Short- and long-term outcomes after non-severe acute kidney injury

A Delphi study to determine the epidemiology and clinical management of patients treated with HDMTX who develop methotrexate (MTX) delayed elimination in France, Germany, Italy, and the UK

Introduction

High-dose methotrexate (HDMTX) is administered for the treatment of some malignancies. Serious complications after the administration of HDMTX are rare, but occasionally MTX may precipitate in the renal tubes causing a delayed elimination leading to renal, multiorgan toxicities and to life-threatening complications. This study aims to estimate the incidence and clinical management of delayed MTX elimination in France, Germany, Italy, and the UK.

Methods

Twelve haemato-oncology and pediatric oncology clinical experts from leading European hospitals participated in the study. A two-round Delphi methodology was used to gather data on different variables relevant to evaluate the HDMTX induced-toxicity impact. For quantitative data, median and interquartile ranges were calculated. Data on prevalence was calculated considering the number of patients in each hospital and the population they cover, and then, extrapolated to the country population.

Results

The total number of patients treated annually with HDMTX in France, Germany, Italy, and the UK is estimated in 7155. Of these, 16% are estimated to develop delayed MTX elimination and around 9% may develop HDMTX-induced acute kidney injury (AKI). Leucovorin, hyperhydration and urine alkalinization are applied to prevent MTX toxicity and precipitation whilst glucarpidase, hemofiltration and hemodialysis are being used for persisting toxic MTX serum levels. Grade 3 systemic toxicities are common in these patients, hematologic and gastrointestinal being the most common ones.

Conclusions

This report provides expert clinical practice experience and opinion of the incidence and management of HDMTX-delayed elimination in France, Germany, Italy and the UK, thereby contributing to the evidence available on this relevant medical condition which can be life-threatening.

Outcomes, Healthcare Resource Utilization, and Costs of Overall, Community-Acquired, and Hospital-Acquired Acute Kidney Injury in COVID-19 Patients

Background: In hospitalized patients with COVID-19, acute kidney injury (AKI) is associated with higher mortality, but data are lacking on healthcare resource utilization (HRU) and costs related to AKI, community-acquired AKI (CA-AKI), and hospital-acquired AKI (HA-AKI). Objectives: To quantify the burden of AKI, CA-AKI, and HA-AKI among inpatients with COVID-19. Methods: This retrospective cohort study included inpatients with COVID-19 discharged from US hospitals in the Premier PINC AI™ Healthcare Database April 1-October 31, 2020, categorized as AKI, CA-AKI, HA-AKI, or no AKI by ICD-10-CM diagnosis codes. Outcomes were assessed during index (initial) hospitalization and 30 days postdischarge. Results: Among 208 583 COVID-19 inpatients, 30%, 25%, and 5% had AKI, CA-AKI, and HA-AKI, of whom 10%, 7%, and 23% received dialysis, respectively. Excess mortality, HRU, and costs were greater for HA-AKI than CA-AKI. In adjusted models, for patients with AKI vs no AKI and HA-AKI vs CA-AKI, odds ratios (ORs) (95% CI) were 3.70 (3.61-3.79) and 4.11 (3.92-4.31) for intensive care unit use and 3.52 (3.41-3.63) and 2.64 (2.52-2.78) for in-hospital mortality; mean length of stay (LOS) differences and LOS ratios (95% CI) were 1.8 days and 1.24 (1.23-1.25) and 5.1 days and 1.57 (1.54-1.59); and mean cost differences and cost ratios were $7163 and 1.35 (1.34-1.36) and $19 127 and 1.78 (1.75-1.81) (all P < .001). During the 30 days postdischarge, readmission LOS was ≥6% longer for AKI vs no AKI and HA-AKI vs CA-AKI; outpatient costs were ≥41% higher for HA-AKI vs CA-AKI or no AKI. Only 30-day new dialysis (among patients without index hospitalization dialysis) had similar odds for HA-AKI vs CA-AKI (2.37-2.8 times higher for AKI, HA-AKI, or CA-AKI vs no AKI). Discussion: Among inpatients with COVID-19, HA-AKI had higher excess mortality, HRU, and costs than CA-AKI. Other studies suggest that interventions to prevent HA-AKI could decrease excess morbidity, HRU, and costs among inpatients with COVID-19. Conclusions: In adjusted models among COVID-19 inpatients, AKI, especially HA-AKI, was associated with significantly higher mortality, HRU, and costs during index admission, and higher dialysis and longer readmission LOS during the 30 days postdischarge. These findings support implementation of interventions to prevent HA-AKI in COVID-19 patients.

Incidence and management of patients with methotrexate delayed elimination in the clinical practice: A Delphi study

INTRODUCTION

High-dose methotrexate (HDMTX) is administered for the treatment of some cancers. HDMTX is usually safe but may crystallize in renal tubules causing acute kidney injury (AKI). Consequently, MTX elimination is delayed, resulting in a severe and life-threatening condition. No studies have been published about the impact of MTX toxicity in Spain. This study aims to estimate the incidence and management of MTX delayed elimination and toxicity.

METHODS

A two-round Delphi study was performed to reach consensus between 10 medical experts on haemato-oncology and paediatric oncology with experience in the management of HDMTX treated patients from leading Spanish hospitals. An online questionnaire was developed based on national and international guidelines and previous evidence regarding HDMTX-related toxicity. Consensus was established at 80% agreement. Median and interquartile ranges were calculated, and incidence data were extrapolated to the Spanish general population.

RESULTS

Out of 1.475 patients estimated to receive HDMTX treatment annually in Spain, 27.5% present MTX delayed elimination and 11.6% develop HDMTX-induced AKI (35.4% with severe systemic toxicities (>grade 3) and 18.8% develop chronic renal disease). Mortality is estimated in 4.2%. Immuno-enzymatic assay is used in most of the hospitals (90%) for MTX serum level monitoring. All experts use increased supportive care and high leucovorin as first-line treatment. Available treatments in experts' hospitals in case toxicity persists are haemodialysis (90% of hospitals), glucarpidase (60%) and hemofiltration (50%). Most prevalent non-renal systemic toxicities are haematologic and mucositis (21-40% of patients). Patients with HDMTX-induced AKI require from intensive care (5% of patients), more than 3 sessions and 4 days of dialysis, and about 8.5 days of hospitalization (non-ICU patients) and 12 days in case of patients requiring ICU.

CONCLUSIONS

These results are the first evidence regarding HDMTX-induced AKI in Spain. Incidence and mortality results are in line with previous studies. Clinical management is based on preventive measures and the treatment depend on the availability in the hospital. The need for effective, safe and rapid treatment for the reduction of MTX toxic levels and the improvement of monitoring methods were noted by experts as urgent needs. Further observational studies to validate these results would be needed.

High risk of acute kidney injury in Malawian trauma patients: a prospective observational cohort study

Background

Trauma is a common cause of acute kidney injury (AKI). Yet little data exist regarding trauma-related-AKI in low-resourced settings, where the majority of deaths from AKI and trauma occur. We prospectively evaluated epidemiology of AKI in hospitalized Malawian trauma patients.

Methods

AKI was defined by creatinine-only Kidney Disease Improving Global Outcomes (KDIGO) criteria. Those with AKI were followed up 3–6 months later to determine persistent kidney abnormalities. We calculated univariate statistics with Wilcoxon rank sum tests, Fisher’s exact, and chi-square tests to compare those with and without AKI. Multivariate log-risk regression modelling was used to determine risk ratios (RR) and 95% confidence intervals (CI) for AKI development.

Results

Of 223 participants, 14.4% (n = 32) developed AKI. Most patients were young (median age 32) males (n = 193, 86.5%) involved in road traffic injuries (n = 120, 53.8%). After adjusting for confounders, those with severe anemia during their admission were 1.4 times (RR 1.4, 95% CI 1.1–1.8) more likely to develop AKI than those without. Overall mortality was 7.6% (n = 17), and those who developed AKI were more likely to die than those who did not (18.8% vs 5.6%, p-value = 0.02). Almost half of those with AKI (n = 32) either died (n = 6) or had persistent kidney dysfunction at follow-up (n = 8).

Conclusion

In one of the few African studies on trauma-related AKI, we found a high incidence of AKI (14.4%) in Malawian trauma patients with associated poor outcomes. Given AKI’s association with increased mortality and potential ramifications on long-term morbidity, urgent attention is needed to improve AKI-related outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02564-y.

Cardio- and Cerebrovascular Outcomes of Postoperative Acute Kidney Injury in Noncardiac Surgical Patients With Hypertension

Background: The cardiovascular and cerebrovascular risk of postoperative acute kidney injury (AKI) in surgical patients is poorly described, especially in the hypertensive population.

Methods: We conducted a retrospective cohort study among all hypertensive patients who underwent elective noncardiac surgery from January 1st, 2012 to August 1st, 2017 at the Third Xiangya Hospital. The primary outcomes were fatal stroke and fatal myocardial infarction (MI). The secondary outcomes were all-cause mortality.

Results: The postoperative cumulative mortality within 3 months, 6 months, 1 year, 2 years, and 5 years were 1.27, 1.48, 2.15, 2.15, and 5.36%, for fatal stroke, and 2.05, 2.27, 2.70, 3.37, and 5.61% for fatal MI, respectively, in patients with postoperative AKI. Compared with non-AKI patients, those with postoperative AKI had a significantly higher risk of fatal stroke and fatal MI within 3 months [hazard ratio (HR): 5.49 (95% CI: 1.88−16.00) and 11.82 (95% CI: 4.56−30.62), respectively], 6 months [HR: 3.58 (95% CI: 1.43−8.97) and 9.23 (95% CI: 3.89−21.90), respectively], 1 year [HR: 3.64 (95% CI: 1.63−8.10) and 5.14 (95% CI: 2.50−10.57), respectively], 2 years [HR: 2.21 (95% CI: 1.03−4.72) and 3.06 (95% CI: 1.66−5.64), respectively], and 5 years [HR: 2.27 (95% CI: 1.30−3.98) and 1.98 (95% CI: 1.16−3.20), respectively]. In subgroup analysis of perioperative blood pressure (BP) lowering administration, postoperative AKI was significantly associated with 1-year and 5-year risk of fatal stroke [HR: 9.46 (95% CI: 2.85−31.40) and 3.88 (95% CI: 1.67−9.01), respectively] in patients with ACEI/ARB, and MI [HR: 6.62 (95% CI: 2.23−19.62) and 2.44 (95% CI: 1.22−4.90), respectively] in patients with CCB.

Conclusion: Hypertensive patients with postoperative AKI have a significantly higher risk of fatal stroke and fatal MI, as well as all-cause mortality, within 5 years after elective noncardiac surgery. In patients with perioperative administration of ACEI/ARB and CCB, postoperative AKI was significantly associated with higher risk of fatal stroke and MI, respectively.

Developing an AKI Consensus Definition for Database Research: Findings From a Scoping Review and Expert Opinion Using a Delphi Process

RATIONALE & OBJECTIVE

The KDIGO (Kidney Disease: Improving Global Outcomes) definition of acute kidney injury (AKI) is frequently used in studies to examine the epidemiology of AKI. This definition is variably interpreted and applied to routinely collected health care data. The aim of this study was to examine this variation and to achieve consensus in how AKI should be defined for research using routinely collected health care data.

SOURCES OF EVIDENCE AND STUDY DESIGN

Scoping review via searching Medline and EMBASE for studies using health care data to examine AKI by using the KDIGO creatinine-based definition. An international panel of experts formed to participate in a modified Delphi process to attempt to generate consensus about how AKI should be defined when using routinely collected laboratory data.

CHARTING METHODS AND ANALYTICAL APPROACH

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) extension for scoping reviews was followed. For the Delphi process, 2 rounds of questions were distributed via internet-based questionnaires to all participants with a prespecified cutoff of 75% agreement used to define consensus.

RESULTS

The scoping review found 174 studies that met the inclusion criteria. The KDIGO definition was inconsistently applied, and the methods for application were poorly described. We found 58 (33%) of papers did not provide a definition of how the baseline creatinine value was determined, and only 34 (20%) defined recovery of kidney function. Of 55 invitees to the Delphi process, 35 respondents participated in round 1, and 25 participated in round 2. Some consensus was achieved in areas related to how to define the baseline creatinine value, which patients should be excluded from analysis of routinely collected laboratory data, and how persistent chronic kidney disease or nonrecovery of AKI should be defined.

LIMITATIONS

The Delphi panel members predominantly came from the United Kingdom, the United States, and Canada, and there were low response rates for some questions in round 1.

CONCLUSIONS

The current methods for defining AKI using routinely collected data are inconsistent and poorly described in the available literature. Experts could not achieve consensus for many aspects of defining AKI and describing its sequelae. The KDIGO guidelines should be extended to include a standardized definition for how AKI should be defined when using routinely collected data.

A flow cytometry approach reveals heterogeneity in conventional subsets of murine renal mononuclear phagocytes

Mononuclear phagocytes (MNPs) participate in inflammation and repair after kidney injury, reflecting their complex nature. Dissection into refined functional subunits has been challenging and would benefit understanding of renal pathologies. Flow cytometric approaches are limited to classifications of either different MNP subsets or functional state. We sought to combine these two dimensions in one protocol that considers functional heterogeneity in each MNP subset. We identified five distinct renal MNP subsets based on a previously described strategy. In vitro polarization of bone marrow-derived macrophages (BMDM) into M1- and M2-like cells suggested functional distinction of CD86 + MHCII + CD206- and CD206 + cells. Combination of both distinction methods identified CD86 + MHCII + CD206- and CD206 + cells in all five MNP subsets, revealing their heterologous nature. Our approach revealed that MNP composition and their functional segmentation varied between different mouse models of kidney injury and, moreover, was dynamically regulated in a time-dependent manner. CD206 + cells from three analyzed MNP subsets had a higher ex vivo phagocytic capacity than CD86 + MHCII + CD206- counterparts, indicating functional uniqueness of each subset. In conclusion, our novel flow cytometric approach refines insights into renal MNP heterogeneity and therefore could benefit mechanistic understanding of renal pathology.

Long-term consequences of acute kidney injury: a narrative review

The incidence of acute kidney injury (AKI) has increased in the past decades. AKI complicates up to 15% of hospitalizations and can reach up to 50-60% in critically ill patients. Besides the short-term impact of AKI in patient outcomes, several studies report the association between AKI and adverse long-term outcomes, such as recurrent AKI episodes in 25-30% of cases, hospital re-admissions in up to 40% of patients, an increased risk of cardiovascular events, an increased risk of progression of chronic kidney disease (CKD) after AKI and a significantly increased long-term mortality. Despite the long-term impact of AKI, there are neither established guidelines on the follow-up care of AKI patients, nor treatment strategies to reduce the incidence of sequelae after AKI. Only a minority of patients have been referred to nephrology post-discharge care, despite the evidence of improved outcomes associated with nephrology referral by addressing cardiovascular risk and risk of progression to CKD. Indeed, AKI survivors should have specialized nephrology follow-up to assess kidney function after AKI, perform medication reconciliation, educate patients on nephrotoxic avoidance and implement strategies to prevent CKD progression. The authors provide a comprehensive review of the transition from AKI to CKD, analyse the current evidence on the long-term outcomes of AKI and describe predisposing risk factors, highlight the importance of follow-up care in these patients and describe the current therapeutic strategies which are being investigated on their impact in improving patient outcomes.

Renal ischemia-reperfusion leads to hypertension and changes in proximal tubule Na+ transport and renin-angiotensin-aldosterone system: Role of NADPH oxidase

Acute renal injury (AKI) is a risk factor for the development of hypertension, which involves oxidative stress, changes in Na⁺ handling, and the intrarenal renin-angiotensin-aldosterone system (RAAS) as underlying mechanisms. We investigated in rats whether renal ischemia-reperfusion (IR) leads to changes in the proximal tubule ATP-dependent Na⁺ transport and the intrarenal content of RAAS components, as well as the role of NADPH oxidase. Rats weighing 300-350 g were submitted to AKI by bilateral IR (n = 25). After IR injury, the animals were followed up for 4 weeks. One part (n = 7) received daily treatment with the NADPH oxidase inhibitor apocynin (100 mg/kg, drinking water), while another part (n = 9) received apocynin 24 h before and after IR. One group was submitted to sham surgery (n = 8). Four weeks after IR, the rats presented elevated systolic blood pressure, as well as increased lipid peroxidation, NADPH oxidase activity, (Na⁺+K⁺)ATPase activity, and upregulation of type 1 angiotensin II receptor in the renal cortex. On the other hand, there was a decrease in Na⁺-ATPase activity and downregulation of the isoforms 1 and 2 of the angiotensin-converting enzyme, type 2 angiotensin II receptor, and of the α and ε isoforms of protein kinase C. Most of these alterations was prevented by both apocynin treatment protocols. Thus, we conclude that AKI-induced by IR may induce changes in proximal tubule ATPases and RAAS components compatible with renal Na⁺ retention and hypertension. These data also indicate that the NADPH oxidase represents a key factor in the origin of these alterations.

Effect of multiple episodes of acute kidney injury on mortality: an observational study

Background

Patients who survive an episode of acute kidney injury (AKI) are more likely to have further episodes of AKI. AKI is associated with increased mortality, with a further increase with recurrent episodes. It is not clear whether this is due to AKI or as a result of other patient characteristics. The aim of this study was to establish whether recurrence of AKI is an independent risk factor for mortality or if excess mortality is explained by other factors.

Methods

This observational cohort study included adult people from the Tayside region of Scotland, with an episode of AKI between 1 January 2009 and 31 December 2009. AKI was defined using the creatinine-based Kidney Disease: Improving Global Outcomes definition. Associations between recurrent AKI and mortality were examined using a Cox proportional hazards model.

Results

Survival was worse in the group identified to have recurrent AKI compared with those with a single episode of AKI [hazard ratio = 1.49, 95% confidence interval (CI) 1.37-1.63; P < 0.001]. After adjustment for comorbidities, stage of reference AKI, sex, age, medicines that predispose to renal impairment or, in the 3 months prior to the reference AKI, deprivation and baseline estimated glomerular filtration rate (eGFR), recurrent AKI was independently associated with an increase in mortality (hazard ratio = 1.25, 95% CI 1.14-1.37; P < 0.001). Increasing stage of reference AKI, age, deprivation, baseline eGFR, male sex, previous myocardial infarction, cerebrovascular disease and diuretic use were all associated with an increased risk of mortality in patients with recurrent AKI.

Conclusions

Recurrent AKI is associated with increased mortality. After adjusting for patient characteristics, the increase in mortality is independently associated with recurrent AKI and is not solely explained by other risk factors.

The Potential for Renal Injury Elicited by Physical Work in the Heat

An epidemic of chronic kidney disease (CKD) is occurring in laborers who undertake physical work in hot conditions. Rodent data indicate that heat exposure causes kidney injury, and when this injury is regularly repeated it can elicit CKD. Studies in humans demonstrate that a single bout of exercise in the heat increases biomarkers of acute kidney injury (AKI). Elevations in AKI biomarkers in this context likely reflect an increased susceptibility of the kidneys to AKI. Data largely derived from animal models indicate that the mechanism(s) by which exercise in the heat may increase the risk of AKI is multifactorial. For instance, heat-related reductions in renal blood flow may provoke heterogenous intrarenal blood flow. This can promote localized ischemia, hypoxemia and ATP depletion in renal tubular cells, which could be exacerbated by increased sodium reabsorption. Heightened fructokinase pathway activity likely exacerbates ATP depletion occurring secondary to intrarenal fructose production and hyperuricemia. Collectively, these responses can promote inflammation and oxidative stress, thereby increasing the risk of AKI. Equivalent mechanistic evidence in humans is lacking. Such an understanding could inform the development of countermeasures to safeguard the renal health of laborers who regularly engage in physical work in hot environments.

Global epidemiology and outcomes of acute kidney injury

Acute kidney injury (AKI) is a commonly encountered syndrome associated with various aetiologies and pathophysiological processes leading to decreased kidney function. In addition to retention of waste products, impaired electrolyte homeostasis and altered drug concentrations, AKI induces a generalized inflammatory response that affects distant organs. Full recovery of kidney function is uncommon, which leaves these patients at risk of long-term morbidity and death. Estimates of AKI prevalence range from <1% to 66%. These variations can be explained by not only population differences but also inconsistent use of standardized AKI classification criteria. The aetiology and incidence of AKI also differ between high-income and low-to-middle-income countries. High-income countries show a lower incidence of AKI than do low-to-middle-income countries, where contaminated water and endemic diseases such as malaria contribute to a high burden of AKI. Outcomes of AKI are similar to or more severe than those of patients in high-income countries. In all resource settings, suboptimal early recognition and care of patients with AKI impede their recovery and lead to high mortality, which highlights unmet needs for improved detection and diagnosis of AKI and for efforts to improve care for these patients.

Length of stay, mortality, and readmissions among Medicare cancer patients treated with glucarpidase and conventional care: a retrospective study

PURPOSE

Glucarpidase (Voraxaze) is used to treat methotrexate (Mtx) toxicity in patients with delayed Mtx clearance due to impaired renal function. We examine hospital length of stay (LOS), mortality, and readmission rates for Medicare cancer patients with delayed clearance of Mtx treated with glucarpidase.

METHODS

Using 2010-2017 Medicare claims data, we identified glucarpidase patients as those hospitalized with indications of select lymphomas or leukemia, inpatient chemotherapy, and glucarpidase treatment. We assessed outcomes of glucarpidase patients relative to those experienced by patients treated for presumed Mtx toxicity using other therapies. These nonglucarpidase patients were identified with a diagnosis of primary central nervous system lymphoma, indications of cancer-chemotherapy toxicity, and acute kidney injury during hospitalization (not present on admission), and were divided into two groups: treated with dialysis (dialysis+) and treated with or without dialysis (dialysis+/-). Inverse-probability treatment weighting using propensity scores was used to adjust for differences between groups.

RESULTS

Patients treated with glucarpidase (n=30) had an average LOS of 14.7 days. They had inpatient, 30-day, and 90-day mortality rates of 3.3%, 13.3%, and 16.7%, respectively, and a 90-day all-cause unplanned readmission rate of 24.1%. The dialysis+ and dialysis+/- groups, respectively, had higher average LOS (40.2, 21.9), higher inpatient mortality (50.6%, 20.8%), and higher 90-day mortality (58.6%, 37.6%). No statistically significant differences in 30-day mortality or 90-day readmission rates were detected between the glucarpidase group and either of the nonglucarpidase groups. Unobservable differences in patient severity may impact the interpretation of our findings.

CONCLUSION

Medicare cancer patients with presumed Mtx toxicity receiving conventional treatment experience long hospitalizations, high intensive-care unit use and high mortality. Glucarpidase patients had lower LOS, inpatient mortality, and 90-day mortality than the non-glucarpidase patients.

Impact of Recurrent Acute Kidney Injury on Patient Outcomes

BACKGROUND/AIMS

Recurrent acute kidney injury (AKI) is common among patients after a first hospitalized AKI. However, little is known about the prognosis of recurrent AKI episodes in chronic kidney disease (CKD) development, cardiovascular events and mortality.

METHODS

A retrospective study included patients admitted to our Hospital from 2000 to 2010. AKI was defined according to the Acute Dialysis Quality Initiative criteria. In the follow-up period after the first AKI episode, clinical, laboratory data and the number of repeated AKI episodes, etiology and severity were recorded.

RESULTS

Among the 359 AKI survivor patients included, 250 new AKI episodes were observed in 122 patients (34%). Variables independently associated to new episodes were: type 2 DM [OR 1.2, 95%CI 1.2-3.8, p=0.001], ischemic heart disease [OR 1.9; 95%CI 1.1-3.6, p=0.012], and SCr at the first AKI event>2,6 mg/dl [OR 1.2; 95%CI 1.03-1.42, p=0.02]. Development of CKD during four years follow-up was more frequent in patients with recurrent AKI, HR [2.2 (95% CI: 1.09-4.3, p=0.003)] and 44% of recurrent AKI patients who developed CKD occurred during the first 6 months after the initial event. Cardiovascular events were more frequent among patients with recurrent AKI patients than in those with one AKI episode (47.2% vs 24%, p=0.001). Mortality at 4 years was higher in the patient subgroup with several episodes of AKI as compared with those with a single episode [HR: 4.5 (95% CI 2.7-7.5) p<0.001].

CONCLUSION

Episodes of recurrent AKI have a high potential to be associated with relevant complications such as cardiovascular events, mortality and CKD development.

[Life after Acute Kidney Injury : Long-term consequences and implications for clinical practice]

Acute kidney injury (AKI) is a common complication in critically ill patients and is accompanied by significantly increased mortality and morbidity. Those complications are not limited to the acute phase of the illness, but may also affect a patient's risk profile long after AKI. Recovery of renal function is observed in the majority of patients although this rate significantly deteriorates with increasing severity of the AKI. After an AKI episode, the long-term risk for the development of chronic kidney disease (CKD) is considerably increased, as well as the risk for cardiovascular and neurological complications. Follow-up of these patients should include general nephroprotective measures such as controlling hypertension as well as avoiding nephrotoxic drugs, as well as repeated evaluations of renal function.