Acute kidney injury increases the risk of end-stage renal disease after cardiac surgery in an Asian population: a prospective cohort study

Leptospirosis: A dual threat - predisposing risk for renal transplant and trigger for renal transplant dysfunction

Leptospirosis (LTPS) is a bacterial infection that affects humans, often with mild or no symptoms. It is estimated that approximately 10 % of patients with LTPS may experience multi-organ dysfunction, including renal abnormalities. In regions where LTPS is widespread, a considerable number of instances involving acute kidney injury (AKI) and chronic kidney disease (CKD) of unknown etiology (CKDu) have been reported. Additionally, studies have shown a correlation between kidney graft dysfunction in patients with stable kidney transplants after LTPS. These findings indicate that exposure to LTPS may increase the likelihood of kidney transplantation due to the onset of both acute and chronic kidney injuries. Simultaneously, it poses a potential risk to the stability of kidney grafts. Unfortunately, there is limited scientific literature addressing this issue, making it difficult to determine the negative impact that LTPS may have, such as its role as a risk factor for the need of kidney transplantation or as a threat to individuals who have undergone kidney transplants. This study aims to shed light on the immune mechanisms triggered during LTPS infection and their importance in both kidney damage and allograft dysfunction.

Validation of a Prediction Model for Acute Kidney Injury after Cardiac Surgery in a Retrospective Asian Cohort

Background: The incidence of postoperative acute kidney injury (AKI) is relatively high in some Asian regions. The objective of this study was to examine the performance of an AKI prediction model developed based on data from a White-dominant population in a retrospective Asian cohort of patients undergoing cardiovascular surgery. Methods: We retrospectively identified 549 patients who underwent elective major cardiovascular surgery (coronary artery bypass graft, valve surgery, and aorta surgery), and excluded those who underwent a percutaneous cardiovascular procedure. Patients with a baseline estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 were also excluded. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) definition. Performance of the prediction model for AKI was expressed as area under the receiver operating characteristic curve (AUC). Results: The prediction model had a good predictive accuracy for postoperative AKI (all AUC > 0.92). The AUC of the prediction model in subgroups of age (<65 years and ≥65 years), sex (male and female), hypertension, and diabetes were all >0.85 (all p values < 0.001). Conclusions: The model could be used to predict postoperative AKI in Asian patients undergoing cardiovascular surgery with a baseline eGFR ≥ 60 mL/min/1.73 m2.

Association of anticoagulation use during continuous kidney replacement therapy and 90-day outcomes: A multicentre study

Introduction

Anticoagulation is recommended during continuous kidney replacement therapy (CKRT) to prolong the filter lifespan for optimal filter performance. We aimed to evaluate the effect of anticoagulation during CKRT on dialysis dependence and mortality within 90 days of intensive care unit (ICU) admission.

Method

Our retrospective observational study evaluated the first CKRT session in critically ill adults with acute kidney injury (AKI) in Singapore from April to September 2017. The primary outcome was a composite of dialysis dependence or death within 90 days of ICU admission; the main exposure variable was anticoagulation use (regional citrate anticoagulation [RCA] or systemic heparin). Multivariable logistic regression was performed to adjust for possible confounders: age, female sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, liver dysfunction, coagulopathy (international normalised ratio[INR] >1.5) and platelet counts of less than 100,000/uL).

Results

The study cohort included 276 patients from 14 participating adult ICUs, of whom 176 (63.8%) experienced dialysis dependence or death within 90 days of ICU admission (19 dialysis dependence, 157 death). Anticoagulation significantly reduced the odds of the primary outcome (adjusted odds ratio [AOR] 0.47, 95% confidence interval [CI] 0.27-0.83, P=0.009). Logistic regression analysis using anticoagulation as a 3-level indicator variable demonstrated that RCA was associated with mortality reduction (AOR 0.46, 95% CI 0.25-0.83, P=0.011), with heparin having a consistent trend (AOR 0.51, 95% CI 0.23-1.14, P=0.102).

Conclusion

Among critically ill patients with AKI, anticoagulation use during CKRT was associated with reduced dialysis or death at 90 days post-ICU admission, which was statistically significant for regional citrate anticoagulation and trended in the same direction of benefit for systemic heparin anticoagulation. Anticoagulation during CKRT should be considered whenever possible.

Recovery after AKI: Effects on outcomes over 15 years

PURPOSE

To examine the effect of kidney recovery on mortality, dialysis and kidney transplantation up to 15 years after AKI.

MATERIALS AND METHODS

We studied 29,726 survivors of critical illness and compared these outcomes stratified by AKI and recovery status at hospital discharge. Kidney recovery was defined as a return of serum creatinine to ≤150% of baseline without dialysis prior to hospital discharge.

RESULTS

Overall AKI occurred in 59.2% in which two thirds developed stage 2-3 AKI. Recovery rate of AKI at hospital discharge was 80.8%. Patients who did not recover experienced the worst 15-year mortality compared to those who recovered and those without AKI (57.8% vs 45.2% vs 30.3%, p < 0.001). This pattern was also found in subgroups of patients with suspected sepsis-associated (57.1% vs 47.9% vs 36.5%, p < 0.001) and cardiac surgery-associated AKI (60.1% vs 41.8% vs 25.9%, p < 0.001). The rates of dialysis and transplantation at 15 years were low and not associated with recovery status.

CONCLUSIONS

Recovery of AKI in critically ill patients at hospital discharge had an effect on long-term mortality for up to 15 years. These results have implications for acute care, follow-up and choice of endpoints for clinical trials.

Acute kidney injury in diabetic patients: A narrative review

Diabetes mellitus (DM) is the most common cause of chronic kidney disease, which leads to end-stage renal failure worldwide. Glomerular damage, renal arteriosclerosis, and atherosclerosis are the contributing factors in diabetic patients, leading to the progression of kidney damage. Diabetes is a distinct risk factor for acute kidney injury (AKI) and AKI is associated with faster advancement of renal disease in patients with diabetes. The long-term consequences of AKI include the development of end-stage renal disease, higher cardiovascular and cerebral events, poor quality of life, and high morbidity and mortality. In general, not many studies discussed extensively "AKI in DM." Moreover, articles addressing this topic are scarce. It is also important to know the cause of AKI in diabetic patients so that timely intervention and preventive strategies can be implemented to decrease kidney injury. Aim of this review article is to address the epidemiology of AKI, its risk factors, different pathophysiological mechanisms, how AKI differs between diabetic and nondiabetic patients and its preventive and therapeutic implications in diabetics. The increasing occurrence and prevalence of AKI and DM, as well as other pertinent issues, motivated us to address this topic.

A Causal-Pathway Phenotype of Chronic Fatigue Syndrome due to Hemodialysis in Patients with End-Stage Renal Disease

BACKGROUND

End-stage renal disease (ESRD) is associated with fatigue and physiosomatic symptoms.

OBJECTIVE

The objective of this study is to delineate the associations between severity of fatigue and physio-somatic symptoms and glomerular filtration rate, inflammatory biomarkers, and Wnt/cateninpathway proteins.

METHODS

The Wnt-pathway related proteins β-catenin, Dickkopf-related protein 1 (DKK1), R-spondin- 1, and sclerostin were measured by ELISA technique in 60 ESRD patients and 30 controls. The Fibromyalgia and Chronic Fatigue Syndrome (FF) Rating Scale was used to assess the severity of FF symptoms.

RESULTS

ESRD is characterized by a significant increase in the total FF score, muscle tension, fatigue, sadness, sleep disorders, gastro-intestinal (GI) symptoms, and a flu-like malaise. The total-FF score was significantly correlated with serum levels of urea, creatinine, and copper (positively), and β-catenin, eGFR, hemoglobin, albumin, and zinc (inversely). The total-FF score was associated with the number of total dialysis and weekly dialysis sessions, and these dialysis characteristics were more important in predicting FF scores than eGFR measurements. Partial Least Squares analysis showed that the FF score comprised two factors that are differently associated with biomarkers: a) 43.0% of the variance in fatigue, GI symptoms, muscle tension, sadness, and insomnia is explained by hemoglobin, albumin, zinc, β-catenin, and R-spondin-1; and b) 22.3% of the variance in irritability, concentration and memory impairments by increased copper and cations/chloride ratio, and male sex.

CONCLUSION

ESRD patients show high levels of fatigue and physio-somatic symptoms associated with hemodialysis and mediated by dialysis-induced changes in inflammatory pathways, the Wnt/catenin pathway, and copper.

Nomogram Prediction Model of Serum Chloride and Sodium Ions on the Risk of Acute Kidney Injury in Critically Ill Patients

Purpose

This study aims to investigate the effect of serum chloride and sodium ions on AKI occurrence in ICU patients, and further constructs a prediction model containing these factors to explore the predictive value of these ions in AKI.

Methods

The clinical information of patients admitted to ICU of Beijing Friendship Hospital Affiliated to Capital Medical University was collected for retrospective analysis. Logistic regression analysis was used to analyzing the influencing factors. A nomogram for predicting AKI risk was constructed with R software and validated by repeated sampling. Afterwards, the effectiveness and accuracy of the model were tested and evaluated.

Results

A total of 446 cases met the requirements of this study, of which 178 developed AKI during their stay in ICU, with an incidence rate of 39.9%. Hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine value and BE value at ICU admission before the diagnosis of AKI were identified as independent risk factors for developing AKI during ICU stay. These predictors were incorporated into the nomogram of AKI risk in critically ill patients, which was constructed by using R software. Receiver operating characteristic curve analysis was further used and showed that the area under the curve of the model was 0.7934 (95% CI 0.742–0.8447), indicating that the model had an ideal value. Finally, further evaluated its clinical effectiveness. The clinical effect curve and decision curve showed that most areas of the decision curve of this model were greater than 0, indicating that this model owned a certain clinical effectiveness.

Conclusion

The nomogram based on hypernatremia, heart failure, sepsis, APACHE II score, and initial creatinine and BE value in ICU can predict the individualized risk of AKI with satisfactory distinguishability and accuracy.

Postoperative Fluid Therapy in Adult Cardiac Surgical Patients and Acute Kidney Injury: A Prospective Observational Study

Background Normal saline (0.9% NS) is a common intravenous fluid used worldwide. Recent studies have shown that NS use is associated with increased incidence of acute kidney injury (AKI) and a need for renal replacement therapy (RRT). The practice is changing toward using balanced solutions to prevent AKI. Postcardiac surgery patients are more prone to develop AKI after cardiopulmonary bypass (CPB). We aim to study the type of fluid administrated, incidence of AKI, need for RRT, and overall outcome of these patients.

Methods This prospective observational study was conducted in the cardiothoracic intensive care unit (cardiothoracic and vascular surgery intensive care unit) in a cohort of 197 adult patients who underwent on pump cardiac surgery in our hospital from July 2021 to October 2021 as a pilot study. Data was analyzed using SPSS 20.0 (IBM, Chicago, Illinois, United States). A p-value < 0.05 was considered significant.

Results In our study, 58 (29.34%) patients developed AKI in the first three postoperative days and 16 (8.12%) patients required RRT. Incidence of AKI was found to be higher in patients who received NS only, as fluid of choice was 34.48% compared with other intravenous fluids. Patients with AKI had higher positive fluid balance (p < 0.001), longer CPB (p < 0.001), and aortic cross clamp (p = 0.006) times. Intensive care unit and hospital stay and mortality rates were higher in AKI patients than those without AKI (p < 0.001).

Conclusion Our study demonstrated that NS was the commonly used crystalloid in our patients and was associated with increased incidence of AKI and RRT when compared with other balanced salts solutions.

Incidence and mortality of acute kidney disease following coronary angiography: a cohort study of 9223 patients

PURPOSE

Acute kidney disease (AKD) is an important state in the evolving kidney diseases. However, there is limited data on the incidence and prognosis of AKD following coronary angiography (CAG). Therefore, we aim to characterize the incidence and prognosis of AKD across a large population of CAG patients.

METHODS

The consecutive patients with baseline and following measurement of serum creatinine (Scr) between 7 and 90 days after CAG procedure were included. The AKD was defined as a decrease in glomerular filtration rate by > 35%, or an increase in Scr of > 50% (from 7 to 90 days). Survival curves, univariate and multivariable cox regressions were used to assess the association between AKD and mortality.

RESULTS

Among 9223 patients (male, 60.3%, mean age, 61.7 ± 9.6), 1540 had AKD. During a median follow-up of 5.4 (IQR 2.2-8.6) years, 1562 (16.9%) patients died. The mortality among the patients with AKD was higher than the non-AKD group (24.8% vs. 15.4%, p < 0.001). AKD was independently associated with a significantly increased risk of all-cause mortality (adjusted hazard ratio [aHR], 1.57; 95% CI 1.39-1.78; p < 0.001).

CONCLUSIONS

Our study suggested that AKD is commonly observed after CAG and increased half mortality risk than those without AKD. More attention needs to be paid to patients suffering from AKD.

Clinical Predictors and Long-term Impact of Acute Kidney Injury on Progression of Diabetic Kidney Disease in Chinese Patients With Type 2 Diabetes

We aim to assess the long-term impact of acute kidney injury (AKI) on progression of diabetic kidney disease (DKD) and all-cause mortality and investigate determinants of AKI in Chinese patients with type 2 diabetes (T2D). A consecutive cohort of 9,096 Chinese patients with T2D from the Hong Kong Diabetes Register was followed for 12 years (mean ± SD age 57 ± 13.2 years; 46.9% men; median duration of diabetes 5 years). AKI was defined based on the Kidney Disease: Improving Global Outcomes (KDIGO) criteria using serum creatinine. Estimated glomerular filtration rate measurements were used to identify the first episode with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Polygenic risk score (PRS) composed of 27 single nucleotide polymorphisms (SNPs) known to be associated with serum uric acid (SUA) in European populations was used to examine the role of SUA in pathogenesis of AKI, CKD, and ESRD. Validation was sought in an independent cohort including 6,007 patients (age 61.2 ± 10.9 years; 59.5% men; median duration of diabetes 10 years). Patients with AKI had a higher risk for developing incident CKD (hazard ratio 14.3 [95% CI 12.69-16.11]), for developing ESRD (12.1 [10.74-13.62]), and for all-cause death (7.99 [7.31-8.74]) compared with those without AKI. Incidence rate for ESRD among patients with no episodes of AKI and one, two, and three or more episodes of AKI was 7.1, 24.4, 32.4, and 37.3 per 1,000 person-years, respectively. Baseline SUA was a strong independent predictor for AKI. A PRS composed of 27 SUA-related SNPs was associated with AKI and CKD in both discovery and replication cohorts but not ESRD. Elevated SUA may increase the risk of DKD through increasing AKI. The identification of SUA as a modifiable risk factor and PRS as a nonmodifiable risk factor may facilitate the identification of individuals at high risk to prevent AKI and its long-term impact in T2D.

Higher Mean Arterial Pressure during Cardiopulmonary Bypass May Not Prevent Acute Kidney Injury in Elderly Patients Undergoing Cardiac Surgery

We aimed to evaluate the role of higher mean arterial pressure (MAP) during cardiopulmonary bypass (CPB) in preventing development of acute kidney injury (AKI). Methods. We evaluated a population of elderly individuals >60 years of age undergoing CPB to find correlation of MAP during CPB with development of AKI after the surgery. Patients who experienced sustained low MAP during the CPB defined as that of <65 mmHg were compared with those that had sustained high MAP of >65 mmHg for their outcome with regard to AKI. The KDIGO criteria were used to define presence of acute kidney injury. Results. Of the total 92 patients, 50 were in the low-pressure group and 42 were in the high-pressure group. The MAP was 61.14 ± 5.54 mmHg in the low-pressure group and 68.97 ± 3.65 mmHg in the high-pressure group (p < 0.001). 13 (26%) in the low-pressure group and 17 (40.48%) in the high-pressure group developed AKI (p = 0.140). Male sex was associated with an increased incidence of cardiac surgery-associated AKI (p = 0.034). Conclusions. A higher MAP in the range of 65-75 mmHg during the cardiopulmonary bypass does not significantly prevent acute kidney injury in elderly patients undergoing cardiac valve surgery.

Meta-analysis of AKI to CKD transition in perioperative patients

Background

Recent research shows AKI increases the risk of incident CKD. We hypothesized that perioperative AKI may confer increased risk of subsequent CKD compared to nonperioperative AKI.

Methods

A MEDLINE search was performed for “AKI, CKD, chronic renal insufficiency, surgery, and perioperative” and related terms yielded 5209 articles. One thousand sixty-five relevant studies were reviewed. One thousand six were excluded because they were review, animal, or pediatric studies. Fifty-nine studies underwent full manuscript review by two independent evaluators. Seventeen met all inclusion criteria and underwent analysis. Two-by-two tables were constructed from AKI +/− and CKD +/− data. The R package metafor was employed to determine odds ratio (OR), and a random-effects model was used to calculate weighted ORs. Leave-1-out, funnel analysis, and structured analysis were used to estimate effects of study heterogeneity and bias.

Results

Nonperioperative studies included studies of oncology, percutaneous coronary intervention, and myocardial infarction patients. Perioperative studies comprised patients from cardiac surgery, vascular surgery, and burns. There was significant heterogeneity, but risk of bias was overall assessed as low. The OR for AKI versus non-AKI patients developing CKD in all studies was 4.31 (95% CI 3.01–6.17; p < 0.01). Nonperioperative subjects demonstrated OR 3.32 for developing CKD compared to non-AKI patients (95% CI 2.06–5.34; p < 0.01) while perioperative patients demonstrated OR 5.20 (95% CI 3.12–8.66; p < 0.01) for the same event.

Conclusions

We conclude that studies conducted in perioperative and nonperioperative patient populations suggest similar risk of development of CKD after AKI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00192-6.

Acute Kidney Injury in Pediatric Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a common complication of type 1 and 2 diabetes and often presents during adolescence and young adulthood. Given the growing incidence of both type 1 and type 2 diabetes in children and adolescents, DKD represents a significant public health problem. Acute kidney injury (AKI) in youth with diabetes is strongly associated with risk of DKD development. This review will summarize the epidemiology and pathophysiology of AKI in children with diabetes, the relationship between AKI and DKD, and the potential therapeutic interventions. Finally, we will appraise the impact of the recent COVID-19 infection pandemic on AKI in children with diabetes.

High-dose ulinastatin to prevent late-onset acute renal failure after orthotopic liver transplantation

Purpose

To compare the efficacy and safety of two distinct doses of ulinastatin on late-onset acute renal failure (LARF) following orthotopic liver transplantation (OLT).

Methods

The high-risk recipients that underwent OLT were divided into two groups according to ulinastatin dose: low-dose (LD) ulinastatin group, 0.8 million U/d; high-dose (HD) ulinastatin group, 1.6 million U/d. The primary outcome was the incidence of LARF, which was defined the newly onset acute kidney injury (AKI) stage III (KDIGO, 2012) within 7–28 post-transplant days. The second outcomes were early multiple organ retrieval assessments, length of hospital stay and safety events.

Results

A total of 174 recipients were included (LD ulinastatin group, n = 55; HD ulinastatin group, n = 119). There was no significant difference in the incidence of LARF between LD (8/55, 14.50%) and HD (9/119, 7.56%) ulinastatin groups (HD vs. LD, HR, 0.49; 95%CI, 0.17–1.37; p = .1295). Multivariate Cox proportion risk regression model revealed HD ulinastatin (HR, 0.57; 95%CI, 0.38–0.98; p = .0464) was an independent protective factor for LARF. Early lactate level, oxygenation, AKI stage, graft function, and sequential organ failure assessment [SOFA] score were significantly improved in HD ulinastatin group versus LD ulinastatin group. No significant adverse events were observed in either group.

Conclusions

Higher dose of ulinastatin (1.6 million U/d) might be preferable to prevent LARF after OLT, and it may contribute to the enhancement of early multiple organ recovery and thus attenuate the incidence of LARF.

Pre-treatment with the angiotensin receptor 1 blocker losartan protects renal blood flow and oxygen delivery after propofol-induced hypotension in pigs

Hypotensive events are strongly correlated to the occurrence of perioperative acute kidney injury, but the underlying mechanisms for this are not completely elucidated. We hypothesised that anaesthesia-induced hypotension causes renal vasoconstriction and decreased oxygen delivery via angiotensin II-mediated renal vasoconstriction. Pigs were anaesthetised, surgically prepared and randomised to vehicle/losartan treatment (0.15 mg*kg⁻¹). A deliberate reduction in arterial blood pressure was caused by infusion of propofol (30 mg*kg⁻¹) for 10 min. Renal function and haemodynamics were recorded 60 min before and after hypotension. Propofol induced hypotension in all animals (p < 0.001). Renal blood flow (RBF) and renal oxygen delivery (RDO₂) decreased significantly regardless of treatment but more so in vehicle-treated compared to losartan-treated (p = 0.001, p = 0.02, respectively). During recovery RBF and RDO₂ improved to a greater extent in the losartan-treated compared to vehicle-treated (+ 28 ml*min⁻¹, 95%CI 8–50 ml*min⁻¹, p = 0.01 and + 3.1 ml*min⁻¹, 95%CI 0.3–5.8 ml*min⁻¹, p = 0.03, respectively). Sixty minutes after hypotension RBF and RDO₂ remained depressed in vehicle-treated, as renal vascular resistance was still increased (p < 0.001). In losartan-treated animals RBF and RDO₂ had normalised. Pre-treatment with losartan improved recovery of renal blood flow and renal oxygen delivery after propofol-induced hypotension, suggesting pronounced angiotensin II-mediated renal vasoconstriction during blood pressure reductions caused by anaesthesia.

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.

Long-term predictive value of acute kidney injury classification in diffuse proliferative lupus nephritis with acute kidney injury

Background

The long-term predictive ability of acute kidney injury (AKI) classification based on “Kidney Disease: Improving Global Outcomes”(KDIGO) AKI diagnosis criteria has not been clinically validated in diffuse proliferative lupus nephritis (DPLN) patients with AKI. Our objective was to assess the long-term predictive value of KDIGO AKI classification in DPLN patients with AKI.

Methods

Retrospective cohort study was conducted by reviewing medical records of biopsy-proven DPLN patients with AKI from the First Affiliated Hospital of Wenzhou Medical University between Jan 1, 2000 and Dec 31, 2014. Multivariate Cox regression and survival analysis were performed.

Results

One hundred sixty-seven DPLN patients were enrolled,82(49%) patients were normal renal function (No AKI), 40(24%) patients entered AKI-1 stage (AKI-1), 26(16%) patients entered AKI-2 stage (AKI-2) and 19(16%) patients entered AKI-3 stage (AKI-3). The mean follow-up of all patients was 5.1 ± 3.8 years. The patient survival without ESRD of all patients was 86% at 5 years and 79% at 10 years. The patient survival rate without ESRD at 10 yr was 94.5% for No AKI patients, 81.8% for AKI-1 patients, 44.9% for AKI-2 patients and 14.6% for AKI-3 patients. The area under the ROC curve for KDIGO AKI classification to predict the primary end point was 0.83 (95% CI: 0.73–0.93) (P < 0.001). In Cox regression analysis, AKI stage was independently associated with primary endpoint, with an adjusted hazard ratio (HR) of 3.8(95% CI 2.1–6.7, P < 0.001).

Conclusion

Severity of AKI based on KDIGO AKI category was associated with progression to ESRD in DPLN patients. Analytical data also confirmed the good discriminative power of the KDIGO AKI classification system for predicting long-term prognosis of DPLN patients with AKI.

Association of Acute Kidney Injury with Cardiovascular Events and Death in Systolic Blood Pressure Intervention Trial

RATIONALE AND OBJECTIVE

In the Systolic Blood Pressure Intervention Trial, the possible relationships between acute kidney injury (AKI) and risk of major cardiovascular events and death are not known.

STUDY DESIGN

Post hoc analysis of a multicenter, randomized, controlled, open-label clinical trial.

SETTING AND PARTICIPANTS

Hypertensive adults without diabetes who were ≥50 years of age with prior cardiovascular disease, chronic kidney disease (CKD), 10-year Framingham risk score > 15%, or age > 75 years were assigned to a systolic blood pressure target of < 120 mm Hg (intensive) or < 140 mm Hg (standard).

PREDICTOR

AKI episodes.

OUTCOMES

The primary outcome was a composite of myocardial infarction, acute coronary syndrome, stroke, decompensated heart failure, or cardiovascular death. The secondary outcome was death from any cause. Analytical Approach: AKI was defined using the Kidney Disease: Improving Global Outcomes modified criteria based solely upon serum creatinine. AKI episodes were identified by serious adverse events or emergency room visits. Cox proportional hazards models assessed the risk for the primary and secondary outcomes by AKI status.

RESULTS

Participants were 68 ± 9 years of age, 36% women (3,332/9,361), and 30% Black race (2,802/9,361), and 17% (1,562/9,361) with cardiovascular disease. Systolic blood pressure was 140 ± 16 mm Hg at study entry. AKI occurred in 4.4% (204/4,678) and 2.6% (120/4,683) in the intensive and standard treatment groups respectively (p < 0.001). Those who experienced AKI had higher risk of cardiovascular events (hazard ratio [HR] 1.52, 95% CI 1.05-2.20, p = 0.026) and death from any cause (HR 2.33, 95% CI 1.56-3.48, p < 0.001) controlling for age, sex, race, baseline systolic blood pressure, body mass index, number of antihypertensive medications, cardiovascular disease and CKD status, hypotensive episodes, and treatment assignment.

LIMITATIONS

The study was not prospectively designed to determine relationships between AKI, cardiovascular events, and death.

CONCLUSIONS

Among older adults with hypertension at high cardiovascular risk, intensive treatment of blood pressure independently increased risk of AKI, which substantially raised risks of major cardiovascular events and death.

Kidney Injury Molecule 1 (KIM-1) as an Early Predictor for Acute Kidney Injury in Post-Cardiopulmonary Bypass (CPB) in Open Heart Surgery Patients

INTRODUCTION

Postoperative acute kidney injury is associated with a higher mortality, a more complicated hospital course with longer hospital stay. Urinary kidney injury molecule 1 may play an important role as an early predictor of acute kidney injury post-cardiopulmonary in open heart surgery.

METHODS

We evaluated 45 patients who underwent open heart surgery from January 2016 to June 2016. Both urinary kidney injury molecule 1 and serum creatinine were evaluated before operation and 3hs and 24hs after operation. Acute kidney injury was diagnosed according to Kidney Disease: Improving Global Outcomes, 2012 guidelines.

RESULTS

In this study, 27 patients developed acute kidney injury. The three hour-post-surgery urinary kidney injury molecule 1 was significantly higher in the acute kidney injury group (P<0.015) and, at the same time, we did not find any significant difference in the serum creatinine levels between the two groups.

CONCLUSION

Although serum creatinine is still the gold standard for diagnosis of acute kidney injury searching for other new markers is mandatory. Urinary kidney injury molecule 1 can be used as simple noninvasive and specific biomarker for early diagnosis of acute kidney injury.

Potential Association of Weight-Based Gentamicin with Increased Acute Kidney Injury in Urologic Prosthetic Surgery

BACKGROUND

Despite the known nephrotoxicity of gentamicin, in 2008 the American Urological Association recommended a weight-based gentamicin dose of 5 mg/kg for antimicrobial prophylaxis during urologic prosthetic surgery.

AIM

To identify and characterize rates of acute kidney injury (AKI) in urologic prosthetic surgery, both before and after the implementation of weight-based gentamicin dosing.

METHODS

We performed a single-institution retrospective study of patients receiving perioperative gentamicin during implant, revision, salvage, or explant of inflatable penile prostheses, malleable penile prostheses, or artificial urinary sphincters between the years 2000 and 2017. Patients were stratified into 2 groups, based on administration of either weight-based gentamicin (5 mg/kg or 2-3 mg/kg in cases of poor renal function) or standard-dose gentamicin (80 mg). Patient characteristics and perioperative outcomes were identified. Patients with available preoperative and postoperative (≤7 days) serum creatinine values were included. AKI was defined by Kidney Disease: Improving Global Outcomes criteria. Comparative analyses were performed between groups.

MAIN OUTCOME MEASURE

Our primary outcome was incidence of AKI, with secondary outcomes including device infection rate and length of stay.

RESULTS

Of the 415 urologic prosthetic surgeries performed during the study period, 124 met inclusion criteria with paired preoperative and postoperative serum creatinine values. 57 received weight-based gentamicin (median dose 5.06 mg/kg, interquartile range [IQR] 3.96-5.94) and 67 received standard-dose gentamicin (median dose 1.07 mg/kg, IQR 1.04-1.06), P < .001. There were no significant differences in preoperative renal function or comorbidities between groups; however, the weight-based group was older (median age 64.0 years, IQR 60.0-68.5) compared with the standard-dose group (median age 61.0 years, IQR 55.0-66.0), P = .01, and comprised fewer explant cases (1.8%, 1 of 57) than the standard-dose group (13.4%, 9 of 67), P = .02. The AKI rate was significantly higher in the weight-based group (15.8%, 9 of 57) compared with the standard-dose group (3.0%, 2 o67), P = .02. Device infection rate was similar between groups (5.3%, 3/56 vs 5.2%, 3 of 58), P = 1.00.

CLINICAL IMPLICATIONS

Our data suggest weight-based perioperative gentamicin prophylaxis may be associated with an increased AKI risk, without noticeably improving infection rates.

STRENGTH & LIMITATIONS

Strengths of our study include the Veterans Affairs population analyzed, as well as rigorous inclusion criteria that allowed for a sensitive assessment of postoperative renal function. Limitations include the retrospective design and small sample size.

CONCLUSION

Weight-based gentamicin dosing may warrant closer perioperative monitoring of renal function, and merits larger investigations to further elucidate risks and benefits. Moore RH, Anele UA, Krzastek SC. Potential Association of Weight-Based Gentamicin with Increased Acute Kidney Injury in Urologic Prosthetic Surgery. J Sex Med 2019;16:137-144.

Long-term risk of adverse outcomes after acute kidney injury: a systematic review and meta-analysis of cohort studies using consensus definitions of exposure

Reliable estimates of the long-term outcomes of acute kidney injury (AKI) are needed to inform clinical practice and guide allocation of health care resources. This systematic review and meta-analysis aimed to quantify the association between AKI and chronic kidney disease (CKD), end-stage kidney disease (ESKD), and death. Systematic searches were performed through EMBASE, MEDLINE, and grey literature sources to identify cohort studies in hospitalized adults that used standardized definitions for AKI, included a non-exposed comparator, and followed patients for at least 1 year. Risk of bias was assessed by the Newcastle-Ottawa Scale. Random effects meta-analyses were performed to pool risk estimates; subgroup, sensitivity, and meta-regression analyses were used to investigate heterogeneity. Of 4973 citations, 82 studies (comprising 2,017,437 participants) were eligible for inclusion. Common sources of bias included incomplete reporting of outcome data, missing biochemical values, and inadequate adjustment for confounders. Individuals with AKI were at increased risk of new or progressive CKD (HR 2.67, 95% CI 1.99-3.58; 17.76 versus 7.59 cases per 100 person-years), ESKD (HR 4.81, 95% CI 3.04-7.62; 0.47 versus 0.08 cases per 100 person-years), and death (HR 1.80, 95% CI 1.61-2.02; 13.19 versus 7.26 deaths per 100 person-years). A gradient of risk across increasing AKI stages was demonstrated for all outcomes. For mortality, the magnitude of risk was also modified by clinical setting, baseline kidney function, diabetes, and coronary heart disease. These findings establish the poor long-term outcomes of AKI while highlighting the importance of injury severity and clinical setting in the estimation of risk.

Acute kidney injury and continuous renal replacement therapy in children; what pediatricians need to know

Acute kidney injury (AKI) is characterized by abrupt deterioration of renal function, and its diagnosis relies on creatinine measurements and urine output. AKI is associated with higher morbidity and mortality, and is a risk factor for development of chronic kidney disease. There is no proven medication for AKI. Therefore, prevention and early detection are important. Physicians should be aware of the risk factors for AKI and should monitor renal function in high-risk patients. Management of AKI includes optimization of volume status and renal perfusion, avoidance of nephrotoxic agents, and sufficient nutritional support. Continuous renal replacement therapy is widely available for critically ill children, and this review provides basic information regarding this therapy. Long-term follow-up of patients with AKI for renal function, blood pressure, and proteinuria is recommended.

Microvascular rarefaction and hypertension in the impaired recovery and progression of kidney disease following AKI in preexisting CKD states

Acute kidney injury (AKI) is a major complication in hospitalized patients and is associated with elevated mortality rates. Numerous recent studies indicate that AKI also significantly increases the risk of chronic kidney disease (CKD), end-stage renal disease (ESRD), hypertension, cardiovascular disease, and mortality in those patients who survive AKI. Moreover, the risk of ESRD and mortality after AKI is substantially higher in patients with preexisting CKD. However, the underlying mechanisms by which AKI and CKD interact to promote ESRD remain poorly understood. The recently developed models that superimpose AKI on rodents with preexisting CKD have provided new insights into the pathogenic mechanisms mediating the deleterious interactions between AKI and CKD. These studies show that preexisting CKD impairs recovery from AKI and promotes the development of mechanisms of CKD progression. Specifically, preexisting CKD exacerbates microvascular rarefaction, failed tubular redifferentiation, disruption of cell cycle regulation, hypertension, and proteinuria after AKI. The purpose of this review is to discuss the potential mechanisms by which microvascular rarefaction and hypertension contribute to impaired recovery from AKI and the subsequent progression of renal disease in preexisting CKD states.

Graft Contrast-Induced Nephropathy Caused by Prerenal Transplant Computed Tomography: A Case Report

BACKGROUND

We report a case of posttransplant contrast-induced nephropathy (CIN) that occurred after performing computed tomography (CT) scanning for pretransplant cardiac and vascular evaluation.

CASE PRESENTATION

The patient had an 8-year history of hemodialysis and was admitted to the hospital for a kidney transplant from a deceased donor. Cardiac CT imaging and 3-dimensional low-extremity CT angiography were performed to confirm the patient's cardiac and iliac artery function. After successful transplantation surgery, the patient had a urine output of 250 mL and a reduced creatinine level from 8.8 to 2.3 mg/dL on postoperative day 4. However, urine output suddenly decreased to 30 mL and the creatinine level suddenly increased to 7.6 md/dL without any symptoms such as fever or graft tenderness. The patient tested negative for panel-reactive antibodies and donor-specific antibodies, and he was discharged 1 week later with an improvement in symptoms. Results of a graft biopsy indicated CIN, and the contrast-enhanced kidney was observed on noncontrast CT imaging that was performed immediately after transplantation to rule out vascular problems as well as other complications.

CONCLUSIONS

There may be residual contrast present from pretransplant CT imaging, which could affect the functional kidney grafts after transplantation and can lead to CIN. This scenario could potentially lead to loss of graft function, suggesting that caution should be observed when ordering CT imaging in this patient population.

Acute Kidney Injury and Progression of Diabetic Kidney Disease

Diabetic kidney disease, commonly termed diabetic nephropathy (DN), is the most common cause of end-stage kidney disease (ESKD) worldwide. The characteristic histopathology of DN includes glomerular basement membrane thickening, mesangial expansion, nodular glomerular sclerosis, and tubulointerstitial fibrosis. Diabetes is associated with a number of metabolic derangements, such as reactive oxygen species overproduction, hypoxic state, mitochondrial dysfunction, and inflammation. In the past few decades, our knowledge of DN has advanced considerably although much needs to be learned. The traditional paradigm of glomerulus-centered pathophysiology has expanded to the tubule-interstitium, the immune response and inflammation. Biomarkers of proximal tubule injury have been shown to correlate with DN progression, independent of traditional glomerular injury biomarkers such as albuminuria. In this review, we summarize mechanisms of increased susceptibility to acute kidney injury in diabetes mellitus and the roles played by many kidney cell types to facilitate maladaptive responses leading to chronic and end-stage kidney disease.

Duration-dependent effects of nicotine exposure on growth and AKT activation in human kidney epithelial cells

Exposure to nicotine is known to cause adverse effects in many target organs including kidney. Epidemiological studies suggest that nicotine-induced kidney diseases are prevalent worldwide. However, the impact of duration of exposure on the nicotine-induced adverse effects in normal kidney cells and the underlying molecular mechanism is still unclear. Hence, the objective of this study was to evaluate both acute and long-term effects of nicotine in normal human kidney epithelial cells (HK-2). Cells were treated with 1 and 10 µM nicotine for acute and long-term duration. The result of cell viability showed that the acute exposure to 1 µM nicotine has no significant effect on growth. However, the 10 µM nicotine caused significant decrease in the growth of HK-2 cells. The long-term exposure resulted in significantly increased cell growth in both 1 and 10 µM nicotine-treated groups. Analysis of cell cycle and expression of marker genes related to proliferation and apoptosis further confirmed the effects of nicotine. Additionally, the analysis of growth signaling pathway revealed the decreased level of pAKT in cells with acute exposure whereas the increased level of pAKT in long-term nicotine-exposed cells. This suggests that nicotine, through modulating the AKT pathway, controls the duration-dependent effects on the growth of HK-2 cells. In summary, this is the first report showing long-duration exposure to nicotine causes increased proliferation of human kidney epithelial cells through activation of AKT pathway.