Canadian Society of Nephrology Commentary on the 2012 KDIGO Clinical Practice Guideline for Acute Kidney Injury

Potential risk factors for early acute kidney injury in patients treated with vancomycin

PURPOSE

The acute kidney injury (AKI) onset owing to vancomycin (VCM) is reported that depend on the area under the blood concentration-time curve (AUC) and occur comparison early phase (early AKI). This study aimed to investigate the occurrence of early AKI in patients treated with VCM and new indicators to avoid early AKI.

METHODS

Adult patients who received VCM treatment for more than 4 days and whose trough values measured at least once on or after day 4 and serum creatinine before day 7 from the initiation of VCM administration between August 2021 and September 2022 at the Yamanashi Prefectural Central Hospital were enrolled. Early AKI (defined as AKI occurring within day 7 from VCM administration) and the association between each AUC (0-24, 24-48, 48-72, 0-48, 24-72, 0-72) were investigated. Furthermore, each AUC cut-off value for early AKI was calculated.

RESULT

In total, 164 patients were enrolled; early AKI developed in 21 patients and most frequently occurred on day 4. All stratified AUC were associated with early AKI development. The AUC cut-off values were AUC0-24: 470.8 μg/mL⋅h; AUC24-48: 473.0 μg/mL⋅h; AUC48-72: 489.7 μg/mL⋅h; AUC0-48: 910.2 μg/mL⋅h; AUC24-72: 1039.2 μg/mL⋅h; and AUC0-72: 1544.0 μg/mL⋅h.

CONCLUSION

The possibility of AKI development owing to the AUC accumulation of VCM was observed (accumulation toxicity). Concentration control through early-phase blood concentration measurements and a transition to AUC0-48 <910.2 μg/mL⋅h may reduce the early-phase AKI onset.

Fenoldopam for Renal Protection in Cardiac Surgery: Pharmacology, Clinical Applications, and Evolving Perspectives

This comprehensive review examines the role of Fenoldopam, a selective dopamine-1 receptor agonist, in preventing and treating acute kidney injury (AKI) during cardiac surgery. AKI remains a significant complication in cardiac surgery, associated with increased morbidity, mortality, and healthcare costs. The review explores Fenoldopam's pharmacological properties, mechanism of action, and clinical applications, synthesizing evidence from randomized controlled trials, meta-analyses, and observational studies. While some studies have shown promising results in improving renal function and reducing AKI incidence, others have failed to demonstrate significant benefits. The review discusses these conflicting findings, explores potential reasons for discrepancies, and identifies areas requiring further research. It also compares Fenoldopam to other renoprotective strategies, including dopamine, diuretics, and N-acetylcysteine. The safety profile of Fenoldopam, including common side effects and contraindications, is addressed. Current guidelines and recommendations for Fenoldopam use in cardiac surgery are presented, along with a cost-effectiveness analysis. The review concludes by outlining future research directions and potential new applications of Fenoldopam in cardiac surgery. By providing a thorough overview of the current state of knowledge, this review aims to facilitate informed decision-making for clinicians and researchers while highlighting areas for future investigation.

Stepped-Wedge Trial of Decision Support for Acute Kidney Injury on Surgical Units

Introduction

Acute kidney injury (AKI) is common in the perioperative setting and associated with poor outcomes. Whether clinical decision support improves early management and outcomes of AKI on surgical units is uncertain.

Methods

In this cluster-randomized, stepped-wedge trial, 8 surgical units in Alberta, Canada were randomized to various start dates to receive an education and clinical decision support intervention for recognition and early management of AKI. Eligible patients were aged ≥18 years, receiving care on a surgical unit, not already receiving dialysis, and with AKI.

Results

There were 2135 admissions of 2038 patients who met the inclusion criteria; mean (SD) age was 64.3 (16.2) years, and 885 (41.4%) were females. The proportion of patients who experienced the composite primary outcome of progression of AKI to a higher stage, receipt of dialysis, or death was 16.0% (178 events/1113 admissions) in the intervention group; and 17.5% (179 events/1022 admissions) in the control group (time-adjusted odds ratio, 0.76; 95% confidence interval [CI], 0.53-1.08; P = 0.12). There were no significant differences between groups in process of care outcomes within 48 hours of AKI onset, including administration of i.v. fluids, or withdrawal of medications affecting kidney function. Both groups experienced similar lengths of stay in hospital after AKI and change in estimated glomerular filtration rate (eGFR) at 3 months.

Conclusion

An education and clinical decision support intervention did not significantly improve processes of care or reduce progression of AKI, length of hospital stays, or recovery of kidney function in patients with AKI on surgical units.

Citrate and low-dose heparin combined anticoagulation in pediatric continuous renal replacement therapy

There remains no optimal anticoagulation protocol for continuous renal replacement therapy (CRRT) with regional citrate anticoagulation (RCA) in pediatric patients with elevated D-dimer levels. We aimed to assess the effects of different anticoagulation strategies on the risk of CRRT filter clotting in these patients. Pediatric patients undergoing CRRT were retrospectively grouped based on pre-CRRT D-dimer levels and anticoagulant: D-RCA group (normal D-dimer, RCA only, n = 22), D+ RCA group (elevated D-dimer, RCA only, n = 50), and D+ RCA+ systemic heparin anticoagulation (SHA) group (elevated D-dimer, RCA combined with SHA, n = 55). The risk of filter clotting and incidence of bleeding were compared among the groups. Among the groups, the D+ RCA+ SHA group had the longest filter lifespan; further, the incidence of bleeding was not increased by concurrent use of low-dose heparin for anticoagulation. Moreover, concurrent heparin anticoagulation was associated with a decreased risk of filter clotting. Contrastingly, high pre-CRRT hemoglobin and D-dimer levels and post-filter ionized calcium level > 0.4 mmol/L were associated with an increased risk of filter clotting. RCA combined with low-dose heparin anticoagulation could reduce the risk of filter clotting and prolong filter lifespan without increasing the risk of bleeding in patients with elevated D-dimer levels undergoing CRRT.

Current Use and Impact of Pulmonary Artery Catheters on the Short-Term Outcomes in Patients With Cardiogenic Shock Treated With an Impella: Findings From the Japan Registry for Percutaneous Ventricular Assist Device (J-PVAD)

OBJECTIVES

This study aimed to investigate the current use and impact of pulmonary artery catheters (PACs) in patients with cardiogenic shock (CS) who underwent Impella support.

DESIGN

This was a prospective multicenter observational study between January 2020 and December 2021 that registered all patients with drug-refractory acute heart failure and in whom the placement of an Impella 2.5, CP, or 5.0 pump was attempted or successful in Japan.

SETTING

Cardiac ICUs in Japan.

PATIENTS

Between January 2020 and December 2021, a total of 3112 patients treated with an Impella were prospectively enrolled in the Japan registry for percutaneous ventricular assist device (J-PVAD). Among them, 2063 patients with CS were divided into two groups according to the PAC use.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was the 30-day mortality, and the secondary endpoints were hemolysis, acute kidney injury, sepsis, major bleeding unrelated to the Impella, and ventricular arrhythmias within 30 days. PACs were used in 1358 patients (65.8%) who underwent an Impella implantation. The use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) was significantly higher in the patients with PACs than in those without. Factors associated with PAC use were the prevalence of hypertension, out-of-hospital cardiac arrest, New York Heart Association classification IV, the lesser prevalence of a heart rate less than 50, and the use of any catecholamine. The primary and secondary endpoints did not significantly differ according to the PAC use. Focusing on the patients with VA-ECMO use, the 30-day mortality and hemolysis were univariately lower in the patients with PACs.

CONCLUSIONS

The J-PVAD findings indicated that PAC use did not have a significant impact on the short-term outcomes in CS patients undergoing Impella support. Further prospective studies are required to explore the clinical implications of PAC-guided intensive treatment strategies in these patients.

Urinary cytokeratin 20 as a predictor for chronic kidney disease following acute kidney injury

BACKGROUNDIdentifying patients with acute kidney injury (AKI) at high risk of chronic kidney disease (CKD) progression remains a challenge.METHODSKidney transcriptome sequencing was applied to identify the top upregulated genes in mice with AKI. The product of the top-ranking gene was identified in tubular cells and urine in mouse and human AKI. Two cohorts of patients with prehospitalization estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2 who survived over 90 days after AKI were used to derive and validate the predictive models. AKI-CKD progression was defined as eGFR < 60 mL/min/1.73 m2 and with minimum 25% reduction from baseline 90 days after AKI in patients with prehospitalization eGFR ≥ 60 mL/min/1.73 m2. AKI-advanced CKD was defined as eGFR < 30 mL/min/1.73 m2 90 days after AKI in those with prehospitalization eGFR 45-59 mL/min/1.73 m2.RESULTSKidney cytokeratin 20 (CK20) was upregulated in injured proximal tubular cells and detectable in urine within 7 days after AKI. High concentrations of urinary CK20 (uCK20) were independently associated with the severity of histological AKI and the risk of AKI-CKD progression. In the Test set, the AUC of uCK20 for predicting AKI-CKD was 0.80, outperforming reported biomarkers for predicting AKI. Adding uCK20 to clinical variables improved the ability to predict AKI-CKD progression, with an AUC of 0.90, and improved the risk reclassification.CONCLUSIONThese findings highlight uCK20 as a useful predictor for AKI-CKD progression and may provide a tool to identify patients at high risk of CKD following AKI.FUNDINGNational Natural Science Foundation of China, National Key R&D Program of China, 111 Plan, Guangdong Key R&D Program.

miR-486-5p protects against rat ischemic kidney injury and prevents the transition to chronic kidney disease and vascular dysfunction

AIM

Acute kidney injury (AKI) increases the risk for progressive chronic kidney disease (CKD). MicroRNA (miR)-486-5p protects against kidney ischemia-reperfusion (IR) injury in mice, although its long-term effects on the vasculature and development of CKD are unknown. We studied whether miR-486-5p would prevent the AKI to CKD transition in rat, and affect vascular function.

METHODS

Adult male rats were subjected to bilateral kidney IR followed by i.v. injection of liposomal-packaged miR-486-5p (0.5 mg/kg). Kidney function and histologic injury were assessed after 24 h and 10 weeks. Kidney endothelial protein levels were measured by immunoblot and immunofluorescence, and mesenteric artery reactivity was determined by wire myography.

RESULTS

In rats with IR, miR-486-5p blocked kidney endothelial cell increases in intercellular adhesion molecule-1 (ICAM-1), reduced neutrophil infiltration and histologic injury, and normalized plasma creatinine (P<0.001). However, miR-486-5p attenuated IR-induced kidney endothelial nitric oxide synthase (eNOS) expression (P<0.05). At 10 weeks, kidneys from rats with IR alone had decreased peritubular capillary density and increased interstitial collagen deposition (P<0.0001), and mesenteric arteries showed impaired endothelium-dependent vasorelaxation (P<0.001). These changes were inhibited by miR-486-5p. Delayed miR-486-5p administration (96 h, 3 weeks after IR) had no impact on kidney fibrosis, capillary density, or endothelial function.

CONCLUSION

In rats, administration of miR-486-5p early after kidney IR prevents injury, and protects against CKD development and systemic endothelial dysfunction. These protective effects are associated with inhibition of endothelial ICAM-1 and occur despite reduction in eNOS. miR-486-5p holds promise for the prevention of ischemic AKI and its complications.

Performances of acute kidney injury biomarkers vary according to sex

Background

Before implementing individualized strategies to treat acute kidney injury (AKI), identifying clusters of patients with divergent pathophysiological mechanisms, diagnosis criteria or outcomes is of the utmost importance. Here we studied sex-related molecular mechanisms in cardiac bypass (CBP) surgery patients developing AKI.

Methods

We compared the characteristics of 1170 patients referred for CBP surgery using multivariate logistic regression and propensity score-based analysis. Performances of the candidate urinary biomarkers at <4 h post-surgery, urinary neutrophil gelatinase-associated lipocalin (uNGAL), [IGFBP7]·[TIMP-2] product (NephroCheck) and a recently developed AKI signature of 204 urinary peptides (AKI204) to predict AKI were compared in both sexes.

Results

Incidence (∼25%) and severity of AKI were similar in men and women, even after adjustment for the usual risk factors of AKI, including baseline estimated glomerular filtration rate, age, diabetes mellitus, length of CBP and red blood cell transfusion. However, at the molecular level, performances of uNGAL, NephroCheck and AKI204 to predict AKI strongly diverged between men and women. In the full cohort, as well as in subgroups of men and women, the multimarker AKI204 signature outperformed uNGAL and NephroCheck and predicted the development of AKI significantly better in women than in men. Analysis of AKI204 at the single-peptide level suggested divergences of AKI mechanisms between sexes due to increased kidney inflammation in women (increased abundance of urinary fragments of osteopontin and uromodulin).

Conclusions

In patients referred for CBP surgery, significant clinical and biological differences between men and women as well as sexual dimorphism of AKI biomarker performances were identified. The urinary peptide signature points to sex-related molecular mechanisms underlying AKI.

Urinary oxygen tension and its role in predicting acute kidney injury: A narrative review

Acute kidney injury occurs frequently in the perioperative setting. The renal medulla often endures hypoxia or hypoperfusion and is susceptible to the imbalance between oxygen supply and demand due to the nature of renal blood flow distribution and metabolic rate in the kidney. The current available evidence demonstrated that the urine oxygen pressure is proportional to the variations of renal medullary tissue oxygen pressure. Thus, urine oxygenation can be a candidate for reflecting the change of oxygen in the renal medulla. In this review, we discuss the basic physiology of acute kidney injury, as well as techniques for monitoring urine oxygen tension, confounding factors affecting the reliable measurement of urine oxygen tension, and its clinical use, highlighting its potential role in early detection and prevention of acute kidney injury.

Advancing Community Care and Access to Follow-up After Acute Kidney Injury Hospitalization: Design of the AFTER AKI Randomized Controlled Trial

Background

Acute kidney injury (AKI) is a common complication among hospitalized patients with long-term implications including chronic kidney disease (CKD). Although models are available to predict the risk of advanced CKD after AKI, there is limited evidence regarding follow-up for patients with AKI after hospital discharge, resulting in variable follow-up care. A risk-stratified follow-up approach may improve appropriateness and efficiency of management for CKD among patients at risk of declining kidney function following AKI.

Objective

The objective was to compare and evaluate the use of a risk-stratified approach to follow-up care vs usual care for patients with AKI after hospital discharge.

Design

This study was a pragmatic randomized controlled trial.

Setting

This study was conducted in 2 large urban hospitals in Alberta, Canada.

Patients

Hospitalized patients with AKI (KDIGO stage 2 or 3) not previously under the care of a nephrologist, expected to survive greater than 90 days being discharged home.

Measurements

We will evaluate whether guideline-recommended CKD care processes are initiated within 90 days, including statin use, angiotensin-converting enzyme inhibitor (ACEi)/angiotensin II receptor blocker (ARB) use in those with proteinuria or diabetes, and nephrologist follow-up if sustained eGFR <30 mL/min/1.73 m2. We will also assess the feasibility of recruitment and the proportion of patients completing the recommended blood and urine tests at 90 days.

Methods

Patients with AKI will be enrolled and randomized near the time of hospital discharge. In the intervention group, low risk patients will receive information regarding AKI, medium risk patients will additionally receive follow-up guidance sent to their primary care physician, and high-risk patients will additionally receive follow-up with a nephrologist. Participants in the intervention and usual care group will receive a requisition for urine testing and bloodwork at 90 days following hospital discharge. Telephone follow-up will be conducted for all study participants at 90 days and 1 year after hospital discharge. Bivariate tests of association will be conducted to evaluate group differences at the follow-up time points.

Limitations

We expect there may be challenges with recruitment due to the significant co-existence of comorbidity in this population.

Conclusions

If the trial shows a positive effect on these processes for kidney care, it will inform larger-scale trial to determine whether this intervention reduces the incidence of long-term clinical adverse events, including CKD progression, cardiovascular events, and mortality following hospitalization with AKI.

Prevalence and Impact of Medical Complications on Clinical Outcomes in Acute Ischemic Stroke Patients After Endovascular Therapy - Data From a Comprehensive Stroke Unit in China

OBJECTIVE

We aim to assess the incidence and impact of in-hospital medical complications (MCs) on clinical outcomes in acute ischemic stroke (AIS) patients after endovascular therapy (EVT).

METHODS

AIS patients who underwent EVT were consecutively recruited from January 2019 to July 2022. The primary outcome was a poor 3-month functional outcome, defined as a modified Rankin Scale score (mRS) of 3-6. The safety variables were symptomatic intracerebral hemorrhage and mortality at 7 and 30 days.

RESULTS

A total of 306 (50.1%) patients experienced at least one of the MCs. The most common MC was pneumonia (42.6%). Multivariate analysis revealed that the setting of MCs was an independent predictor of a poor 3-month functional outcome (adjusted odds ratio [aOR] 4.40, 95% confidence interval [CI] 3.01-6.42; P < 0.001). In the subgroup analysis, this trend was significant, especially in the patients aged 60-75 years (aOR 5.87, 95% CI 3.45-9.97; P < 0.001) or with baseline NIHSS (≤16) (aOR 5.05, 95% CI 2.84-9.01; P < 0.001). For individuals, cardiac events (aOR 8.56, 95% CI 4.05-18.09; P < 0.001), pneumonia (aOR 5.08, 95% CI 3.42-7.55; P < 0.001), and gastrointestinal bleeding (GIB) (aOR 6.12, 95% CI 3.40-11.01; P < 0.001) were independently associated with the poor 3-month outcome. The setting of MCs was independently associated with symptomatic intracerebral hemorrhage (aOR 2.11, 95% CI 1.22-3.64; P = 0.007) and mortality at 30 days (aOR 2.11, 95% CI 1.22-3.64; P = 0.007) after adjustment, but not with mortality at 7 days.

CONCLUSIONS

MCs in AIS patients after EVT have a high incidence, despite successful reperfusion, adversely affecting clinical outcomes and increasing short-term mortality.

Citrate anticoagulation in plasma exchange followed by continuous renal replacement therapy in critically ill children

OBJECTIVE

To investigate the effectiveness and safety of regional citrate-anticoagulated (RCA) plasma exchange (PE) and whether citrate-related metabolic disorders can be improved by sequential RCA continuous renal replacement therapy (CRRT).

METHODS

This retrospective, single-center observational study included 79 critically ill children requiring PE followed by CRRT (June 2018 to June 2021) at the Pediatric Intensive Care Unit of Hunan Children's Hospital, China. Patients were divided into the RCA-PE (n = 30) and systemic heparin anticoagulation (SHA-PE) (n = 49) groups. Filter level comparison post-PE assessed RCA-PE efficacy, and metabolic changes occurring pre- and post-PE and CRRT were used to evaluate the effect of CRRT on RCA-based anticoagulation safety.

RESULTS

The RCA-PE group had a better overall filter performance than the SHA-PE group. Two hours after PE, pH and HCO₃- levels increased more significantly for the RCA-PE than the SHA-PE group. The RCA-PE incidence of metabolic alkalosis was 48.3%, higher by 4.2% (p < 0.001) compared to the SHA-PE group. In the RCA-PE group, pH and HCO₃- decreased significantly 4 h after CRRT; the metabolic alkalosis caused by RCA-PE decreased to 13.8% (p = 0.005). No significant difference in pH, HCO₃-, and metabolic alkalosis incidence was observed between the two groups 4 h after CRRT.

CONCLUSIONS

The overall filtration performance of RCA-PE is superior to that of SHA-PE followed by CRRT. The metabolic complications associated with RCA-PE are mainly metabolic alkalosis that can be improved by using CRRT after RCA-PE and this is a better alternative for anticoagulation during PE in critically ill children.

Follow-up Care of Critically Ill Patients With Acute Kidney Injury: A Cohort Study

Rationale & Objective

To evaluate follow-up care of critically ill patients with acute kidney injury (AKI).

Study Design

Retrospective cohort study.

Setting & Participants

Patients admitted to the intensive care unit (ICU) with AKI in Alberta, Canada from 2005 to 2018, who survived to discharge without kidney replacement therapy or estimated glomerular filtration rate <15 mL/min/1.73 m2.

Exposure

AKI (defined as ≥50% or ≥0.3 mg/dL serum creatinine increase).

Outcomes

The primary outcome was the cumulative incidence of an outpatient serum creatinine and urine protein measurement at 3 months postdischarge. Secondary outcomes included an outpatient serum creatinine or urine protein measurement or a nephrologist visit at 3 months postdischarge.

Analytical Approach

Patients were followed from hospital discharge until the first of each outcome of interest, death, emigration from the province, kidney replacement therapy (maintenance dialysis or kidney transplantation), or end of study period (March 2019). We used non-parametric methods (Aalen-Johansen) to estimate the cumulative incidence functions of outcomes accounting for competing events (death and kidney replacement therapy).

Results

There were 29,732 critically ill adult patients with AKI. The median age was 68 years (IQR, 57-77), 39% were female, and the median baseline estimated glomerular filtration rate was 72 mL/min/1.73 m2 (IQR, 53-90). The cumulative incidence of having an outpatient creatinine and urine protein measurement at 3 months postdischarge was 25% (95% CI, 25-26). At 3 months postdischarge, 64% (95% CI, 64-65) had an outpatient creatinine measurement, 28% (95% CI, 27-28) had a urine protein measurement, and 5% (95% CI, 4-5) had a nephrologist visit.

Limitations

We lacked granular data, such as urine output.

Conclusions

Many critically ill patients with AKI do not receive the recommended follow-up care. Our findings highlight a gap in the transition of care for survivors of critical illness and AKI.

Regional citrate anticoagulation (RCA) in critically ill patients undergoing renal replacement therapy (RRT): expert opinion from the SIAARTI-SIN joint commission

Renal replacement therapies (RRT) are essential to support critically ill patients with severe acute kidney injury (AKI), providing control of solutes, fluid balance and acid-base status. To maintain the patency of the extracorporeal circuit, minimizing downtime periods and blood losses due to filter clotting, an effective anticoagulation strategy is required.Regional citrate anticoagulation (RCA) has been introduced in clinical practice for continuous RRT (CRRT) in the early 1990s and has had a progressively wider acceptance in parallel to the development of simplified systems and safe protocols. Main guidelines on AKI support the use of RCA as the first line anticoagulation strategy during CRRT in patients without contraindications to citrate and regardless of the patient's bleeding risk.Experts from the SIAARTI-SIN joint commission have prepared this position statement which discusses the use of RCA in different RRT modalities also in combination with other extracorporeal organ support systems. Furthermore, advise is provided on potential limitations to the use of RCA in high-risk patients with particular attention to the need for a rigorous monitoring in complex clinical settings. Finally, the main findings about the prospective of optimization of RRT solutions aimed at preventing electrolyte derangements during RCA are discussed in detail.

Prolonged Intermittent Kidney Replacement Therapy

Kidney replacement therapy (KRT) is a vital, supportive treatment for patients with critical illness and severe AKI. The optimal timing, dose, and modality of KRT have been studied extensively, but gaps in knowledge remain. With respect to modalities, continuous KRT and intermittent hemodialysis are well-established options, but prolonged intermittent KRT is becoming more prevalent worldwide, particularly in emerging countries. Compared with continuous KRT, prolonged intermittent KRT offers similar hemodynamic stability and overall cost savings, and its intermittent nature allows patients time off therapy for mobilization and procedures. When compared with intermittent hemodialysis, prolonged intermittent KRT offers more hemodynamic stability, particularly in patients who remain highly vulnerable to hypotension from aggressive ultrafiltration over a shorter duration of treatment. The prescription of prolonged intermittent KRT can be tailored to patients' progression in their recovery from critical illness, and the frequency, flow rates, and duration of treatment can be modified to avert hemodynamic instability during de-escalation of care. Dosing of prolonged intermittent KRT can be extrapolated from urea kinetics used to calculate clearance for continuous KRT and intermittent hemodialysis. Practice variations across institutions with respect to terminology, prescription, and dosing of prolonged intermittent KRT create significant challenges, especially in creating specific drug dosing recommendations during prolonged intermittent KRT. During the coronavirus disease 2019 pandemic, prolonged intermittent KRT was rapidly implemented to meet the KRT demands during patient surges in some of the medical centers overwhelmed by sheer volume of patients with AKI. Ideally, implementation of prolonged intermittent KRT at any institution should be conducted in a timely manner, with judicious planning and collaboration among nephrology, critical care, dialysis and intensive care nursing, and pharmacy leadership. Future analyses and clinical trials with respect to prescription and delivery of prolonged intermittent KRT and clinical outcomes will help to guide standardization of practice.

Relationship between preoperative lymphocyte to monocyte ratio and surgery outcome in type A aortic dissection

Background

Lymphocyte-to-monocyte ratio (LMR) is associated with the mortality of cardiovascular diseases. However, the relationship between preoperative LMR and the prognosis of patients with Stanford type A aortic dissection (TAAD) undergoing surgical treatment remains to be determined.

Methods

We enrolled 879 patients with TAAD undergoing surgical treatment between January 2018 and December 2021. Patients were divided into two groups: the Deceased group and the Survived group. The baseline clinical and operative characteristics of the two groups were compared and analyzed.

Results

In univariate and multivariate logistic regression analysis, the association between LMR and in-hospital mortality was significant, and LMR (OR = 1.598, 95% CI 1.114-2.485, P = 0.022) remained significant after adjusting for confounders.

Conclusion

Lower LMR may be independently associated with higher in-hospital mortality in TAAD undergoing surgical treatment.

Evaluation of nephrotoxicity and ototoxicity following amikacin administration once daily or every 48 hours in neonates

The purpose of this study was to evaluate the effects of once daily (OD) or every 48 hours (every-48-h) administration of amikacin (AMK) on renal function and ototoxicity in neonates. We investigated the frequency of nephrotoxicity and ototoxicity in neonates who received AMK OD or every-48-h from April 2015 to March 2021 and underwent dose evaluation by therapeutic drug monitoring (TDM). In addition, the relationships among birth weight, gestational age, AMK peak and trough values, total duration of AMK administration, and total AMK dose were examined separately for nephrotoxicity and ototoxicity. AMK was administered OD in 38 patients and every-48-h in 62 patients. Nephrotoxicity was observed in 8 patients on OD versus 36 patients on every-48-h administration (P < .001), and ototoxicity was observed in 2 patients on OD versus 12 patients on every-48-h administration (P = .192). For nephrotoxicity, only the trough value was relevant (P = .007). In terms of ototoxicity, there were no influencing factors. The risk of nephrotoxicity was higher with every-48-h AMK administration than with OD AMK administration, with nephrotoxicity depending on the trough value. However, compared with OD, the every-48-h group had lower body weight and possibly poorer original renal function. In addition, ototoxicity did not differ by administration method. Based on these results, every-48-h administration of AMK can be used as safely as OD by performing TDM and preventing high concentrations.

Cardiorenal Interactions: A Review

A complex interaction occurs between cardiac and renal function. They are intricately tied together, and a range of disorders in both the heart and kidneys can alter the function of the other. The pathophysiology is complex, and these conditions are termed cardiorenal syndromes. They can be acute and/or chronic in nature, they result in and from hemodynamic consequences, systemic congestion, and metabolic abnormalities, and they lead to dysfunction of both the heart and kidneys. The aim of this article is to provide a review for cardiologists and intensivists who are treating patients for whom cardiac and renal interactions may complicate their picture. We review acute kidney injuries, management of the complications of renal dysfunction, renal replacement therapy, and cardiorenal syndromes.

Canadian Association of Radiologists Guidance on Contrast Associated Acute Kidney Injury

Iodinated contrast media (ICM) is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after ICM administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. This revised guidance document was developed by a multidisciplinary CAR Working Group of radiologists and nephrologists, and summarizes changes in practice related to contrast administration, screening, and risk stratification since the last guideline. It reviews the scientific evidence for contrast associated AKI and provides consensus-based recommendations for its prevention and management in the Canadian healthcare context. This article is a joint publication in the Canadian Association of Radiologists Journal and Canadian Journal of Kidney Health and Disease, intended to inform both communities of practice.

Comparison of different modalities of continuous renal replacement therapy with regional sodium citrate anticoagulation in paediatric patients

BACKGROUND

To evaluate the efficacy and safety of continuous renal replacement therapy (CRRT) modalities with regional sodium citrate anticoagulation (RCA) in children.

METHODS

This retrospective study was conducted at the paediatric intensive care unit of Hunan Children's Hospital in China. Medical records of paediatric patients hospitalised for RCA-CRRT between April 2017 and March 2021 were reviewed. Patients received continuous venovenous haemodialysis, continuous venovenous haemofiltration (CVVH), or continuous venovenous haemodiafiltration (CVVHDF).

RESULTS

Patients on continuous venovenous haemodialysis (n = 2) were excluded because of their small sample size. The remaining participants were divided into CVVH and CVVHDF groups; 80 patients received CRRT, with 40 and 62 sessions in the CVVH and CVVHDF groups, respectively. The filtre lifespan was longer in the CVVHDF group than in the CVVH group (median value [interquartile range]; 47 [15] hours vs. 35 [17.5] hours; p = 0.029). Compared with the CVVHDF group, the hazard ratio for filtre lifespan in the CVVH group was 3.023 (95% confidence interval 1.820-5.023, p < 0.001). There were no significant differences in ionised calcium levels of the circuits between the two groups at different time points (p < 0.05). Metabolic alkalosis, hyperlactataemia, hypocalcaemia, and hypercalcaemia occurred in both groups, with metabolic alkalosis being the most common complication. No patients in either group experienced sodium citrate accumulation or hypernatraemia. Inter-group differences in the incidence of these complications were not statistically significant (p > 0.05).

CONCLUSIONS

Our results suggest that CVVHDF is a better option for RCA-CRRT than CVVH.

Admission Lysophosphatidic Acid Is Related to Impaired Kidney Function in Acute Aortic Dissection: 2-Year Retrospective Follow-Up Study

Background

Delayed treatment of acute aortic dissection (AAD)-related acute kidney injury (AKI) significantly increases the burden of chronic kidney disease (CKD) and mortality. Lysophosphatidic acid (LPA) is a shared mediator of kidney disease and AAD. Here, we evaluated the relationship between LPA and kidney injury in AAD patients.

Methods

We measured the plasma concentration of LPA in a cohort of 80 patients with AAD. Least Absolute Shrinkage and Selection Operator (LASSO) regression and Logistic regression were used to evaluate the effect and interaction of LPA on AKI. Additive generalized model and penalized spline method were used to describe the non-linear association. Multivariable analyses with the Cox proportional-hazards model were used for subgroup analysis and interaction in LPA and subsequent CKD.

Results

The participant’s average age was 54.27 ± 11.00 years, 68.75% of them were males, and the incidence of AKI was 43.75%. Patients with AKI had higher levels of LPA on admission, and the more significant the increase, the higher the risk of AKI. There was a non-linear positive correlation between admission LPA and AKI, and the premeditated inflection point was 346.33 (μg/dL) through two-piecewise linear regression and recursive algorithm. Subgroup analysis identified a stronger association between admission LPA and AKI in the elder, female and medically treated patients. The incidence of CKD was 22.67% in the 2-year follow-up. Patients with subsequent CKD had higher LPA levels on admission in the follow-up cohort, and a similar interaction trend was also observed through Cox proportional—hazards model.

Conclusion

Admission LPA levels show a non-linear positive correlation with AKI and increase the risk of subsequent CKD, which is more pronounced in elderly, female, and medically treated patients.

Canadian Association of Radiologists Guidance on Contrast-Associated Acute Kidney Injury

Purpose

Iodinated contrast media is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after iodinated contrast administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow-up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations.

Information sources

Published literature, including clinical trials, retrospective cohort series, review articles, and case reports, along with expert opinions from radiologists and nephrologists across Canada.

Methods

The leadership of the CAR formed a working group of radiologists and nephrologists with expertise in contrast administration and patient management related to contrast-associated AKI. We conducted a comprehensive review of the published literature to evaluate the evidence about contrast as a cause of AKI, and to inform evidence-based recommendations. Based on the available literature, the working group developed consensus recommendations.

Key Findings

The working group developed 21 recommendations, on screening, choice of iodinated contrast media, prophylaxis, medication considerations, and post contrast administration management. The key changes from the 2012 guidelines were (1) Simplification of screening to a simple questionnaire, and not delaying emergent examinations due to a need for creatinine measurements (2) Prophylaxis considerations only for patients with estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 (3) Not recommending the routine discontinuation of any drugs to decrease risk of AKI, except metformin when eGFR is less than 30 mL/min/1.73 m2 and (4) Not requiring routine follow up serum creatinine measurements post iodinated contrast administration.

Limitations

We did not conduct a formal systematic review or meta-analysis. We did not evaluate our specific suggestions in the clinical environment.

Implications

Given the importance of iodinated contrast media use in diagnosis and management, and the low risk of AKI after contrast use, these guidelines aim to streamline the processes around iodinated contrast use in most clinical settings. As newer evidence arises that may change or add to the recommendations provided, the working group will revise these guidelines.

The association between lymphocyte-monocyte ratio and postoperative acute kidney injury in patients with acute type A aortic dissection

BACKGROUND

The aim of this study was to investigate the relationship between baseline lymphocyte-monocyte ratio (LMR) and postoperative acute kidney injury (AKI) in patients with acute type A aortic dissection (ATAAD).

METHODS

ATAAD patients undergoing surgery in Nanjing First Hospital were enrolled from January 2019 to April 2021. Lymphocyte and monocyte were measured on admission. Multivariable logistic regression analyses were performed to explore the relationship between LMR and postoperative AKI. We also used receiver operating characteristic (ROC), net reclassification index (NRI) and integrated discrimination improvement (IDI) analyses to assess the predictive ability of LMR.

RESULTS

Among the 159 recruited patients, 47 (29.6%) were diagnosed with AKI. Univariate logistic regression analysis indicated that ATAAD patients with higher levels of LMR were prone to have lower risk to develop AKI (odds ratio [OR], 0.493; 95% confidence interval [CI] 0.284-0.650, P = 0.001). After adjustment for the potential confounders, LMR remained an independent related factor with postoperative AKI (OR 0.527; 95% CI 0.327-0.815, P = 0.006). The cutoff value for LMR to predict AKI was determined to be 2.67 in the ROC curve analysis (area under curve: 0.719). NRI and IDI further confirmed the predictive capability of LMR in postoperative AKI.

CONCLUSION

Elevated baseline LMR levels were independently associated with lower risk of postoperative AKI in ATAAD patients.

Heparin-free regional anticoagulation of haemodialysis filters with calcium-free dialysate: is citrate mandatory?

Background

There is an unmet need to develop safe and successful heparin-free regional anticoagulation modalities in haemodialysed patients at risk of bleeding. Whether the addition of citrate as a prefilter injection or in the dialysate itself is required to reach anticoagulation objectives when calcium-free dialysate is used as regional anticoagulation remains unclear.

Methods

In this monocentric retrospective study, we report our experience of 908 dialysis sessions performed with a calcium-free citrate-containing dialysate and calcium reinjection according to the ionic dialysance, without additional heparin.

Results

Premature termination for filter clotting occurred in 20 sessions (2.2%) and duration of session was >4.5 h in 135 (15%; maximum duration 6 h). In addition, we could investigate the citrate, calcium and acid–basis status during haemodialysis sessions performed with (citrate group, n = 20 sessions) or without (citrate-free group, n = 19 sessions) citrate in the dialysate. In 20 sessions performed in patients with underlying liver disorders and using calcium-free citrate-containing dialysate, patients’ ionized calcium (iCa) and serum citrate levels were stable and remained within the normal range, respectively. Post-filter iCa was below 0.4 mmol/L in 19/20 sessions and citrate was 0.304 mmol/L (range: 0.011; 0.548). In 19 sessions that used calcium and citrate-free dialysate, post-filter iCa was 0.41 mmol/L (0.34; 0.5) and all sessions extended to 4 h or beyond.

Conclusions

Regional anticoagulation of haemodialysis with a calcium-free dialysate and calcium reinjection according to the ionic dialysance is safe. Adding citrate to the dialysate is not mandatory to prevent dialysis circuit clotting in most patients.

ATF3: a novel biomarker for the diagnosis of acute kidney injury after cardiac surgery

Background

To investigate the expression of ATF3 in the blood and urine of adult patients undergoing cardiopulmonary bypass (CPB) surgery and to identify the changes during the perioperative period of CPB, and to determine whether ATF3 can be used as a biological marker for the early diagnosis of acute kidney injury (AKI).

Methods

We prospectively studied 83 patients who underwent elective CPB (ECB). Relevant clinical information was collected. Blood and urine samples were collected preoperatively (T0) and at 2 h (T1), 6 h (T2), 12 h (T3), 24 h (T4), and 48 h (T5) after surgery, and grouped according to the occurrence of AKI. The changes in ATF3 levels were observed, and the accuracy of the diagnosis of AKI was compared through receiver operating characteristic (ROC) curve analysis. Factors influencing the expression of ATF3 at baseline were also analyzed.

Results

A total of 83 adult patients undergoing cardiac surgery with CPB were included, and 42 of them developed AKI. The levels of serum ATF3 (sATF3) in the AKI group were significantly higher than those in the non-AKI group 24 h after surgery, and the difference was statistically significant (662.62±204.72 vs. 586.93±175.87; P=0.0345). Urinary ATF3 (uATF3) increased significantly 6 h after surgery, and the area under the ROC curve (AUC) for diagnosing AKI 12 h after surgery was 0.691 (95% CI: 0.576–0.807). When uATF3 was higher than 1,216 pg/mL, the sensitivity and specificity for the diagnosis of AKI were 0.43 and 0.85, respectively. On the other hand, the preoperative expression of ATF3 was negatively correlated with the preoperative creatinine level, but not affected by the patient’s age, weight, gender, preoperative cardiac function, preoperative blood routine examination and liver function.

Conclusions

ATF3 can be expressed early in the blood and urine of patients after CPB and can be used as a diagnostic marker for AKI after CPB in adult patients.

Prescribing Continuous Kidney Replacement Therapy in Acute Kidney Injury: A Narrative Review

Severe acute kidney injury is a common complication in critically ill patients, often necessitating support with a modality of kidney replacement therapy. Continuous kidney replacement therapies (CKRTs) have become a mainstay in the management of patients with acute kidney injury in the intensive care unit. Understanding the fundamentals of CKRT is necessary to safely and effectively prescribe treatment. In this narrative review, we summarize critical aspects of CKRT management, including selection of the mode of therapy; choice of hemofilter/hemodialyzer used; determination of the blood flow rate, composition and flow rates of dialysate and/or replacement fluids, and the ultrafiltration rate; and use and methods of anticoagulation. Requirements for vascular access and appropriate monitoring and dose adjustment of medications and a plan for monitoring the delivery of therapy and ensuring appropriate nutritional management are also discussed.

Predictors of acute kidney injury in patients with acute decompensated heart failure in emergency departments in China

Objective

This retrospective multicentre observational study was performed to assess the predictors of acute kidney injury (AKI) in patients with acute decompensated heart failure (ADHF) in emergency departments in China.

Methods

In total, 1743 consecutive patients with ADHF were recruited from August 2017 to January 2018. Clinical characteristics and outcomes were compared between patients with and without AKI. Predictors of AKI occurrence and underdiagnosis were assessed in multivariate regression analyses.

Results

Of the 1743 patients, 593 (34.0%) had AKI. AKI was partly associated with short-term all-cause mortality and cost. Cardiovascular comorbidities such as coronary heart disease, diabetes mellitus, and hypertension remained significant predictors of AKI in the univariate analysis. AKI was significantly more likely to occur in patients with a lower arterial pH, lower albumin concentration, higher creatinine concentration, and higher N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration. Patients treated with inotropic agents were significantly more likely to develop AKI during their hospital stay.

Conclusion

This study suggests that cardiovascular comorbidities, arterial pH, the albumin concentration, the creatinine concentration, the NT-proBNP concentration, and use of inotropic agents are predictors of AKI in patients with ADHF.

Dialysis disequilibrium on CKRT: avoiding the steep slippery slope

BACKGROUND

Current guidelines for initiation of kidney replacement do not include specific recommendations for prescription parameters and monitoring.

CASE OUTLINE

A 16-year-old girl presented with kidney failure with creatinine of 19.8 mg/dL and BUN of 211 mg/dL. She initiated continuous kidney replacement therapy (CKRT) with clearance of 1,300 mL/min/1.73 m² which was increased to 1,950 mL/min/1.73 m² at 17 h of stable therapy.

COMPLICATIONS

At 31 h of therapy, she developed generalized seizure activity. CT imaging was negative for acute intracranial process, and EEG demonstrated diffuse encephalopathy. CKRT was discontinued, and BUN was noted to be 47 mg/dL at that time (a 79% reduction from presenting BUN).

KEY MANAGEMENT POINTS

• The potential for development of DDS is not isolated to intermittent hemodialysis and may occur later in presentation. • A decreased clearance rate should be considered in those with risk factors for development of dialysis disequilibrium syndrome (DDS). • Frequent monitoring of BUN/serum osmolality is important to allow for adjustment of the KRT prescription following initiation of therapy. • Additional research is needed to guide risk assessment for DDS and therapeutic timing and goals in the early stages of KRT initiation. • Inclusion of more specific guidelines surrounding DDS would assist in providing important support for nephrologists.

LIST OF RELEVANT GUIDELINES

KDIGO clinical practice guideline for acute kidney injury [1] Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease [2] The Renal Association Clinical Practice Guideline Acute Kidney Injury (AKI) [3] The Japanese Clinical Practice Guideline for Acute Kidney Injury [4].

Optimization of Acute Kidney Injury (AKI) Time Definitions Using the Electronic Health Record: A First Step in Automating In-Hospital AKI Detection

Kidney Disease: Improving Global Outcomes (KDIGO) acute kidney injury (AKI) definitions were evaluated for cases detected and their respective outcomes using expanded time windows to 168 h. AKI incidence and outcomes with expanded time intervals were identified in the electronic health records (EHRs) from 126,367 unique adult hospital admissions (2012-2014) and evaluated using multivariable logistic regression with bootstrap sampling. The incidence of AKI detected was 7.4% (n = 9357) using a 24-h time window for both serum creatinine (SCr) criterion 1a (≥0.30 mg/dL) and 1b (≥50%) increases from index SCr, with additional cases of AKI identified: 6963 from 24-48 h.; 2509 for criterion 1b from 48 h to 7 days; 3004 cases (expansion of criterion 1a and 1b from 48 to 168 h). Compared to patients without AKI, adjusted hospital days increased if AKI (criterion 1a and 1b) was observed using a 24-h observation window (5.5 days), 48-h expansion (3.4 days), 48-h to 7-day expansion (6.5 days), and 168-h expansion (3.9 days); all are p < 0.001. Similarly, the adjusted risk of in-hospital death increased if AKI was detected using a 24-h observation window (odds ratio (OR) = 16.9), 48-h expansion (OR = 5.5), 48-h to 7-day expansion (OR = 4.2), and 168-h expansion (OR = 1.6); all are p ≤ 0.01. Expanding the time windows for both AKI SCr criteria 1a and 1b standardizes and facilitates EHR AKI detection, while identifying additional clinically relevant cases of in-hospital AKI.

Acute Kidney Injury Results in Long-Term Diastolic Dysfunction That Is Prevented by Histone Deacetylase Inhibition

•

This is the first long-term (1-year) study to evaluate both the kidney and systemic sequelae of acute kidney injury in mice.

•

Serial kidney function was measured via transcutaneous glomerular filtration rate.

•

AKI resulted in diastolic dysfunction, followed by hypertension. Ejection fraction was preserved. One year after AKI, cardiac ATP levels were reduced compared with sham controls.

•

Mice treated with the histone deacetylase inhibitor, ITF2357, maintained normal diastolic function normal blood pressure, and normal cardiac ATP after AKI.

•

Metabolomics data suggest that treatment with ITF2357 preserves pathways related to energy metabolism.

Growing epidemiological data demonstrate that acute kidney injury (AKI) is associated with long-term cardiovascular morbidity and mortality. Here, the authors present a 1-year study of cardiorenal outcomes following bilateral ischemia-reperfusion injury in male mice. These data suggest that AKI causes long-term dysfunction in the cardiac metabolome, which is associated with diastolic dysfunction and hypertension. Mice treated with the histone deacetylase inhibitor, ITF2357, had preservation of cardiac function and remained normotensive throughout the study. ITF2357 did not protect against the development of kidney fibrosis after AKI.

Different Severity of Clinical Outcomes Between the 2 Subgroups of Stage 1 Acute Kidney Injury After Liver Transplantation

BACKGROUND

Although the Kidney Disease: Improving Global Outcomes (KDIGO) criteria is used to define acute kidney injury (AKI) after liver transplantation, the criteria was criticized for including 2 heterogeneous groups of different serum creatinine (sCr) criteria together in AKI stage 1. We investigated whether there are significant differences in clinical outcomes between 2 subgroups of patients within AKI stage 1.

METHODS

A total of 1440 cases were reviewed. The AKI stage 1 (n = 443) were divided into 2 subgroups based on changes in sCr level (stage 1a: ≥0.3 mg/dL of absolute sCr increase, n = 251; stage 1b: ≥50% relative sCr increase, n = 192). Propensity score analysis was performed between stage 1a and 1b groups, yielding 157 matched pairs. We compared the length of hospital stay, early allograft dysfunction, and 5-year all-cause mortality between these subgroups after matching. Kaplan-Meier analyses were performed to compare the graft or overall survival between the subgroups after matching. Sensitivity analysis for Acute Kidney Injury Network (AKIN) criteria was performed.

RESULTS

Length of hospital stay and 5-year all-cause mortality was significantly worse in patients with stage 1b compared to stage 1a after matching. Five-year graft or patient survival was significantly worse in patients with stage 1b compared to stage 1a after matching (Log-rank test P = 0.022 and P = 0.027, respectively). These results were the same regarding AKIN criteria.

CONCLUSIONS

The KDIGO criteria for AKI stage 1 could be further divided into 2 substages with different severity of clinical outcomes. This modified criteria could give additional prognostic information in patients undergoing liver transplantation.

Development and initial implementation of electronic clinical decision supports for recognition and management of hospital-acquired acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is common in hospitalized patients and is associated with poor patient outcomes and high costs of care. The implementation of clinical decision support tools within electronic medical record (EMR) could improve AKI care and outcomes. While clinical decision support tools have the potential to enhance recognition and management of AKI, there is limited description in the literature of how these tools were developed and whether they meet end-user expectations.

METHODS

We developed and evaluated the content, acceptability, and usability of electronic clinical decision support tools for AKI care. Multi-component tools were developed within a hospital EMR (Sunrise Clinical Manager™, Allscripts Healthcare Solutions Inc.) currently deployed in Calgary, Alberta, and included: AKI stage alerts, AKI adverse medication warnings, AKI clinical summary dashboard, and an AKI order set. The clinical decision support was developed for use by multiple healthcare providers at the time and point of care on general medical and surgical units. Functional and usability testing for the alerts and clinical summary dashboard was conducted via in-person evaluation sessions, interviews, and surveys of care providers. Formal user acceptance testing with clinical end-users, including physicians and nursing staff, was conducted to evaluate the AKI order set.

RESULTS

Considerations for appropriate deployment of both non-disruptive and interruptive functions was important to gain acceptability by clinicians. Functional testing and usability surveys for the alerts and clinical summary dashboard indicated that the tools were operating as desired and 74% (17/23) of surveyed healthcare providers reported that these tools were easy to use and could be learned quickly. Over three-quarters of providers (18/23) reported that they would utilize the tools in their practice. Three-quarters of the participants (13/17) in user acceptance testing agreed that recommendations within the order set were useful. Overall, 88% (15/17) believed that the order set would improve the care and management of AKI patients.

CONCLUSIONS

Development and testing of EMR-based decision support tools for AKI with clinicians led to high acceptance by clinical end-users. Subsequent implementation within clinical environments will require end-user education and engagement in system-level initiatives to use the tools to improve care.

Dividing Stage 1 Acute Kidney Injury After Cardiac or Thoracic Aortic Surgery

BACKGROUND

Although the Kidney Disease: Improving Global Outcomes (KDIGO) criteria are used to define acute kidney injury, the criteria have limitations for including 2 different serum creatinine criteria in stage 1. We hypothesized that there would be differences in clinical outcomes between the 2 subgroups of stage 1 acute kidney injury in patients undergoing cardiac or thoracic aortic surgery.

METHODS

We reviewed 2510 cases. Patients with KDIGO stage 1 were divided into 2 subgroups (stage 1a: 0.3 mg/dL or greater of absolute increase in serum creatinine, n = 376; and stage 1b: 50% or greater relative increase, n = 365). Propensity score analysis was performed between stage 1a and 1b groups, yielding 240 pairs. We compared the length of hospital stay, the incidence of cardiovascular complications, 5-year all-cause mortality between these subgroups. Overall survival was compared between the subgroups after propensity score matching. We performed sensitivity analysis for Acute Kidney Injury Network (AKIN) criteria.

RESULTS

Length of hospital stay and 5-year all-cause mortality were worse in patients with KDIGO stage 1b compared with stage 1a. Five-year patient survival was significantly worse in patients with stage 1b compared with stage 1a after matching (log rank test, P = .002). We found similar results regarding AKIN criteria. Subgroup analysis showed that the significant difference in survival existed only when baseline serum creatinine was 0.8 mg/dL or greater.

CONCLUSIONS

The KDIGO or AKIN criteria for stage 1 acute kidney injury could be further divided into 2 substages with different severity of clinical outcomes. These modified criteria could give additional prognostic information in patients undergoing cardiac or thoracic aortic surgery.

Recent Advances in the Role of Natural Killer Cells in Acute Kidney Injury

Growing evidence is revealing a central role for natural killer (NK) cells, cytotoxic cells belonging to the broad family of innate lymphoid cells (ILCs), in acute and chronic forms of renal disease. NK cell effector functions include both the recognition and elimination of virus-infected and tumor cells and the capability of sensing pathogens through Toll-like receptor (TLR) engagement. Notably, they also display immune regulatory properties, exerted thanks to their ability to secrete cytokines/chemokines and to establish interactions with different innate and adaptive immune cells. Therefore, because of their multiple functions, NK cells may have a major pathogenic role in acute kidney injury (AKI), and a better understanding of the molecular mechanisms driving NK cell activation in AKI and their downstream interactions with intrinsic renal cells and infiltrating immune cells could help to identify new potential biomarkers and to select clinically valuable novel therapeutic targets. In this review, we discuss the current literature regarding the potential involvement of NK cells in AKI.

A nonrandomized open-label phase 2 trial of nonischemic heart preservation for human heart transplantation

Pre-clinical heart transplantation studies have shown that ex vivo non-ischemic heart preservation (NIHP) can be safely used for 24 h. Here we perform a prospective, open-label, non-randomized phase II study comparing NIHP to static cold preservation (SCS), the current standard for adult heart transplantation. All adult recipients on waiting lists for heart transplantation were included in the study, unless they met any exclusion criteria. The same standard acceptance criteria for donor hearts were used in both study arms. NIHP was scheduled in advance based on availability of device and trained team members. The primary endpoint was a composite of survival free of severe primary graft dysfunction, free of ECMO use within 7 days, and free of acute cellular rejection ≥2R within 180 days. Secondary endpoints were I/R-tissue injury, immediate graft function, and adverse events. Of the 31 eligible patients, six were assigned to NIHP and 25 to SCS. The median preservation time was 223 min (IQR, 202–263) for NIHP and 194 min (IQR, 164–223) for SCS. Over the first six months, all of the patients assigned to NIHP achieved event-free survival, compared with 18 of those assigned to SCS (Kaplan-Meier estimate of event free survival 72.0% [95% CI 50.0–86.0%]). CK-MB assessed 6 ± 2 h after ending perfusion was 76 (IQR, 50–101) ng/mL for NIHP compared with 138 (IQR, 72–198) ng/mL for SCS. Four deaths within six months after transplantation and three cardiac-related adverse events were reported in the SCS group compared with no deaths or cardiac-related adverse events in the NIHP group. This first-in-human study shows the feasibility and safety of NIHP for clinical use in heart transplantation. ClinicalTrial.gov, number NCT03150147

Ischemia and reperfusion damage contribute to early graft dysfunction and recipient’s death. Here the authors show the feasibility and safety of a non-ischemic heart preservation method for heart transplantation in a non-randomized trial.

Effects of pneumoperitoneum with carbon dioxide on renal and hepatic functions in rats

Introduction

Laparoscopic surgery is a preferred method based on its many benefits. However, increasing abdominal pressure by CO₂ insufflation during the implementation of this technique poses challenges.

Aim

To determine the degree of renal and liver injury that occurs in a pneumoperitoneum (PP) model of prolonged CO₂ insufflation.

Material and methods

Twenty-one female Sprague Dawley rats were separated randomly into three groups. Group 1 was the control group and given anesthesia for 3 h. In group 2, PP was administered under anesthesia for 1 h. In the last group, PP was administered under anesthesia to animals for 3 h. We measured renal and liver injury biomarkers and made a histopathological evaluation to estimate the degree of injury and assessed the correlation of biomarkers including kidney injury molecule-1 (KIM-1) with histopathological findings.

Results

Histopathological analysis according to the kidney ischemia tubular damage score showed a statistically significant difference between the 3 groups (p < 0.001). There was an increase in KIM-1 levels in the groups, although it was not statistically significant (p = 0.062, p = 0.156, p = 0.350 respectively). According to the correlation test in this research, KIM-1 results had a statistically significant association with creatinine, urea, aspartate aminotransferase and alanine aminotransferase levels in all control and study groups.

Conclusions

According to our results, the increase in KIM-1 was correlated with Cr levels and compatible with histopathological analysis. Moreover, intra-abdominal pressure statistically significantly increased the degree of kidney injury and there was not a significant increase in the levels of KIM-1. There was no difference in liver damage between groups.

Development and Validation of a Risk Prediction Model of Vancomycin-Associated Nephrotoxicity in Elderly Patients: A Pilot Study

This exploratory study aimed to develop a risk prediction model of vancomycin‐associated nephrotoxicity (VANT) in elderly patients. Clinical information of elderly patients who received vancomycin therapy from January 2016 to June 2018 was retrieved. A total of 255 patients were included in this study. Univariate analysis and multivariable logistic regression analysis revealed that vancomycin trough concentration ≥ 20 mg/L (odds ratio (OR) = 3.009; 95% confidence interval (CI) 1.345–6.732), surgery (OR = 3.357; 95% CI 1.309–8.605), the Charlson Comorbidities Index ≥ 4 points (OR = 2.604; 95% CI 1.172–5.787), concomitant use of cardiotonic drug (OR = 3.283; 95% CI 1.340–8.042), plasma volume expander (OR = 3.459; 95% CI 1.428–8.382), and piperacillin/tazobactam (OR = 2.547; 95% CI 1.680–6.007) were risk factors for VANT in elderly patients. Furthermore, a VANT risk prediction model was developed, which had good discriminative power and was well‐calibrated.

Thyroid Hormone Is Related to Postoperative AKI in Acute Type A Aortic Dissection

BACKGROUND

Renal function is profoundly influenced by thyroid hormone levels. This study was designed to evaluate the association between preoperative thyroid hormones and postoperative acute kidney injury (AKI) in acute type A aortic dissection (ATAAD) patients.

METHODS

A total of 88 patients with ATAAD who underwent surgeries in Beijing Anzhen Hospital and 274 healthy controls from July 2016 to December 2016 were included in this study. Propensity-score matching was used to compare thyroid hormone levels. Additionally, in a cohort study of ATAAD patients, multivariable regression and stratification analyses were conducted to examine the association of preoperative thyroid hormones with postoperative AKI.

RESULTS

Compared with healthy controls, ATAAD patients presented with lower preoperative levels of total triiodothyronine (TT3) (P < 0.01), free triiodothyronine (FT3) (P < 0.01), and thyroid-stimulating hormone (TSH) (P < 0.01) and a higher preoperative level of free thyroxine (FT4) (P < 0.01). The overall occurrence of postoperative AKI was 45.5%. Multivariate regression revealed that low levels of TT3 (OR = 0.07, 95% CI, 0.01-0.86, P = 0.04) were independently associated with postoperative AKI. Subgroup analyses showed that the association between TT3 and AKI was significant in patients with normal TSH levels (OR = 0.001 95% CI, 0.001-0.16, P < 0.01) but not in patients with lower TSH levels (P = 0.12).

CONCLUSION

The present study showed that a low level of TT3 was a predictor of postoperative AKI in ATAAD patients, especially in patients with normal TSH. The thyroid function should be checked before surgical intervention of patients with ATAAD, and patients with low T3 might be at higher risk of postoperative AKI.

Role of Artificial Intelligence in Kidney Disease

Artificial intelligence (AI), as an advanced science technology, has been widely used in medical fields to promote medical development, mainly applied to early detections, disease diagnoses, and management. Owing to the huge number of patients, kidney disease remains a global health problem. Challenges remain in its diagnosis and treatment. AI could take individual conditions into account, produce suitable decisions and promise to make great strides in kidney disease management. Here, we review the current studies of AI applications in kidney disease in alerting systems, diagnostic assistance, guiding treatment and evaluating prognosis. Although the number of studies related to AI applications in kidney disease is small, the potential of AI in the management of kidney disease is well recognized by clinicians; AI will greatly enhance clinicians' capacity in their clinical practice in the future.

[Perioperative complications and mortality in elderly patients following surgery for femoral fracture: prospective observational study]

BACKGROUND AND OBJECTIVES

Perioperative management of femoral fractures in elderly patients has been studied to determine modifiable causes of complications and death. The aim of this study was to evaluate the mortality rate and its causes in the elderly population with FF. We also evaluated perioperative complications and their association with postoperative mortality.

METHOD

In this prospective and observational study, we evaluated 182 patients, by questionnaire and electronic medical record, from the moment of hospitalization to one year after surgery. Statistical analyzes using the multivariate Cox proportional hazards model and Kaplan-Meier curves were performed to detect independent mortality factors.

RESULTS

Fifty-six patients (30.8%) died within one year after surgery, and the main cause of death was infection followed by septic shock. The main complication, both preoperatively and postoperatively, was hydroelectrolytic disorder. For every one-unit (one-year) increase in age, the odds ratio for death increased by 4%. With each new preoperative complication, the odds ratio for death increased by 28%. Patients ASA III or IV had a 95% higher odds ratio for death than patiets ASA I or II.

CONCLUSIONS

Increasing age and number of preoperative complications, in addition to ASA classification III or IV, were independent factors of increased risk of death in the population studied. The mortality rate was 30.8%, and infection followed by septic shock was the leading cause of death.

Secretory Leukocyte Protease Inhibitor (SLPI)-A Novel Predictive Biomarker of Acute Kidney Injury after Cardiac Surgery: A Prospective Observational Study

Acute kidney injury (AKI) is one of the most frequent complications after cardiac surgery and is associated with poor outcomes. Biomarkers of AKI are crucial for the early diagnosis of this condition. Secretory leukocyte protease inhibitor (SLPI) is an alarm anti-protease that has been implicated in the pathogenesis of AKI but has not yet been studied as a diagnostic biomarker of AKI. Using two independent cohorts (development cohort (DC), n = 60; validation cohort (VC), n = 148), we investigated the performance of SLPI as a diagnostic marker of AKI after cardiac surgery. Serum and urinary levels of SLPI were quantified by ELISA. SLPI was significantly elevated in AKI patients compared with non-AKI patients (6 h, DC: 102.1 vs. 64.9 ng/mL, p < 0.001). The area under the receiver operating characteristic curve of serum SLPI 6 h after surgery was 0.87 ((0.76–0.97); DC). The addition of SLPI to standard clinical predictors significantly improved the predictive accuracy of AKI (24 h, VC: odds ratio (OR) = 3.91 (1.44–12.13)). In a subgroup, the increase in serum SLPI was evident before AKI was diagnosed on the basis of serum creatinine or urine output (24 h, VC: OR = 4.89 (1.54–19.92)). In this study, SLPI was identified as a novel candidate biomarker for the early diagnosis of AKI after cardiac surgery.

Roadblocks and Opportunities to the Implementation of Novel Therapies for Acute Kidney Injury: A Narrative Review

Background:

Acute kidney injury (AKI) is a complex and heterogeneous clinical syndrome with limited effective treatment options. Therefore, a coherent research structure considering AKI pathophysiology, treatment, translation, and implementation is critical to advancing patient care in this area.

Purpose of review:

In this narrative review, we discuss novel therapies for AKI from their journey from bench to bedside to population and focus on roadblocks and opportunities to their successful implementation.

Sources of information:

Peer-reviewed articles, opinion pieces from research leaders and research funding agencies, and clinical and research expertise.

Methods:

This narrative review details the challenges of translation of preclinical studies in AKI and highlights trending research areas and innovative designs in the field. Key developments in preclinical research, clinical trials, and knowledge translation are discussed. Furthermore, this article discusses the current need to involve patients in clinical research and the barriers and opportunities for effective knowledge translation.

Key findings:

Preclinical studies have largely been unsuccessful in generating novel therapies for AKI, due both to the complexity and heterogeneity of the disease, as well as the limitations of commonly available preclinical models of AKI. The emergence of kidney organoid technology may be an opportunity to reverse this trend. However, the roadblocks encountered at the bench have not precluded researchers from running well-designed and impactful clinical trials, and the field of renal replacement therapy in AKI is highlighted as an area that has been particularly active. Meanwhile, knowledge translation initiatives are bolstered by the presence of large administrative databases to permit ongoing monitoring of clinical practices and outcomes, with research output from such evaluations having the potential to directly impact patient care and inform the generation of meaningful clinical practice guidelines.

Limitations:

There are limited objective data examining the process of knowledge creation and translation in AKI, and as such the opinions and research areas of the authors are significantly drawn upon in the discussion.

Implications:

The use of an organized knowledge-to-action framework involving multiple stakeholders, especially patient partners, is critical to translating basic research findings to improvements in patient care in AKI, an area where effective treatment options are lacking.

Ototoxicity and Nephrotoxicity With Elevated Serum Concentrations Following Vancomycin Overdose: A Retrospective Case Series

Although a high vancomycin serum concentration is known to be associated with nephrotoxicity, its association with ototoxicity is not well known. The purpose of our study was to examine the latter association in pediatric patients, especially in cases of accidental overdose. Pediatric patients who received vancomycin at our facility between March 2010 and December 2015 with a serum trough concentration > 30 mg/L were enrolled. Age, sex, neonatal hearing screening results, estimated peak vancomycin serum concentration, duration of drug exposure, renal function, and hearing test results were collected. The estimated duration of concentrations above 30 or 80 mg/L were simulated with the Sawchuk-Zaske method. We defined a "high concentration" and "toxic concentration" of vancomycin as 30 to 80 mg/L and > 80 mg/L, respectively. Ototoxicity was assessed based on the auditory brain stem response. We identified 4 females and 2 males with normal hearing at birth. Four of the 6 patients were ≤ 3 months old. All the patients reached an estimated peak serum concentration of > 80 mg/L, and 5 exceeded 150 mg/L. The estimated duration of exposure to a high concentration and toxic concentration of vancomycin was 15 to 62 hours and 8 to 43 hours, respectively. All the patients experienced transient renal dysfunction. Although transient ototoxicity was found in 1 patient, prolonged ototoxicity was not observed in any of the patients. All the patients had received an accidental overdose of vancomycin. Prolonged hearing loss due to a high vancomycin serum concentration was not found in any of the subjects in the present report.

Prediction of mortality and organ failure based on coagulation and fibrinolysis markers in patients with acute pancreatitis: A retrospective study

This study explored the predictive value of coagulation and fibrinolysis markers with acute pancreatitis (AP)-related mortality and organ failure.We retrospectively reviewed and analyzed coagulation and fibrinolysis markers and clinical outcomes of the patients with AP.A total of 273 patients with AP were enrolled, 7 patients died and 28 patients suffered from organ failure. Uni- and multivariate logistic regression identified the differences of all of the coagulation and fibrinolysis markers as risk factors for AP-related mortality. The differences of APTT value, TT value, D-dimmer level, FDP level, and AT III level were risk factors for organ failure. Furthermore, the OR of the differences of platelet, PT, APTT, TT, fibrinogen, D-dimmer, FDP, and AT III was substantially improved by grouping with intervals of 10 × 10/L, 2 seconds, 5 seconds, 3 seconds, 0.5 g/L, 3 mg/L FEU, 5 mg/L and 10%, respectively. The risk of mortality can increase up to 1.62, 5.17, and 5.60 fold for every 10 × 10/L, 2 seconds and 5 seconds of increase in platelet, PT and APTT, respectively. There is approximate 2-fold increase in risk of organ failure for every 2 seconds of TT increase. In receiver operating characteristic analysis, there is no difference in the predictive power of bedside index for severity in acute pancreatitis (BISAP) with them in mortality or organ failure.In patients with AP, the dynamic changes of coagulation and fibrinolysis markers are good predictors for AP-related mortality and organ failure, especially platelet, PT and APTT in mortality and TT in organ failure.

Incidence and Prognosis of Acute Kidney Diseases and Disorders Using an Integrated Approach to Laboratory Measurements in a Universal Health Care System

Importance

Abnormal measurements of kidney function or structure may be identified that do not meet criteria for acute kidney injury (AKI) or chronic kidney disease (CKD) but nonetheless may require medical attention. The Kidney Disease: Improving Global Outcomes Clinical Practice Guideline for AKI proposed criteria for the definition of acute kidney diseases and disorders (AKD), which include AKI; however, the incidence and prognosis of AKD without AKI remain unknown.

Objective

To characterize the incidence and outcomes of AKD without AKI, with or without CKD.

Design, Setting, and Participants

Retrospective cohort study including all adult residents in a universal health care system in Alberta, Canada, without end-stage kidney disease (ESKD) and with at least 1 serum creatinine measurement between January 1 and December 31, 2008, in a community or hospital setting. Data analysis took place in 2018.

Main Outcomes and Measures

The Kidney Disease: Improving Global Outcomes guideline definitions for CKD, AKI, and AKD based on serum creatinine, estimated glomerular filtration rate, and albuminuria criteria were applied to estimate the proportion of patients with CKD, AKI, and AKD without AKI, and combinations of the conditions. Patients were followed up for up to 8 years (study end date, June 31, 2016) to characterize their risks of mortality, development of new CKD, progression of preexisting CKD, and ESKD.

Results

Among 1 109 099 Alberta residents included in the cohort, the mean (SD) age was 52.3 (17.6) years, and 43.0% were male. Findings showed that AKD without AKI was common (3.8 individuals without preexisting CKD and 0.6 with preexisting CKD per 100 population tested). In Cox proportional hazards and competing risks models over a median (interquartile range) of 6.0 (5.7-6.3) years of follow-up, AKD without AKI (compared with no kidney disease) was associated with higher risks of developing new CKD (37.4% vs 7.4%%; adjusted sub-hazard ratio [sHR], 3.17; 95% CI, 3.10-3.23), progression of preexisting CKD (49.5% vs 34.6%; adjusted sHR, 1.38; 95% CI, 1.33-1.44), ESKD (0.6% vs 0.1%; adjusted sHR, 8.56; 95% CI, 7.32-10.01), and death (25.8% vs 7.3%; adjusted hazard ratio, 1.42; 95% CI, 1.39-1.45).

Conclusions and Relevance

Criteria for AKD identified many patients who did not meet the criteria for CKD or AKI but had overall modestly increased risks of incident and progressive CKD, ESKD, and death. The clinical importance of AKD remains to be determined.

The Incidence and Risk Factors of Low Oxygenation After Orthotropic Liver Transplantation

Background

This study was designed to observe incidence and risk factors of low oxygenation after orthotropic liver transplantation (OLT).

Material/Methods

We retrospectively evaluated all adult patients who underwent living-donor OLT between January 1, 2017 and December 31, 2017. Postoperative low oxygenation was defined as PaO₂/FiO₂ <300 mmHg within 24 hours after surgery. Early acute kidney injury (AKI) after OLT was also defined when AKI was happened with 24 hours after operative.

Results

A total of 301 patients, aged 50.35±10.29 years were enrolled. Of these patients, 100 patients (33.2%) suffered postoperative low oxygenation (PaO₂/FiO₂=251.80±35.84). Compared with the normal oxygenation group, body mass index (BMI) (24.48±3.53 versus 23.1±3.27 kg/m², P=0.001), preoperative hemoglobin (115.79±29.27 versus 111.52±29.80 g/L, P=0.033), preoperative MELD (22.25±6.54 versus 20.24±5.74, P=0.008), and intraoperative urinary volume (1.25 [0.76, 1.89] versus 2.04 [1.49, 3.68] mL/kg/h, P=0.003) were higher in low oxygenation group. There were more cases of earlier AKIs that occurred after OLT in low oxygenation patients than that in normal group (47% versus 23.4%, P<0.001). Logistic analysis showed that the preoperative BMI (hazard ration [HR]=1.107, [1.010, 1.212], P=0.029) and early AKI after OLT (HR=2.115, [1.161, 3.855], P=0.014) were independent risk factors for postoperative low oxygenation.

Conclusions

The incidence of postoperative low oxygenation after liver transplantation in adults was 33.2%. BMI and early AKI after OLT were correlated with postoperative hypoxemia.

LPS removal reduces CD80-mediated albuminuria in critically ill patients with Gram-negative sepsis

LPS-induced sepsis is a leading cause of acute kidney injury (AKI) in critically ill patients. LPS may induce CD80 expression in podocytes with subsequent onset of proteinuria, a risk factor for progressive chronic kidney disease (CKD) frequently observed after AKI. This study aimed to investigate the therapeutic efficacy of LPS removal in decreasing albuminuria through the reduction of podocyte CD80 expression. Between January 2015 and December 2017, 70 consecutive patients with Gram-negative sepsis-induced AKI were randomized to either have coupled plasma filtration and adsorption (CPFA) added to the standard care ( n = 35) or not ( n = 35). To elucidate the possible relationship between LPS-induced renal damage, proteinuria, and CD80 expression in Gram sepsis, a swine model of LPS-induced AKI was set up. Three hours after LPS infusion, animals were treated or not with CPFA for 6 h. Treatment with CPFA significantly reduced serum cytokines, C-reactive protein, procalcitonin, and endotoxin levels in patients with Gram-negative sepsis-induced AKI. CPFA significantly lowered also proteinuria and CD80 urinary excretion. In the swine model of LPS-induced AKI, CD80 glomerular expression, which was undetectable in control pigs, was markedly increased at the podocyte level in LPS-exposed animals. CPFA significantly reduced LPS-induced proteinuria and podocyte CD80 expression in septic pigs. Our data indicate that LPS induces albuminuria via podocyte expression of CD80 and suggest a possible role of timely LPS removal in preventing the maladaptive repair of the podocytes and the consequent increased risk of CKD in sepsis-induced AKI.

Application potential of stem/progenitor cell-derived extracellular vesicles in renal diseases

Extracellular vesicles (EVs) are nanometer-sized and membrane-bound vesicles, including exosomes and microvesicles. EVs can deliver bioactive macromolecules such as proteins, lipids, and nucleic acids, allowing intercellular communication in multicellular organisms. EVs are secreted by all cell types including stem/progenitor cells. Stem/progenitor cell-derived EVs have been identified to exert immunomodulatory effects on target cells through transferring protein molecules as well as regulatory effects on the phenotype of target cells through fusion with the target cells membrane and/or through direct endocytosis by target cells to transfer nucleic acid substances (such as mRNA, miRNA) to the target cells. In both human and animal models, the use of stem/progenitor cells (such as bone marrow mesenchymal stromal cells) has been shown to promote the recovery of kidney diseases such as acute kidney injury and chronic kidney disease. Stem/progenitor cell-derived extracellular vesicles are an important mechanism by which stem/progenitor cells might repair kidney injury. Here, this review will discuss the latest advances concerning the application potential of stem/progenitor cell-derived extracellular vesicles in renal diseases, including the aspects as follows: anti-inflammatory, proliferation-promoting and anti-apoptotic, proangiogenic, antifibrotic and renal cancer progression-promoting. Therefore, stem/progenitor cell-derived extracellular vesicles may be a promising treatment tool for renal diseases.