The Frequency and Outcome of Acute Kidney Injury in a Tertiary Hospital: Which Factors Affect Mortality?

The incidence of acute kidney injury and its association with mortality in patients diagnosed with COVID-19 followed up in intensive care unit

INTRODUCTION

The kidneys are some of the most frequently affected organs during coronavirus disease 2019 (COVID-19). This multicenter study evaluated the incidence of and risk factors for acute kidney injury (AKI) in COVID-19 patients followed up in intensive care unit (ICU) and its association with mortality.

METHODS

Three hundred twenty-eight patients diagnosed with COVID-19 and hospitalized in ICU were included. Risk factors associated with AKI and mortality were evaluated.

RESULTS

Eighty-eight patients (27.9%) were diagnosed with AKI. AKI was significantly associated with older age, higher baseline creatinine level, lower albumin level, and coexistence of cardiovascular disease and chronic obstructive pulmonary disease. Mortality in the entire study group was significantly associated with AKI, older age, requirement of invasive mechanical ventilation, higher neutrophil level, lower lymphocyte, and albumin levels.

CONCLUSION

AKI is frequently seen during the course of COVID-19 and is associated with high mortality. Identifying AKI-related risk factors appears essential in the management of COVID-19 patients.

The place of infectious markers in predicting culture positivity in patients with renal failure hospitalized with suspected infection

Infectious diseases are an important cause of mortality in patients with renal failure. The markers used to diagnose infection in patients with renal failure have various limitations. Culture positivity is an objective guide in that context. The purpose of this study was to examine the effectiveness of frequently used markers of bacterial infection in predicting culture positivity in renal failure patients with renal failure hospitalized with suspected bacterial infection over an approximately 1.5-year period were included in this prospective observational study. Patients' demographic and laboratory findings were recorded. Demographic and laboratory findings and mortality were compared between patients with and without culture-positivity. Parameters affecting culture positivity were also analyzed. Four hundred twenty-six patients (median age 67.50, 45.5% female) were included in the study. Culture positivity was determined in 54.5% of patients. Hospital stay was longer (p < 0.001) and leukocyte (p < 0.001), neutrophil percentage (p < 0.05) and CRP (p < 0.001) values were significantly higher in culture-positive patients. Mortality was also significantly higher in culture-positive patients than in culture-negative patients (p < 0.05). CRP was determined as a predictor of culture positivity at logistic regression analysis (p = 0.000, exp ß [1.004]). Culture positivity was determined in more than half of the patients hospitalized with suspected bacterial infection. CRP, a longstanding marker, was identified as a parameter predicting culture positivity. We think that the determination in further studies of a cut-off point for CRP in determining culture positivity may be a useful diagnostic guide.

Predictors of successful discontinuation from renal replacement therapy during AKI: A meta-analysis

The predictors of weaning time of renal replacement therapy (RRT) remain controversial for special patients suffering from acute kidney injury (AKI). The present work aims to perform a meta-analysis to evaluate proper predictors of RRT weaning in AKI patients. We systematically searched EMBASE, PubMed, and Cochrane Central Register of Controlled trials for literatures between 1984 and June 2019. Studies evaluating predictors of weaning success of RRT in patients of AKI were included. Random-effects model or fixed-effects model meta-analyses were performed to compute a standard mean difference (SMD). Newcastle-Ottawa Scale was employed to assess the risk of bias. We included 10 observational trials including 1453 patients. Twelve predictors including urine output, serum creatinine, serum urea, mean arterial pressure, central venous pressure, lactate, serum potassium, serum bicarbonate, pH value, SOFA score, urinary urea, and urinary creatinine were identified, showing urine output (p = 0.0000), serum creatinine (p = 0.008), serum potassium (p = 0.02), serum bicarbonate (p = 0.01), pH value (p = 0.03), urinary urea (p = 0.002), and urinary creatinine (p = 0.02) were significantly associated with weaning success. With the limited evidence, we speculate that urine output, serum creatinine, serum potassium, serum bicarbonate, pH value, urinary urea, and urinary creatinine might be associated with successful weaning.

Acute Kidney Injury in Asia: Disease Burden

Acute kidney injury (AKI) is a common and critical clinical disorder with non-negligible morbidity and mortality and remains a large public health problem. Asia, as the world's largest and most populous continent, is crucial in eliminating unsatisfactory outcomes of AKI. The diversities in climate, customs, and economic status lead to various clinical features of AKI across Asia. In this review, we focus on the epidemiologic data and clinical features of AKI in different Asian countries and clinical settings, and we show the huge medical and economic burden of AKI in Asian countries. Drugs and sepsis are the most common etiologies for AKI, however, an adequate surveillance system has not been well established. There is significant undertreatment of AKI in many regions, and medical resources for renal replacement therapy are not universally available. Although substantial improvement has been achieved, health care for AKI still needs improvement, especially in developing regions.

Assessment of Risk of Harm Associated With Intensive Blood Pressure Management Among Patients With Hypertension Who Smoke: A Secondary Analysis of the Systolic Blood Pressure Intervention Trial

IMPORTANCE

The randomized Systolic Blood Pressure Intervention Trial (SPRINT) showed that lowering systolic blood pressure targets for adults with hypertension reduces cardiovascular morbidity and mortality in general. However, whether the overall benefit from intensive blood pressure control masks important heterogeneity in risk is unknown.

OBJECTIVE

To test the hypothesis that the overall benefit observed in SPRINT masked important heterogeneity in risk from intensive blood pressure control.

DESIGN, SETTING, AND PARTICIPANTS

In this exploratory, hypothesis-generating, ad hoc, secondary analysis of data obtained from 9361 participants in SPRINT, a random forest-based analysis was used to identify potential heterogeneous treatment effects using half of the trial data. Cox proportional hazards regression models were applied to test potential heterogeneous treatment effects on the remaining data. The original trial was conducted at 102 sites in the United States between November 2010 and March 2013. This analysis was conducted between November 2016 and August 2017.

INTERVENTIONS

Participants were assigned a systolic blood pressure target of less than 120 mm Hg (intervention treatment) or of less than 140 mm Hg (standard treatment).

MAIN OUTCOMES AND MEASURES

The primary composite cardiovascular outcome was myocardial infarction, other acute coronary syndromes, stroke, heart failure, or death from cardiovascular causes.

RESULTS

Of 9361 participants in SPRINT, 466 participants (5.0%) were current smokers with systolic blood pressure greater than 144 mm Hg at baseline, with 230 participants (49.4%) randomized to the training data set and 236 participants (50.6%) randomized to the testing data set; 286 participants (61.4%) were male, and the mean (SD) age was 60.7 (7.2) years. Combinations of 2 covariates (ie, baseline smoking status and systolic blood pressure) distinguished participants who were differentially affected by the intervention. In the testing data, Cox proportional hazards models for the primary outcome revealed a number needed to harm of 43.7 to cause 1 event across 3.3 years among participants who, at baseline, were current smokers with systolic blood pressure greater than 144 mm Hg (10.9% [12 of 110] of primary outcome events for intervention treatment vs 4.8% [6 of 126] for standard treatment; hazard ratio, 10.6; 95% CI, 1.3-86.1; P = .03). This subgroup was also associated with a higher likelihood to experience acute kidney injury under intensive blood pressure control (with a frequency of 10.0% [11 of 110] of acute kidney injury events for intervention treatment vs 3.2% [4 of 126] for standard treatment; hazard ratio, 9.4; 95% CI, 1.2-77.3; P = .04).

CONCLUSIONS AND RELEVANCE

In this secondary analysis of SPRINT data, current smokers with a baseline systolic blood pressure greater than 144 mm Hg had a higher rate of cardiovascular events in the intensive treatment group vs the standard treatment group. Further research is needed to evaluate the potential tradeoffs of intensive blood pressure control in hypertensive smokers.

Enhanced proliferation and differentiation of HO-1 gene-modified bone marrow-derived mesenchymal stem cells in the acute injured kidney

The aim of the present study was to investigate the effect of heme oxygenase-1 (HO-1) overexpression on the survival and differentiation ability of bone marrow‑derived mesenchymal stem cells (BMSCs) in the acute kidney injury (AKI) microenvironment. HO-1-BMSCs and enhanced green fluorescent protein (eGFP)-BMSCs were constructed. Rat ischemia/reperfusion (I/R)‑AKI-kidney homogenate supernatant was prep-ared to treat the BMSCs, eGFP-BMSCs and HO-1-BMSCs in vitro. In the AKI microenvironment, the HO-1-BMSCs exhibited a smaller proportion of cells at the G0/G1 phase, and a larger proportion of cells expressing proliferating cell nuclear antigen (PCNA) and cytokeratin 18 (CK18). Phosphorylated protein kinase B (Akt) and extracellular signal‑regulated kinase (ERK) protein levels were observed to be increased in the HO-1-BMSCs compared with the BMSCs. LY294002 and PD98059 each inhibited the above effects. BMSCs, eGFP-BMSCs and HO-1-BMSCs were implanted into an I/R-AKI rat model. The proportions of PCNA+ BMSCs and CK18+ BMSCs were higher in the HO-1-BMSCs group compared with the BMSCs group, which resulted in a decreased acute tubular necrosis score and improved renal function for the AKI rats. In conclusion, the enhanced proliferation and differentiation of HO-1-BMSCs suggest the beneficial effects of such cells in the BMSC-based therapy of AKI. The mechanism underlying these effects may involve the stimulation of Akt and ERK signaling.

Predictive Factors Upon Discontinuation of Renal Replacement Therapy for Long-Term Chronic Dialysis and Death in Acute Kidney Injury Patients

The specific timing for discontinuing renal replacement therapy (RRT) in acute kidney injury (AKI) patients is debatable. The predictive abilities of variables at the time of discontinuation of RRT for the long-term prognoses of patients have not been explored. This study aimed to explore the prognostic factors upon discontinuation of RRT for long-term chronic dialysis and death of patients with acute RRT-requiring AKI, thus improving decision making regarding the discontinuation of RRT and the follow-up of patients thereafter. A cohort of 302 AKI patients who required acute RRT and remained alive and free of dialysis for at least 30 days after discharge from January 2009 to December 2012 were followed up. The predictive abilities of general characteristics, RRT details, and variables upon discontinuation of RRT for long-term chronic dialysis and all-cause death were evaluated using Cox proportional hazards models. Kaplan-Meier analysis with a log-rank test was used to compare the survival curves between the strata of levels of good predictors upon discontinuation of RRT. After a median follow-up time of 4.1 years, 20 (6.6%) patients initiated chronic dialysis and 56 (18.5%) patients died. A higher CysC level upon discontinuation of RRT (HR 1.520, 95% CI 1.082-2.135; P = 0.016), comorbid chronic kidney disease, and a higher non-renal Charlson comorbidity index (CCI) were independently predictive for chronic dialysis. The hemoglobin level upon discontinuation of RRT was inversely predictive of death (HR 0.986, 95% CI 0.973-0.999; P = 0.035), and comorbid malignancy, the presence of multiple organ dysfunction syndrome, and a higher non-renal CCI also predicted death. Urine output upon discontinuation of RRT was marginally inversely predictive of death (HR 0.997, 95% CI 0.994-1.000; P = 0.056). Patients who discontinued RRT with CysC levels <2.97 mg/L, hemoglobin levels >85 g/L, and urine output >1130 mL/24 h showed significantly higher non-chronic dialysis and survival rates according to a log-rank test. Our study suggested that upon discontinuation of RRT, higher serum CysC levels had the most promising predictive value for long-term chronic dialysis, and lower hemoglobin levels predicted long-term death; lower urine output also marginally predicted long-term death. Based on the remission of the comprehensive condition, lower CysC levels and higher hemoglobin levels and urine output should be considered in the decision to stop RRT. Patients showing worse levels of these indices upon discontinuation of RRT should undergo stricter follow-up and treatment to improve long-term outcomes.

Artificial Organs 2015: A Year in Review

In this Editor's Review, articles published in 2015 are organized by category and briefly summarized. We aim to provide a brief reflection of the currently available worldwide knowledge that is intended to advance and better human life while providing insight for continued application of technologies and methods of organ Replacement, Recovery, and Regeneration. As the official journal of The International Federation for Artificial Organs, The International Faculty for Artificial Organs, the International Society for Rotary Blood Pumps, the International Society for Pediatric Mechanical Cardiopulmonary Support, and the Vienna International Workshop on Functional Electrical Stimulation, Artificial Organs continues in the original mission of its founders "to foster communications in the field of artificial organs on an international level." Artificial Organs continues to publish developments and clinical applications of artificial organ technologies in this broad and expanding field of organ Replacement, Recovery, and Regeneration from all over the world. We take this time also to express our gratitude to our authors for providing their work to this journal. We offer our very special thanks to our reviewers who give so generously of their time and expertise to review, critique, and especially provide meaningful suggestions to the author's work whether eventually accepted or rejected. Without these excellent and dedicated reviewers, the quality expected from such a journal could not be possible. We also express our special thanks to our Publisher, John Wiley & Sons for their expert attention and support in the production and marketing of Artificial Organs. We look forward to reporting further advances in the coming years.

Acute Kidney Injury in Asia

BACKGROUND

Acute kidney injury (AKI) is a common disorder and is associated with a high morbidity and mortality worldwide. The diversity of the climate and of the socioeconomic and developmental status in Asia has a great influence on the etiology and presentation of AKI in different regions. In view of the International Society of Nephrology's 0by25 initiative, more and more attention has been paid to AKI in Asian countries.

SUMMARY

In this review, we summarize the recent achievements with regard to the prevalence and clinical patterns of AKI in Asian countries. Epidemiological studies have revealed the huge medical and economic burden of AKI in Eastern Asian countries, whereas the true epidemiological picture of AKI in the tropical areas is still not well understood. In high-income Asian regions, the presentation of AKI resembles that in other developed countries in Europe and North America. In low-income regions and tropical areas, infections, environmental toxins, and obstetric complications remain the major culprits in most cases of AKI. Preventive opportunities are missed because of failure to recognize the risk factors and early signs of AKI. Patients often present late for treatment or are recognized late by physicians, which leads to more severe kidney injury, multiorgan involvement, and increased mortality. There is significant undertreatment of AKI in many regions, and medical resources for renal replacement therapy are not universally available.

KEY MESSAGES

More efforts should be made to increase public awareness, establish preventive approaches in communities, educate health-care practitioner entities to achieve better recognition, and form specialist renal teams to improve the treatment of AKI. The choice of renal replacement therapy should fit patients' needs, and peritoneal dialysis can be practiced more frequently in the treatment of AKI patients.

FACTS FROM EAST AND WEST

(1) More than 90% of the patients recruited in AKI studies using KDIGO-equivalent criteria originate from North America, Europe, or Oceania, although these regions represent less than a fifth of the global population. However, the pooled incidence of AKI in hospitalized patients reaches 20% globally with moderate variance between regions. (2) The lower incidence rates observed in Asian countries (except Japan) may be due to a poorer recognition rate, for instance because of less systematically performed serum creatinine tests. (3) AKI patients in South and Southeastern Asia are younger than in East Asia and Western countries and present with fewer comorbidities. (4) Asian countries (and to a certain extent Latin America) face specific challenges that lead to AKI: nephrotoxicity of traditional herbal and less strictly regulated nonprescription medicines, environmental toxins (snake, bee, and wasp venoms), and tropical infectious diseases (malaria and leptospirosis). A higher incidence and less efficient management of natural disasters (particularly earthquakes) are also causes of AKI that Western countries are less likely to encounter. (5) The incidence of obstetric AKI decreased globally together with an improvement in socioeconomic levels particularly in China and India in the last decades. However, antenatal care and abortion management must be improved to reduce AKI in women, particularly in rural areas. (6) Earlier nephrology referral and better access to peritoneal dialysis should improve the outcome of AKI patients.