Acute kidney injury (AKI) is a common clinical syndrome that carries a poor prognosis even in cases with seemingly mild or reversible renal dysfunction. Although this potentially devastating disease is associated with increased mortality, early detection and timely intervention may improve clinical outcomes. In this regard, a standardized definition and classification of AKI, reflecting prognosis on the basis of evidence, may allow early recognition and stage-based management of the disease. Nevertheless, there has been considerable variability and inconsistency in the definition and classification of AKI, resulting in failure to bridge the gap between research and clinical practice. The definition of AKI has evolved, with the introduction of the "Risk, Injury, Failure, Loss, and End-stage renal disease" (RIFLE), and "AKI Network" (AKIN) criteria. The recent "Kidney Disease Improving Global Outcomes" (KDIGO) guidelines proposed a uniform definition of AKI, essentially merging the RIFLE and AKIN criteria. This review will focus on the definition and classification of AKI, as proposed by KDIGO in 2012, and their use in clinical practice for clinicians.
Acute Kidney Injury* ; Classification ; Mortality ; Prognosis

Acute kidney injury (AKI), characterized by an acute decline in renal function, commonly develops in hospitalized patients and is associated with increased morbidity and mortality. Recent studies have identified new therapeutic strategies for its management. In this review, we will discuss the definition, etiology, and general treatment of AKI.
Acute Kidney Injury ; Contrast Media ; Humans ; Infusions, Intravenous ; Mortality

Introduction: Since the breakout of COVID-19 in December 2019, the virus has already affected and taken millions of lives over the past year. There is still much to learn about this disease. It has been postulated that the human kidney is a potential pathway for COVID-19 due to the presence of the ACE2 receptors found in the surfaces of kidney cells. Some studies that demonstrated acute tubular necrosis and lymphocyte infiltration among post mortem COVID-19 patients, concluding that the virus could directly damage the kidney, increasing the risk of the development of Acute Kidney Injury (AKI) among patients with COVID-19. This study investigated the incidence and severity of AKI among hospitalized COVID-19 patients and the association of the degree of AKI with regards to the severity and outcomes of COVID-19 patients. Methods: This was a single-center cross-sectional study retrospective chart review of COVID-19 patients who developed AKI. Descriptive statistics were used to summarize the general and clinical characteristics of the patients. Frequency and proportion were used for categorical variables. Shapiro-Wilk test was used to determine the normality distribution of continuous variables. Continuous quantitative data that met the normality assumption was described using mean and standard deviation, while those that did not were described using median and range. Continuous variables which are normally distributed were compared using the One-way ANOVA, while those variables that are not normally distributed were compared using the Kruskal-Wallis H test. For categorical variables, the Chi-square test was used to compare the outcomes. If the expected percentages in the cells are less than 5%, Fisher's Exact Test was used instead. Results: A total of 1441 COVID-19 in-patients from March 1, 2020 to March 1, 2021 were reviewed, 59 of whom were excluded. Among the adults with COVID-19 who developed AKI, 60% were in stage I, 10% in stage II, and 30% in stage III. The incidence of AKI among COVID-19 in-patients at Makati Medical Center was 13.10% (95% CI 11.36% - 14.99%). Among the 181 patients, 79 (43.65%, 95% CI 36.30 - 51.20) had died. The mortality rate is 22.02% for Stage I, 50% for Stage II, and 85.19% for Stage III. The median length of hospital stay was 12 days, ranging from 1 day up to 181 days. Full renal recovery on discharge was observed only in one-third of the patients. It was observed in 44.95% of those in Stage I, 27.78% of those in Stage II, and 5.56% of those in Stage III. Conclusion The study demonstrated that the incidence of AKI in hospitalized COVID-19 patients was 13.1% (95% CI 11.36% - 14.99%), which was lower than previously reported. This could be attributed to the longer study period wherein, to date, we have a better understanding of the disease and had already established a standard of care for treatment for the disease attributing to the decreased incidence of AKI among COVID-19 patients than what was initially reported. The development of AKI has a direct correlation with the degree of infection. Among patients who developed AKI, 20% required renal replacement therapy. Overall development of AKI increases the risk of mortality among hospitalized COVID-19 patients. The stage of AKI has a direct correlation with regards to mortality and has an indirect relationship with regards to renal recovery.
Acute Kidney Injury ; COVID-19 ; Renal Replacement Therapy ; Mortality

Despite substantial advances in dialysis techniques and machines, acute kidney injury (AKI) requiring renal replacement therapy (RRT) is still associated with up to 60% in-hospital mortality. However, there is little information on whether RRT overcomes the significant morbidity and mortality of AKI. What is most important in the treatment of AKI is that RRT is not a cause-specific therapy but life-supportive management. This review discusses the indications of, proper initiation of, and optimal prescription for RRT to improve the survival of critically ill patients with AKI.
Acute Kidney Injury* ; Critical Illness* ; Dialysis ; Hospital Mortality ; Humans ; Mortality ; Prescriptions ; Renal Replacement Therapy

Despite substantial advances in dialytic techniques and machines, acute kidney injury (AKI) requiring renal replacement therapy (RRT) is associated with up to 60% in-hospital mortality. But, there is no full detail of definite RRT to overcome the significant morbidity and mortality of AKI. What is most important in the treatment for AKI is that RRT is not a cause-specific therapy but a life-supportive management. This review discusses the indications of, proper initiation of, and optimal prescription for RRT to improve the survival of the patients with AKI.
Acute Kidney Injury ; Hospital Mortality ; Humans ; Kidney ; Prescriptions ; Renal Replacement Therapy

Acute kidney injury (AKI) has various triggers, such as ischemia, nephrotoxins, radiocontrast, and bacterial endotoxins. It occurs in about one-third of patients treated in the intensive care unit. There is a higher mortality in patients with AKI compared with their non-AKI counterparts. The diagnosis of AKI usually depends on serum creatinine (SCr) measurements. However, SCr is a delayed and unreliable indicator of AKI. The lack of early biomarkers has limited the ability to manage AKI. Fortunately, understanding the early stress response of the kidney to injury has resulted in the identification and validation of several potential novel urine and blood biomarkers. Recently, new biomarkers of AKI with more favorable characteristics than SCr have been identified and studied in various experimental and clinical settings. This article reviews the most well-established biomarkers of AKI.
Acute Kidney Injury* ; Biomarkers* ; Creatinine ; Diagnosis ; Endotoxins ; Humans ; Intensive Care Units ; Ischemia ; Kidney ; Mortality

BACKGROUND: Few data showed the optimal blood pressure (BP) in noncritically ill patients with acute kidney injury (AKI) relative to mortality or severe AKI. We therefore sought to analyze the data that exist for the ideal target range for BP in noncritically ill patients with AKI. METHODS: We performed a retrospective cohort study involving 1,612 hospitalized patients who were diagnosed with AKI using the Kidney Disease: Improving Global Outcomes definition based on serum creatinine measurements for a period of 1 year. The average systolic BP (SBP) was categorized into 10-mmHg increments (within 48 hours after the development of AKI). The primary outcome was a composite of severe AKI or 90-day mortality. RESULTS: The composite outcome rate in patients was 18.7% (302/1,612). The relationship between BP and the composite outcome followed a U-shaped curve, with an increased event rate observed at both low and high BP values. The average SBP after AKI predicted the composite outcome after adjusting for baseline variables (reference SBP: 120–129 mmHg; < 100 mmHg: hazard ratio [HR] 1.84, P = 0.015; 100–109 mmHg: HR 1.56, P = 0.038; 110–119 mmHg: HR 1.15, P = 0.483; 130–139 mmHg: HR 1.51, P = 0.045; ≥ 140 mmHg: HR 1.73, P = 0.005). CONCLUSION: Among noncritically ill patients with AKI, a U-shaped curve association was observed between the average SBP within 48 hours after AKI and the composite primary outcome of this study, with the lowest event rate for SBP ranging from approximately 110 to 129 mmHg.
Acute Kidney Injury ; Blood Pressure ; Cohort Studies ; Creatinine ; Humans ; Kidney Diseases ; Mortality ; Retrospective Studies

Acute renal failure is the generic term for an abrupt and sustained decrease in renal function resulting in retention of nitrogenous and non nitrogenous waste product. This may results in life threatening consequences including volume overload, hyperkalemia, and metabolic acidosis. Acute renal failure is both common and carries high mortality rate, but as it is often preventable, identification of patients at risk and and appropriate management are crucial. This review summarized the most recent information on definition, epidemiology, clinical causes and management of acute renal failure in pediatric patients.
Acidosis ; Acute Kidney Injury* ; Epidemiology ; Humans ; Hyperkalemia ; Mortality ; Nitrogen ; Pediatrics* ; Waste Products

BACKGROUND: Many epidemiologic studies have reported on the controversial concept of the obesity paradox. The presence of acute kidney injury (AKI) can accelerate energy-consuming processes, particularly in patients requiring continuous renal replacement therapy (CRRT). Thus, we aimed to investigate whether obesity can provide a survival benefit in this highly catabolic condition. METHODS: We conducted an observational study in 212 patients who had undergone CRRT owing to various causes of AKI between 2010 and 2014. The study end point was defined as death that occurred within 30 days after the initiation of CRRT. RESULTS: Patients were categorized into three groups according to tertiles of body mass index (BMI). During ≥30 days after the initiation of CRRT, 39 patients (57.4%) in the highest tertile died, as compared with 58 patients (78.4%) in the lowest tertile (P = 0.02). In a multivariable analysis adjusted for cofounding factors, the highest tertile of BMI was significantly associated with a decreased risk of death (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.37–0.87; P = 0.01). This significant association remained unaltered for 60-day (HR, 0.64; 95% CI, 0.43–0.94; P = 0.03) and 90-day mortality (HR, 0.66; 95% CI, 0.44–0.97; P = 0.03). CONCLUSION: This study showed that a higher BMI confer a survival benefit over a lower BMI in AKI patients undergoing CRRT.
Acute Kidney Injury* ; Body Mass Index* ; Epidemiologic Studies ; Humans ; Mortality* ; Obesity ; Observational Study ; Renal Replacement Therapy*

Radiocontrast nephropathy (RCN) is one of the most common etiologies of hospital-acquired acute kidney injury (AKI), accounting for more than 10% of cases. Although most patients who develop RCN have mild and transient decrement in renal function and do not require renal replacement therapy, RCN is associated with significant prolongation of hospitalization and increased morbidity and mortality. Volume expansion with isotonic saline or isotonic sodium bicarbonate before and after radiocontrast administration has been shown to decrease the risk of RCN in high-risk patients. The infusion of isotonic saline or sodium bicarbonate has significant clinical limits, requiring the need for overnight hospitalization and causing volume overload in patients with renal dysfunction. On the contrary, N-acetylcysteine (NAC) is inexpensive, convenient and free of significant complications. It is therefore reasonable to employ this agent, albeit with recognition that its benefit may be limited in published trials. In this issue of the Journal, Seo and Kim compare the efficacy of oral NAC alone with half saline hydration for preventing radiocontrast nephropathy in patients with renal dysfunction. They found that there was no significant difference in the incidence of RCN in the two groups. In addition, although there was no statistical difference between both groups, they stressed the role of nitric oxide (NO) in the prevention of RCN. Consequently, they conclude that oral NAC alone may be effective to prevent RCN in patients with the risk of volume overload after bolus hydration. However, this is a single-center study and requires validation across additional clinical settings including the group of more rapid infusion rate than 12 h pre- and postprocedure used in this study. Therefore, additional large, multicenter, randomized, controlled trials will be required to define the true role of NAC in preventing RCN.
Acetylcysteine* ; Acute Kidney Injury ; Hospitalization ; Humans ; Incidence ; Mortality ; Nitric Oxide ; Renal Replacement Therapy ; Sodium Bicarbonate