Recovery after Critical Illness and Acute Kidney Injury.

AKI is a common complication in hospitalized and critically ill patients. Its incidence has steadily increased over the past decade. Whether transient or prolonged, AKI is an independent risk factor associated with poor short- and long-term outcomes, even if patients do not require KRT. Most patients with early AKI improve with conservative management; however, some will require dialysis for a few days, a few weeks, or even months. Approximately 10%-30% of AKI survivors may still need dialysis after hospital discharge. These patients have a higher associated risk of death, rehospitalization, recurrent AKI, and CKD, and a lower quality of life. Survivors of critical illness may also suffer from cognitive dysfunction, muscle weakness, prolonged ventilator dependence, malnutrition, infections, chronic pain, and poor wound healing. Collaboration and communication among nephrologists, primary care physicians, rehabilitation providers, physical therapists, nutritionists, nurses, pharmacists, and other members of the health care team are essential to create a holistic and patient-centric care plan for overall recovery. Integration of the patient and family members in health care decisions, and ongoing education throughout the process, are vital to improve patient well-being. From the nephrologist standpoint, assessing and promoting recovery of kidney function, and providing appropriate short- and long-term follow-up, are crucial to prevent rehospitalizations and to reduce complications. Return to baseline functional status is the ultimate goal for most patients, and dialysis independence is an important part of that goal. In this review, we seek to highlight the varying aspects and stages of recovery from AKI complicating critical illness, and propose viable strategies to promote recovery of kidney function and dialysis independence. We also emphasize the need for ongoing research and multidisciplinary collaboration to improve outcomes in this vulnerable population.

Risk factors, predictions, and progression of acute kidney injury in hospitalized COVID-19 patients: An observational retrospective cohort study.

OBJECTIVES: Studies have shown that acute kidney injury (AKI) occurrence post SARS-CoV-2 infection is complex and has a poor prognosis. Therefore, more studies are needed to understand the rate and the predications of AKI involvement among hospitalized COVID-19 patients and AKI's impact on prognosis while under different types of medications. PATIENTS AND METHODS: This study is a retrospective observational cohort study conducted at Bahrain Defence Force (BDF) Royal Medical Services. Medical records of COVID-19 patients admitted to BDF hospital, treated, and followed up from April 2020 to October 2020 were retrieved. Data were analyzed using univariate and multivariate logistic regression with covariate adjustment, and the odds ratio (OR) and 95% confidence (95% CI) interval were reported. RESULTS: Among 353 patients admitted with COVID-19, 47.6% developed AKI. Overall, 51.8% of patients with AKI died compared to 2.2% of patients who did not develop AKI (p< 0.001 with OR 48.6 and 95% CI 17.2-136.9). Besides, deaths in patients classified with AKI staging were positively correlated and multivariate regression analysis revealed that moderate to severe hypoalbuminemia (<32 g/L) was independently correlated to death in AKI patients with an OR of 10.99 (CI 95% 4.1-29.3, p<0.001). In addition, 78.2% of the dead patients were on mechanical ventilation. Besides age as a predictor of AKI development, diabetes and hypertension were the major risk factors of AKI development (OR 2.04, p<0.01, and 0.05 for diabetes and hypertension, respectively). Also, two or more comorbidities substantially increased the risk of AKI development in COVID-19 patients. Furthermore, high levels upon hospital admission of D-Dimer, Troponin I, and ProBNP and low serum albumin were associated with AKI development. Lastly, patients taking ACEI/ARBs had less chance to develop AKI stage II/III with OR of 0.19-0.27 (p<0.05-0.01). CONCLUSIONS: The incidence of AKI in hospitalized COVID-19 patients and the mortality rate among AKI patients were high and correlated with AKI staging. Furthermore, laboratory testing for serum albumin, hypercoagulability and cardiac injury markers maybe indicative for AKI development. Therefore, clinicians should be mandated to perform such tests on admission and follow-up in hospitalized patients.

Renal Considerations in COVID-19: Biology, Pathology, and Pathophysiology.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemic of epic proportion. Beyond pulmonary involvement in coronavirus disease 2019 (COVID-19), a significant subset of patients experiences acute kidney injury. Patients who die from severe disease most notably show diffuse acute tubular injury on postmortem examination with a possible contribution of focal macro- and microvascular thrombi. Renal biopsies in patients with proteinuria and hematuria have demonstrated a glomerular dominant pattern of injury, most notably a collapsing glomerulopathy reminiscent of findings seen in human immunodeficiency virus (HIV) in individuals with apolipoprotein L-1 (APOL1) risk allele variants. Although various mechanisms have been proposed for the pathogenesis of acute kidney injury in SARS-CoV-2 infection, direct renal cell infection has not been definitively demonstrated and our understanding of the spectrum of renal involvement remains incomplete. Herein we discuss the biology, pathology, and pathogenesis of SARS-CoV-2 infection and associated renal involvement. We discuss the molecular biology, risk factors, and pathophysiology of renal injury associated with SARS-CoV-2 infection. We highlight the characteristics of specific renal pathologies based on native kidney biopsy and autopsy. Additionally, a brief discussion on ancillary studies and challenges in the diagnosis of SARS-CoV-2 is presented.

Renal allograft function in kidney transplant recipients infected with SARS-CoV 2: An academic single center experience.

BACKGROUND: Kidney transplant recipients are a unique cohort in regard to SARS-CoV 2 susceptibility and clinical course, owing to their immunosuppressed state and propensity for kidney injury. The primary purpose of this study is to ascertain if, in kidney transplant recipients, SARS-CoV 2 infection impacts long term renal allograft function. METHODS: This retrospective, single-center study reviewed 53 kidney transplant recipients with a positive SARS-CoV-2 PCR at NMH from January 1, 2020 to June 30, 2020. RESULTS: Change in eGFR from baseline kidney function prior to infection to 90 days after the first positive SARS-CoV 2 test was +1.76%, -17.5% and -23.16% the mild, moderate and severe disease groups respectively. There was a significant decline in kidney function in the moderate and severe disease cohorts as compared to the mild disease cohort, with respective p values of p = 0.0002 and p = 0.021. Relative to the mild disease cohort, the moderate and severe disease cohorts also demonstrated significantly increased risk of developing AKI (66%, 85%), both with p values of P = 0.0001. CONCLUSIONS: Clinically severe SARS-CoV 2 infection is associated with greater risk of acute kidney injury and greater decline in renal allograft function at 90 days post infection, compared to mild disease.

Pathophysiology of COVID-19-associated acute kidney injury.

Although respiratory failure and hypoxaemia are the main manifestations of COVID-19, kidney involvement is also common. Available evidence supports a number of potential pathophysiological pathways through which acute kidney injury (AKI) can develop in the context of SARS-CoV-2 infection. Histopathological findings have highlighted both similarities and differences between AKI in patients with COVID-19 and in those with AKI in non-COVID-related sepsis. Acute tubular injury is common, although it is often mild, despite markedly reduced kidney function. Systemic haemodynamic instability very likely contributes to tubular injury. Despite descriptions of COVID-19 as a cytokine storm syndrome, levels of circulating cytokines are often lower in patients with COVID-19 than in patients with acute respiratory distress syndrome with causes other than COVID-19. Tissue inflammation and local immune cell infiltration have been repeatedly observed and might have a critical role in kidney injury, as might endothelial injury and microvascular thrombi. Findings of high viral load in patients who have died with AKI suggest a contribution of viral invasion in the kidneys, although the issue of renal tropism remains controversial. An impaired type I interferon response has also been reported in patients with severe COVID-19. In light of these observations, the potential pathophysiological mechanisms of COVID-19-associated AKI may provide insights into therapeutic strategies.

Comparison of renal histopathology and gene expression profiles between severe COVID-19 and bacterial sepsis in critically ill patients.

BACKGROUND: The mechanisms driving acute kidney injury (AKI) in critically ill COVID-19 patients are unclear. We collected kidney biopsies from COVID-19 AKI patients within 30 min after death in order to examine the histopathology and perform mRNA expression analysis of genes associated with renal injury. METHODS: This study involved histopathology and mRNA analyses of postmortem kidney biopsies collected from patients with COVID-19 (n = 6) and bacterial sepsis (n = 27). Normal control renal tissue was obtained from patients undergoing total nephrectomy (n = 12). The mean length of ICU admission-to-biopsy was 30 days for COVID-19 and 3-4 days for bacterial sepsis patients. RESULTS: We did not detect SARS-CoV-2 RNA in kidney biopsies from COVID-19-AKI patients yet lung tissue from the same patients was PCR positive. Extensive acute tubular necrosis (ATN) and peritubular thrombi were distinct histopathology features of COVID-19-AKI compared to bacterial sepsis-AKI. ACE2 mRNA levels in both COVID-19 (fold change 0.42, p = 0.0002) and bacterial sepsis patients (fold change 0.24, p < 0.0001) were low compared to control. The mRNA levels of injury markers NGAL and KIM-1 were unaltered compared to control tissue but increased in sepsis-AKI patients. Markers for inflammation and endothelial activation were unaltered in COVID-19 suggesting a lack of renal inflammation. Renal mRNA levels of endothelial integrity markers CD31, PV-1 and VE-Cadherin did not differ from control individuals yet were increased in bacterial sepsis patients (CD31 fold change 2.3, p = 0.0006, PV-1 fold change 1.5, p = 0.008). Angiopoietin-1 mRNA levels were downregulated in renal tissue from both COVID-19 (fold change 0.27, p < 0.0001) and bacterial sepsis patients (fold change 0.67, p < 0.0001) compared to controls. Moreover, low Tie2 mRNA expression (fold change 0.33, p = 0.037) and a disturbed VEGFR2/VEGFR3 ratio (fold change 0.09, p < 0.0001) suggest decreased microvascular flow in COVID-19. CONCLUSIONS: In a small cohort of postmortem kidney biopsies from COVID-19 patients, we observed distinct histopathological and gene expression profiles between COVID-19-AKI and bacterial sepsis-AKI. COVID-19 was associated with more severe ATN and microvascular thrombosis coupled with decreased microvascular flow, yet minimal inflammation. Further studies are required to determine whether these observations are a result of true pathophysiological differences or related to the timing of biopsy after disease onset.

Urine biomarkers for the prediction of mortality in COVID-19 hospitalized patients.

Risk factors associated with severity and mortality attributable to COVID-19 have been reported in different cohorts, highlighting the occurrence of acute kidney injury (AKI) in 25% of them. Among other, SARS-CoV-2 targets renal tubular cells and can cause acute renal damage. The aim of the present study was to evaluate the usefulness of urinary parameters in predicting intensive care unit (ICU) admission, mortality and development of AKI in hospitalized patients with COVID-19. Retrospective observational study, in a tertiary care hospital, between March 1st and April 19th, 2020. We recruited adult patients admitted consecutively and positive for SARS-CoV-2. Urinary and serum biomarkers were correlated with clinical outcomes (AKI, ICU admission, hospital discharge and in-hospital mortality) and evaluated using a logistic regression model and ROC curves. A total of 199 COVID-19 hospitalized patients were included. In AKI, the logistic regression model with a highest area under the curve (AUC) was reached by the combination of urine blood and previous chronic kidney disease, with an AUC of 0.676 (95%CI 0.512-0.840; p = 0.023); urine specific weight, sodium and albumin in serum, with an AUC of 0.837 (95% CI 0.766-0.909; p < 0.001) for ICU admission; and age, urine blood and lactate dehydrogenase levels in serum, with an AUC of 0.923 (95%CI 0.866-0.979; p < 0.001) for mortality prediction. For hospitalized patients with COVID-19, renal involvement and early alterations of urinary and serum parameters are useful as prognostic factors of AKI, the need for ICU admission and death.

Endothelial Dysfunction for Acute Kidney Injury in Coronavirus Disease 2019: How Concerned Should We Be?

CONTEXT: The outbreak of coronavirus disease 2019 (CO-VID-19) has rapidly evolved into a global pandemic. Kidney dysfunction is common among patients with COVID-19, and patients who develop acute kidney injury (AKI) have inferior outcomes. There is a growing body of evidence that AKI occurs in a substantial number of patients with COVID-19 and that developing AKI is associated with significantly worse outcomes for COVID-19 patients. The risk for death was amplified when AKI resulted in kidney replacement therapy (KRT). Subject of Review: The Study of the Treatment and Outcomes in Critically Ill Patients with COVID-19 (STOP-COVID) conducted a multicenter retrospective observational study enrolling 3,099 critically ill adults with COVID-19 admitted to intensive care units (ICUs) (J Am Soc Nephrol 2021;32:161-176). A total of 637 of 3,099 patients (20.6%) developed AKI treated with KRT (AKI-KRT) within 14 days of ICU admission, 350 of whom (54.9%) died within 28 days of ICU admission. Predictors of COVID-19 patients' progress to AKI-KRT were higher BMI, higher stages of CKD, lower ratio of the partial pressure of arterial oxygen over the fraction of inspired oxygen (PaO2:FiO2 ratio) on ICU admission, and greater number of vasopressors received on ICU admission. Second Opinion: Recently, some investigations revealed that the independent predictors of COVID-19 with AKI include older age, Black race, diabetes, hypertension, cardiovascular disease, mechanical ventilation, higher interleukin-6 level, and use of vasopressor medications. It seems that the underlying comorbidities with preexisting vascular endothelial damage and/or the more serious critically ill CO-VID-19 patients can contribute to the development of AKI and even AKI-KRT.

Coronavirus disease 2019 and kidney injury.

PURPOSE OF REVIEW: In this paper, we seek to review coronavirus disease 2019 (COVID-19) associated kidney injury with a focus on what is known about pathophysiology. RECENT FINDINGS: Kidney injury is a common complication of SARS-CoV-2 infection and is associated with increased morbidity and mortality. Acute tubular necrosis and glomerular injury are two common findings. Direct viral effect, endothelial dysfunction, and podocyte and tubular epithelial injury have been described. COVID-19-related glomerular injury may also be associated with high-risk APOL1 genotype. SUMMARY: Data on COVID-19 renal involvement have suggested novel mechanisms of kidney injury that need to be further elucidated. More data are needed on renal involvement in milder disease, renal-specific therapeutic interventions, and long-term sequelae.

Favipiravir use in children with COVID-19 and acute kidney injury: is it safe?

BACKGROUND: The rising number of infections due to Severe Acute Respiratory Syndrome Coronavirus-2 (popularly known as COVID-19) has brought to the fore new antiviral drugs as possible treatments, including favipiravir. However, there is currently no data regarding the safety of this drug in patients with kidney impairment. The aim of this paper, therefore, is to share our experience of the use of favipiravir in pediatric patients affected by COVID-19 with any degree of kidney impairment. METHODS: The study enrolled pediatric patients aged under 18 years and confirmed as suffering from COVID-19 and multisystem inflammatory syndrome in children (MIS-C) with any degree of kidney injury, who were treated with favipiravir at the time of admission. RESULTS: Out of a total of 11 patients, 7 were diagnosed with MIS-C and 4 with severe COVID-19. The median age of the cases was 15.45 (9-17.8) years and the male/female ratio was 7/4. At the time of admission, the median serum creatinine level was 1.1 mg/dl. Nine patients were treated with favipiravir for 5 days, and 2 patients for 5 days followed by remdesivir for 5-10 days despite kidney injury at the time of admission. Seven patients underwent plasma exchange for MIS-C while 2 severely affected cases underwent continuous kidney replacement therapy (CKRT) as well. One severe COVID-19 patient received plasma exchange as well as CKRT. Serum creatinine values returned to normal in mean 3.07 days. CONCLUSIONS: Favipiravir seems a suitable therapeutic option in patients affected by COVID-19 with kidney injury without a need for dose adjustment.

Characteristics and outcomes of critically ill patients with covid-19 in Sakarya, Turkey: a single centre cohort study

Background/aim: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Turkey on March 10, 2020 and the number of the patients are increasing day by day. Coronavirus disease 2019 (Covid-19) has high mortality rates in intensive care units (ICUs). We aimed to describe the demographic characteristics, comorbidities, treatment protocols, and clinical outcomes among the critically ill patients admitted to the ICU of our hospital. Materials and methods: This cohort study included 103 consecutive patients who had laboratory confirmed Covid-19 and admitted to ICU of Sakarya University Training and Research Hospital between March 19 and April 13, 2020. The final date of the follow-up was April 18. Results: The mean age of the patients was 69.6 ± 14.1 years. Most of the patients had increased CRP (99%), serum ferritin (73.8%), d-dimer (82.5%), and hs-troponin levels (38.8%). 34 patients (33%) had lymphocytopenia, 24 patients (23.3%) had thrombocytopenia. 63 patients (61.2%) developed acute respiratory distress syndrome (ARDS), 31 patients (30.1%) had acute kidney injury, and 52 patients (50.5%) had multiple organ dysfunction syndrome (MODS) during follow-up. Sixty-two patients (60.2%) received mechanical ventilation. As of April 18, of the 103 patients, 52 (50.5%) had died, 30 (29.1%) had been discharged from the ICU, 21 (20.4%) were still in the ICU. Conclusions: Covid-19 has high mortality rates in ICU. Patients with elevated procalcitonin, hs-troponin, d-dimer, and CRP levels and lower platelet count at admission have higher mortality.

The Importance of the World Kidney Day World Kidney Day - 11 March 2021 - Living Well with Kidney Disease.

World Kidney Day (WKD) is a global campaign to raise awareness of the importance of our kidneys to overall health and to reduce the frequency and impact of kidney disease and associated health problems worldwide. Kidney disease is a non-communicable disease (NCD) and currently affects around 850 million people worldwide. One in ten adults has chronic kidney disease (CKD). The global burden of CKD is increasing, and is projected to become the 5th most common cause of years of life lost globally by 2040. CKD is a major cause of catastrophic health expenditure. The costs of dialysis and transplantation consume 2-3% of the annual healthcare budget in high-income countries. Crucially, kidney disease can be prevented and progression to end-stage kidney disease can be delayed with appropriate access to basic diagnostics and early treatment. This year World Kidney Day continues to raise awareness of the increasing burden of kidney diseases worldwide and to strive for kidney health for everyone, everywhere. During the pandemic with COVID 19 patients kidneys are also damaged, apart from the respiratory tract and other organs. It can lead to an increase in acute renal failure and consequent chronic kidney insufficiency, as well as number of deaths. Therefore, it is important to evaluate the renal function in each patient with COVID 19 virus. In the Republic of North Macedonia from 2006 to present day nephrologists and other medical personnel devoted to the early diagnosis, prevention and treatment of renal disease have participated in the activities of the World Kidney Day. These activities were supported by the Macedonian Society of Nephrology, Dialysis, Transplantation and Artificial Organs, the Department of Nephrology at the Medical Faculty, the Macedonian Academy of Sciences and Arts, the Government of the Republic of North Macedonia, non-governmental nephrology organizations (NEFRON) and the media. There were lectures and presentation devoted to the various theme of the WKD, publications in journals, as well as activities for examination of the renal function of patients in the medical centers. The activities during the WKD contributed to the improvement of the nephrological protection of the citizens of the Republic of N. Macedonia.

COVID-19 neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital.

Many patients with SARS-CoV-2 infection develop neurological signs and symptoms; although, to date, little evidence exists that primary infection of the brain is a significant contributing factor. We present the clinical, neuropathological and molecular findings of 41 consecutive patients with SARS-CoV-2 infections who died and underwent autopsy in our medical centre. The mean age was 74 years (38-97 years), 27 patients (66%) were male and 34 (83%) were of Hispanic/Latinx ethnicity. Twenty-four patients (59%) were admitted to the intensive care unit. Hospital-associated complications were common, including eight patients (20%) with deep vein thrombosis/pulmonary embolism, seven (17%) with acute kidney injury requiring dialysis and 10 (24%) with positive blood cultures during admission. Eight (20%) patients died within 24 h of hospital admission, while 11 (27%) died more than 4 weeks after hospital admission. Neuropathological examination of 20-30 areas from each brain revealed hypoxic/ischaemic changes in all brains, both global and focal; large and small infarcts, many of which appeared haemorrhagic; and microglial activation with microglial nodules accompanied by neuronophagia, most prominently in the brainstem. We observed sparse T lymphocyte accumulation in either perivascular regions or in the brain parenchyma. Many brains contained atherosclerosis of large arteries and arteriolosclerosis, although none showed evidence of vasculitis. Eighteen patients (44%) exhibited pathologies of neurodegenerative diseases, which was not unexpected given the age range of our patients. We examined multiple fresh frozen and fixed tissues from 28 brains for the presence of viral RNA and protein, using quantitative reverse-transcriptase PCR, RNAscope® and immunocytochemistry with primers, probes and antibodies directed against the spike and nucleocapsid regions. The PCR analysis revealed low to very low, but detectable, viral RNA levels in the majority of brains, although they were far lower than those in the nasal epithelia. RNAscope® and immunocytochemistry failed to detect viral RNA or protein in brains. Our findings indicate that the levels of detectable virus in coronavirus disease 2019 brains are very low and do not correlate with the histopathological alterations. These findings suggest that microglial activation, microglial nodules and neuronophagia, observed in the majority of brains, do not result from direct viral infection of brain parenchyma, but more likely from systemic inflammation, perhaps with synergistic contribution from hypoxia/ischaemia. Further studies are needed to define whether these pathologies, if present in patients who survive coronavirus disease 2019, might contribute to chronic neurological problems.

COVID-19 and the kidney: A South African state healthcare experience.

The first documented case of SARS-CoV-2 infection was confirmed in South Africa (SA) in March 2020. The Western Cape (WC) province was the initial epicenter. The pandemic peaked in July 2020 when 76,851 cases were documented and 2,323 deaths reported. COVID-19 can have multisystem involvement. Acute kidney injury (AKI) is well-documented and associated with increased mortality. We report our experience as the pandemic evolved in the WC province, focusing on those patients with a SARS-CoV-2 positive test presenting with AKI. We also reviewed our chronic dialysis cohort and renal transplant recipients who tested positive to assess incidence and outcomes. All patients presenting to nephrology services at the four main public hospitals were included. Information regarding demographics, co-morbidities, medical care, laboratory data, and outcomes were recorded. There were 86 patients referred with AKI, 48 required dialysis, and 47 died. There were 52 patients admitted to the intensive care unit with AKI (37 received dialysis, 1 of whom survived). In those presenting with AKI, diabetes, obesity, hypertension, and HIV were the most common comorbidities. Of the 295 patients receiving chronic dialysis within our services, 31 tested positive for SARS-CoV-2, and 6 died. Of the 45 kidney transplant recipients who tested positive, 9 died. Only 3 required dialysis. In conclusion, we report a high rate of AKI and poor prognosis in those requiring kidney replacement therapy, a better prognosis than anticipated was found in our chronic dialysis cohort, and high numbers of admissions were required for renal transplant recipients.

Role of blood pressure dysregulation on kidney and mortality outcomes in COVID-19. Kidney, blood pressure and mortality in SARS-CoV-2 infection.

BACKGROUND: In February 2020 the corona virus disease 2019 (COVID-19) infection started spreading throughout Italy, hitting the Lombardy region very hard. Despite the high diffusion, only a subset of patients developed severe COVID-19: around 25% of them developed acute kidney injury (AKI) and one-third of them died. Elderly patients and patients with high comorbidities were identified as being at higher risk of severe COVID-19. METHODS: Our prospective observational cohort study includes 392 consecutive patients hospitalized for COVID-19 in Milan (median age 67 years, 75% male). We evaluated the relationship between blood pressure at presentation, presence of AKI at Emergency Department admission and during hospitalization, and total in-hospital mortality (24%). RESULTS: Although 58% of our study patients reported a history of hypertension (HYP) (86% on treatment), 30% presented with low blood pressure levels. Only 5.5% were diagnosed with AKI on admission; 75% of hypertensive patients discontinued therapy during hospitalization (only 20% were on treatment at discharge). Gender and hypertension were strongly associated with AKI at admission (odds ratio 11). Blood pressure was inversely correlated with increased risk of AKI upon admission, regardless of the severity of respiratory distress. Age over 65, history of hypertension, and severity of respiratory distress were the main predictors of AKI, which developed in 34.7% of cases during hospitalization. AKI was associated with increased in-hospital mortality. Hypertension and low blood pressure at presentation were the main predictors of in-hospital mortality, together with age over 65, baseline pulmonary involvement, and severity of illness. CONCLUSIONS: In patients hospitalized for COVID-19, hypertension and low blood pressure at presentation are important risk factors for AKI and mortality. Early reduction of antihypertensive therapy may improve outcomes in patients with SARS-CoV-2 infection.