A review of Covid-19 and acute kidney injury: from pathophysiology to clinical results

ELMO CPAP: an innovative type of ventilatory support for COVID-19-related acute respiratory distress syndrome

OBJECTIVE

To assess whether the use of ELMO, a helmet for noninvasive ventilation created in Brazil, had a positive impact on the prognosis of patients with hypoxemic respiratory failure caused by severe COVID-19.

METHODS

This is a retrospective study of 50 critically ill COVID-19 patients. Epidemiological, clinical, and laboratory data were collected on ICU admission, as well as before, during, and after ELMO use. Patients were divided into two groups (success and failure) according to the outcome.

RESULTS

ELMO use improved oxygenation parameters such as Pao2, Fio2, and the Pao2/Fio2 ratio, and this contributed to a gradual reduction in Fio2, without an increase in CO2, as determined by arterial blood gas analysis. Patients in the success group had significantly longer survival (p < 0.001), as determined by the Kaplan-Meier analysis, less need for intubation (p < 0.001), fewer days of hospitalization, and a lower incidence of acute kidney injury in comparison with those in the failure group.

CONCLUSIONS

The significant improvement in oxygenation parameters, the longer survival, as reflected by the reduced need for intubation and by the mortality rate, and the absence of acute kidney injury suggest that the ELMO CPAP system is a promising tool for treating ARDS and similar clinical conditions.

Clinical and Epidemiological Characteristics of Patients with COVID-19 Admitted to the Intensive Care Unit: A Two-Year Retrospective Analysis

In March 2020, COVID-19 was characterized as a pandemic by the World Health Organization. Hospitalized patients affected by COVID-19 presented with severe respiratory and motor impairment, especially those who required intensive treatment and invasive mechanical ventilation, with sequelae that extended after the period of hospitalization. Thus, the aim of the current study was to verify the clinical and epidemiological characteristics of patients with COVID-19 admitted to the Intensive Care Unit in 2020 and 2021, according to age group. Methods: A retrospective cohort study. Data were collected through the “ICUs Brasileiras” between March 2020 and November 2021 for severe acute respiratory syndrome (SARS) due to COVID-19. The following were analyzed: the number of hospital admissions, days in the ICU and hospital, clinical aspects (non-invasive or invasive ventilatory support, comorbidities, frailty, SAPS 3 and SOFA severity scales, use of amines and renal support), and ICU and hospital mortality rate. Results: A total of 166,966 ICU hospital admissions were evaluated over the evaluated quarters. The main results showed a peak in the number of hospitalizations between March and May 2021, with a higher percentage of males. The peak of ICU admissions for 7 days was between March and May 2021 and 21 days between March and May 2020. In addition, higher deaths were observed in the age groups between 40 and 80 years between 2020 and 2021, with the group above 81 being the age group with the highest mortality. Mortality in the ICU of ventilated patients was higher in the age group above 70 years. Another observation was the predominance of SAPS 3 and the peak of mechanical ventilation for more than 7 days between June and August 2021. Conclusion: The clinical and epidemiological characteristics of patients with COVID-19 were influenced by age group, showing higher mortality over 81 years and over 70 years in the ICU supported by mechanical ventilation, maintained for 7 days from June to August 2021. The years 2020 and 2021 also showed differences for patients with COVID-19, with greater hospitalization between March and May 2021, especially in the ICU for 7 days, and between March and May 2020 for the 21-day period.

The Investigation of Kidney Involvement in 430 Hospitalized Patients with Omicron COVID-19 in Tianjin, China

INTRODUCTION

This study evaluated the incidence, clinical characteristics, and risk factors of kidney involvement in patients with the Omicron variant infection in the post-acute treatment phase in Tianjin, China.

METHODS

Data were collected from 430 patients with Omicron variant infection in Tianjin, China. Demographics, comorbidities, laboratory blood tests, urinalysis, vaccination status, and COVID-19 clinical classification were assessed. Patients were grouped based on kidney involvement, and associated risk factors of kidney involvement were also investigated.

RESULTS

Asymptomatic, mild, ordinary, and severe patients with Omicron COVID-19 variant comprised 1.5%, 49.1%, 48.9%, and 0.5% of the sample population, respectively, without critical illness or death. The incidences of hematuria, proteinuria, and concurrent hematuria and proteinuria were 14.7%, 14.2%, and 5.1%, respectively. Patients with and without kidney involvement differed in age, body mass index (BMI), comorbidity, creatinine levels, estimated glomerular filtration rate, and C-reactive protein (CRP) levels. Age, hypertension, higher CRP levels, and higher BMI were linked with kidney involvement.

CONCLUSION

The majority of the patients suffered from mild or ordinary symptoms of Omicron COVID-19 infection. The primary kidney involvement was hematuria and proteinuria. Proteinuria was significantly associated with Omicron variant infection, and patients with hypertensive comorbidity, higher CRP, and higher creatinine levels were at increased risk of proteinuria after Omicron variant infection.

Acute kidney injury in coronavirus infectious disease: a study of incidence, risk factors, and prognosis during the first wave of the disease in Brazil

INTRODUCTION

Acute kidney injury (AKI) is one of the main complications of COVID-19 caused by SARS-CoV-2. This study aimed to evaluate the incidence of AKI in Brazilian hospitalized patients diagnosed with COVID-19 and identify the risk factors associated with its onset and those associated with its prognosis.

METHODS

A prospective cohort study of hospitalized patients diagnosed with COVID-19 at a public and tertiary university hospital in São Paulo from March to December 2020.

RESULTS

There were 347 patients hospitalized with COVID-19, 52.4% were admitted to the intensive care unit (ICU) and 47.6% were admitted to the wards. The overall incidence of AKI was 46.4%, more frequent in the ICU (68.1% vs 22.4, p < 0.01) and the overall mortality was 36.1%. Acute kidney replacement therapy was indicated in 46.6% of patients with AKI. In the general population, the factors associated with AKI were older age (OR 1.03, CI 1-1.05, p < 0.05), mechanical ventilation (OR 1.23, CI 1.06-1.83, p < 0.05), presence of proteinuria (OR 1.46, CI 1.22-1.93, p < 0.05), and use of vasoactive drugs (OR 1.26, CI 1.07-1.92, p < 0.05). Mortality was higher in the elderly (OR 1.08, CI 1.04-1.11, p < 0.05), in those with AKI (OR 1.12, CI 1.02-2.05, p < 0.05), particularly KDIGO stage 3 AKI (OR 1.10, CI 1.22-2.05, p < 0.05) and in need of mechanical ventilation (OR 1.13, CI 1.03-1.60, p < 0.05).

CONCLUSION

AKI was frequent in hospitalized patients with COVID-19 and the factors associated with its development were older age, mechanical ventilation, use of vasoactive drugs, and presence of proteinuria, being a risk factor for death.

Influence of early hemodialysis on the septic acute kidney injury outcome

OBJECTIVE

to analyze the influence of early hemodialysis on the outcome of acute septic kidney injury.

METHOD

this is an observational, analytical, prospective study with patients diagnosed with acute septic kidney injury on hemodialysis. A questionnaire for data collection was used as an instrument. We used the Shapiro-Wilk, nonparametric Kruskal-Wallis, Mann-Whitney U, Student t and chi-square tests for analysis.

RESULTS

of the 40 patients analyzed, 60% were male, with a mean age of 55 (±16.8) years, and length of hospital stay of 43 (±26.2) days. When separating patients undergoing early and late hemodialysis into two groups, an increase in serum creatinine (p = 0.001) was observed in those who underwent late hemodialysis, however, creatinine ≥ 4mg/dl is one of the characteristics of this group. In both groups, there was a high mortality: 62.5% (10) in the early hemodialysis group and 41.7% (10) in the late hemodialysis group, with vasopressor use (p = 0.001) being the main risk factor.

CONCLUSION

early onset of hemodialysis in acute septic kidney injury based on KDIGO definitions did not influence the outcome. However, vasopressor use associated with hemodialysis in septic patients was a predictor of death.

The Perspective of Vitamin D on suPAR-Related AKI in COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of millions of people around the world. Severe vitamin D deficiency can increase the risk of death in people with COVID-19. There is growing evidence that acute kidney injury (AKI) is common in COVID-19 patients and is associated with poorer clinical outcomes. The kidney effects of SARS-CoV-2 are directly mediated by angiotensin 2-converting enzyme (ACE2) receptors. AKI is also caused by indirect causes such as the hypercoagulable state and microvascular thrombosis. The increased release of soluble urokinase-type plasminogen activator receptor (suPAR) from immature myeloid cells reduces plasminogen activation by the competitive inhibition of urokinase-type plasminogen activator, which results in low plasmin levels and a fibrinolytic state in COVID-19. Frequent hypercoagulability in critically ill patients with COVID-19 may exacerbate the severity of thrombosis. Versican expression in proximal tubular cells leads to the proliferation of interstitial fibroblasts through the C3a and suPAR pathways. Vitamin D attenuates the local expression of podocyte uPAR and decreases elevated circulating suPAR levels caused by systemic inflammation. This decrease preserves the function and structure of the glomerular barrier, thereby maintaining renal function. The attenuated hyperinflammatory state reduces complement activation, resulting in lower serum C3a levels. Vitamin D can also protect against COVID-19 by modulating innate and adaptive immunity, increasing ACE2 expression, and inhibiting the renin–angiotensin–aldosterone system. We hypothesized that by reducing suPAR levels, appropriate vitamin D supplementation could prevent the progression and reduce the severity of AKI in COVID-19 patients, although the data available require further elucidation.

Rhabdomyolysis-Induced AKI (RIAKI) Including the Role of COVID-19

Rhabdomyolysis is a compound disease that may be induced by many factors, both congenital and acquired. Statin therapy is considered one of the most common acquired factors. However, recent scientific reports suggest that serious complications such as rhabdomyolysis are rarely observed. Researchers suggest that, in many cases, side effects that occur with statin therapy, including muscle pain, can be avoided with lower-dose statin therapy or in combination therapy with other drugs. One of the most recent agents discovered to contribute to rhabdomyolysis is COVID-19 disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Rhabdomyolysis is defined as a damage to striated muscle cells with escape of intracellular substances into the bloodstream. These substances, including myoglobin, creatine kinase (CK), potassium, and uridine acid, are markers of muscle damage and early complications of rhabdomyolysis. Symptoms may be helpful in establishing the diagnosis. However, in almost 50% of patients, they do not occur. Therefore, the diagnosis is confirmed by serum CK levels five times higher than the upper limit of normal. One of the late complications of this condition is acute kidney injury (AKI), which is immediately life-threatening and has a high mortality rate among patients. Therefore, the prompt detection and treatment of rhabdomyolysis is important. Markers of muscle damage, such as CK, lactate dehydrogenase (LDH), myoglobin, troponins, and aspartate aminotransferase (AST), are important in diagnosis. Treatment of rhabdomyolysis is mainly based on early, aggressive fluid resuscitation. However, therapeutic interventions, such as urinary alkalinization with sodium bicarbonate or the administration of mannitol or furosemide, have not proven to be beneficial. In some patients who develop AKI in the course of rhabdomyolysis, renal replacement therapy (RRT) is required.

Cardiorenal syndrome: long road between kidney and heart

Almost 200 years ago, the first evidence described by Robert Bright (1836) showed the strong interaction between the kidneys and heart and, since then, the scientific community has dedicated itself to better understanding the mechanisms involved in the kidney-heart relationship, known in recent decades as cardiorenal syndrome (CRS). This syndrome includes a wide clinical variety that affects the kidneys and heart, in an acute or chronic manner. Moreover, it is well established in the literature that the immune system, the sympathetic nervous system, the renin-angiotensin-aldosterone, and the oxidative stress actively play a strong role in the cellular and molecular processes present in CRS. More recently, uremic molecules and epigenetic factors have been also shown to be key mediators in the development of syndrome. The present review intends to present the state of the art regarding CRS and to show the paths known, until now, in the long road between the kidneys and heart.

Influência da hemodiálise precoce no desfecho da lesão renal aguda séptica

RESUMO Objetivo: analisar a influência da hemodiálise precoce no desfecho da lesão renal aguda séptica. Método: estudo observacional, analítico, prospectivo, com pacientes diagnosticados com lesão renal aguda séptica em hemodiálise. Foi utilizado como instrumento um questionário para coleta de dados. Utilizaram-se para análise os testes Shapiro-Wilk, o não paramétrico de Kruskal-Wallis, U de Mann-Whitney, t de Student e do Qui-Quadrado. Resultados: dos 40 pacientes analisados, 60% eram do sexo masculino, com média de 55 (±16,8) anos, e tempo de internação hospitalar de 43 (±26,2) dias. Ao separar em dois grupos, pacientes submetidos à hemodiálise precoce e à hemodiálise tardia, observou-se naqueles que realizaram tardiamente a hemodiálise um aumento de creatinina sérica (p = 0,001), entretanto a creatinina ≥ 4mg/dl é umas das características desse grupo. Em ambos os grupos, houve uma alta mortalidade: 62,5% (10) no grupo de hemodiálise precoce e 41,7% (10) no grupo de hemodiálise tardia, sendo o uso de vasopressor (p = 0,001) o principal fator de risco. Conclusão o início precoce da hemodiálise na lesão renal aguda séptica com base nas definições do KDIGO não influenciou no desfecho. Contudo, o uso do vasopressor associado à hemodiálise em pacientes sépticos foi um fator preditor ao óbito.