Acute kidney injury 2016: diagnosis and diagnostic workup

Antitumor effect of Iso-mukaadial acetate on MCF-7 breast cancer mice xenograft model

Antitumor drugs used today have shown significant efficacy and are derived from natural products such as plants. Iso-mukaadial acetate (IMA) has previously been shown to possess anticancer properties by inducing apoptosis. The purpose of this study was to investigate the therapeutic effect of IMA in the breast cancer xenograft mice model. Female athymic nude mice were used and inoculated with breast cancer cells subcutaneously. Untreated group one served as a negative control and positive control group two (cisplatin) was administered intravenously. IMA was administered orally to group three (100 mg/kg) and group four (300 mg/kg). Blood was collected (70 μL) from the tail vein on day zero, day one and day three. Tumor regression was measured every second day and body mass was recorded each day. Estimation of serum parameters for renal indices was examined using a creatinine assay. Histopathological analysis was conducted to evaluate morphological changes of liver, kidney, and spleen tissues before and after compound administration under a fluorescence light microscope. Histopathological analysis of tumors was conducted before and after compound administration. Apoptotic analysis using the TUNEL system was conducted on liver, kidney, and spleen tissues. Tumor shrinkage and reduction in body mass were observed after treatment with IMA. Serum creatinine was slightly elevated after treatment with IMA at a dosage of 100 and 300 mg/kg. Histopathological results of the liver exhibited no changes before and after IMA while the kidney and spleen tissues showed changes in the cellular structure. IMA showed no cytotoxic effect on the tumor cells, and cell proliferation was observed. Apoptotic assay stain with TUNEL showed apoptotic cells in spleen tissue and kidney but no apoptotic cells were observed in liver tissue section treated with IMA. IMA showed clinical toxic signs that resulted in the suffering and death of the mice immediately after IMA administration. Histopathology of tumor cells showed that IMA did not inhibit cell proliferation and no cellular damage was observed. Therefore, based on the results obtained, we cannot make any definitive conclusion on the complete effect of IMA in vivo. IMA is toxic, poorly soluble, and not safe to use in animal studies. The objective of the study was not achieved, and the hypothesis was rejected.

[Artificial intelligence and acute kidney injury]

Digitalization is increasingly finding its way into intensive care units and with it artificial intelligence (AI) for critically ill patients. One promising area for the use of AI is in the field of acute kidney injury (AKI). The use of AI is primarily focused on the prediction of AKI, but further approaches are also being used to classify existing AKI into different phenotypes. Different AI models are used for prediction. The area under the receiver operating characteristic curve values (AUROC) achieved with these models vary and are influenced by several factors, such as the prediction time and the definition of AKI. Most models have an AUROC between 0.650 and 0.900, with lower values for predictions further into the future and when applying Acute Kidney Injury Network (AKIN) instead of KDIGO criteria. Classification into phenotypes already makes it possible to categorize patients into groups with different risks of mortality or requirement of renal replacement therapy (RRT), but the etiologies or therapeutic consequences derived from this are still lacking. However, all the models suffer from AI-specific shortcomings. The use of large databases does not make it possible to promptly include recent changes in therapy and the implementation of new biomarkers in a relevant proportion. For this reason, serum creatinine and urinary output, with their known limitations, dominate current AI models for prediction impairing the performance of the current models. On the other hand, the increasingly complex models no longer allow physicians to understand the basis on which the warning of a threatening AKI is calculated and subsequent initiation of therapy should take place. The successful use of AIs in routine clinical practice will be highly determined by the trust of the physicians in the systems and overcoming the aforementioned weaknesses. However, the clinician will remain irreplaceable as the decisive authority for critically ill patients by combining measurable and nonmeasurable parameters.

Acute Kidney Injury Resulting From Hemoglobinuria After Pulsed-Field Ablation in Atrial Fibrillation: Is it Preventable?

BACKGROUND

High-voltage pulses can cause hemolysis.

OBJECTIVES

The authors evaluated the occurrence of hemoglobinuria after pulsed-field ablation (PFA) and its impact on renal function in patients with atrial fibrillation (AF).

METHODS

A consecutive series of patients with AF undergoing PFA were included in this analysis. The initial patients who did not receive postablation hydration immediately after the procedure were classified as group 1 (n = 28), and the rest of the study patients who received planned fluid infusion (0.9% sodium chloride ≥2 L) after the procedure were categorized as group 2 (n = 75).

RESULTS

Of the 28 patients in group 1, 21 (75%) experienced hemoglobinuria during the 24 hours after catheter ablation. The mean postablation serum creatinine (S-Cr) was significantly higher than the baseline value in those 21 patients (1.46 ± 0.28 mg/dL vs 0.86 ± 0.24 mg/dL, P < 0.001). Of those 21 patients, 4 (19%) had S-Cr. >2.5 mg/dL (mean: 2.95 ± 0.21 mg/dL). The mean number of PF applications was significantly higher in those 4 patients than in the other 17 patients experiencing hemoglobinuria (94.63 ± 3.20 vs 46.75 ± 9.10, P < 0.001). In group 2 patients, no significant changes in S-Cr were noted. The group 2 patients received significantly higher amounts of fluid infusion after catheter ablation than did those in group 1 (2,082.50 ± 258.08 mL vs 494.01 ± 71.65 mL, P < 0.001). In multivariable analysis, both hydration (R2 = 0.63, P < 0.01) and number of PFA applications (R2 = 0.33, P < 0.01) were independent predictors of postprocedure acute kidney injury.

CONCLUSIONS

On the basis of our findings, both the number of PFA applications and postablation hydration were independent predictors of renal insult that could be prevented using planned fluid infusion immediately after the procedure.

Temporal trends in critical care utilization and outcomes in allogeneic hematopoietic stem cell transplant recipients

Historically, the prognosis of allogeneic hematopoietic stem cell transplant (allo-HCT) recipients who require intensive care unit (ICU) admission has been poor. We aimed to describe the epidemiological trends of ICU utilization and outcomes in allo-HCT patients. We conducted a retrospective cohort study including adults (≥ 18) undergoing allo-HCT between 01/01/2005 and 31/12/2020 at Mayo Clinic, Rochester. Temporal trends in outcomes were assessed by robust linear regression modelling. Risk factors for hospital mortality were chosen a priori and assessed with multivariable logistic regression modelling. Of 1,249 subjects, there were 486 ICU admissions among 287 individuals. Although older patients underwent allo-HCT (1.64 [95% CI: 1.11 to 2.45] years per year; P = 0.025), there was no change in ICU utilization over time (P = 0.91). The ICU and hospital mortality rates were 19.2% (55/287) and 28.2% (81/287), respectively. There was a decline in ICU mortality (-0.38% [95% CI: -0.70 to -0.06%] per year; P = 0.035). The 1-year post-HCT mortality for those requiring ICU admission was 56.1% (161/287), with no significant difference over time, versus 15.8% (141/891, 71 missing) among those who did not. The frequency and duration of invasive mechanical ventilation (IMV) declined. In multivariable analyses, higher serum lactate, higher sequential organ failure assessment (SOFA) scores, acute respiratory distress (ARDS), and need for IMV were associated with greater odds of hospital mortality. Over time, rates of ICU utilization have remained stable, despite increasing patient age. Several trends suggest improvement in outcomes, notably lower ICU mortality and frequency of IMV. However, long-term survival remains unchanged. Further work is needed to improve long-term outcomes in this population.

Indexed neutrophil gelatinase associated lipocalin: a novel biomarker for the assessment of acute kidney injury

INTRODUCTION

Acute kidney injury (AKI) is a clinically relevant and common complication among patients with acute coronary syndrome. Neutrophil gelatinase-associated lipocalin (NGAL), secreted from different cells including renal tubules, has been widely studied as an early marker for kidney injury. However, chronic kidney disease (CKD) could impact NGAL levels and alter their predictive performance. Some studies attempted to address this issue by setting different cutoff values for patients with CKD, with limited success to date. Our aim was to evaluate a novel estimated glomerular filtration rate (eGFR)-adjusted "indexed NGAL" and its ability to predict in-hospital AKI among patients with ST elevation myocardial infarction.

METHODS

We performed a prospective, observational, single center study involving patients with ST elevation myocardial infarction admitted to the coronary intensive care unit. Serum samples for baseline NGAL were collected within 24 h following hospital admission. The eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. In-hospital AKI was determined as occurring after ≥ 24 h from admission. To perform an individualized adjustment, we used the result of 24 h NGAL divided by the eGFR measured upon admission to the hospital (Indexed-NGAL; I-NGAL).

RESULTS

Our cohort includes 311 patients, of whom 123 (40%) had CKD, and 66 (21%) suffered in-hospital AKI. NGAL levels as well as I-NGAL levels were significantly higher in patients with AKI (136 vs. 86, p < 0.01 and 3.13 VS. 1.06, p < 0.01, respectively). Multivariate analysis revealed I-NGAL to be independently associated with AKI (OR 1.34 (1.10-1.58), p < 0.01). I-NGAL had a higher predictive ability than simple NGAL results (AUC-ROC of 0.858 vs. 0.778, p < 0.001).

CONCLUSION

Adjusting NGAL values according to eGFR yields a new indexed NGAL value that enables better prediction of AKI regardless of baseline kidney function.

Retinoic acid receptor α activity in proximal tubules prevents kidney injury and fibrosis

Chronic kidney disease (CKD) is characterized by a gradual loss of kidney function and affects ~13.4% of the global population. Progressive tubulointerstitial fibrosis, driven in part by proximal tubule (PT) damage, is a hallmark of late stages of CKD and contributes to the development of kidney failure, for which there are limited treatment options. Normal kidney development requires signaling by vitamin A (retinol), which is metabolized to retinoic acid (RA), an endogenous agonist for the RA receptors (RARα, β, γ). RARα levels are decreased in a mouse model of diabetic nephropathy and restored with RA administration; additionally, RA treatment reduced fibrosis. We developed a mouse model in which a spatiotemporal (tamoxifen-inducible) deletion of RARα in kidney PT cells of adult mice causes mitochondrial dysfunction, massive PT injury, and apoptosis without the use of additional nephrotoxic substances. Long-term effects (3 to 4.5 mo) of RARα deletion include increased PT secretion of transforming growth factor β1, inflammation, interstitial fibrosis, and decreased kidney function, all of which are major features of human CKD. Therefore, RARα's actions in PTs are crucial for PT homeostasis, and loss of RARα causes injury and a key CKD phenotype.

Review of the limitations of current biomarkers in acute kidney injury clinical practices

Acute kidney injury is a prevalent disease in hospitalized patients and is continuously increasing worldwide. Various efforts have been made to define and classify acute kidney injury to understand the progression of this disease. Furthermore, deviations from structure and kidney function and the current diagnostic guidelines are not adequately placed due to baseline serum creatinine values, which are rarely known and estimated based on glomerular function rate, resulting in misclassification of acute kidney injury staging. Hence, the current guidelines are still developing to improve and understand the clinical implications of risk factors and earlier predictive biomarkers of acute kidney injury. Yet, studies have indicated disadvantages and limitations with the current acute kidney injury biomarkers, including lack of sensitivity and specificity. Therefore, the present narrative review brings together the most current evidenced-based practice and literature associated with the limitations of the gold standard for acute kidney injury diagnoses, the need for novel acute kidney injury biomarkers, and the process for biomarkers to be qualified for diagnostic use under the following sections and themes. The introduction section situates the anatomy and normal and abnormal kidney functions related to acute kidney injury disorders. Guidelines in providing acute kidney injury definitions and classification are then considered, followed by a discussion of the disadvantages of standard markers used to diagnose acute kidney injury. Characteristics of an ideal acute kidney injury biomarker are discussed concerning sensitivity, specificity, and anatomic location of injury. A particular focus on the role and function of emerging biomarkers is discussed in relation to their applications and significance to the prognosis and severity of acute kidney injury. Findings show emerging markers are early indicators of acute kidney injury prediction in different clinical settings. Finally, the process required for a biomarker to be applied for diagnostic use is explained.

Antibiotic-Associated Acute Kidney Injury Among Older Adults: A Case-Crossover Study

BACKGROUND AND OBJECTIVES

Drug-related acute kidney injury is quite common in older adults. The associated drugs, including antibiotics, are often co-prescribed. The objective of this study was to ascertain antibiotic-associated acute kidney injury (AKI) in older adults aged 65 years or above in New Zealand using a case-crossover study design.

METHODS

The International Statistical Classification of Diseases and Related Health Problems, tenth revision, Australian modification code N17.x was used to identify all individuals aged 65 years and above with a diagnosis of incident AKI on admission between 1 January 2005 and 31 December 2020, from the New Zealand National Minimum Data Set. A case-crossover cohort for antibiotic exposures, with a 3 day case period and two 30 day washout periods, summed up to a 66 day study period, was created. Using conditional logistic regression, the changed odds of AKI due to exposure to an antibiotic was calculated as matched odds ratios and their 95% confidence intervals.

RESULTS

A total of 2399 incident cases of AKI were identified between 2005 and 2020 among older adults. The adjusted odds of consuming sulfamethoxazole/trimethoprim antibiotic during the case period was 3.57 times (95% CI 2.86-4.46) higher than the reference period among the incident AKI cases. Fluoroquinolone utilization was also associated with incident AKI (adjusted OR = 2.56; 95% CI 1.90-3.46).

CONCLUSION

The potential of sulfamethoxazole/trimethoprim and fluoroquinolones to be associated with AKI raises the significant need for vigilant prescribing of these antibiotics in older adults.

Continuous renal replacement therapy in neonates and children: what does the pediatrician need to know? An overview from the Critical Care Nephrology Section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

Continuous renal replacement therapy (CRRT) is the preferred method for renal support in critically ill and hemodynamically unstable children in the pediatric intensive care unit (PICU) as it allows for gentle removal of fluids and solutes. The most frequent indications for CRRT include acute kidney injury (AKI) and fluid overload (FO) as well as non-renal indications such as removal of toxic metabolites in acute liver failure, inborn errors of metabolism, and intoxications and removal of inflammatory mediators in sepsis. AKI and/or FO are common in critically ill children and their presence is associated with worse outcomes. Therefore, early recognition of AKI and FO is important and timely transfer of patients who might require CRRT to a center with institutional expertise should be considered. Although CRRT has been increasingly used in the critical care setting, due to the lack of standardized recommendations, wide practice variations exist regarding the main aspects of CRRT application in critically ill children.     Conclusion: In this review, from the Critical Care Nephrology section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC), we summarize the key aspects of CRRT delivery and highlight the importance of adequate follow up among AKI survivors which might be of relevance for the general pediatric community. What is Known: • CRRT is the preferred method of renal support in critically ill and hemodynamically unstable children in the PICU as it allows for gentle removal of fluids and solutes. • Although CRRT has become an important and integral part of modern pediatric critical care, wide practice variations exist in all aspects of CRRT. What is New: • Given the lack of literature on guidance for a general pediatrician on when to refer a child for CRRT, we recommend timely transfer to a center with institutional expertise in CRRT, as both worsening AKI and FO have been associated with increased mortality. • Adequate follow-up of PICU patients with AKI and CRRT is highlighted as recent findings demonstrate that these children are at increased risk for adverse long-term outcomes.

An Investigation of Contrast-Induced Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Intervention: A Cross-Sectional Study From Pakistan

Background and objective Contrast-induced acute kidney injury (CIAKI) is a complication observed among individuals undergoing primary percutaneous coronary intervention (PCI) and is associated with high morbidity and mortality rates. It is characterized by an elevation in serum creatinine (SCr) levels >0.5 mg/dl or a 50% relative increase in SCr from the baseline value following exposure to contrast within a 48- to 72-hour timeframe, in the absence of any alternative causes for acute kidney injury (AKI). This study aimed to assess the incidence of CIAKI in patients following PCI. Methods This prospective study was conducted from July to December 2022, after obtaining ethical approval from the institutional ethics committee (reference no: 147/LRH/MTI). A total of 159 consecutive patients who met the selection criteria were enrolled. A detailed patient and family history was obtained, and a thorough physical examination was conducted. Baseline tests, including SCr, were performed, with SCr repeated 72 hours post-PCI. All investigations were performed in the affiliated hospital's main laboratory and conducted by the same biochemist. Results The study included 159 patients presenting with myocardial infarction, angina pectoris, or ischemic features on EKG, exercise tolerance test (ETT), or echocardiogram and underwent PCI. The patients had a mean age of 51 ± 9 years, baseline SCr of 0.77 ± 0.41 mg/dl, SCr 72 hours post-procedure of 0.83 ± 0.41 mg/dl, and an average contrast volume of 128.6 ± 63 ml; 87 (55%) patients were male, and 72 (45%) were female. CIAKI was observed in 15 (9.4%) patients. Hypertension and diabetes mellitus were the most prevalent comorbidities. Male gender, diabetes mellitus, and hypertension had a clinically significant association with the development of CIAKI (p<0.05). ST-elevation myocardial infarction (STEMI) was the predominant clinical presentation in 81 (50.9%) cases. Conclusions This study examines the frequency, risk factors, and associations of CIAKI following PCI at a tertiary care hospital in a low-middle-income country. We believe our findings provide future directions for identifying and minimizing the risk of CIAKI in this patient population.

Urinary cell cycle biomarkers for the prediction of renal non-recovery in patients with septic acute kidney injury: a prospective study

BACKGROUND

Poor prognosis has been associated with the absence of renal recovery after acute kidney injury (AKI). This study aimed to investigate whether urinary biomarkers at 0 and 24 h could be used independently or in conjunction with a clinical model to predict renal non-recovery in septic AKI.

METHODS

A prospective observational study was conducted to measure the urinary levels of insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinase-2 (TIMP-2) at the time of AKI diagnosis (0 h) and 24 h later. Renal non-recovery within 7 days was defined as the outcome. The predictive value of urinary biomarkers for renal non-recovery in septic AKI was assessed using the area under the curve (AUC).

RESULTS

A total of 198 individuals with septic AKI were included in the final analysis. Among them, 38.9% (n = 77) did not experience renal recovery within 7 days. The combination of urinary IGFBP7 and TIMP-2 at the initial time point demonstrated prognostic value for non-recovery of renal function, with an AUC of 0.782. When [TIMP-2]*[IGFBP7] was measured at 0 h, the clinical prognostic model, incorporating AKI stage 2-3 and the non-renal sequential organ failure assessment score, showed an improved AUC of 0.822 (with a sensitivity of 88.3% and specificity of 59.5%).

CONCLUSIONS

The combination of urinary [TIMP-2]*[IGFBP7] at 0 h exhibited moderate predictive ability for renal non-recovery in cases of septic AKI. However, there is potential to enhance the prognostic capabilities of the [TIMP-2]*[IGFBP7]-clinical prediction model.

Factors Associated with 1-Year Mortality in Elderly Patients (Age ≥ 80 Years) with Cancer Undergoing Major Abdominal Surgery: A Retrospective Cohort Study

BACKGROUND

The number of elderly patients undergoing major abdominal surgery is increasing, but the factors affecting their postoperative outcomes remain unclear. This study aimed to identify the factors associated with 1-year mortality among elderly patients (age ≥ 80 years) with cancer undergoing major abdominal surgery.

METHODS

This retrospective cohort study was conducted from March 2009 to December 2020. The study enrolled 378 patients 80 years old or older who underwent major abdominal surgery. The main outcome was 1-year mortality, and the factors associated with mortality were analyzed.

RESULTS

Of the 378 patients, 92 died at 1 year (24.3%), whereas the 30-day mortality rate was 4% (n = 15). In the multivariate analysis, the factors independently associated with 1-year mortality were preoperative Eastern Cooperative Oncology Group (ECOG) performance status (PS) score higher than 1 (odds ratio [OR], 3.189; 95% confidence interval [CI], 1.595-6.377; p = 0.001), preoperative weight loss greater than 3 kg (OR, 2.145; 95% CI, 1.044-4.404; p = 0.038), use of an intraoperative vasopressor (OR, 3.090; 95% CI, 1.188-8.042; p = 0.021), and postoperative red blood cell units (OR, 1.212; 95% CI, 1.045-1.405; p = 0.011). Survival was associated with perioperative management according to an enhanced recovery after surgery (ERAS) protocol (OR, 0.370; 95% CI, 0.160-0.854; p = 0.006) and supramesocolic surgery (OR, 0.371; 95% CI, 0.158-0.871; p = 0.023).

CONCLUSION

The study identified several factors associated with an encouraging 1-year mortality rate in this setting. These results highlight the need for identification of suitable targets to optimize pre-, intra-, and postoperative management in order to improve outcomes for this vulnerable population.

Perfusion and T2 Relaxation Time as Predictors of Severity and Outcome in Sepsis-Associated Acute Kidney Injury: A Preclinical MRI Study

BACKGROUND

Preventing sepsis-associated acute kidney injury (S-AKI) can be challenging because it develops rapidly and is often asymptomatic. Probability assessment of disease progression for therapeutic follow-up and outcome are important to intervene and prevent further damage.

PURPOSE

To establish a noninvasive multiparametric MRI (mpMRI) tool, including T1 , T2 , and perfusion mapping, for probability assessment of the outcome of S-AKI.

STUDY TYPE

Preclinical randomized prospective study.

ANIMAL MODEL

One hundred and forty adult female SD rats (65 control and 75 sepsis).

FIELD STRENGTH/SEQUENCE

9.4T; T1 and perfusion map (FAIR-EPI) and T2 map (multiecho RARE).

ASSESSMENT

Experiment 1: To identify renal injury in relation to sepsis severity, serum creatinine levels were determined (31 control and 35 sepsis). Experiment 2: Animals underwent mpMRI (T1 , T2 , perfusion) 18 hours postsepsis. A subgroup of animals was immediately sacrificed for histology examination (nine control and seven sepsis). Result of mpMRI in follow-up subgroup (25 control and 33 sepsis) was used to predict survival outcomes at 96 hours.

STATISTICAL TESTS

Mann-Whitney U test, Spearman/Pearson correlation (r), P < 0.05 was considered statistically significant.

RESULTS

Severely ill septic animals exhibited significantly increased serum creatinine levels compared to controls (70 ± 30 vs. 34 ± 9 μmol/L, P < 0.0001). Cortical perfusion (480 ± 80 vs. 330 ± 140 mL/100 g tissue/min, P < 0.005), and cortical and medullary T2 relaxation time constants were significantly reduced compared to controls (41 ± 4 vs. 37 ± 5 msec in cortex, P < 0.05, 52 ± 7 vs. 45 ± 6 msec in medulla, P < 0.05). The combination of cortical T2 relaxation time constants and perfusion results at 18 hours could predict survival outcomes at 96 hours with high sensitivity (80%) and specificity (73%) (area under curve of ROC = 0.8, Jmax  = 0.52).

DATA CONCLUSION

This preclinical study suggests combined T2 relaxation time and perfusion mapping as first line diagnostic tool for treatment planning.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY STAGE: 2.

Acute kidney injury associated with nephrotoxic drugs in critically ill patients: a multicenter cohort study using electronic health record data

Background

Nephrotoxic drugs frequently cause acute kidney injury (AKI) in adult intensive care unit (ICU) patients. However, there is a lack of large pharmaco-epidemiological studies investigating the associations between drugs and AKI. Importantly, AKI risk factors may also be indications or contraindications for drugs and thereby confound the associations. Here, we aimed to estimate the associations between commonly administered (potentially) nephrotoxic drug groups and AKI in adult ICU patients whilst adjusting for confounding.

Methods

In this multicenter retrospective observational study, we included adult ICU admissions to 13 Dutch ICUs. We measured exposure to 44 predefined (potentially) nephrotoxic drug groups. The outcome was AKI during ICU admission. The association between each drug group and AKI was estimated using etiological cause-specific Cox proportional hazard models and adjusted for confounding. To facilitate an (independent) informed assessment of residual confounding, we manually identified drug group-specific confounders using a large drug knowledge database and existing literature.

Results

We included 92 616 ICU admissions, of which 13 492 developed AKI (15%). We found 14 drug groups to be associated with a higher hazard of AKI after adjustment for confounding. These groups included established (e.g. aminoglycosides), less well established (e.g. opioids) and controversial (e.g. sympathomimetics with α- and β-effect) drugs.

Conclusions

The results confirm existing insights and provide new ones regarding drug associated AKI in adult ICU patients. These insights warrant caution and extra monitoring when prescribing nephrotoxic drugs in the ICU and indicate which drug groups require further investigation.

Moving toward a contemporary classification of drug-induced kidney disease

Drug-induced kidney disease (DIKD) accounts for about one-fourth of all cases of acute kidney injury (AKI) in hospitalized patients, especially in critically ill setting. There is no standard definition or classification system of DIKD. To address this, a phenotype definition of DIKD using expert consensus was introduced in 2015. Recently, a novel framework for DIKD classification was proposed that incorporated functional change and tissue damage biomarkers. Medications were stratified into four categories, including "dysfunction without damage," "damage without dysfunction," "both dysfunction and damage," and "neither dysfunction nor damage" using this novel framework along with predominant mechanism(s) of nephrotoxicity for drugs and drug classes. Here, we briefly describe mechanisms and provide examples of drugs/drug classes related to the categories in the proposed framework. In addition, the possible movement of a patient's kidney disease between certain categories in specific conditions is considered. Finally, opportunities and barriers to adoption of this framework for DIKD classification in real clinical practice are discussed. This new classification system allows congruencies for DIKD with the proposed categorization of AKI, offering clarity as well as consistency for clinicians and researchers.

Retrospective evaluation of acute kidney injury in horses treated with nonnitrogenous bisphosphonates (2013-2020): 8 cases

OBJECTIVE

To describe a population of horses with acute kidney injury (AKI) following administration of bisphosphonates including clinical signs, clinicopathologic data, treatment, and outcome.

DESIGN

Retrospective study from August 2013 to July 2020.

SETTING

Veterinary university teaching hospital.

ANIMALS

Eight adult horses with AKI following administration of nonnitrogenous bisphosphonates.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Five horses received intramuscular clodronate (5/8; 62.5%) and 3 horses received intravenous tiludronate (3/8; 37.5%). Six horses (6/8; 75%) received concurrent nonsteroidal anti-inflammatory drugs. The most common initial presenting complaint was poor appetite (6/8; 75%), followed by abnormal urination (2/8; 25%). At the time of initial evaluation, the mean serum or plasma creatinine was 451.72 ± 190.06 μmol/L (5.11 ± 2.15 mg/dL) and BUN was 18.84 ± 8.85 mmol/L (52.75 ± 24.77 mg/dL). Five horses (5/6; 83.3%) had either an increased number of red blood cells (n = 4) or hemoprotein (n = 1) in the urine. All horses were treated with IV isotonic, balanced crystalloids either as a bolus, continuous rate infusion, or a combination of the 2. Seven horses (7/8; 87.5%) survived the initial episode of AKI and 1 horse (1/8; 12.5%) was euthanized. Of the 7 surviving horses, 2 horses (2/7; 28.5%) went on to develop chronic renal dysfunction. Warmblood breeds were overrepresented in the AKI group (P = 0.008; odds ratio: 11.5, 95% confidence interval: 1.8-72.1), when compared to horses that received bisphosphonates during the study period and did not develop AKI.

CONCLUSIONS

Bisphosphonate administration, with or without concurrent nonsteroidal anti-inflammatory drugs, can be associated with AKI in horses. Serum creatinine should be monitored prior to and following bisphosphonate treatment to minimize this risk. Further evaluation of renal function is warranted in horses that develop clinical signs of poor appetite, lethargy, or altered urination in the days following bisphosphonate treatment.

Geniposide ameliorates acute kidney injury via enhancing the phagocytic ability of macrophages towards neutrophil extracellular traps

Acute kidney injury (AKI) is a clinically serious disorder associated with high mortality rates and an increased risk of progression to end-stage renal disease. As an essential supportive treatment for patients with respiratory failure, mechanical ventilation not only save many critically ill patients, but also affect glomerular filtration function by changing renal hemodynamics, neurohumoral and positive end-expiratory pressure, eventually leading to AKI. AMP-activated protein kinase (AMPK), a crucial energy homeostasis regulator, could enhance macrophage phagocytic ability and inhibit inflammation, but whether it can engulf neutrophil extracellular traps (NETs) and alleviate mechanical ventilation-associated AKI is still unclear. In this study, we found that geniposide significantly ameliorated histopathological damage, reduced serum Cre and BUN levels. Besides, geniposide can also induce AMPK activation and enhance macrophage phagocytic ability toward NETs. Moreover, geniposide can markedly reduce the levels of high mobility group box 1 (HMGB1), and these effects were dependent on AMPK-PI3K/Akt signaling. Altogether, these results indicated that geniposide promoted macrophage efferocytosis by inducing AMPK-PI3K/Akt signaling activation, clearing NETs and ameliorating AKI.

Association between perioperative statin treatment and short-term clinical outcomes following transcatheter aortic valve implantation: a retrospective cohort study

BACKGROUND

Studies have found statin treatment to be associated with improved 1-year survival after transcatheter aortic valve implantation (TAVI), suggesting pleiotropic effects of statins on preventing perioperative complications. Statin treatment is not associated with postoperative cardiovascular complications or mortality; however, other postoperative complications have not been investigated.

AIM

To explore whether preoperative statin treatment is associated with a lower short-term risk of mortality, readmission and major postoperative complications in older patients undergoing TAVI.

METHODS

A retrospective cohort study including patients aged 65 years and older who had undergone a comprehensive geriatric assessment prior to TAVI between January 2014 and January 2021. The primary outcomes were 90-day mortality, 90-day readmissions and major postoperative complications according to the Clavien-Dindo classification. Multivariable logistic regression was performed with adjustment for potential confounders, namely age, gender, comorbidity, body mass index, smoking, diminished renal function, alcohol use and falls .

RESULTS

This study included 584 patients, of whom 324 (55.5%) were treated with a statin. In the statin treated group, 15 (4.6%) patients died within 90 days of TAVI compared with 10 (3.8%) patients in the non statin group (adjusted OR 1.17; 95% CI 0.51 to 2.70). The number of 90-day readmissions was 39 (12.0%) and 34 (13.1%) (adjusted OR 0.91; 95% CI 0.54 to 1.52), respectively. In the statin treated group, 115 (35.5%) patients experienced a major complication compared with 98 (37.7%) in the non-statin group (adjusted OR 0.95; 95% CI 0.67 to 1.37).

CONCLUSION

Preoperative statin treatment is not associated with improved short-term outcomes after TAVI. A randomised controlled trial with different statin doses may be warranted to investigate whether initiating statin treatment before TAVI improves both postoperative outcomes and long-term survival.

Urine-HILIC: Automated Sample Preparation for Bottom-Up Urinary Proteome Profiling in Clinical Proteomics

Urine provides a diverse source of information related to a patient's health status and is ideal for clinical proteomics due to its ease of collection. To date, most methods for the preparation of urine samples lack the throughput required to analyze large clinical cohorts. To this end, we developed a novel workflow, urine-HILIC (uHLC), based on an on-bead protein capture, clean-up, and digestion without the need for bottleneck processing steps such as protein precipitation or centrifugation. The workflow was applied to an acute kidney injury (AKI) pilot study. Urine from clinical samples and a pooled sample was subjected to automated sample preparation in a KingFisher™ Flex magnetic handling station using the novel approach based on MagReSyn® HILIC microspheres. For benchmarking, the pooled sample was also prepared using a published protocol based on an on-membrane (OM) protein capture and digestion workflow. Peptides were analyzed by LCMS in data-independent acquisition (DIA) mode using a Dionex Ultimate 3000 UPLC coupled to a Sciex 5600 mass spectrometer. The data were searched in Spectronaut™ 17. Both workflows showed similar peptide and protein identifications in the pooled sample. The uHLC workflow was easier to set up and complete, having less hands-on time than the OM method, with fewer manual processing steps. Lower peptide and protein coefficient of variation was observed in the uHLC technical replicates. Following statistical analysis, candidate protein markers were filtered, at ≥8.35-fold change in abundance, ≥2 unique peptides and ≤1% false discovery rate, and revealed 121 significant, differentially abundant proteins, some of which have known associations with kidney injury. The pilot data derived using this novel workflow provide information on the urinary proteome of patients with AKI. Further exploration in a larger cohort using this novel high-throughput method is warranted.

Future Directions in Optimizing Anesthesia to Reduce Perioperative Acute Kidney Injury

BACKGROUND

Perioperative acute kidney injury (AKI) is common in surgical patients and is associated with high morbidity and mortality. There are currently few options for AKI prevention and treatment. Due to its complex pathophysiology, there is no efficient medication therapy to stop the onset of the injury or repair the damage already done. Certain anesthetics, however, have been demonstrated to affect the risk of perioperative AKI in some studies. The impact of anesthetics on renal function is particularly important as it is closely related to the prognosis of patients. Some anesthetics can induce anti-inflammatory, anti-necrotic, and anti-apoptotic effects. Propofol, sevoflurane, and dexmedetomidine are a few examples of anesthetics that have protective association with AKI in the perioperative period.

SUMMARY

In this study, we reviewed the clinical characteristics, risk factors, and pathogenesis of AKI. Subsequently, the protective effects of various anesthetic agents against perioperative AKI and the latest research are introduced.

KEY MESSAGE

This work demonstrates that a thorough understanding of the reciprocal effects of anesthetic drugs and AKI is crucial for safe perioperative care and prognosis of patients. However, more complete mechanisms and pathophysiological processes still need to be further studied.

Early clinical indicators of acute kidney injury caused by administering high-dose methotrexate therapy to juvenile pigs

Introduction

Early identification of compromised renal clearance caused by high-dose methotrexate (HDMTX) is essential for initiating timely interventions that can reduce acute kidney injury and MTX-induced systemic toxicity.

Methods

We induced acute kidney injury (AKI) by infusing 42 juvenile pigs with 4 g/kg (80 g/m2) of MTX over 4 hours without high-volume alkalinizing hydration therapy. Concentrations of serum creatinine and MTX were measured at 15 time points up to 148 hours, with 10 samples collected during the first 24 hours after the start of the HDMTX infusion.

Results

During the first 28 hours, 81% of the pigs had increases in the concentrations of serum creatinine in one or more samples indicative of AKI (i.e., > 0.3g/dL increase). A rate of plasma MTX clearance of less than 90% during the initial 4 hours after the HDMTX infusion and a total serum creatinine increase at 6 and 8 hours after starting the infusion greater than 0.3 g/dL were predictive of AKI at 28 hours (p < 0.05 and p < 0.001, respectively). At conclusion of the infusion, pigs with a creatinine concentration more than 0.3 g/dL higher than baseline or serum MTX greater than 5,000 μmol/L had an increased risk of severe AKI.

Conclusions

Our findings suggest that serum samples collected at conclusion and shortly after HDMTX infusion can be used to predict impending AKI. The pig model can be used to identify biological, environmental, and iatrogenic risk factors for HDMTX-induced AKI and to evaluate interventions to preserve renal functions, minimize acute kidney injury, and reduce systemic toxicity.

Acute kidney injury in the critical care setting

Acute kidney injury is a sudden reduction in renal function which impairs the kidneys' ability to maintain fluid, electrolyte and acid-base balance. The syndrome often develops secondary to severe illness and is associated with a significant increase in morbidity and mortality rate in critically ill patients. This article gives an overview of the pathophysiology and aetiology of acute kidney injury, as well as the associated complications and clinical diagnostic signs. The authors also describe some common causes of the syndrome in critically ill patients, specifically sepsis, liver failure and cardiac failure, and discuss patient management in the critical care setting, with a focus on haemodynamic support and continuous renal replacement therapy.

Combining Machine Learning and Urine Oximetry: Towards an Intraoperative AKI Risk Prediction Algorithm

Acute kidney injury (AKI) affects up to 50% of cardiac surgery patients. The definition of AKI is based on changes in serum creatinine relative to a baseline measurement or a decrease in urine output. These monitoring methods lead to a delayed diagnosis. Monitoring the partial pressure of oxygen in urine (PuO2) may provide a method to assess the patient's AKI risk status dynamically. This study aimed to assess the predictive capability of two machine learning algorithms for AKI in cardiac surgery patients. One algorithm incorporated a feature derived from PuO2 monitoring, while the other algorithm solely relied on preoperative risk factors. The hypothesis was that the model incorporating PuO2 information would exhibit a higher area under the receiver operator characteristic curve (AUROC). An automated forward variable selection method was used to identify the best preoperative features. The AUROC for individual features derived from the PuO2 monitor was used to pick the single best PuO2-based feature. The AUROC for the preoperative plus PuO2 model vs. the preoperative-only model was 0.78 vs. 0.66 (p-value < 0.01). In summary, a model that includes an intraoperative PuO2 feature better predicts AKI than one that only includes preoperative patient data.

LTBP4 Protects Against Renal Fibrosis via Mitochondrial and Vascular Impacts

BACKGROUND

As a part of natural disease progression, acute kidney injury (AKI) can develop into chronic kidney disease via renal fibrosis and inflammation. LTBP4 (latent transforming growth factor beta binding protein 4) regulates transforming growth factor beta, which plays a role in renal fibrosis pathogenesis. We previously investigated the role of LTBP4 in chronic kidney disease. Here, we examined the role of LTBP4 in AKI.

METHODS

LTBP4 expression was evaluated in human renal tissues, obtained from healthy individuals and patients with AKI, using immunohistochemistry. LTBP4 was knocked down in both C57BL/6 mice and human renal proximal tubular cell line HK-2. AKI was induced in mice and HK-2 cells using ischemia-reperfusion injury and hypoxia, respectively. Mitochondrial division inhibitor 1, an inhibitor of DRP1 (dynamin-related protein 1), was used to reduce mitochondrial fragmentation. Gene and protein expression were then examined to assess inflammation and fibrosis. The results of bioenergetic studies for mitochondrial function, oxidative stress, and angiogenesis were assessed.

RESULTS

LTBP4 expression was upregulated in the renal tissues of patients with AKI. Ltbp4-knockdown mice showed increased renal tissue injury and mitochondrial fragmentation after ischemia-reperfusion injury, as well as increased inflammation, oxidative stress, and fibrosis, and decreased angiogenesis. in vitro studies using HK-2 cells revealed similar results. The energy profiles of Ltbp4-deficient mice and LTBP4-deficient HK-2 cells indicated decreased ATP production. LTBP4-deficient HK-2 cells exhibited decreased mitochondrial respiration and glycolysis. Human aortic endothelial cells and human umbilical vein endothelial cells exhibited decreased angiogenesis when treated with LTBP4-knockdown conditioned media. Mitochondrial division inhibitor 1 treatment ameliorated inflammation, oxidative stress, and fibrosis in mice and decreased inflammation and oxidative stress in HK-2 cells.

CONCLUSIONS

Our study is the first to demonstrate that LTBP4 deficiency increases AKI severity, consequently leading to chronic kidney disease. Potential therapies focusing on LTBP4-associated angiogenesis and LTBP4-regulated DRP1-dependent mitochondrial division are relevant to renal injury.

Piper nigrum Extract: Dietary Supplement for Reducing Mammary Tumor Incidence and Chemotherapy-Induced Toxicity

A low piperine fractional Piper nigrum extract (PFPE) was prepared by mixing cold-pressed coconut oil and honey in distilled water, namely, PFPE-CH. In this study, PFPE-CH was orally administered as a dietary supplement to decrease the risk of tumor formation and reduce the side effects of chemotherapeutic drugs during breast cancer treatment. The toxicity study demonstrated no mortality or adverse effects after administrating PFPE-CH at 5000 mg/kg during a 14-day observation period. Additionally, PFPE-CH at 86 mg/kg BW/day did not cause any harm to the kidney or liver function of the rats for six months. In a cancer prevention study, treatment with PFPE-CH at 100 mg/kg BW for 101 days induced oxidative stress and increased the immune response by altering the levels of cancer-associated cytokines (IL-4, IL-6, and IFN-g), leading to a reduction in the tumor incidence of up to 71.4% without any adverse effects. In combination with doxorubicin, PFPE-CH did not disrupt the anticancer effects of the drug in rats with mammary tumors. Surprisingly, PFPE-CH reduced chemotherapy-induced toxicity by improving some hematological and biochemical parameters. Therefore, our results suggest that PFPE-CH is safe and effective in reducing breast tumor incidence and toxicity of chemotherapeutic drugs during cancer treatment in mammary tumor rats.

The Potential Biotherapeutic Targets of Contrast-Induced Acute Kidney Injury

Contrast-induced acute kidney injury (CI-AKI) is manifested by an abrupt decline in kidney function as a consequence of intravascular exposure to contrast media. With the increased applicability of medical imaging and interventional procedures that utilize contrast media for clinical diagnosis, CI-AKI is becoming the leading cause of renal dysfunction. The pathophysiological mechanism associated with CI-AKI involves renal medullary hypoxia, the direct toxicity of contrast agents, oxidative stress, apoptosis, inflammation, and epigenetic regulation. To date, there is no effective therapy for CI-AKI, except for the development of strategies that could reduce the toxicity profiles of contrast media. While most of these strategies have failed, evidence has shown that the proper use of personalized hydration, contrast medium, and high-dose statins may reduce the occurrence of CI-AKI. However, adequate risk predication and attempts to develop preventive strategies can be considered as the key determinants that can help eliminate CI-AKI. Additionally, a deeper understanding of the pathophysiological mechanism of CI-AKI is crucial to uncover molecular targets for the prevention of CI-AKI. This review has taken a step further to solidify the current known molecular mechanisms of CI-AKI and elaborate the biomarkers that are used to detect early-stage CI-AKI. On this foundation, this review will analyze the molecular targets relating to apoptosis, inflammation, oxidative stress, and epigenetics, and, thus, provide a strong rationale for therapeutic intervention in the prevention of CI-AKI.

Mortality, Intensive Care Unit Admission, and Intubation among Hospitalized Patients with COVID-19: A One-Year Retrospective Study in Jordan

COVID-19 is a public health crisis that has caused numerous deaths, necessitated an increased number of hospital admissions, and led to extended inpatient stays. This study aimed to identify the factors associated with COVID-19 mortality, intensive care unit admission, intubation, and length of hospital stay among Jordanian patients. This was a one-year retrospective study of 745 COVID-19 patients admitted to Jordan University Hospital. Data regarding the patients’ demographics, clinical and co-morbid conditions, imaging, laboratory parameters, mortality, intensive care unit admission (ICU), and intubation were collected from their medical records using a coding manual. The data revealed that the overall rates of COVID-19-related mortality, ICU admission, and invasive intubation were 23.0%, 28.3%, and 10.8%, respectively. Chronic kidney disease (CKD), troponin, lactate dehydrogenase (LDH), and O2 saturation <90% were significantly associated with the mortality rate. The variables that were significantly associated with ICU admission were heart failure and the use of remdesivir. However, O2 saturation <90% and gastrointestinal (GI) symptoms were the only variables associated with invasive intubation. The findings of this study suggest that study-related health outcomes can be used to predict the severity of COVID-19, and they can inform future research aiming to identify specific populations who are at a higher risk of COVID-19 complications.

Interventions, Barriers, and Proposed Solutions Associated With the Implementation of a Protocol That Uses Clinical Decision Support and a Stress Biomarker Test to Identify ICU Patients at High-Risk for Drug Associated Acute Kidney Injury

BACKGROUND

Damage biomarkers are helpful in early identification of patients who are at risk of developing acute kidney injury (AKI). Investigations are ongoing to identify the optimal role of stress/damage biomarkers in clinical practice regarding AKI risk prediction, surveillance, diagnosis, and prognosis.

OBJECTIVE

To determine the impact of utilizing a clinical decision support system (CDSS) to guide stress biomarker testing in intensive care unit (ICU) patients at risk for drug-induced acute kidney injury (D-AKI).

METHODS

A protocol was designed utilizing a clinical decision support system (CDSS) alert to identify patients that were ordered 3 or more potentially nephrotoxic medications, suggesting risk for progressing to AKI from nephrotoxic burden. Once alerted to these high-risk patients, the pharmacist determined if action was needed by ordering a stress biomarker test, tissue inhibitor of metalloproteinase-2-insulin-like growth factor-binding protein 7 (TIMP-2•IGFBP7). If the biomarker test result was elevated, the pharmacist provided nephrotoxin stewardship recommendations to the team. Pharmacists recorded the response to the clinical decision support alert, ordering, and interpreting the TIMP-2•IGFBP7, and information regarding clinical interventions. An alert in conjunction with TIMP-2•IGFBP7 as a strategy for AKI risk prediction and stimulant for patient care management was assessed. In addition, barriers and solutions to protocol implementation were evaluated.

RESULTS

There were 394 total activities recorded by pharmacists for 345 unique patients. Ninety-three (93/394; 23.6%) actionable alerts resulted in a TIMP-2•IGFBP7 test being ordered. Thirty-one TIMP-2•IGFBP7 results were >0.3 (31/81; 38.3%), suggesting a high-risk of progression to AKI, which prompted 191 pharmacist/team interventions. On average, there were 1.64 interventions per patient in the low-risk patients, 3.43 in high-risk patients, and 3.75 in the highest-risk patients.

CONCLUSION AND RELEVANCE

Stress biomarkers can be used in conjunction with CDSS alerts to affect therapeutic decisions in ICU patients at high-risk for D-AKI.

Microvascular dysfunction following cardiopulmonary bypass plays a central role in postoperative organ dysfunction

Despite significant advances in surgical technique and strategies for tissue/organ protection, cardiac surgery involving cardiopulmonary bypass is a profound stressor on the human body and is associated with numerous intraoperative and postoperative collateral effects across different tissues and organ systems. Of note, cardiopulmonary bypass has been shown to induce significant alterations in microvascular reactivity. This involves altered myogenic tone, altered microvascular responsiveness to many endogenous vasoactive agonists, and generalized endothelial dysfunction across multiple vascular beds. This review begins with a survey of in vitro studies that examine the cellular mechanisms of microvascular dysfunction following cardiac surgery involving cardiopulmonary bypass, with a focus on endothelial activation, weakened barrier integrity, altered cell surface receptor expression, and changes in the balance between vasoconstrictive and vasodilatory mediators. Microvascular dysfunction in turn influences postoperative organ dysfunction in complex, poorly understood ways. Hence the second part of this review will highlight in vivo studies examining the effects of cardiac surgery on critical organ systems, notably the heart, brain, renal system, and skin/peripheral tissue vasculature. Clinical implications and possible areas for intervention will be discussed throughout the review.

Clinical and subclinical acute kidney injury in children with mild-to-moderate COVID-19

BACKGROUND

Our aim was to identify acute kidney injury (AKI) and subacute kidney injury using both KDIGO criteria and urinary biomarkers in children with mild/moderate COVID-19.

METHODS

This cross-sectional study included 71 children who were hospitalized with a diagnosis of COVID-19 from 3 centers in Istanbul and 75 healthy children. We used a combination of functional (serum creatinine) and damage (NGAL, KIM-1, and IL-18) markers for the definition of AKI and subclinical AKI. Clinical and laboratory features were evaluated as predictors of AKI and subclinical AKI.

RESULTS

Patients had significantly higher levels of urinary biomarkers and urine albumin-creatinine ratio than healthy controls (p < 0.001). Twelve patients (16.9%) developed AKI based on KDIGO criteria, and 22 patients (31%) had subclinical AKI. AKI group had significantly higher values of neutrophil count on admission than both subclinical AKI and non-AKI groups (p < 0.05 for all). Neutrophil count was independently associated with the presence of AKI (p = 0.014).

CONCLUSIONS

This study reveals that even children with a mild or moderate disease course are at risk for AKI. Association between neutrophil count and AKI may point out the role of inflammation in the development of AKI.

IMPACT

The key message of our article is that not only children with severe disease but also children with mild or moderate disease have an increased risk for kidney injury due to COVID-19. Urinary biomarkers enable the diagnosis of a significant number of patients with subclinical AKI in patients without elevation in serum creatinine. Our findings reveal that patients with high neutrophil count may be more prone to develop AKI and should be followed up carefully. We conclude that even children with mild or moderate COVID-19 disease courses should be evaluated for AKI and subclinical AKI, which may improve patient outcomes.

The impact of urine flow on urine oxygen partial pressure monitoring during cardiac surgery

PURPOSE

Urine oxygen partial pressure (PuO₂) may be useful for assessing acute kidney injury (AKI) risk. The primary purpose of this study was to quantify the ability of a novel urinary oxygen monitoring system to make real-time PuO₂ measurements intraoperatively which depends on adequate urine flow. We hypothesized that PuO₂ data could be acquired with enough temporal resolution to provide real-time information in both AKI and non-AKI patients.

METHODS

PuO₂ and urine flow were analyzed in 86 cardiac surgery patients. PuO₂ data associated with low (< 0.5 ml/kg/hr) or retrograde urine flow were discarded. Patients were excluded if > 70% of their data were discarded during the respective periods, i.e., during cardiopulmonary bypass (CPB), before CPB (pre-CPB), and after CPB (post-CPB). The length of intervals of discarded data were recorded for each patient. The median length of intervals of discarded data were compared between AKI and non-AKI patients and between surgical periods.

RESULTS

There were more valid PuO₂ data in CPB and post-CPB periods compared to the pre-CPB period (81% and 90% vs. 31% of patients included, respectively; p < 0.001 and p < 0.001). Most intervals of discarded data were < 3 minutes during CPB (96%) and post-CPB (98%). The median length was < 25 s during all periods and there was no significant difference in the group median length of discarded data intervals for AKI and non-AKI patients.

CONCLUSIONS

PuO₂ measurements were acquired with enough temporal resolution to demonstrate real-time PuO₂ monitoring during CPB and the post-CPB period.

CLINICALTRIALS

GOV IDENTIFIER

NCT03335865, First Posted Date: Nov. 8th, 2017.

Relationship between piperacillin concentrations, clinical factors and piperacillin/tazobactam-associated acute kidney injury

BACKGROUND

Piperacillin/tazobactam, a commonly used antibiotic, is associated with acute kidney injury (AKI). The relationship between piperacillin concentrations and AKI remains unknown.

OBJECTIVE

Estimate piperacillin exposures in critically ill children and young adults administered piperacillin/tazobactam to identify concentrations and clinical factors associated with piperacillin-associated AKI.

PATIENTS AND METHODS

We assessed piperacillin pharmacokinetics in 107 patients admitted to the paediatric ICU who received at least one dose of piperacillin/tazobactam. Piperacillin AUC, highest peak (Cmax) and highest trough (Cmin) in the first 24 hours of therapy were estimated. Piperacillin-associated AKI was defined as Kidney Disease: Improving Global Outcomes (KDIGO) Stage 2/3 AKI present >24 hours after initial piperacillin/tazobactam dose. Likelihood of piperacillin-associated AKI was rated using the Naranjo Adverse Drug Reaction Probability Scale. Multivariable logistic regression was performed to identify patient and clinical predictors of piperacillin-associated AKI.

RESULTS

Out of 107 patients, 16 (15%) were rated as possibly or probably having piperacillin-associated AKI. Estimated AUC and highest Cmin in the first 24 hours were higher in patients with piperacillin-associated AKI (2042 versus 1445 mg*h/L, P = 0.03; 50.1 versus 10.7 mg/L, P < 0.001). Logistic regression showed predictors of piperacillin-associated AKI included higher Cmin (OR: 5.4, 95% CI: 1.7-23) and age (OR: 1.13, 95% CI: 1.05-1.25).

CONCLUSIONS

We show a relationship between estimated piperacillin AUC and highest Cmin in the first 24 hours of piperacillin/tazobactam therapy and piperacillin-associated AKI, suggesting total piperacillin exposure early in the course is associated with AKI development. These data could serve as the foundation for implementation of model-informed precision dosing to reduce AKI incidence in patients given piperacillin/tazobactam.

Noninvasively differentiating acute and chronic nephropathies via multiparametric urea-CEST, nuclear Overhauser enhancement-CEST, and quantitative magnetization transfer MRI

PURPOSE

Standardized blood tests often lack adequate sensitivity and specificity to capture the gradual progression of renal injuries. We suggest a multiparametric molecular MRI approach as a noninvasive tool for monitoring renal function loss and distinguishing different types of renal injuries.

METHODS

CEST and quantitative magnetization transfer (qMT) imaging were performed on cisplatin (n = 16) and aristolochic acid (AA)-induced nephropathy (n = 22) mouse models at 7T with an infusion of either saline or urea. Seven-pool Lorentzian fitting was applied for the analysis of CEST Z-spectra, and the T1 -corrected CEST contrast apparent exchange-dependent relaxation (AREX) from urea (+1 ppm) and two nuclear Overhauser enhancement (NOE) pools (-1.6 and -3.5 ppm) were measured. Similarly, qMT spectra were fitted into two-pool Ramani equation and the relative semi-solid macromolecular pool-size ratio was measured. Histology of mouse kidneys was performed to validate the MR findings.

RESULTS

AA model showed disrupted spatial gradients of urea in the kidney and significantly decreased NOE CEST and qMT contrast. The cisplatin model showed slightly decreased qMT contrast only. The orrelation of MR parameters to histological features showed that NOE CEST and qMT imaging are sensitive to both acute and chronic injuries, whereas urea CEST shows a significant correlation only to acute injuries.

CONCLUSION

These results indicate that our multiparametric approach allows comprehensive and totally noninvasive monitoring of renal function and histological changes for distinguishing different nephropathies.

Autophagy and necroptosis in cisplatin-induced acute kidney injury: Recent advances regarding their role and therapeutic potential

Cisplatin (CP) is a broad-spectrum antineoplastic agent, used to treat many different types of malignancies due to its high efficacy and low cost. However, its use is largely limited by acute kidney injury (AKI), which, if left untreated, may progress to cause irreversible chronic renal dysfunction. Despite substantial research, the exact mechanisms of CP-induced AKI are still so far unclear and effective therapies are lacking and desperately needed. In recent years, necroptosis, a novel subtype of regulated necrosis, and autophagy, a form of homeostatic housekeeping mechanism have witnessed a burgeoning interest owing to their potential to regulate and alleviate CP-induced AKI. In this review, we elucidate in detail the molecular mechanisms and potential roles of both autophagy and necroptosis in CP-induced AKI. We also explore the potential of targeting these pathways to overcome CP-induced AKI according to recent advances.

Prediction of acute kidney injury after total aortic arch replacement with serum cystatin C and urine N-acetyl-β-d-glucosaminidase: A prospective observational study

BACKGROUND

Acute kidney injury (AKI) after total aortic arch replacement (TAAR) is frequent and associated with adverse outcomes, whereas its early detection remains a challenge. Serum cystatin C (sCysC) and urinary N-acetyl-β-d-glucosaminidase (uNAG) are clinically available renal biomarkers, but their combination for AKI detection requires more evidence. This study aimed to assess the discriminative abilities of these biomarkers in AKI after TAAR.

MATERIALS AND METHODS

Patients undergoing TAAR were included in this prospective observational study. The AKI prediction model was developed and internal verificated, and the significance of each variable was analyzed by random forest (RF). Finally, the best predictive critical values of sCysC and uNAG were explored by the AUC-ROC curve.

RESULTS

The AUC-ROC of the prediction model was substantially enhanced by adding sCysC and uNAG (0.909 vs 0.844, p < 0.001), and the clinical utility and risk reclassification were significantly improved. Additionally, the RF showed that sCysC and uNAG ranked first and second. The AUC-ROC for each were 0.864 and 0.802 respectively, and the cut-off values were 1.395 mg/L and 31.90 U/g Cre respectively.

CONCLUSION

The prediction model incorporating functional marker sCysC and tubular injury marker uNAG can improve the discriminative abilities of AKI after TAAR.

How to interpret serum creatinine increases during decongestion

During decongestion in acute decompensated heart failure (ADHF), it is common to observe elevations in serum creatinine (sCr) values due to vascular congestion, a mechanism that involves increased central venous pressure that has a negative impact on the nephron, promoting greater absorption of water and sodium, increased interstitial pressure in an encapsulated organ developing "renal tamponade" which is one of main physiopathological mechanism associated with impaired kidney function. For the treatment of this syndrome, it is recommended to use diuretics that generate a high urinary output and natriuresis to decongest the venous system, during this process the sCr values can rise, a phenomenon that may bother some cardiologist and nephrologist, since raise the suspicion of kidney damage that could worsen the prognosis of these patients. It is recommended that increases of up to 0.5 mg/dL from baseline are acceptable, but some patients have higher increases, and we believe that an arbitrary number would be impractical for everyone. These increases in sCr may be related to changes in glomerular hemodynamics and true hypovolemia associated with decongestion, but it is unlikely that they are due to structural injury or truly hypoperfusion and may even have a positive connotation if accompanied by an effective decongestion and be associated with a better prognosis in the medium to long term with fewer major cardiovascular and renal events. In this review, we give a comprehensive point of view on the interpretation of creatinine elevation during decongestion in patients with ADHF.

Single value of NephroCheck™ performed at 4 hours after surgery does not predict acute kidney injury in off-pump coronary artery bypass surgery

Background

Quantification of urinary tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding protein (IFGBP-7), which is commercially known as NephroCheck™(NC) test have been suggested as promising tools for the early detection of acute kidney injury (AKI) after cardiac surgery involving cardio-pulmonary bypass (CPB).

Objectives

The aim of the present study was to test the hypothesis that single value of postoperative NC test performed at 4 hours after surgery can predict AKI in off-pump coronary artery bypass grafting (OPCABG) surgery.

Setting and Design

This prospective single-center study was conducted at the tertiary cardiac center in India from December 2017 to November 2018.

Methods

Ninety adult patients of both sex undergoing elective OPCABG were included. Anesthesia was standardized to all patients. Urine samples were collected preoperatively and at 4 hours after surgery for NC test. Urine output, serum creatinine, estimated glomerular filtration rate (eGFR) were also measured. AKI staging was based on kidney disease improving global outcomes (KDIGO) guidelines.

Statistical Analysis

To assess the predictability of NC test for the primary endpoint, area under the receiver operating characteristic curve (ROC), was calculated.

Results

Thirteen patients developed AKI in the study cohort (14.4%) out of which 7 patients (7.8%) developed stage 2/3 AKI and the remaining stage 1 AKI. Baseline renal parameters were similar between AKI and non-AKI group. The area under curve (AUC) of NC test at 4 hours after surgery was 0.60 [95% confidence interval (CI): 0.42-0.77]. Postoperative NC test performed at 4 hours after surgery did not predict AKI in this study population (P = 0.24). There were no significant differences in duration of mechanical ventilation, length of intensive care stay and hospital stay between the two groups (P > 0.05).

Conclusion

NephroCheck^™ test performed at 4 hours after surgery did not identify patients at risk for developing AKI following OPCABG surgery.

Long-term outcomes in patients who received veno-venous extracorporeal membrane oxygenation and renal replacement therapy: a retrospective cohort study

Background

Acute kidney injury (AKI) is a frequent complication in patients with severe respiratory failure receiving extracorporeal membrane oxygenation (ECMO). However, little is known of long-term kidney function in ECMO survivors. We aimed to assess the long-term mortality and kidney outcomes in adult patients treated with veno-venous ECMO (VV-ECMO).

Methods

This was a single-centre retrospective study of adult patients (≥ 18 years old) who were treated with VV-ECMO at a commissioned ECMO centre in the UK between 1st September 2010, and 30th November 2016. AKI was defined and staged using the serum creatinine and urine output criteria of the Kidney Diseases: Improving Global Outcomes (KDIGO) classification. The primary outcome was 1-year mortality. Secondary outcomes were long-term mortality (up to March 2020), 1-year incidence of end-stage kidney disease (ESKD) or chronic kidney disease (CKD) among AKI patients who received renal replacement therapy (AKI-RRT), AKI patients who did not receive RRT (AKI-no RRT) and patients without AKI (non-AKI).

Results

A total of 300 patients [57% male; median age 44.5; interquartile range (IQR) 34–54] were included in the final analysis. Past medical histories included diabetes (12%), hypertension (17%), and CKD (2.3%). The main cause of severe respiratory failure was pulmonary infection (72%). AKI occurred in 230 patients (76.7%) and 59.3% received renal replacement therapy (RRT). One-year mortality was 32% in AKI-RRT patients vs. 21.4% in non-AKI patients (p = 0.014). The median follow-up time was 4.35 years. Patients who received RRT had a higher risk of 1-year mortality than those who did not receive RRT (adjusted HR 1.80, 95% CI 1.06, 3.06; p = 0.029). ESKD occurred in 3 patients, all of whom were in the AKI-RRT group. At 1-year, 41.2% of survivors had serum creatinine results available. Among these, CKD was prevalent in 33.3% of AKI-RRT patients vs. 4.3% in non-AKI patients (p = 0.004).

Conclusions

VV-EMCO patients with AKI-RRT had high long-term mortality. Monitoring of kidney function after hospital discharge was poor. In patients with follow-up creatinine results available, the CKD prevalence was high at 1 year, especially in AKI-RRT patients. More awareness about this serious long-term complication and appropriate follow-up interventions are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01046-0.

Acute kidney injury in critical COVID-19: a multicenter cohort analysis in seven large hospitals in Belgium

Background

Acute kidney injury (AKI) has been reported as a frequent complication of critical COVID-19. We aimed to evaluate the occurrence of AKI and use of kidney replacement therapy (KRT) in critical COVID-19, to assess patient and kidney outcomes and risk factors for AKI and differences in outcome when the diagnosis of AKI is based on urine output (UO) or on serum creatinine (sCr).

Methods

Multicenter, retrospective cohort analysis of patients with critical COVID-19 in seven large hospitals in Belgium. AKI was defined according to KDIGO within 21 days after ICU admission. Multivariable logistic regression analysis was used to explore the risk factors for developing AKI and to assess the association between AKI and ICU mortality.

Results

Of 1286 patients, 85.1% had AKI, and KRT was used in 9.8%. Older age, obesity, a higher APACHE II score and use of mechanical ventilation at day 1 of ICU stay were associated with an increased risk for AKI. After multivariable adjustment, all AKI stages were associated with ICU mortality. AKI was based on sCr in 40.1% and UO in 81.5% of patients. All AKI stages based on sCr and AKI stage 3 based on UO were associated with ICU mortality. Persistent AKI was present in 88.6% and acute kidney disease (AKD) in 87.6%. Rapid reversal of AKI yielded a better prognosis compared to persistent AKI and AKD. Kidney recovery was observed in 47.4% of surviving AKI patients.

Conclusions

Over 80% of critically ill COVID-19 patients had AKI. This was driven by the high occurrence rate of AKI defined by UO criteria. All AKI stages were associated with mortality (NCT04997915).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04086-x.

Subphenotypes of acute kidney injury in adults

PURPOSE OF REVIEW

Acute kidney injury is a heterogeneous syndrome and as such is associated with multiple predisposing conditions and causes all of which affect outcomes. Such heterogeneity may conceal the potential benefit of therapies when generally applied to patients with acute kidney injury (AKI). The discovery of pathophysiology-based subphenotypes could be of benefit in allocating current and future therapies to specific groups.

RECENT FINDINGS

Clinical subphenotypes group patients into categories according to predisposing factors, disease severity, and trajectory. These may be helpful in assessing patient outcomes. Analyses of existing databases have revealed biological subphenotypes that are characterized by levels of biomarkers indicative of hyperinflammation and endothelial injury. Patients with increased levels of these biomarkers display higher mortality rates compared with those with lower levels and there is potential that this group might respond differently to therapies. However, challenges remain in the validation, generalizability, and application of these subphenotypes.

SUMMARY

Subphenotyping may help reduce heterogeneity under the umbrella term of acute kidney injury. Despite challenges remain, the identification of AKI subphenotypes has opened the potential of AKI research focused on better targeted therapies.

Diagnosis, severity stratification and management of adult acute pancreatitis–current evidence and controversies

Acute pancreatitis (AP) is a disease spectrum ranging from mild to severe with an unpredictable natural course. Majority of cases (80%) are mild and self-limiting. However, severe AP (SAP) has a mortality risk of up to 30%. Establishing aetiology and risk stratification are essential pillars of clinical care. Idiopathic AP is a diagnosis of exclusion which should only be used after extended investigations fail to identify a cause. Tenets of management of mild AP include pain control and management of aetiology to prevent recurrence. In SAP, patients should be resuscitated with goal-directed fluid therapy using crystalloids and admitted to critical care unit. Routine prophylactic antibiotics have limited clinical benefit and should not be given in SAP. Patients able to tolerate oral intake should be given early enteral nutrition rather than nil by mouth or parenteral nutrition. If unable to tolerate per-orally, nasogastric feeding may be attempted and routine post-pyloric feeding has limited evidence of clinical benefit. Endoscopic retrograde cholangiopancreatogram should be selectively performed in patients with biliary obstruction or suspicion of acute cholangitis. Delayed step-up strategy including percutaneous retroperitoneal drainage, endoscopic debridement, or minimal-access necrosectomy are sufficient in most SAP patients. Patients should be monitored for diabetes mellitus and pseudocyst.

Alterations in the Kynurenine-Tryptophan Pathway and Lipid Dysregulation Are Preserved Features of COVID-19 in Hemodialysis

Coronavirus disease 2019 (COVID-19)-induced metabolic alterations have been proposed as a source for prognostic biomarkers and may harbor potential for therapeutic exploitation. However, the metabolic impact of COVID-19 in hemodialysis (HD), a setting of profound a priori alterations, remains unstudied. To evaluate potential COVID-19 biomarkers in end-stage kidney disease (CKD G5), we analyzed the plasma metabolites in different COVID-19 stages in patients with or without HD. We recruited 18 and 9 asymptomatic and mild, 11 and 11 moderate, 2 and 13 severely affected, and 10 and 6 uninfected HD and non-HD patients, respectively. Plasma samples were taken at the time of diagnosis and/or upon admission to the hospital and analyzed by targeted metabolomics and cytokine/chemokine profiling. Targeted metabolomics confirmed stage-dependent alterations of the metabolome in non-HD patients with COVID-19, which were less pronounced in HD patients. Elevated kynurenine levels and lipid dysregulation, shown by an increase in circulating free fatty acids and a decrease in lysophospholipids, could distinguish patients with moderate COVID-19 from non-infected individuals in both groups. Kynurenine and lipid alterations were also associated with ICAM-1 and IL-15 levels in HD and non-HD patients. Our findings support the kynurenine pathway and plasma lipids as universal biomarkers of moderate and severe COVID-19 independent of kidney function.

The effect of preeclampsia on adverse maternal outcomes in Sidama region, Ethiopia: a prospective open cohort study

Ethiopia has made improvements in the reduction of maternal mortality; the high burden of preeclampsia remains a concern in the Sidama region. This study aimed to measure the effect of preeclampsia on adverse maternal outcomes and identify risk factors among women with preeclampsia in Sidama region. A prospective open cohort study was conducted from August 8, 2019, to October 1, 2020. We enrolled a total of 1015 the pregnant women who had preeclampsia and normotensive women at ≥ 20 weeks of gestation and followed them until 42 days after delivery. A log-binomial logistic regression model was used to estimate the incidence of adverse maternal outcomes and its risk factors. There were 276 adverse maternal outcomes observed in the preeclampsia group compared to 154 adverse maternal outcomes in the normotensive group (P < 0.001). Women with severe features of preeclampsia had a 43% (aRR = 1.43, 95% CI 1.3-1.58) higher risk for adverse maternal outcomes compared to women without severe features of preeclampsia. Women without severe features of preeclampsia had a 39% (aRR = 1.39, 95% CI 1.2-1.76) higher risk for adverse maternal outcomes compared to women in the normotensive group. More adverse maternal outcomes occurred among women with preeclampsia after controlling for confounders.

Fluid management in acute kidney injury: from evaluating fluid responsiveness towards assessment of fluid tolerance

Despite the widespread use of intravenous fluids in acute kidney injury (AKI), solid evidence is lacking. Intravenous fluids mainly improve AKI due to true hypovolaemia, which is difficult to discern at the bedside unless it is very pronounced. Empiric fluid resuscitation triggered only by elevated serum creatinine levels or oliguria is frequently misguided, especially in the presence of fluid intolerance syndromes such as increased extravascular lung water, capillary leak, intra-abdominal hypertension, and systemic venous congestion. While fluid responsiveness tests clearly identify patients who will not benefit from fluid administration (i.e. those without an increase in cardiac output), the presence of fluid responsiveness does not guarantee that fluid therapy is indicated or even safe. This review calls for more attention to the concept of fluid tolerance, incorporating it into a practical algorithm with systematic venous Doppler ultrasonography assessment to use at the bedside, thereby lowering the risk of detrimental kidney congestion in AKI.

Postoperative Blood Pressure Deficit and Acute Kidney Injury After Liver Transplant

OBJECTIVES

Acute kidney injury is a common cause of morbidity in liver transplant recipients. In critically ill patients who received an orthotopic liver transplant, we examined whether those with acute kidney injury had a greater deficit between pretransplant and posttransplant hemodynamic pressure-related parameters compared with those without acute kidney injury in the early postoperative period.

MATERIALS AND METHODS

We included patients who underwent an orthotopic liver transplant during the study period. We obtained premorbid and intensive care unit time-weighted average values for hemodynamic pressure-related parameters (systolic, diastolic, and mean arterial pressure; central venous pressure; mean perfusion pressure; and diastolic perfusion pressure) and calculated deficits in those values. We defined acute kidney injury progression as an increase of ≥1 Kidney Disease: Improving Global Outcomes stage.

RESULTS

We included 150 eligible transplantrecipients, with 88 (59%) having acute kidney injury progression. Acute kidney injury was associated with worse clinical outcomes. All achieved pressure-related values were similar between transplant recipients with or without acute kidney injury progression. However, those with acute kidney injury versus those without progression had greater diastolic perfusion pressure deficit at 12 hours (-8.33% vs 1.93%; P = .037) and 24 hours (-7.38% vs 5.11%; P = .002) and increased central venous pressure at 24 hours (46.13% vs 15%; P = .043) and 48 hours (40% vs 20.87%; P = .039).

CONCLUSIONS

Patients with acute kidney injury progression had a greater diastolic perfusion pressure deficit and increased central venous pressure compared with patients without progression. Such deficits might be modifiable risk factors for the prevention of acute kidney injury progression.

Necrotizing Fasciitis Presenting as Generalized Weakness, Malaise, and Acute Kidney Injury

Necrotizing fasciitis (NF) is a surgical emergency that must be diagnosed promptly in order to avoid serious consequences or death. Additionally, symptoms of this condition are similar to less severe skin and soft tissue infections such as cellulitis or erysipelas and can be easily confused. In this case, the patient presented to the emergency department with systemic symptoms, notably malaise and generalized weakness. A cutaneous complaint, a "labial cyst", was only elicited after more specific questioning. Laboratory investigations revealed abnormal renal function tests (RFTs), suggestive of an acute kidney injury. An abdominal/pelvic computed tomography (CT) showed gas in the subcutaneous tissue. These findings led to clinical suspicion of NF, prompting a general surgery consultation. The surgeon proceeded to perform extensive debridement following the discovery of necrotic tissue. The prompt diagnosis and treatment of this condition resulted in patient survival and expected recovery. It is, therefore, critical to keep this condition in mind when diagnosing apparent skin and soft tissue infections presenting with abnormal RFTs due to the possibility of rapid decline and death if the NF is left untreated. Additionally, this is a case of less frequent Fournier's gangrene in a non-diabetic female. Finally, it underlines the importance of eliciting additional symptoms, even those that may seem unrelated, or less concerning, to the patient's initial complaint.

Noninvasive and Invasive Renal Hypoxia Monitoring in a Porcine Model of Hemorrhagic Shock

Up to 50% of patients with trauma develop acute kidney injury (AKI), in part due to poor renal perfusion after severe blood loss. AKI is currently diagnosed based on a change in serum creatinine concentration from baseline or prolonged periods of decreased urine output. Unfortunately, baseline serum creatinine concentration data is unavailable in most patients with trauma, and current estimation methods are inaccurate. In addition, serum creatinine concentration may not change until 24-48 h after the injury. Lastly, oliguria must persist for a minimum of 6 h to diagnose AKI, making it impractical for early diagnosis. AKI diagnostic approaches available today are not useful for predicting risk during the resuscitation of patients with trauma. Studies suggest that urinary partial pressure of oxygen (PuO2) may be useful for assessing renal hypoxia. A monitor that connects the urinary catheter and the urine collection bag was developed to measure PuO2 noninvasively. The device incorporates an optical oxygen sensor that estimates PuO2 based on luminescence quenching principles. In addition, the device measures urinary flow and temperature, the latter to adjust for confounding effects of temperature changes. Urinary flow is measured to compensate for the effects of oxygen ingress during periods of low urine flow. This article describes a porcine model of hemorrhagic shock to study the relationship between noninvasive PuO2, renal hypoxia, and AKI development. A key element of the model is the ultrasound-guided surgical placement in the renal medulla of an oxygen probe, which is based on an unsheathed optical microfiber. PuO2 will also be measured in the bladder and compared to the kidney and noninvasive PuO2 measurements. This model can be used to test PuO2 as an early marker of AKI and assess PuO2 as a resuscitative endpoint after hemorrhage that is indicative of end-organ rather than systemic oxygenation.

Postoperative serum myoglobin as a predictor of early allograft dysfunction after liver transplantation

Background

Early allograft dysfunction (EAD) is a common postliver transplant complication that has been associated with graft failure and risk for poor prognosis. There are many risk factors for the incidence of EAD after liver transplantation (LT). This study investigated whether elevated postoperative myoglobin (Mb) increases the incidence of EAD in liver transplanted recipients.

Methods

A total of 150 adult recipients who measured Mb within 3 days after liver transplantation between June 2019 and June 2021 were evaluated. Then, all patients were divided into two groups: the EAD group and the non-EAD group. Univariate and multivariate logistic regression analyses were performed, and receiver operating characteristic curves (ROCs) were constructed.

Results

The incidence of EAD was 53 out of 150 patients (35.3%) in our study. Based on the multivariate logistic analysis, the risk of EAD increased with elevated postoperative Mb (OR = 1.001, 95% CI 1.000–1.001, P = 0.002). The Mb AUC was 0.657, and it was 0.695 when combined with PCT. When the subgroup analysis was conducted, the AUC of serum Mb prediction was better in patients whose preoperative model for end-stage liver disease score  ≤ 15 or operative time ≥ 10 h (AUC = 0.751, 0.758, respectively, or 0.760, 0.800 when combined with PCT).

Conclusion

Elevated Mb significantly increased the risk of postoperative EAD, suggesting that postoperative Mb may be a novel predictor of EAD after liver transplantation.

The study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2100044257, URL: http://www.chictr.org.cn).

Vancomycin Loading Doses and Nephrotoxicity on Medicine Teaching Services

Background

Infectious Disease Society of America (IDSA) guidelines recommend the usage of a loading dose when using vancomycin for seriously ill patients. While the relationship between vancomycin and nephrotoxicity is the focus of many studies, few studies have examined the relationship between vancomycin loading doses and nephrotoxicity.

Methods

We performed a retrospective cohort study examining vancomycin dosing for internal medicine teaching services' patients over the 2014-15 academic year at one academic medical center. We generated a list of all hospitalized patients aged 18-85 who received vancomycin and were admitted to a teaching service. Nephrotoxicity was determined by 7-day acute kidney injury (AKI) rate. Patients in the loading dose cohort were compared with those in the standard-dose cohort. Primary modeling used multivariable logistic regression with AKI as our outcome of interest.

Results

Four hundred and thirty-eight patients were included for analysis. The loading dose (n = 365, 83%) and standard dosing (n = 73, 17%) cohorts were not significantly different regarding demographics, GFR, nephrotoxic drug exposure, total vancomycin received, trough levels, or comorbidities and were only significantly different regarding body mass index (BMI). The 7-day AKI rate was not significantly different between the two arms (6.3% in the standard dosing arm and 8.2% in the loading dose arm, p = 0.6).

Conclusion

Few studies have examined the relationship between nephrotoxicity and vancomycin loading doses. The results of this study provide evidence that the use of loading doses is not significantly associated with increased 7-day AKI rate.

ISCCM Guidelines on Acute Kidney Injury and Renal Replacement Therapy

Acute kidney injury (AKI) is a complex syndrome with a high incidence and considerable morbidity in critically ill patients. Renal replacement therapy (RRT) remains the mainstay of treatment for AKI. There are at present multiple disparities in uniform definition, diagnosis, and prevention of AKI and timing of initiation, mode, optimal dose, and discontinuation of RRT that need to be addressed. The Indian Society of Critical Care Medicine (ISCCM) AKI and RRT guidelines aim to address the clinical issues pertaining to AKI and practices to be followed for RRT, which will aid the clinicians in their day-to-day management of ICU patients with AKI.

How to cite this article

Mishra RC, Sodhi K, Prakash KC, Tyagi N, Chanchalani G, Annigeri RA, et al. ISCCM Guidelines on Acute Kidney Injury and Renal Replacement Therapy. Indian J Crit Care Med 2022;26(S2):S13-S42.