Predicting Risk of Recurrent Acute Kidney Injury: A Systematic Review

Incidence, predictors, clinical outcomes, and economic burden of recurrent acute kidney injury: a retrospective cohort study

OBJECTIVE

This study aimed to assess the incidence, predictors, mortality, and economic outcomes of recurrent Acute kidney injury (AKI) in Jordan.

METHODS

This was a retrospective cohort study that included adult patients who were admitted with AKI to university hospitals in the country from 2010-2019. Recurrent episodes of AKI, laboratory data, baseline medication list, and death dates were retrieved from patient's medical records. The incidence rate of recurrent AKI was estimated. Predictors of recurrent AKI and mortality during the five years post-discharge was evaluated. Total admission charges were described and evaluated in total and by service provided.

RESULTS

Among 1162 AKI patients, 57 patients (4.9%) died during the index admission (first admission during the study period), and among the survivors, 220 patients were re-hospitalized with a recurrent AKI during five years of follow-up. Patients with higher discharge serum creatinine level (SCr) at index admission had higher odds of AKI recurrence (OR = 1.001). Patients who were on respiratory, antineoplastic, or anticoagulant medications were also more susceptible to recurrence; ORs were 1.69, 2.77, and 4.16, respectively. Patients who were elderly, with recurrent AKI episodes, or with a more extended hospital stay at index admission were more likely to die during the five years post discharge. The median charge of recurrent admissions was higher than the median charge of the index admissions; 1519.17 JOD ($2142.7) versus 1362.85 JOD ($1922.2), respectively.

CONCLUSIONS

Recurrent AKI is associated with increased mortality and health expenditures. Higher discharge SCr levels at index admission, and chronic comorbidities are associated with a higher likelihood of AKI recurrence.

Harm! foul! How acute kidney injury SHReDDs patient futures

PURPOSE OF REVIEW

Transition from acute kidney injury (AKI) to chronic kidney disease (CKD) is increasingly accepted. Less well recognized, but supported by very similar data, is development of disease of other organ systems after AKI. Awareness of other-organ sequelae of AKI may inform efforts to improve the care of patients after AKI.

RECENT FINDINGS

Stroke, hypertension, reproductive risk, dementia, and death (SHReDD) are sequelae, which occur with increased risk relative to that of non-AKI within 6 months-3 years after AKI diagnosis, and which are supported by preclinical/mechanistic study. Adjusted hazard ratios for these sequelae are strikingly similar to that of AKI-CKD, ranging from 1.2 to 3.0. Mechanistic studies suggest kidney-centric mechanisms including sodium regulation, volume status regulation, and the renin-angiotensin system are drivers of long-term, extra-renal, change.

SUMMARY

Further clinical characterization and mechanistic insight is necessary, and may have considerable translational impact. Programs which screen or follow post-AKI patients may increase clinical utility if focus is expanded to include the SHReDD complications.

Acute kidney injury increases risk of kidney stones-a retrospective propensity score matched cohort study

BACKGROUND

Acute kidney injury (AKI) is common. An episode of AKI may modify the risk of developing kidney stones by potential long-term effects on urine composition. We aimed to investigate the association between AKI and the risk of kidney stone presentations.

METHODS

The retrospective cohort study used patient data (1 January 2008-31 December 2017), from an Australian Local Health District, which included AKI diagnosis, demographics, comorbidities and kidney stone admissions. Time-varying Cox proportional hazards and propensity-matched analysis were used to determine the impact of AKI on the risk of kidney stones. To address possible population inhomogeneity in comparisons between no AKI and hospitalized AKI, sub-group analysis was done comparing inpatient and outpatient AKI versus no AKI, to assess consistency of association with future stones. Sensitivity analysis was undertaken to capture the impact of a known AKI status and AKI severity.

RESULTS

Out of 137 635 patients, 23 001 (17%) had an AKI diagnosis and 2295 (2%) had kidney stone presentations. In the unadjusted analysis, AKI was associated with kidney stones, with AKI used as a time-varying exposure, [hazard ratio (HR) 1.32, 95% confidence interval (CI) 1.16-1.50)]. Both inpatient-AKI (HR 1.19, 95% CI 1.01-1.39) and outpatient-AKI (HR 1.59, 95% CI 1.30-1.94) were significantly associated with future stones compared to no AKI subjects. This association persisted in the adjusted analysis (HR 1.45, 95% CI 1.26-1.66), propensity-matched dataset (HR 1.67, 95% CI 1.40-1.99) and sensitivity analysis. There was a dose-response relationship with higher stages of AKI being associated with a greater risk of kidney stones.

CONCLUSIONS

In a large cohort of patients, AKI is associated with a greater risk of kidney stones, which increases with higher stages of AKI. This association should be examined in other cohorts and populations for verification.

Acute Kidney Injury Among Patients with Multi-Drug Resistant Infection: A Study from Jordan

Background

Acute kidney injury (AKI) is a well-known complication for hospitalized patients. Sepsis and various infections play a significant role in increasing the incidence of AKI. The present study evaluated the risk for Multidrug-resistant (MDR) infections and its effect on the incidence of AKI, hospitalization, need for dialysis, and mortality.

Methods

In a retrospective study design, data were collected from all adult patients with a positive multi-drug resistant culture who were admitted to King Abdullah University Hospital (KAUH). Records of 436 patients were reviewed between January 2017 - December 2018 with at least one year of follow-up.

Results

The mean age was 57.3 years (SD± 23.1), and 58.5% were males. The most common source of positive cultures was sputum, with 50% positive cultures. The incidence of AKI was 59.2%. The most isolated microorganism was Acinetobacter baumannii (76.8%), followed by Pseudomonas aeruginosa (14.9%).On multivariate analysis, age (OR 1.1, 95% CI 1.1-1.2, P=0.001), HTN (OR 1.8, 95% CI 1.0-3.3, P=0.02), DM (OR 1.1, 95% CI 0.6-1.9, P=0.69) and the use of Foley catheter on chronic bases (OR 4.3, 95% CI 2.6-6.8, P<0.0001) were strong predictors of AKI. Among patients with AKI, 74.4% died compared to 44.4% among non-AKI patients (p<0.001).

Conclusion

In patients with MDR, AKI incidence, hospitalization, and mortality were high. Early detection and addressing the problem may decrease bad outcomes, and health education for reducing antibiotic abuse is needed to lower MDR.

The Biological Roles of Urea: A Review of Preclinical Studies

Urea is an organic compound that has been reported to be effective against many pathological conditions. However, many other studies have reported the toxic effects of urea. These controversies on the biological roles of urea remain unresolved. This review aims to evaluate the biological roles of urea in experimental animals from data published in peer-reviewed journals. A PubMed search was conducted using the phrase, "urea application in experimental animals." A total of 13 publications that met the inclusion criteria were evaluated. The test substance, animal model, number of animals, doses, duration of treatment, and effects were recorded. Regarding the toxic effect, urea caused decreased excretion of other nitrogenous compounds, increased oxidative stress, decreased insulin, and impairment of beta-cell glycolysis. Furthermore, it caused endothelial dysfunction, loss of synapsis, and decreased olfaction. Regarding the therapeutic effects, urea caused increased growth, increased digestion, and decreased hepatic dysfunction. It also induced apoptosis of tumor cells and exerted neuroprotective properties. Products containing urea should be used with caution, especially in individuals with symptoms of chronic kidney disease. However, more studies are needed to elucidate the mechanisms of its therapeutic effects.

Gliko BMSC: A potential strategy of treatment for renal fibrosis

Objective

There are many researches on using bone marrow mesenchymal stem cells (BMSCs) in the treatment of acute kidney injury (AKI), which has certain effects, but the mechanism of action is still unclear. Previous researches show that glioma-associated oncogene homolog 1 (Gli 1) can promote the proliferation and migration of cells, which can also promote renal fibrosis. Therefore, we investigate the influence of Gli-regulated BMSCs on repairing AKI and renal fibrosis induced by limb Ischemia-Reperfusion (I/R).

Methods

The Crispr-Cas9 technique was adopted to knock out the Gli1 gene from the mouse BMSCs according to green fluorescent tracing, and the BMSCs (BMSCs-Gliko) with Gli1 gene knocked out and the BMSCs as control group were obtained. The cell proliferation, apoptosis, cycle and SHH signal pathway gene level were tested. The mice were built to the AKI model with inducing I/R injury, then the BMSCs-Gliko and BMSCs cells were injected into the mice, and their IL-1, IL-1B, TNF-a, serum creatinine (Scr) and blood urea nitrogen (BUN) levels were tested; Western blot was employed to test the expression of α-SMA, SMAD2 and SMAD4 in the renal tissues of mice. Finally, flow cytometry was used to test the content of BMSCs containing green fluorescence in the blood of mice.

Results

The BMSCs-Gliko containing green fluorescence and the mouse AKI model were built; both BMSCs and BMSCs-Gliko can reduce the damage level, and BMSCs-Gliko outperformed BMSCs in protecting renal tubules and anti-fibrosis. Our study also shows that BMSCs-Gliko stayed longer in the blood of mice, which might also be one of the reasons why BMSCs-Gliko outperformed BMSCs in preventing renal tubules and fibrosis. To sum it up, could be key target of using.

Histopathology of the kidney and seroprevalence of leptospirosis in wild rats in Baghdad Province, Iraq

Background and Aim: Leptospirosis, caused by pathogenic leptospires, is a globally emerging infectious disease affecting both humans and animals, which act as reservoirs, with large outbreaks worldwide. The role of rats in dispersing leptospirosis was never investigated in Iraq. Because of the seriousness of the disease and the scarce data regarding this disease in Iraq, this study determines the incidence of leptospirosis in rats and its renal histopathological profile. Materials and Methods: Of 211 captured rats, 82 apparently healthy rats were included in this study. After euthanatizing, 3-5-ml blood was collected by cardiac puncture. Approximately 0.5 cm3 of the kidney was collected for routine histopathology and stained using hematoxylin and eosin (H&E) and Warthin–Starry (WS) stains. Blood smears were prepared and stained with the WS stain. Results: All rats (100%) with different age groups were immunoglobulin G (IgG)-positive, and 90.24% of them had the IgG against leptospiral antigens in kidney tissues. The juvenile age group had higher IgG levels than other age groups. Considering sex, no significant differences in the overall results were observed. Serum concentrations of blood urea nitrogen and creatinine showed significant increments in the sub-adult and adult IgG- positive groups compared with the IgG-negative groups. No significant alterations were observed in the juvenile group. Using WS stains, 13 and 1 blood smears and 0 and 8 kidney tissues were positive for leptospires in the sub-adult and adult groups, respectively. Microscopical findings of the renal cortex and medulla in the sub-adult IgG-positive group showed hemorrhage, glomerular deterioration, tubular cell degeneration and necrosis with cast formation, periarterial edema, and focal hemorrhage with congestion of peritubular arteries. The adult IgG-positive group revealed deterioration similar to that in the sub-adult group and tended to be chronic. No leptospires were observed using H&E staining. Conclusion: IgG-positive carrier rats refer to previously exposed or infected rats. Understanding the risk of transmitting the disease to human and animals through a carrier rat's urine is highly predicted and possible mitigation of zoonotic transmission.

Retrospective Analysis of Mortality Cases in Advanced and Metastatic Solid Tumors With Concurrent Prerenal Azotemia

BACKGROUND/AIM

A retrospective study of cases with metastatic or advanced solid tumors complicated with AKI (acute kidney injury) with prerenal azotemia.

PATIENTS AND METHODS

Criteria included: (1) advanced or metastatic solid tumors that led to mortality; (2) prerenal azotemia identified upon renal function evaluation and (3) BUN to Cr ratio (BCR)≥15. We also compared the outcomes of patients with BCR>20 with those of patients with BCR=15-20.

RESULTS

A total of 218 patients with solid tumors were enrolled. One hundred and forty (64%) and 78 (36%) patients had BCR>20 and 15-20, respectively. Before AKI occurrence, 136 (62%) had thromboembolic complications and 96 (44%) paraneoplastic syndromes. Median survival time was 1 week in all patients. Median survival time was statistically different between the groups with BCR15-20 and BCR>20 (p<0.005, log-rank test).

CONCLUSION

Cancer patients with concurrent AKI and prerenal azotemia carry a very poor prognosis.

Exercise as a therapeutic option for acute kidney injury: mechanisms and considerations for the design of future clinical studies

Acute kidney injury (AKI) is a known risk factor for chronic kidney disease (CKD) and end stage kidney disease (ESKD). The progression from AKI to CKD, despite being well recognised, is not completely understood, although sustained inflammation and fibrosis are implicated. A therapeutic intervention targeting the post AKI stage could reduce the progression to CKD, which has high levels of associated morbidity and mortality. Exercise has known anti-inflammatory effects with animal AKI models demonstrating its use as a therapeutic agent in abrogating renal injury. This suggests the use of an exercise rehabilitation programme in AKI patients following discharge could attenuate renal damage and improve long term patient outcomes. In this review article we outline considerations for future clinical studies of exercise in the AKI population.

Long-Term Outcomes in Patients with Acute Kidney Injury

The long-term sequelae of AKI have received increasing attention so that its associations with a number of adverse outcomes, including higher mortality and development of CKD, are now widely appreciated. These associations take on particular importance when considering the high incidence of AKI, with a lack of proven interventions and uncertainties around optimal care provision meaning that the long-term sequelae of AKI present a major unmet clinical need. In this review, we examine the published data that inform our current understanding of long-term outcomes following AKI and discuss potential knowledge gaps, covering long-term mortality, CKD, progression to ESKD, proteinuria, cardiovascular events, recurrent AKI, and hospital readmission.

Effect of nephrology follow-up on long-term outcomes in patients with acute kidney injury: A systematic review and meta-analysis

AIM

Acute kidney injury (AKI) is associated with poor short-term and long-term clinical outcomes. The role of nephrology follow-up in post-AKI management remains uncertain.

METHODS

A systematic review and meta-analysis were performed examining all randomized controlled trials and observational studies assessing the effect of nephrology follow-up on patients' clinical outcomes. The primary outcome was all-cause mortality. The secondary outcomes were renal outcomes, which were defined as a composite of requirement of permanent dialysis and recurrent AKI. Pooled analysis was performed using a random-effect model.

RESULTS

We identified six studies (8972 patients, mean follow-up of 49 months). Five were retrospective cohort studies and one was a prospective cohort study. Risk of bias was a concern with all studied. Only four studies reported primary and/or secondary outcomes and were included. Compared with patients without nephrology follow-up, patients with nephrology follow-up had significantly reduced mortality by 22% (three studies, 3240 patients, relative risk [RR] = 0.78, 95% confidence interval [CI] = 0.70-0.88, I² = 0.0%). Nephrology follow-up did not improve composite renal outcomes with high heterogeneity due to significant differences in reported renal outcomes and follow-up period (two studies, 2537 patients, RR = 1.72, 95% CI = 0.49-6.05, I² = 90.1%).

CONCLUSION

Current evidence from observational studies is biased. It suggests long-term survival benefits with post-discharge nephrology follow-up in AKI patients. However, due to its low quality, such evidence is only hypothesis-generating. Nonetheless, it provides a rationale for future randomized controlled trials of nephrology follow-up in AKI patients. SUMMARY AT A GLANCE The present meta-analysis assessed the effect of nephrology follow-up on patients' clinical outcomes, and suggested long-term survival benefits in acute kidney injury (AKI) survivors. Although the study inherently comprises potential risks of bias due to paucity of available data, the results provide a rationale for future randomized controlled trials.

Acute Kidney Injury and In-Hospital Mortality: A Retrospective Analysis of a Nationwide Administrative Database of Elderly Subjects in Italy

Background: The aim of this study was to investigate the association between acute kidney injury (AKI) and in-hospital mortality (IHM) in a large nationwide cohort of elderly subjects in Italy. Methods: We analyzed the hospitalization data of all patients aged ≥65 years, who were discharged with a diagnosis of AKI, which was identified by the presence of the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM), and extracted from the Italian Health Ministry database (January 2000 to December 2015). Data regarding age, gender, dialysis treatment, and comorbidity, including the development of sepsis, were also collected. Results: We evaluated 760,664 hospitalizations, the mean age was 80.5 ± 7.8 years, males represented 52.2% of the population, and 9% underwent dialysis treatment. IHM was 27.7% (210,661 admissions): Deceased patients were more likely to be older, undergoing dialysis treatment, and to be sicker than the survivors. The population was classified on the basis of tertiles of comorbidity score (the first group 7.48 ± 1.99, the second 13.67 ± 2,04, and third 22.12 ± 4.13). IHM was higher in the third tertile, whilst dialysis-dependent AKI was highest in the first. Dialysis-dependent AKI was associated with an odds ratios (OR) of 2.721; 95% confidence interval (CI) 2.676–2.766; p < 0.001, development of sepsis was associated with an OR of 1.990; 95% CI 1.948–2.033; p < 0.001, the second tertile of comorbidity was associated with an OR of 1.750; 95% CI 1.726–1.774; p < 0.001, and the third tertile of comorbidity was associated with an OR of 2.522; 95% CI 2.486–2.559; p < 0.001. Conclusions: In elderly subjects with AKI discharge codes, IHM is a frequent complication affecting more than a quarter of the investigated population. The increasing burden of comorbidity, dialysis-dependent AKI, and sepsis are the major risk factors.