperuricosuria (42.5%), potassium leak (32.2%), phosphate leak (28.7%) and normoglycemic glycosuria (20.7%). Mean age was 55.7 years. 32.9% patients developed AKI. PTD group had higher odds of developing AKI (odds ratio 17.5 for stage 1, 24.8 for stage 2 and 25.5 for stage 3; p<0.0001). The mean duration of hospital stay was 9 days higher in the PTD group (p<0.001). PTD group also had higher odds of transferring to ICU (OR = 9.4, p = 0.002), need for mechanical ventilation (OR = 10.1, p = 0.002) and death (OR = 10.3, p = 0.001). 32.6% had complete PTD recovery during follow-up.

CONCLUSION

Proximal tubular dysfunction is highly prevalent in COVID-19 patients very early in the disease and may act as a predictor of AKI, ICU transfer, need for mechanical ventilation and death.

Burden and risk profile of acute kidney injury in severe COVID-19 pneumonia admissions: a Finding from Jimma University medical center, Ethiopia

BACKGROUND

Acute kidney injury (AKI) is a serious complication of the Corona Virus Disease of 2019 (COVID-19). However, data on its magnitude and risk factors among hospitalized patients in Ethiopia is limited. This study aimed to determine the magnitude of AKI and associated factors among patients admitted for severe COVID-19 pneumonia.

METHODS

An institution-based retrospective cross-sectional study was conducted among 224 patients admitted to Jimma University Medical Center in Ethiopia for severe COVID-19 pneumonia from May 2020 to December 2021. Systematic random sampling was used to select study participants. Medical records were reviewed to extract sociodemographic, clinical, laboratory, therapeutic, and comorbidity data. Bivariable and multivariable logistic regressions were performed to examine factors associated with AKI. The magnitude of the association between the explanatory variables and AKI was estimated using an adjusted odds ratio (AOR) with a 95% confidence interval (CI), and significance was declared at a p-value of 0.05.

RESULTS

The magnitude of AKI was 42% (95% CI: 35.3-48.2%) in the study area. Mechanical ventilation, vasopressors, and antibiotics were required in 32.6, 3.7, and 97.7% of the patients, respectively. After adjusting for possible confounders, male sex (AOR 2.79, 95% CI: 1.3-6.5), fever (AOR 6.5, 95% CI: 2.7-15.6), hypoxemia (AOR 5.1, 95% CI: 1.4-18.9), comorbidities (AOR 2.8, 95% CI: 1.1-7.0), and severe anemia (AOR 10, 95% CI: 1.7-65.7) remained significantly associated with higher odds of AKI.

CONCLUSION

The burden of AKI among patients with severe COVID-19 pneumonia is high in our setting. Male sex, abnormal vital signs, chronic conditions, and anemia can identify individuals at increased risk and require close monitoring and prevention efforts.

Factors associated with acute kidney injury (AKI) and mortality in COVID-19 patients in a Sub-Saharan African intensive care unit: a single-center prospective study

INTRODUCTION

Acute kidney injury (AKI) is a complication of severe coronavirus disease 2019 (COVID-19). Kidney damage associated with COVID-19 could take specific features due to environmental and socio-cultural factors. This study evaluates the incidence of AKI, the associated factors, and mortality in COVID-19 patients in a Sub-Saharan African intensive care unit.

METHODS

In a prospective cohort study conducted in the intensive care unit (ICU) of the Centre Médical de Kinshasa (CMK), consecutive patients admitted for COVID-19 were screened for the presence of AKI between 27 March, 2020 and 27 January 2022. AKI was defined according to Kidney Disease Improving Global Outcomes (KDIGO) guidelines. The primary outcome was occurrence of AKI. The secondary outcome was 48 days' mortality and recovery of the renal function at intensive care unit (ICU) discharge. Survival (time-to death) curves were built using the Kaplan Meier methods. Multivariate analyses were performed by logistic regression to identify factors associated with AKI and Cox regression to explore the association between AKI and in-hospital mortality. The significance level of the p-value was set at 0.05.

RESULTS

The median(IQR) sequential organ failure assessment score (SOFA) score and mean age of patients (215) including in our cohort were respectively 3(2-4) and 58.9 ± 14.9 years. The incidence of AKI was 28.4% with stages 1, 2, or 3 AKI accounted for 39.3%, 11.5%, and 49.2%, respectively. Hemodialysis was required in 16 out 215 (7.4%) patients. Dyspnea (adjusted odds ratio (aOR):2.27 [1.1--4.57] p = 0.021), SOFA ≥5 (aOR:3.11[1.29-7.53] p = 0.012), AST/ALT ratio (aOR: 1.53 [1.09-1.79] p = 0.015), N/L ratio (aOR:2.09 [1.09-3.20] p = 0.016), mechanical ventilation (aOR: 3.20 [1.66-10.51] p = 0.005) and Amikacin (aOR: 2.91 [1.37-6.18] p = 0.006) were the main factors associated with AKI. Patients with AKI had a mortality rate of 52.5% and 67.2% of the survivors did not recover kidney function at the end of hospitalization. Adjusted Cox regression analysis revealed that COVID-19-associated AKI was independently associated with in-hospital death (HR:2.96 [1.93-4.65] p = 0.013) compared to non-AKI patients.

CONCLUSIONS

AKI was present in three out of ten COVID-19 patients. The most significant factors associated with AKI were dyspnea, SOFA ≥ 5, AST/ALT and N/L ratio, mechanical ventilation and Amikacin. AKI has been associated with an almost threefold increase in overall mortality and seven out of ten survivors did not recover kidney function after AKI.

Construction and validation of prognostic models in critically Ill patients with sepsis-associated acute kidney injury: interpretable machine learning approach

BACKGROUND

Acute kidney injury (AKI) is a common complication in critically ill patients with sepsis and is often associated with a poor prognosis. We aimed to construct and validate an interpretable prognostic prediction model for patients with sepsis-associated AKI (S-AKI) using machine learning (ML) methods.

METHODS

Data on the training cohort were collected from the Medical Information Mart for Intensive Care IV database version 2.2 to build the model, and data of patients were extracted from Hangzhou First People's Hospital Affiliated to Zhejiang University School of Medicine for external validation of model. Predictors of mortality were identified using Recursive Feature Elimination (RFE). Then, random forest, extreme gradient boosting (XGBoost), multilayer perceptron classifier, support vector classifier, and logistic regression were used to establish a prognosis prediction model for 7, 14, and 28 days after intensive care unit (ICU) admission, respectively. Prediction performance was assessed using the receiver operating characteristic (ROC) curve and decision curve analysis (DCA). SHapley Additive exPlanations (SHAP) were used to interpret the ML models.

RESULTS

In total, 2599 patients with S-AKI were included in the analysis. Forty variables were selected for the model development. According to the areas under the ROC curve (AUC) and DCA results for the training cohort, XGBoost model exhibited excellent performance with F1 Score of 0.847, 0.715, 0.765 and AUC (95% CI) of 0.91 (0.90, 0.92), 0.78 (0.76, 0.80), and 0.83 (0.81, 0.85) in 7 days, 14 days and 28 days group, respectively. It also demonstrated excellent discrimination in the external validation cohort. Its AUC (95% CI) was 0.81 (0.79, 0.83), 0.75 (0.73, 0.77), 0.79 (0.77, 0.81) in 7 days, 14 days and 28 days group, respectively. SHAP-based summary plot and force plot were used to interpret the XGBoost model globally and locally.

CONCLUSIONS

ML is a reliable tool for predicting the prognosis of patients with S-AKI. SHAP methods were used to explain intrinsic information of the XGBoost model, which may prove clinically useful and help clinicians tailor precise management.

Risk Factors and Clinical Characteristics of Acute Kidney Injury in Patients with COVID-19: A Systematic Review and Meta-Analysis

Acute kidney injury (AKI) is associated with a worse prognosis in coronavirus disease 2019 (COVID-19) patients. Identification of AKI, particularly in COVID-19 patients, is important for improving patients' management. The study aims to assess risk factors and comorbidities of AKI in COVID-19 patients. We systematically searched PubMed and DOAJ databases for relevant studies involving confirmed COVID-19 patients with data on risk factors and comorbidities of AKI. The risk factors and comorbidities were compared between AKI and non-AKI patients. A total of 30 studies involving 22385 confirmed COVID-19 patients were included. Male (OR: 1.74 (1.47, 2.05)), diabetes (OR: 1.65 (1.54, 1.76)), hypertension (OR: 1.82 (1.12, 2.95)), ischemic cardiac disease (OR: 1.70 (1.48, 1.95)), heart failure (OR: 2.29 (2.01, 2.59)), chronic kidney disease (CKD) (OR: 3.24 (2.20, 4.79)), chronic obstructive pulmonary disease (COPD) (OR: 1.86 (1.35, 2.57)), peripheral vascular disease (OR: 2.34 (1.20, 4.56)), and history of nonsteroidal anti-inflammatory drugs (NSAID) (OR: 1.59 (1.29, 1.98)) were independent risk factors associated with COVID-19 patients with AKI. Patients with AKI presented with proteinuria (OR: 3.31 (2.59, 4.23)), hematuria (OR: 3.25 (2.59, 4.08)), and invasive mechanical ventilation (OR: 13.88 (8.23, 23.40)). For COVID-19 patients, male gender, diabetes, hypertension, ischemic cardiac disease, heart failure, CKD, COPD, peripheral vascular disease, and history of use of NSAIDs are associated with a higher risk of AKI.

Identification of the regulatory mechanism of ACE2 in COVID-19-induced kidney damage with systems genetics approach

Studies showed that SARS-CoV-2 can directly target the kidney and induce renal damage. As the cell surface receptor for SARS-CoV-2 infection, the angiotensin-converting enzyme 2 (ACE2) plays a pivotal role for renal physiology and function. Thus, it is important to understand ACE2 through which pathway influences the pathogenesis of renal damage induced by COVID-19. In this study, we first performed an eQTL mapping for Ace2 in kidney tissues in 53 BXD mice strains. Results demonstrated that Ace2 is highly expressed and strongly controlled by a genetic locus on chromosome 16 in the kidney, with six genes (Dnase1, Vasn, Usp7, Abat, Mgrn1, and Rbfox1) dominated as the upstream modulator, as they are highly correlated with Ace2 expression. Gene co-expression analysis showed that Ace2 co-variates are significantly involved in the renin-angiotensin system (RAS) pathway which acts as a reno-protector. Importantly, we also found that Ace2 is positively correlated with Pdgf family members, particularly Pdgfc, which showed the most association among the 76 investigated growth factors. Mammalian Phenotype Ontology enrichment indicated that the cognate transcripts for both Ace2 and Pdgfc were mainly involved in regulating renal physiology and morphology. Among which, Cd44, Egfr, Met, Smad3, and Stat3 were identified as hub genes through protein-protein interaction analysis. Finally, in aligning with our systems genetics findings, we found ACE2, pdgf family members, and RAS genes decreased significantly in the CAKI-1 kidney cancer cells treated with S protein and receptor binding domain structural protein. Collectively, our data suggested that ACE2 work with RAS, PDGFC, as well as their cognate hub genes to regulate renal function, which could guide for future clinical prevention and targeted treatment for COVID-19-induced renal damage outcomes. KEY MESSAGES: • Ace2 is highly expressed and strongly controlled by a genetic locus on chromosome 16 in the kidney. • Ace2 co-variates are enriched in the RAS pathway. • Ace2 is strongly correlated with the growth factor Pdgfc. • Ace2 and Pdgfc co-expressed genes involved in the regulation of renal physiology and morphology. • SARS-CoV-2 spike glycoprotein induces down-regulation of Ace2, RAS, and Pdgfc.

Acute kidney injury outcomes in covid-19 patients: systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of coronavirus-19 disease (COVID-19). Therefore, we decided to perform a systematic review and meta-analysis with data from the literature to relate the development of COVID-19 associated-AKI with comorbidities, medications, and the impact of mechanical ventilation.

METHODS

We performed a systematic review using the Newcastle-Ottawa scale and a meta-analysis using the R program. Relevant studies were searched in the PubMed, Medline, and SciELO electronic databases. Search filters were used to include reports after 2020 and cohort studies.

RESULTS

In total, 1166 articles were identified and 55 English-written articles were included based on the risk of bias. Of all COVID-19-hospitalized patients presenting with AKI (n = 18029) classified as Kidney Disease Improving Global Outcomes stage 1 to 3, approximately 18% required mechanical ventilation and 39.2 % died. Around 11.3% of the patients required kidney replacement therapy (KRT) and of these, 1093 died and 321 required continuous KRT. Death is more frequent in individuals with AKI [OR 6.03, 95%CI: 5.73-6.74; p<0.01]. Finally, mechanical ventilation is an aggravating factor in the clinical conditions studied [OR 11.01, 95%CI: 10.29-11.77; p<0.01].

CONCLUSION

Current literature indicates AKI as an important complication in COVID-19. In this context, we observed that comorbidities, such as chronic kidney disease and heart failure, were more related to the development of AKI. In addition, mechanical ventilation was seen as an aggravating factor in this scenario.

Clinical characteristics of new-onset acute kidney injury in patients with established acute respiratory distress syndrome: A prospective single-center post hoc observational study

Background

We assessed the incidence and clinical characteristics of acute kidney injury (AKI) in acute respiratory distress syndrome (ARDS) patients and its effect on clinical outcomes.

Methods

We conducted a single-center prospective longitudinal study. Patients who met the Berlin definition of ARDS in the medical ICU in China-Japan Friendship Hospital from March 1, 2016, to September 30, 2020, were included. AKI was defined according to the KDIGO clinical practice guidelines. Early and late AKI were defined as AKI occurring within 48 h after ARDS was diagnosed or after 48 h, respectively.

Results

Of the 311 ARDS patients, 161 (51.8%) developed AKI after ICU admission. Independent risk factors for AKI in ARDS patients were age (OR 1.027, 95% CI 1.009–1.045), a history of diabetes mellitus (OR 2.110, 95%CI 1.100–4.046) and chronic kidney disease (CKD) (OR 9.328, 95%CI 2.393–36.363), APACHE II score (OR 1.049, 95%CI 1.008–1.092), average lactate level in the first 3 days (OR 1.965, 95%CI 1.287–3.020) and using ECMO support (OR 2.359, 95%CI 1.154–4.824). Early AKI was found in 91 (56.5%) patients and late AKI was found in 70 (43.5%). Early AKI was related to the patient’s underlying disease and the severity of hospital admission, while late AKI was related to the application of nephrotoxic drugs. The mortality rate of ARDS combined with AKI was 57.1%, which was independently associated with shock (OR 54.943, 95%CI 9.751–309.573).

Conclusion

A significant number of patients with ARDS developed AKI, and the mortality rate for ARDS patients was significantly higher when combined with AKI. Therapeutic drug monitoring should be routinely used to avoid drug toxicity during treatment.

Association between the Use of Antibiotics and the Development of Acute Renal Injury in Patients Hospitalized for COVID-19 in a Hospital in the Peruvian Amazon

Introduction: A significant antibiotic prescribing pattern associated with the COVID-19 pandemic has been described. Multiple protocols included empirical antimicrobials, leading to a substantial increase in antimicrobial consumption in medical care. A higher mortality rate is described among patients diagnosed with COVID-19 who received antibiotics. Objectives: To determine the association between the use of antibiotics and the development of acute renal injury in patients infected with SARS-CoV-2 in patients treated at the Hospital II EsSalud de Ucayali, 2021. Methods: A cross-sectional-analytical study was conducted, evaluating the medical records of patients admitted to the intensive care unit between July 2020 and July 2021. For the statistical analysis, measures of central tendency and dispersion, statistical hypothesis contrast tests were used in relation to acute kidney injury (AKI), antibiotic use and associated factors, derived from linear regression models. Results: The factors that were positively associated with the development of AKI were sepsis (aPR: 2.86; 95% CI: 1.26–6.43), shock (aPR:2.49; 95% CI: 1.28–4.86), mechanical ventilation (aPR:9.11; 95% CI: 1.23–67.57), and use of vancomycin (aPR: 3.15; 95% CI: 1.19–8.27). Conclusions: In the Peruvian Amazon, there is a high consumption and inadequate prescription of antibiotics. The drugs most commonly used for the treatment of COVID-19 were: aminoglycosides, vancomycin, ivermectin, azithromycin, tocilizumab, and corticosteroids. The development of AKI among hospitalized patients was found to be related to vancomycin administration. In addition, an association was found with the use of mechanical ventilation, a high body mass index, and the presence of complications such as sepsis or shock. Therefore, inappropriate antibiotic use for COVID-19 has been associated with multiple negative outcomes and consequences.

Desfechos de lesão renal aguda em pacientes com covid-19: revisão sistemática e metanálise

Resumo Antecedentes: Lesão renal aguda (LRA) é uma complicação frequente da doença do coronavírus-19 (COVID-19). Desta forma, decidimos realizar uma revisão sistemática e uma metanálise com dados da literatura para relacionar o desenvolvimento de LRA associada à COVID-19 com comorbidades, medicamentos e o impacto da ventilação mecânica. Métodos: Realizamos uma revisão sistemática usando a escala de Newcastle-Ottawa e uma metanálise utilizando o programa R. Estudos relevantes foram pesquisados nos bancos de dados eletrônicos PubMed, Medline e SciELO. Foram utilizados filtros de pesquisa para incluir relatos após 2020 e estudos de coorte. Resultados: No total, foram identificados 1166 artigos, e foram incluídos 55 artigos escritos em língua inglesa com base no risco de viés. De todos os pacientes hospitalizados por COVID-19 apresentando LRA (n = 18029) classificados como Kidney Disease Improving Global Outcomes estágios 1 a 3, aproximadamente 18% necessitaram de ventilação mecânica e 39,2% foram a óbito. Cerca de 11,3% dos pacientes necessitaram de terapia renal substitutiva (TRS) e destes, 1093 foram a óbito e 321 necessitaram de TRS contínua. O óbito é mais frequente em indivíduos com LRA [OR 6,03; IC95%: 5,73-6,74; p<0,01]. Por fim, a ventilação mecânica é um fator agravante nas condições clínicas estudadas [OR 11,01; IC95%: 10,29-11,77; p<0,01]. Conclusão: A literatura atual indica a LRA como uma complicação importante na COVID-19. Neste contexto, observamos que comorbidades, como doença renal crônica e insuficiência cardíaca, estiveram mais relacionadas ao desenvolvimento de LRA. Além disso, a ventilação mecânica foi vista como um fator agravante neste cenário.

The correlation study on chest CT features and kidney injury in severe COVID-19 pneumonia from a multicenter cohort study

BACKGROUND

Among confirmed severe COVID-19 patients, although the serum creatinine level is normal, they also have developed kidney injury. Early detection of kidney injury can guide doctors to choose drugs reasonably. Study found that COVID-19 have some special chest CT features. The study aimed to explore which chest CT features are more likely appear in severe COVID-19 and the relationship between related (special) chest CT features and kidney injury or clinical prognosis.

METHODS

In this retrospective study, 162 patients of severe COVID-19 from 13 medical centers in China were enrolled and divided into three groups according to the estimated glomerular filtration rate (eGFR) level: Group A (eGFR < 60 ml/min/1.73 m²), Group B (60 ml/min/1.73 m² ≤ eGFR < 90 ml/min/1.73 m²), and Group C (eGFR ≥ 90 ml/min/1.73 m²). The demographics, clinical features, auxiliary examination, and clinical prognosis were collected and compared. The chest CT features and eGFR were assessed using univariate and multivariate Cox regression. The influence of chest CT features on eGFR and clinical prognosis were calculated using the Cox proportional hazards regression model.

RESULTS

Demographic and clinical features showed significant differences in age, hypertension, and fatigue among the Group A, Group B, and Group C (all P < 0.05). Auxiliary examination results revealed that leukocyte count, platelet count, C-reactive protein, aspartate aminotransferase, creatine kinase, respiratory rate ≥ 30 breaths/min, and CT images rapid progression (>50%) within 24-48 h among the three groups were significantly different (all P < 0.05). Compared to Group C (all P < 0.017), Groups A and B were more likely to show crazy-paving pattern. Logistic regression analysis indicated that eGFR was an independent risk factor of the appearance of crazy-paving pattern. The eGFR and crazy-paving pattern have a mutually reinforcing relationship, and eGFR (HR = 0.549, 95% CI = 0.331-0.909, P = 0.020) and crazy-paving pattern (HR = 2.996, 95% CI = 1.010-8.714, P = 0.048) were independent risk factors of mortality. The mortality of severe COVID-19 with the appearance of crazy-paving pattern on chest CT was significantly higher than that of the patients without its appearance (all P < 0.05).

CONCLUSIONS

The crazy-paving pattern is more likely to appear in the chest CT of patients with severe COVID-19. In severe COVID-19, the appearance of the crazy-paving pattern on chest CT indicates the occurrence of kidney injury and proneness to death. The crazy-paving pattern can be used by doctors as an early warning indicator and a guidance of reasonable drug selection.

The predictive value of the Oxford Acute Severity of Illness Score for clinical outcomes in patients with acute kidney injury

Objective

To compare the performance of the Oxford Acute Severity of Illness Score (OASIS), the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, the Simplified Acute Physiology Score II (SAPS II), and the Sequential Organ Failure Assessment (SOFA) score in predicting 28-day mortality in acute kidney injury (AKI) patients.

Methods

Data were extracted from the Beijing Acute Kidney Injury Trial (BAKIT). A total of 2954 patients with complete clinical data were included in this study. Receiver operating characteristic (ROC) curves were used to analyze and evaluate the predictive effects of the four scoring systems on the 28-day mortality risk of AKI patients and each subgroup. The best cutoff value was identified by the highest combined sensitivity and specificity using Youden’s index.

Results

Among the four scoring systems, the area under the curve (AUC) of OASIS was the highest. The comparison of AUC values of different scoring systems showed that there were no significant differences among OASIS, APACHE II, and SAPS II, which were better than SOFA. Moreover, logistic analysis revealed that OASIS was an independent risk factor for 28-day mortality in AKI patients. OASIS also had good predictive ability for the 28-day mortality of each subgroup of AKI patients.

Conclusion

OASIS, APACHE II, and SAPS II all presented good discrimination and calibration in predicting the 28-day mortality risk of AKI patients. OASIS, APACHE II, and SAPS II had better predictive accuracy than SOFA, but due to the complexity of APACHE II and SAPS II calculations, OASIS is a good substitute.

Trial Registration

This study was registered at www.chictr.org.cn (registration number Chi CTR-ONC-11001875). Registered on 14 December 2011.

Correlation of AKI with risk factors, ventilatory support, renal replacement therapy in a cohort of COVID-19 patients

Introduction:

There is a scarcity of information on the incidence and outcomes of acute kidney injury (AKI) in COVID-19 patients in India. Therefore, we analyzed the correlation of AKI risk factors, ventilatory support, and renal replacement therapy and compared the outcomes of first and second COVID-19 waves in this tertiary care center.

Methods:

We retrospectively analyzed the patients' medical records with a positive RT-PCR for COVID-19 between July 2020 and May 2021. We looked at the clinical outcomes of the first and second COVID-19 waves and documented the frequency, risk factors for AKI, and the relationship between AKI and in-hospital mortality. Univariate and multivariate binomial logistic regression yielded odds ratios for the risk variables of AKI. Risk differences and age-adjusted odds ratios, as well as 99.5% confidence intervals, were used to compare COVID-19 outcomes between the first and second waves.

Results:

Of the 1260 hospitalized patients with COVID-19, 86 (6.8%) presented with AKI and 8 (0.7%) patients required dialysis. The most common comorbidity was diabetes mellitus (55.2%), hypertension (42.1%), hypothyroidism (11.3%), and coronary artery disease (8.1%). A total of 229 (18.17%) patients were admitted to ICU, 574 (45.5%) received ventilation, and 26 (2.0%) required mechanical ventilation.The incidence of in-hospital death in the patients with AKI as per the stage from 1 to 3 was 9 (15.8%), 7 (35%), and 5 (55.6%), respectively.Compared to the first wave, the second wave cohort had a lower risk of AKI (adj OR: 0.426; CI: 0.232–0.782) and mortality (adj OR: 0.252; CI: 0.090–0.707).

Conclusions:

In our study, AKI prevalence was 6.8%, the need for ventilation was 45.5%, ECMO 0.2%, and the mortality rate 2.9%. Second wave of COVID-19 exhibits improved clinical outcomes compared to the first wave.

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].

The impact of transient and persistent acute kidney injury in hospital mortality in COVID-19 patients

INTRODUCTION

Acute kidney injury (AKI) has been described in Coronavirus Disease 2019 (COVID-19) patients and is considered a marker of disease severity and a negative prognostic factor for survival. In this study, the authors aimed to study the impact of transient and persistent acute kidney injury (pAKI) on in-hospital mortality in COVID-19 patients.

METHODS

This was a retrospective observational study of patients hospitalized with COVID-19 in the Department of Medicine of the Centro Hospitalar Universitario Lisboa Norte, Lisbon, Portugal, between March 2020 and August 2020. A multivariate analysis was performed to predict AKI development and in-hospital mortality.

RESULTS

Of 544 patients with COVID-19, 330 developed AKI: 166 persistent AKI (pAKI), 164 with transient AKI. AKI patients were older, had more previous comorbidities, had higher need to be medicated with RAAS inhibitors, had higher baseline serum creatine (SCr) (1.60 mg/dL vs 0.87 mg/dL), higher NL ratio, and more severe acidemia on hospital admission, and more frequently required admission in intensive care unit, mechanical ventilation, and vasopressor use. Patients with persistent AKI had higher SCr level (1.71 mg/dL vs 1.25 mg/dL) on hospital admission. In-hospital mortality was 14.0% and it was higher in AKI patients (18.5% vs 7.0%). CKD and serum ferritin were independent predictors of AKI. AKI did not predict mortality, but pAKI was an independent predictor of mortality, as was age and lactate level.

CONCLUSION

pAKI was independently associated with in-hospital mortality in COVID-19 patients but its impact on long-term follow-up remains to be determined.

Incidence and risk factors of acute kidney injury in COVID-19 patients with and without acute respiratory distress syndrome (ARDS) during the first wave of COVID-19: a systematic review and Meta-Analysis

BACKGROUND

Acute kidney injury (AKI) is common among patients with COVID-19. However, AKI incidence may increase when COVID-19 patients develop acute respiratory distress syndrome (ARDS). Thus, this systematic review and meta-analysis aimed to assess the incidence and risk factors of AKI, need for kidney replacement therapy (KRT), and mortality rate among COVID-19 patients with and without ARDS from the first wave of COVID-19.

METHODS

The databases MEDLINE and EMBASE were searched using relevant keywords. Only articles available in English published between December 1, 2019, and November 1, 2020, were included. Studies that included AKI in COVID-19 patients with or without ARDS were included. Meta-analyses were conducted using random-effects models.

RESULTS

Out of 618 studies identified and screened, 31 studies met the inclusion criteria. A total of 27,500 patients with confirmed COVID-19 were included. The overall incidence of AKI in patients with COVID-19 was 26% (95% CI 19% to 33%). The incidence of AKI was significantly higher among COVID-19 patients with ARDS than COVID-19 patients without ARDS (59% vs. 6%, p < 0.001). Comparing ARDS with non-ARDS COVID-19 cohorts, the need for KRT was also higher in ARDS cohorts (20% vs. 1%). The mortality among COVID-19 patients with AKI was significantly higher (Risk ratio = 4.46; 95% CI 3.31-6; p < 0.00001) than patients without AKI.

CONCLUSION

This study shows that ARDS development in COVID-19-patients leads to a higher incidence of AKI and increased mortality rate. Therefore, healthcare providers should be aware of kidney dysfunction, especially among elderly patients with multiple comorbidities. Early kidney function assessment and treatments are vital in COVID-19 patients with ARDS.

Coronavirus Disease 2019 as Cause of Viral Sepsis: A Systematic Review and Meta-Analysis

OBJECTIVE

Coronavirus disease 2019 is a heterogeneous disease most frequently causing respiratory tract infection, which can induce respiratory failure and multiple organ dysfunction syndrome in its severe forms. The prevalence of coronavirus disease 2019-related sepsis is still unclear; we aimed to describe this in a systematic review.

DATA SOURCES

MEDLINE (PubMed), Cochrane, and Google Scholar databases were searched based on a prespecified protocol (International Prospective Register for Systematic Reviews: CRD42020202018).

STUDY SELECTION

Studies reporting on patients with confirmed coronavirus disease 2019 diagnosed with sepsis according to sepsis-3 or according to the presence of infection-related organ dysfunctions necessitating organ support/replacement were included in the analysis. The primary end point was prevalence of coronavirus disease 2019-related sepsis among adults hospitalized in the ICU and the general ward. Among secondary end points were the need for ICU admission among patients initially hospitalized in the general ward and the prevalence of new onset of organ dysfunction in the ICU. Outcomes were expressed as proportions with respective 95% CI.

DATA EXTRACTION

Two reviewers independently screened and reviewed existing literature and assessed study quality with the Newcastle-Ottawa Scale and the Methodological index for nonrandomized studies.

DATA SYNTHESIS

Of 3,825 articles, 151 were analyzed, only five of which directly reported sepsis prevalence. Noting the high heterogeneity observed, coronavirus disease 2019-related sepsis prevalence was 77.9% (95% CI, 75.9-79.8; I2 = 91%; 57 studies) in the ICU, and 33.3% (95% CI, 30.3-36.4; I2 = 99%; 86 studies) in the general ward. ICU admission was required for 17.7% (95% CI, 12.9-23.6; I2 = 100%) of ward patients. Acute respiratory distress syndrome was the most common organ dysfunction in the ICU (87.5%; 95% CI, 83.3-90.7; I2 = 98%).

CONCLUSIONS

The majority of coronavirus disease 2019 patients hospitalized in the ICU meet Sepsis-3 criteria and present infection-associated organ dysfunction. The medical and scientific community should be aware and systematically report viral sepsis for prognostic and treatment implications.

Incidence and Outcome of Acute Kidney Injury in Patients Hospitalized With Coronavirus Disease-19 at a Tertiary Care Medical Center in Saudi Arabia

Introduction The systemic acute respiratory syndrome coronavirus (SARS-CoV-2) has been associated with acute kidney injury (AKI). We retrospectively studied the incidence and outcome of AKI in patients hospitalized with COVID-19 at King Abdulaziz Medical City (KAMC) Riyadh, Kingdom of Saudi Arabia. Methods A retrospective cohort study was conducted after ethical approval from the institutional review board of King Abdullah International Medical Research Center (KAIMRC). Subjects were identified by Data Management Office of KAIMRC. The data were extracted from electronic medical records using a customized data collection sheet. The study included all adult patients (>18 years) who tested positive for COVID-19 by polymerase chain reaction and were admitted at KAMC from March 2020 until the end of September 2020. Patients with a history of end-stage kidney diseases and patients where adequate data were not available to establish diagnosis of AKI were excluded. Patient demographics, comorbid conditions, medications, use of mechanical ventilation, and 30-day mortality were recorded. Results During the study period (01 March 2020 to 30 September 2020) 1293 patients were hospitalized at KAMC with the diagnosis of COVID-19. After excluding the patients who met the exclusion criteria, data were collected for 1025 patients [male 582 (56.8%); female 443 (43.2%)]. On univariate analysis, increasing age, male gender, use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, diuretics, and vasopressors, presence of chronic kidney disease, coronary artery disease, chronic obstructive pulmonary disease, dyslipidemia, diabetes mellitus, heart failure, and hypertension, kidney transplant status, and mechanical ventilation were associated with development of AKI. On multivariate logistic regression analysis, independent predictors of AKI were restricted to increasing age, presence of chronic kidney disease, hypertension, kidney transplant status, use of vasopressors, and mechanical ventilation. For patients who developed AKI, 30-day mortality was 40.7% compared to 3.7% for those who did not develop AKI (p<0.001). Conclusion For hospitalized patients with COVID-19, we observed an incidence of AKI of 36%. Increasing age, presence of chronic kidney disease and hypertension, kidney transplant status, use of vasopressors, and mechanical ventilation were independently associated with development of AKI. Presence of AKI was associated with higher 30-day mortality (40.7% vs 3.7%).

Acute kidney injury in COVID-19: multicentre prospective analysis of registry data

Background

Acute kidney injury (AKI) is a common and important complication of coronavirus disease 2019 (COVID-19). Further characterization is required to reduce both short- and long-term adverse outcomes.

Methods

We examined registry data including adults with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection admitted to five London Hospitals from 1 January to 14 May 2020. Prior end-stage kidney disease was excluded. Early AKI was defined by Kidney Disease: Improving Global Outcomes creatinine criteria within 7 days of admission. Independent associations of AKI and survival were examined in multivariable analysis. Results are given as odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals.

Results

Among 1855 admissions, 455 patients (24.5%) developed early AKI: 200 (44.0%) Stage 1, 90 (19.8%) Stage 2 and 165 (36.3%) Stage 3 (74 receiving renal replacement therapy). The strongest risk factor for AKI was high C-reactive protein [OR 3.35 (2.53-4.47), P < 0.001]. Death within 30 days occurred in 242 (53.2%) with AKI compared with 255 (18.2%) without. In multivariable analysis, increasing severity of AKI was incrementally associated with higher mortality: Stage 3 [HR 3.93 (3.04-5.08), P < 0.001]. In 333 patients with AKI surviving to Day 7, 134 (40.2%) recovered, 47 (14.1%) recovered then relapsed and 152 (45.6%) had persistent AKI at Day 7; an additional 105 (8.2%) patients developed AKI after Day 7. Persistent AKI was strongly associated with adjusted mortality at 90 days [OR 7.57 (4.50-12.89), P < 0.001].

Conclusions

AKI affected one in four hospital in-patients with COVID-19 and significantly increased mortality. Timing and recovery of COVID-19 AKI is a key determinant of outcome.

Prospective selected biomarkers in COVID-19 diagnosis and treatment

COVID-19 has become a global health concern, due to the high transmissible nature of its causal agent and lack of proper treatment. Early diagnosis and nonspecific medical supports of the patients appeared to be effective strategy so far to combat the pandemic caused by COVID-19 outbreak. Biomarkers can play pivotal roles in timely and proper diagnosis of COVID-19 patients, as well as for distinguishing them from other pulmonary infections. Besides, biomarkers can help in reducing the rate of mortality and evaluating viral pathogenesis with disease prognosis. This article intends to provide a broader overview of the roles and uses of different biomarkers in the early diagnosis of COVID-19, as well as in the classification of COVID-19 patients into multiple risk groups.

SARS-CoV-2 Infection and the Kidneys: An Evolving Picture

Since December 2019, a novel coronavirus known as Severe Acute Respiratory Virus 2 (SARS-CoV-2) has caused an outbreak of a respiratory illness worldwide. Even though SARS-CoV-2 primarily affects the respiratory system, other organs such as the heart and kidneys are implicated. The pathophysiology of Acute Kidney Injury (AKI) in coronavirus 2019 (COVID-19) patients is not clearly defined. Direct kidney injury results from virus entry through angiotensin-converting enzyme-2 (ACE2) receptors which are highly expressed by the podocytes and proximal convoluted tubules, as suggested by "viral-like" particles on electron microscopy. However, the link between the presence of viral particles in kidney tissue and kidney injury has not been fully explained. Furthermore, it is also hypothesized that collapsing focal segmental glomerulosclerosis (FSGS), myoglobin toxicity, sepsis-linked, and glomeruli fibrin thrombi is part of the mechanism for AKI. Reported cases link FSGS and high-risk apolipoprotein 1 (APOL1) alleles in patients of African ancestry. Typically, these patients present with AKI and nephrotic-range proteinuria. The rate of AKI in hospitalized patients is high and associated with a higher mortality rate in older patients with comorbidities. Even higher mortality is now being reported in patients with chronic kidney disease and kidney transplant recipients due to immune system dysfunction. Herein, we review the current literature on kidney disease and pathogenesis in COVID-19 patients.

Post COVID-19 infection: Long-term effects on liver and kidneys

Coronavirus disease 2019 is a pandemic, which has affected millions of people across the globe in the year 2020. This disease is caused by a virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that belongs to the family of coronaviruses and primarily affects the respiratory system. This infection has a wide spectrum of clinical manifestations ranging from asymptomatic form to mild, moderate and severe forms depending upon the age, comorbidity and immunity of an affected individual. Hyper-inflammatory response due to SARS-CoV-2 adversely affect several internal organs. Besides lung injury, which is the main outcome of SARS-CoV-2 infection, it has been reported to adversely impact other organs including the liver and kidneys. SARS-CoV-2 virus can also have a direct adverse impact on liver as well as kidneys due to systemic inflammatory response or drug toxicity, leading to elevated levels of liver injury markers and acute kidney injury. Clinical outcomes of SARS-CoV-2 infection could be worse in patients suffering from pre-existing liver and kidney disease. So far, there have been several reports on the mechanism of liver and kidney injury during SARS-CoV-2 viral attack. However, the long-term impact of this infection on these organs is yet to be understood. This review summarizes the possible causes and effects of SARS-CoV-2 on the liver and kidneys during the infection and post recovery based on available literature.

Diabetes is most important cause for mortality in COVID-19 hospitalized patients: Systematic review and meta-analysis

The presence of SARS-CoV-2 was officially documented in Europe at the end of February 2020. Despite many observations, the real impact of COVID-19 in the European Union (EU), its underlying factors and their contribution to mortality and morbidity outcomes were never systematically investigated. The aim of the present work is to provide an overview and a meta-analysis of main predictors and of country differences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-associated mortality rate (MR) in hospitalized patients. Out of 3714 retrieved articles, 87 studies were considered, including 35,486 patients (mean age 60.9 ± 8.2 years) and 5867 deaths. After adjustment for confounders, diabetes mellitus was the best predictors of MR in an age- and sex-dependent manner, followed by chronic pulmonary obstructive diseases and malignancies. In both the US and Europe, MR was higher than that reported in Asia (25[20;29] % and 20[17;23] % vs. 13[10;17]%; both p < 0.02). Among clinical parameters, dyspnea, fatigue and myalgia, along with respiratory rate, emerged as the best predictors of MR. Finally, reduced lymphocyte and platelet count, along with increased D-dimer levels, all significantly contributed to increased mortality. The optimization of glucose profile along with an adequate thrombotic complications preventive strategy must become routine practice in diseased SARS-CoV-2 infected patients.

Risk Factors for Acute Kidney Injury in COVID-19 Patients: A Systematic Review

BACKGROUND: Acute kidney injury (AKI) in coronavirus disease-19 (COVID-19) has high incidence and mortality. Risk factors for AKI in COVID-19 patients are not well explored. This systematic review provides a combination of available evidence regarding risk factors of AKI in COVID-19 patients. METHODS: A systematic research was performed in Medline, Cochrane Central Register of Controlled Trials, and ScienceDirect journal databases from 2019 to August 2020. The study selection process was plotted using a Preferred Reporting Items for Systematic Review and Meta-Analyses flow diagram. RESULTS: Out of 553 studies found, four full-text studies met the inclusion criteria and were included in qualitative analysis. There are 2205 COVID-19 patients with AKI (36.44%) from 6051 COVID-19 patients. Age was a risk factors for AKI in two studies (odds ratio [OR] 1.03 [p < 0.001], OR 1.03 [p < 0.007]). Critical condition of patient is risk factors for AKI (OR 8.155 [p = 0.006]). Hirsch et al. stated that diabetes mellitus (OR 1.74 [p < 0.001]), cardiovascular disease (OR 1.48 [p < 0.001]), and hypertension (OR 1.25 [p = 0.02]) are also risk factors. Laboratory results such as elevated procalcitonin (PCT) and estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2 showed positive association to AKI in COVID-19 patients (OR 4.822 [p = 0.037]; OR 13.451 [p = 0.016]). A higher sequential organ failure assessment (SOFA) score at admission is one of the risk factors (OR 1.498 [p = 0.027]). CONCLUSION: Demographics, clinical classification of COVID-19, comorbidities, SOFA score, PCT, and eGFR can help clinicians predict AKI in COVID-19 patients.

COVID-19 and the Kidney: A Worrisome Scenario of Acute and Chronic Consequences

Acute kidney injury (AKI) is a common finding in patients with coronavirus disease 2019 (COVID-19) and has been associated with higher rates of death when compared to COVID-19 patients without kidney injury. Whereas the definitive pathogenesis of COVID-19-related AKI (CoV-AKI) is not clear, histopathologic evidence seems to point at multiple etiologies for the disease, including indirect and direct viral kidney injury. The high incidence of CoV-AKI, along with the aggressive clinical presentation of this entity, have increased the demands for kidney replacement therapies, rapidly overwhelming the supplies of healthcare systems even in major tertiary care centers. As a result, nephrologists have come up with alternatives to maximize the efficiency of treatments and have developed non-conventional therapeutic alternatives such as the implementation of acute peritoneal dialysis for critically ill patients. The long-term implications of CoV-AKI are yet unknown, though early studies suggest that around one third of the patients who survive will remain dependent on kidney replacement therapy. Nephrologists and healthcare workers need to be familiar with the clinical presentation and therapeutic challenges of CoV-AKI in order to develop strategies to mitigate the burden of the disease for patients, and for services providing kidney replacement therapies.

Clinical and therapeutic outcomes of COVID-19 intensive care units (ICU) patients: a retrospective study in Ghana

The COVID-19 pandemic had caused significant morbidity and mortality, with over a million deaths recorded to date. Mortality recorded among severe-critically ill patients admitted to intensive care units (ICU) has been significantly high, especially in most COVID-19 epicenters. Reports on the unique clinical characteristics and outcomes from the ICU admissions are on-going with isolated studies in Africa. This study was a retrospective single-centre study involving all polymerase chain reaction (PCR) confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) patients admitted to the medical intensive care unit (MICU) of the department of medicine and therapeutics, Korle-Bu Teaching Hospital, over the period of 13^th April - 28^th June 2020. Twenty-two (22) patients in total fulfilled the inclusion criteria and are included in this report. Patients' socio-demographic characteristics, clinical and laboratory parameters outcomes as well as treatment modalities employed were extracted from their respective medical records and analyzed using STATA version 14. Dyspnoea, fever and cough were most common associated symptoms. The mean duration of admission at the ICU was 4.1 ± 3.0 days with five deaths (22.7%). About 91% (20/22) had at least one comorbidity with hypertension as the most prevalent. The median oxygen saturation/fraction of inspired oxygen (SpO₂/FiO₂) level was significantly higher in persons with only COVID-19 pneumonia compared to those with complicated respiratory failure (p<0.001). Six (27.3%) out of the 22 patients had non-invasive ventilation, with only 1/22 (4.5%) receiving mechanical ventilation. Although non-significant, the mean duration of ICU stay was relatively shorter in patients who received therapeutic doses of anticoagulation (p=0.32). Duration of treatment with methylprednisolone was significantly associated with patient outcomes (p=0.04) and serum ferritin levels had a tendency to negatively affect outcome (p=0.06). Clearly there are still no specific targeted medications for COVID-19 treatment, except for empirically symptoms-guided treatments and management of mild to critically ill patients. Early use of systemic corticosteroids for severe to critically ill patients in the ICU using S/F ratio and CRP levels may improve outcomes.

Pragmatic Recommendations for the Prevention and Treatment of Acute Kidney Injury in Patients with COVID-19 in Low- and Middle-Income Countries

Current recommendations for the management of patients with COVID-19 and acute kidney injury (AKI) are largely based on evidence from resource-rich settings, mostly located in high-income countries. It is often unpractical to apply these recommendations to resource-restricted settings. We report on a set of pragmatic recommendations for the prevention, diagnosis, and management of patients with COVID-19 and AKI in low- and middle-income countries (LMICs). For the prevention of AKI among patients with COVID-19 in LMICs, we recommend using isotonic crystalloid solutions for expansion of intravascular volume, avoiding nephrotoxic medications, and using a conservative fluid management strategy in patients with respiratory failure. For the diagnosis of AKI, we suggest that any patient with COVID-19 presenting with an elevated serum creatinine level without available historical values be considered as having AKI. If serum creatinine testing is not available, we suggest that patients with proteinuria should be considered to have possible AKI. We suggest expansion of the use of point-of-care serum creatinine and salivary urea nitrogen testing in community health settings, as funding and availability allow. For the management of patients with AKI and COVID-19 in LMICS, we recommend judicious use of intravenous fluid resuscitation. For patients requiring dialysis who do not have acute respiratory distress syndrome (ARDS), we suggest using peritoneal dialysis (PD) as first choice, where available and feasible. For patients requiring dialysis who do have ARDS, we suggest using hemodialysis, where available and feasible, to optimize fluid removal. We suggest using locally produced PD solutions when commercially produced solutions are unavailable or unaffordable.

Stratification of Acute Kidney Injury in COVID-19

Despite myriad improvements in the care of COVID-19 patients, atypical manifestations are least appreciated during the current pandemic. Because COVID-19 is primarily manifesting as an acute respiratory illness with interstitial and alveolar pneumonia, the possibility of viral invasions into the other organs cannot be disregarded. Acute kidney injury (AKI) has been associated with various viral infections including dengue, chikungunya, Zika, and HIV. The prevalence and risks of AKI during the course of COVID-19 have been described in few studies. However, the existing literature demonstrate great disparity across findings amid variations in methodology and population. This article underscores the propensity of AKI among COVID-19 patients, limitations of the exiting evidence, and importance of timely identification during the case management. The prevalence of AKI is variable across the studies ranging from 4.7% to 81%. Evidence suggest old age, comorbidities, ventilator support, use of vasopressors, black race, severe infection, and elevated levels of baseline serum creatinine and d-dimers are independent risk factors of COVID-19 associated with AKI. COVID-19 patients with AKI also showed unsatisfactory renal recovery and higher mortality rate as compared with patients without AKI. These findings underscore that AKI frequently occurs during the course of COVID-19 infection and requires early stratification and management.

Acute Kidney Injury in COVID-19: The Chinese Experience

Coronavirus disease 2019 (COVID-19) is spreading rapidly worldwide. Here, we review recently published studies on COVID-19-associated acute kidney injury (AKI) in China. The pooled incidence of AKI in all reported COVID-19 patients was 6.5%, with a much higher rate in patients from the intensive care unit (32.5%). AKI is associated with the severity of COVID-19 and mortality rates, which is similar to other kidney abnormalities including proteinuria and hematuria. The renal tubule is the main site of injury in COVID-19 patients, and the etiology of renal impairment in COVID-19 patients likely is diverse and multifactorial. Apart from direct viral attack via angiotensin-converting enzyme 2 and transmembrane serine proteases 2, hypoxia and hypercoagulability also may contribute to the occurrence of renal injury. To date, there is only randomized controlled trial evidence to support the use of dexamethasone in patients requiring oxygen therapy and remdesivir for shortening the time to recovery, with no specific treatment for COVID-19-associated AKI. Studies researching kidney pathologies or reporting renal outcome and prognosis are in urgent need. Further studies are urgently warranted to identify risk factors, to predict prognosis and renal outcome, to explore the exact mechanisms of renal injury, and to suggest targeted interventions.