Reduction in Nephrotoxic Antimicrobial Exposure Decreases Associated Acute Kidney Injury in Pediatric Hematopoietic Stem Cell Transplant Patients

Cystatin C Outperforms Creatinine in Predicting Cefepime Clearance in Pediatric Stem Cell Transplant Recipients

Pediatric hematopoietic stem cell transplant (HSCT) patients are at risk of developing both sepsis and altered kidney function. Cefepime is used for empiric coverage post-HSCT and requires dose adjustment based on kidney function. Since cefepime's antimicrobial efficacy is determined by the time free concentrations exceed bacterial minimum inhibitory concentration (MIC), it is important to assess kidney function accurately to ensure adequate concentrations. Serum creatinine (SCr) is routinely used to estimate glomerular filtration rate (eGFR) but varies with muscle mass, which can be significantly lower in HSCT patients, making SCr an inaccurate kidney function biomarker. Cystatin C (CysC) eGFR is independent of muscle mass, though steroid use increases CysC. Objectives of this study were to describe how eGFR impacts cefepime pharmacokinetic/pharmacodynamic (PK/PD) target attainment in pediatric HSCT patients, to investigate which method of estimating GFR (SCr, CysC, combined) best predicts cefepime clearance, and to explore additional predictors of cefepime clearance. Patients admitted to the pediatric HSCT unit who received ≥2 cefepime doses were prospectively enrolled. We measured total cefepime peak/trough concentrations between the second and fourth cefepime doses and measured SCr and CysC if not already obtained clinically within 24h of cefepime samples. eGFRs were calculated with Chronic Kidney Disease in Children U25 equations. Bayesian estimates of cefepime clearance were determined with a pediatric cefepime PK model and PK software MwPharm++. Simple linear regression was used to compare cefepime clearance normalized to body surface area (BSA) to BSA-normalized SCr-, CysC-, and SCr-/CysC-eGFRs, while multiple linear regression was used to account for additional predictors of cefepime clearance. For target attainment, we assessed the percentage of time free cefepime concentrations exceeded 1x MIC (%fT>1x MIC) and 4x MIC (%fT>4x MIC) using a susceptibility breakpoint of 8 mg/L for Pseudomonas aeruginosa. We enrolled 53 patients (ages 1 to 30 years, median 8.9 years). SCr- and CysC-eGFRs were lower in patients who attained 100% fT>1xMIC compared to those who did not attain this target: 115 versus 156 mL/min/1.73m2 (p = .01) for SCr-eGFR and 73.5 versus 107 mL/min/1.73m2 (p < .001) for CysC-eGFR. SCr-eGFR was weakly positively correlated with cefepime clearance (adjusted [a]r2= 0.14), while CysC-eGFR and SCr-/CysC-eGFR had stronger positive correlations (ar2 = 0.30 CysC, ar2 = 0.28 combo. There was a weak, significant linear association between increasing CysC-eGFR and decreased %fT>1xMIC (ar2 = 0.32) and %fT>4xMIC (ar2 = 0.14). No patients with a CysC-eGFR >120 mL/min/1.73 m2 achieved 100% fT>1xMIC or 50% fT>4x MIC. In multiple regression models, underlying diagnosis of hemoglobinopathy (in all models) and being pretransplant (in SCr and combined models) were associated with increased cefepime clearance, while concomitant use of calcineurin inhibitors was associated with decreased cefepime clearance in all models. Overall, the combo-eGFR model with timing pretransplant, hemoglobinopathy, and use of calcineurin inhibitors had the best performance (ar2 = 0.63). CysC-based eGFRs (CysC alone and combined) predicted cefepime clearance better than SCr-eGFR, even after considering steroid use. Increasing CysC eGFR correlated with decreased probability of PD target attainment, raising concerns for underdosing at high eGFRs. CysC should be included when estimating kidney function to provide adequate dosing of cefepime in pediatric HSCT patients.

A proposed framework for advancing acute kidney injury risk stratification and diagnosis in children: a report from the 26th Acute Disease Quality Initiative (ADQI) conference

Acute kidney injury (AKI) in children is associated with increased morbidity, reduced health-related quality of life, greater resource utilization, and higher mortality. Improvements in the timeliness and precision of AKI diagnosis in children are needed. In this report, we highlight existing, novel, and on-the-horizon diagnostic and risk-stratification tools for pediatric AKI, and outline opportunities for integration into clinical practice. We also summarize pediatric-specific high-risk diagnoses and exposures for AKI, as well as the potential role of real-time risk stratification and clinical decision support to improve outcomes. Lastly, the key characteristics of important pediatric AKI phenotypes will be outlined. Throughout, we identify key knowledge gaps, which represent prioritized areas of focus for future research that will facilitate a comprehensive, timely and personalized approach to pediatric AKI diagnosis and management.

Risk factors for acute kidney injury in pediatric patients after hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Risk factors for acute kidney injury (AKI) in pediatric patients after hematopoietic stem cell transplantation (HSCT) remain controversial.

OBJECTIVES

This study aimed to identify risk factors for AKI following HSCT in the pediatric population.

DATA SOURCES

PubMed, Embase, Web of Science, Cochrane Library, and Scopus databases were searched from inception to February 8, 2023.

STUDY ELIGIBILITY CRITERIA

Studies meeting the following criteria were included: (1) The study was a case-control, cohort study, or cross-sectional design, (2) the study was performed among pediatric and young patients aged 21 years or younger undergoing HSCT, (3) the study measured at least one related factor for AKI after pediatric HSCT, (4) the study included a sample of at least ten patients, and (5) original articles published in English in peer-reviewed scientific journals.

PARTICIPANTS AND INTERVENTIONS

Children who were undergoing pediatric HSCT.

STUDY APPRAISAL AND SYNTHESIS METHODS

We assessed the quality of the included studies and analyzed them with a random-effect model.

RESULTS

Fifteen studies with a total of 2,093 patients were included. All were cohort studies of high quality. The overall pooled incidence of AKI was 47.4% (95%CI 0.35, 0.60). We found significant associations between post-transplant AKI in pediatric patients and unrelated donor [odds ratio (OR) = 1.74, 95% confidence interval (CI) 1.09-2.79], cord blood stem cell transplantation (OR = 3.14, 95%CI 2.14-4.60), and veno-occlusive disease (VOD)/sinusoidal obstruction syndrome (SOS) (OR = 6.02, 95%CI 1.40-25.88). Other controversial factors such as myeloablative conditioning (MAC), acute graft vs. host disease (aGVHD), and the use of calcineurin inhibitors (CNI) were not found to be related to AKI after pediatric HSCT.

LIMITATIONS

Results were limited mainly by heterogeneity in the characteristics of patients and transplantation.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Posttransplant AKI in children is a common complication. Unrelated donors, cord blood stem cell transplantation, and VOD/SOS might be risk factors for AKI after pediatric HSCT. Further large-scale studies are still needed to draw firm conclusions.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42022382361 A higher resolution version of the Graphical abstract is available as Supplementary information.

Nephrotoxin Exposure and Acute Kidney Injury in Adults

BACKGROUND

Rates of nephrotoxic AKI are not well described in adults due to lack of a clear definition, debate over which drugs should be considered nephrotoxins, and illness-related confounding. Nephrotoxic Injury Negated by Just-in Time Action (NINJA), a program that reduces rates of nephrotoxic AKI in pediatric populations, may be able to address these concerns, but whether NINJA can be effectively applied to adults remains unclear.

METHODS

In this retrospective cohort study conducted at the University of Iowa Hospital, we included adult patients admitted to a general hospital floor for ≥48 hours during 2019. The NINJA algorithm screened charts for high nephrotoxin exposure and AKI. After propensity score matching, Cox proportional hazard modeling was used to evaluate the relationship between nephrotoxic exposure and all-stage AKI, stage 2-3 AKI, or death. Additional analyses evaluated the most frequent nephrotoxins used in this population.

RESULTS

Of 11,311 patients, 1527 (16%) had ≥1 day of high nephrotoxin exposure. Patients with nephrotoxic exposures subsequently developed AKI in 29% of cases, and 22% of all inpatient AKI events met nephrotoxic AKI criteria. Common nephrotoxins were vancomycin, iodinated contrast dye, piperacillin-tazobactam, acyclovir, and lisinopril. After propensity score matching, Cox proportional hazard models for high nephrotoxin exposure were significantly associated with all AKI (hazard ratio [HR] 1.43, 1.19-1.72, P<0.001), stage 2-3 AKI (HR 1.78, 1.18-2.67, P=0.006), and mortality (HR 2.12, 1.09-4.11, P=0.03).

CONCLUSIONS

Nephrotoxin exposure in adults is common and is significantly associated with AKI development, including stage 2-3 AKI.

Decreases in Nephrotoxic Pain Medications Are Not Associated With Increased Opioid Utilization in Critically Ill Children

OBJECTIVES

Quality improvement initiatives to decrease rates of nephrotoxic medication exposure have reduced rates of acute kidney injury (AKI) in noncritically ill children. The objective of our study was to analyze the implementation of a similar program in critically ill children and to measure important balancing measures including opioid and benzodiazepine exposure.

DESIGN

Prospective quality improvement study.

SETTING

PICU at Children's Hospital Colorado between 2018 and 2020.

PATIENTS

All children admitted to PICU.

INTERVENTIONS

Quality improvement initiative called Nephrotoxic Injury Negated by Just-In-Time Action (NINJA).

MEASUREMENT AND MAIN RESULTS

Eight thousand eight hundred thirty-three PICU patient admissions were included. Mean rates of nephrotoxic medication exposure/1,000 PICU patient days decreased from 46 to 26, whereas rates of nephrotoxic AKI/1,000 PICU patient days did not change. Nonsteroidal anti-inflammatory drug dispenses per 1,000 patient days were reduced from 521 to 456. Similarly, opioid and benzodiazepine exposures per 1,000 patient days were reduced from 812 to 524 and 441 to 227, respectively, during the study observation period.

CONCLUSIONS

The NINJA intervention was efficaciously implemented in our single-center PICU. Nephrotoxic exposure is a modifiable factor that did not inadvertently increase exposure to opioids and benzodiazepines.

Nephrotoxic Exposures and Acute Kidney Injury in Noncritically Ill Children Stratified by Service

OBJECTIVE

The Nephrotoxic Injury Negated by Just-in-Time Action (NINJA) program is a multicenter, quality improvement initiative that identifies patients at risk for nephrotoxic medication-associated acute kidney injury (NTMx-AKI). The purpose of this study was to (1) evaluate the prevalence and types of NTMx exposures and (2) determine the prevalence of NTMx-AKI categorized by service. Exploratory analysis evaluated potential associations between hospital measures and NTMx-AKI.

METHODS

This is a single-center, retrospective chart review of NTMx exposures from January 2019 to June 2020 in noncritically ill children. High NTMx exposures were defined as ≥3 simultaneous nephrotoxins or ≥3 days of either intravenous vancomycin or aminoglycoside. Prevalence of high NTMx and NTMx-AKI rate were normalized to 1000 patient days. A retrospective case-control analysis assessed for potential associations with development of NTMx-AKI.

RESULTS

There were 609 NTMx exposures in 565 patients and 44 (7.2%) episodes of NTMx-AKI. The NTMx prevalence rate per 1000 patient days was highest among liver, neurosurgery, and gastroenterology services. The most commonly used NTMx were vancomycin, intravenous contrast, and nonsteroidal antiinflammatory drugs. The NTMx-AKI rate in exposed patients ranged from 0% to 14% across service lines. AKI was most often attributable to vancomycin. Univariable analyses suggest type and duration of NTMx exposure are associated with development of NTMx-AKI but not with severity.

CONCLUSIONS

NTMx exposures and NTMx-AKI are variable across services. Partnerships with antimicrobial stewardship and multicenter studies are needed to modify NTMx-AKI risk. Ongoing surveillance is needed in patients who do not have normalization of creatinine before discharge.

Long-Term Healthcare Cost Savings of a Pediatric Nephrotoxic Medication-Associated Acute Kidney Injury Reduction Program in a Simulated Sample

BACKGROUND

Nephrotoxic medication exposure is a common cause of acute kidney injury (AKI) in hospitalized children and is associated with chronic kidney disease (CKD). The pharmacist-reliant NINJA program reduced nephrotoxic medication exposure and associated AKI.

OBJECTIVES

We assess potential healthcare cost savings from reduced CKD by preventing AKI with the NINJA program for a pediatric population through age 21.

METHODS

We simulated a cohort of 1000 hospitalized non-critically ill children. From the published literature, 310 develop AKI, 267 survive to 6 months, and 10-70% develop CKD, and NINJA implementation reduced AKI by 23.8%. Allowing for varying CKD rates, we estimated a range of NINJA's savings. We assumed an annual GFR decline of 1.2 (noHTN) ml/min/1.73 m² for half the sample and 1.7 (HTN) ml/min/1.73 m² for the other half to account for CKD progression without and with hypertension (HTN). We model attributable costs including CKD stage-related medications and outpatient visits/tests in 2018 dollars discounted at 3%. We subtract the cost of NINJA screening (daily serum creatinine and pharmacist time) from net savings. We exclude end-stage renal disease (ESRD) and hospitalization costs.

RESULTS

No intervention estimated CKD related costs are $761,852 to $5,735,027. Post-NINJA cost decreases to $616,086 to $4,312,183 (net savings: $145,766 to $1,422 183). Total savings, accounting for NINJA screening ($256,680) are -$110,914 to $1,1 165 503. The breakeven AKI to CKD conversion rate is 13-14% with growth hormone cost included, and 64-65% without.

CONCLUSION

The NINJA program is likely cost beneficial, with greater savings into adulthood by avoiding/delaying ESRD and its costs.

Recent Advances of Acute Kidney Injury in Hematopoietic Cell Transplantation

Acute kidney injury (AKI) is a common complication of allogeneic hematopoietic cell transplantation (allo-HCT) and is associated with non-relapse mortality (NRM) and quality of life (QOL). Multiple factors may contribute to AKI during allo-HCT and are often present at the same time making it difficult to determine the cause of AKI in each patient. Nephrotoxic drugs, infections, thrombotic microangiopathy (TMA), and sinusoidal obstruction syndrome (SOS) are well described causes of AKI during allo-HCT. Acute graft-versus-host disease (aGVHD) is a major complication of allo-HCT that mainly targets the intestines, liver, and skin. However, recent studies suggest aGVHD may also attack the kidney and contribute to AKI following allo-HCT. For example, severe aGVHD is associated with AKI, suggesting a link between the two. In addition, animal models have shown donor immune cell infiltration and increased expression of inflammatory cytokines in recipient kidneys after allo-HCT. Therefore, aGVHD may also target the kidney and contribute to AKI following allo-HCT. Herein, we describe the etiology, diagnosis, risk factors, pathophysiology, prevention, and treatment of renal injury after allo-HCT. In addition, we highlight emerging evidence that aGVHD may contribute to the development of AKI after allo-HCT.

Kidney Disease Following Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (SCT) provides a curative option for the treatment of several malignancies. Its growing use is associated with an increased burden of kidney disease. Acute kidney injury is usually seen within the first 100 days of transplantation and has an incidence ranging between 12 and 73%, with the highest rate in myeloablative allogeneic SCT. A large subset of patients after SCT develop chronic kidney disease. They can be broadly classified into thrombotic microangiopathy, nephrotic syndrome, and calcineurin toxicity. Dialysis requirement after SCT is associated with mortality exceeding 80%. Given the higher morbidity and mortality related to development kidney disease, nephrologists need to be aware of the various causes and best treatment options.

Impact of decreasing vancomycin exposure on acute kidney injury in stem cell transplant recipients

OBJECTIVE

To evaluate the change in vancomycin days of therapy (DOT) and vancomycin-associated acute kidney injury (AKI) after an antimicrobial stewardship program (ASP) intervention to decrease vancomycin use in stable patients after hematopoietic stem cell transplantation (HSCT).

DESIGN

Retrospective cohort study and quasi-experimental interrupted time series analysis. Change in unit-level vancomycin DOT per 1,000 inpatient days after the intervention was assessed using segmented Poisson regression. Subject-specific risk of vancomycin-associated AKI was evaluated using a random intercept logistic regression model with mediation analysis.

SETTING

HSCT unit at a single quaternary-care pediatric hospital.

PARTICIPANTS

Inpatients aged 3 months and older who underwent HSCT between January 1, 2015, and March 31, 2019 (27 months before and after the intervention) who received any dose of vancomycin.

INTERVENTION

An ASP intervention in April 2017 creating a new practice guideline to decrease prolonged (>72 hours) vancomycin courses for stable HSCT patients with febrile neutropenia.

RESULTS

Overall, 439 vancomycin exposures (234 before the intervention and 205 after the intervention) occurring across 300 transplants and 259 subjects were included. The mean vancomycin DOT was 307 per 1,000 inpatient days (95% confidence interval [CI], 272-342) and decreased after the intervention to 207 per 1,000 inpatient days (95% CI, 173-240). In multivariable analyses, the odds of AKI in the postintervention period were 37% lower than in the preintervention period (adjusted OR, 0.63; 95% CI, 0.42-0.95; P = .0268); 56% of the excess risk was mediated by vancomycin DOT.

CONCLUSIONS

An ASP intervention successfully decreased vancomycin use after HSCT and resulted in a decrease in AKI. Reducing empiric antibiotic exposure for stable patients after HSCT can improve clinical outcomes.

Lowered Risk of Nephrotoxicity through Intervention against the Combined Use of Vancomycin and Tazobactam/Piperacillin: A Retrospective Cohort Study

The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We sought to evaluate interventions against the combined use of VCM and TAZ/PIPC. This retrospective cohort study involved patients who considered the combined use of VCM and TAZ/PIPC as a treatment. Patients that had either or both antimicrobials replaced were assigned to the intervention group, whereas those who were continued on combination therapy were assigned to the comparison group. The primary endpoint was the incidence of acute kidney injury (AKI). The survival rate of patients on day 30 was evaluated as the secondary endpoint. The comparison and intervention groups were composed of 65 and 68 patients, respectively, and the incidence rates of AKI were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified the intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). For the incidence of AKI of grade greater than 1, the hazard ratio was 0.114 (95% CI, 0.025 to 0.497). The survival rates on day 30 in the comparison and intervention groups were 92.3% and 91.2%, respectively, with a relative risk of 0.988 (95% CI, 0.892 to 1.094). The trough VCM concentration was not associated with the incidence of AKI in patients receiving the combination therapy. This study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity. IMPORTANCE The combined use of vancomycin (VCM) and tazobactam/piperacillin (TAZ/PIPC) is a major risk factor for nephrotoxicity. We retrospectively evaluated interventions against the combined use of VCM and TAZ/PIPC. Patients for whom either or both antimicrobials were replaced were assigned to the intervention group (65 patients), whereas those who were continued on combination therapy were assigned to the comparison group (68 patients). The primary endpoint was the incidence of acute kidney injury (AKI). The incidence rates of AKI in the intervention and comparison groups were 44.6% and 17.6%, respectively. Cox proportional hazard analysis identified intervention as the only independent factor against AKI development, with a hazard ratio of 0.282 (95% confidence interval [CI], 0.141 to 0.565). In conclusion, this study demonstrated that intervention against the combined use of VCM and TAZ/PIPC can lower the risk of nephrotoxicity.

Urinary neutrophil gelatinase-associated lipocalin rules out nephrotoxic acute kidney injury in children

BACKGROUND

Nephrotoxic medication exposure is a common cause of acute kidney injury (AKI) in hospitalized children. A key component of the NINJA quality improvement initiative is systematic daily serum creatinine assessment in non-critically ill children exposed to ≥ 3 nephrotoxic medications on 1 day, or intravenous aminoglycoside or vancomycin for ≥ 3 days. Daily venipuncture is invasive and associated with disposable and personnel healthcare costs. Urine neutrophil gelatinase-associated lipocalin (uNGAL) is a marker of renal tubular injury associated with certain nephrotoxic medications. We investigated whether uNGAL is a reliable screening tool for AKI in NINJA and could decrease the need for daily venipuncture.

METHODS

This two-center prospective study enrolled 113 children who met NINJA criteria from May 2018 through March 2019. Daily urine samples were obtained for up to the first 7 days of qualifying exposure and 2 days after exposure ended. Our primary outcome was severe AKI (KDIGO stage 2 or 3 AKI). Maximum uNGAL was highest concentration on the day of, or 3 days prior to, severe AKI. The highest uNGAL level from all assessment days was used for patients who did not develop AKI or severe AKI.

RESULTS

Urine NGAL thresholds of 150 and 300 ng/ml demonstrated excellent specificity (92.4 and 97.1% respectively) and negative predictive values (93.3 and 92.8% respectively) for ruling out severe AKI.

CONCLUSIONS

We suggest that uNGAL could be used to supplant some of the daily serum creatinine venipunctures in NINJA. The most optimal combination of serum creatinine and uNGAL assessment requires further study.

Development of the Three Antimicrobial Stewardship E's (TASE) framework and Association between Stewardship Interventions and intended Results (ASIR) analysis to identify key facility-specific interventions and strategies for successful antimicrobial stewardship

BACKGROUND

Successful antimicrobial stewardship (AS) interventions have been described previously. Currently, a uniform operational approach to planning and implementing successful AS interventions does not exist. From 2015 to 2019, concomitant vancomycin and piperacillin-tazobactam use (CVPTU) for >48 hours at Vanderbilt University Medical Center (VUMC) significantly decreased through AS efforts. We analyzed the interventions that led to this change and created a model to inform future intervention planning and development.

METHODS

VUMC adult admissions from January 2015 to August 2019 were evaluated for CVPTU. Percentage of admissions receiving CVPTU >48 hours, the primary outcome, was evaluated using statistical process control charts. We created the Three Antimicrobial Stewardship E's (TASE) framework and Association between Stewardship Interventions and intended Results (ASIR) analysis to assess potential intensity and impact of interventions associated with successful change during this time period and to identify guiding principles for development of future initiatives.

RESULTS

The mean percentage of admissions receiving CVPTU per month declined from 4.2% to 0.7%. Over 8 time periods, we identified 4 high, 3 moderate and 1 low intervention intensity periods. Continuous provider-level AS education was present throughout. Creation and dissemination of division and department algorithms and reinforcement via computerized provider order entry sets preceded the largest reduction in CVPTU and sustained prescribing practice changes.

CONCLUSIONS

The TASE framework and ASIR analysis successfully identified pivotal interventions and strategies needed to effect and sustain change at VUMC. Further research is needed to validate its effectiveness as a stewardship intervention planning tool at our institution and others.

Improving the quality of neonatal acute kidney injury care: neonatal-specific response to the 22nd Acute Disease Quality Initiative (ADQI) conference

With the adoption of standardized neonatal acute kidney injury (AKI) definitions over the past decade and the concomitant surge in research studies, the epidemiology of and risk factors for neonatal AKI have become much better understood. Thus, there is now a need to focus on strategies designed to improve AKI care processes with the goal of reducing the morbidity and mortality associated with neonatal AKI. The 22nd Acute Dialysis/Disease Quality Improvement (ADQI) report provides a framework for such quality improvement in adults at risk for AKI and its sequelae. While many of the concepts can be translated to neonates, there are a number of specific nuances which differ in neonatal AKI care. A group of experts in pediatric nephrology and neonatology came together to provide neonatal-specific responses to each of the 22nd ADQI consensus statements.

Postoperative acute kidney injury in adult non-cardiac surgery: joint consensus report of the Acute Disease Quality Initiative and PeriOperative Quality Initiative

Postoperative acute kidney injury (PO-AKI) is a common complication of major surgery that is strongly associated with short-term surgical complications and long-term adverse outcomes, including increased risk of chronic kidney disease, cardiovascular events and death. Risk factors for PO-AKI include older age and comorbid diseases such as chronic kidney disease and diabetes mellitus. PO-AKI is best defined as AKI occurring within 7 days of an operative intervention using the Kidney Disease Improving Global Outcomes (KDIGO) definition of AKI; however, additional prognostic information may be gained from detailed clinical assessment and other diagnostic investigations in the form of a focused kidney health assessment (KHA). Prevention of PO-AKI is largely based on identification of high baseline risk, monitoring and reduction of nephrotoxic insults, whereas treatment involves the application of a bundle of interventions to avoid secondary kidney injury and mitigate the severity of AKI. As PO-AKI is strongly associated with long-term adverse outcomes, some form of follow-up KHA is essential; however, the form and location of this will be dictated by the nature and severity of the AKI. In this Consensus Statement, we provide graded recommendations for AKI after non-cardiac surgery and highlight priorities for future research.

Acute Kidney Injury Following Pediatric Liver Transplant

OBJECTIVE

To determine the incidence, severity, and risk factors of postoperative acute kidney injury in pediatric liver transplant patients with and without inborn errors of metabolism.

DESIGN

Retrospective cohort study.

SETTING

Single-center PICU.

PATIENTS

All children less than or equal to 18 years old who received a liver transplant between January 2009 and July 2019.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Following exclusion criteria there were 92 transplant encounters. After excluding patients who received combined kidney-liver transplantation, acute kidney injury occurred in 57% of patients (N = 49), with 25.6% (N = 22) stage 1, 15.1% (N = 13) stage 2, and 16.3% (N = 14) stage 3. In an adjusted analysis, metabolic indication for transplant was not significantly associated with presence of acute kidney injury (p = 0.45). For the subset of patients without inborn errors of metabolism, the odds of having acute kidney injury was 1.50 (95% CI: 1.00-2.26) for each 1-unit increase in preoperative INR after adjusting for the covariates of age, preoperative albumin, CMV status of donor, and preoperative creatinine. In the full cohort, as well as the sample of children without inborn errors of metabolism, presence of acute kidney injury was associated with longer total hospital stay as well as number of ICU days.

CONCLUSIONS

Acute kidney injury in the early postoperative period is common in pediatric liver transplant patients (57%), 31.4% of whom had severe disease. In patients without inborn errors of metabolism, each unit increase in preoperative INR suggests a higher risk of acute kidney injury after adjusting for covariates including preoperative creatinine. This finding suggests an association between the severity of preoperative synthetic liver function and the risk of developing postoperative acute kidney injury which requires further investigation.

Nephrotoxins and nephrotoxic acute kidney injury

Although the concept of nephrotoxicity has been recognized for more than 80 years, interest in nephrotoxins has intensified dramatically over the past two decades. Much of this attention has rightfully been focused on pharmaceutical agents and iatrogenic harm; however, it is important for providers to recognize that nephrotoxins can be found in naturally occurring substances as well. Although nephrotoxins exist in a myriad of forms, the means by which they induce injury can be organized into a few categories. For most of these agents, regardless of the mechanism, the final common pathway is acute kidney injury (AKI). Unfortunately, therapeutic options are limited and no treatments currently exist to reverse nephrotoxic AKI once it occurs. As a result, current strategies focus on increased awareness, nephrotoxin avoidance, early injury detection, and mitigation of disease severity. The goal of this review is to summarize our current understanding of nephrotoxic mechanisms and the epidemiology of nephrotoxic AKI. Additionally, avoidance and preventative strategies are discussed, screening approaches are suggested, and chronic monitoring recommendations are made.

Precision Dosing Priority Criteria: Drug, Disease, and Patient Population Variables

The administered dose of a drug modulates whether patients will experience optimal effectiveness, toxicity including death, or no effect at all. Dosing is particularly important for diseases and/or drugs where the drug can decrease severe morbidity or prolong life. Likewise, dosing is important where the drug can cause death or severe morbidity. Since we believe there are many examples where more precise dosing could benefit patients, it is worthwhile to consider how to prioritize drug–disease targets. One key consideration is the quality of information available from which more precise dosing recommendations can be constructed. When a new more precise dosing scheme is created and differs significantly from the approved label, it is important to consider the level of proof necessary to either change the label and/or change clinical practice. The cost and effort needed to provide this proof should also be considered in prioritizing drug–disease precision dosing targets. Although precision dosing is being promoted and has great promise, it is underutilized in many drugs and disease states. Therefore, we believe it is important to consider how more precise dosing is going to be delivered to high priority patients in a timely manner. If better dosing schemes do not change clinical practice resulting in better patient outcomes, then what is the use? This review paper discusses variables to consider when prioritizing precision dosing candidates while highlighting key examples of precision dosing that have been successfully used to improve patient care.

The use of low doses of methotrexate during peri-cell infusion period may be a risk factor for acute kidney injury in patients subjected to hematopoietic stem cell transplantation

Acute kidney injury (AKI) after hematopoietic stem cell transplantation (HSCT) is associated with high mortality rates. To determine the incidence and risk factors associated with AKI in patients undergoing HSCT during the infusion period, patients admitted for HSCT from 2012 to 2015 were studied. AKI was classified according to the KDIGO (Kidney Disease Improving Global Outcomes) criteria. We analyzed the main comorbidities, underlying conditions, types of transplant, preparative regimens, and use of potentially nephrotoxic drugs as risk factors for AKI. Among the 180 patients (median age 53 years), 69 (36.5%) developed AKI (23 KDIGO 1, 28 KDIGO 2, and 18 KDIGO 3), 49 (50.0%) undergoing allogeneic and 20 (22.3%) autologous transplantation, and 18 (9.4%) required dialysis. The main comorbidities were hypertension (38; 19.8%), and diabetes (19; 9.9%). The median pre-transplant creatinine was 0.7 mg/dl. Twenty-one patients died (10.9%). The risk factors for AKI in allogeneic HSCT were as follows: baseline estimated glomerular filtration rate (eGFR) (RR 1.12 (1.02-1.22), p = 0.019), use of vasopressors (RR 3.72 (2.20-6.29), p < 0.001), and use of methotrexate (RR 1.83 (1.08-3.11), p = 0.025). Male gender (RR 5.91 (1.65-21.16), p = 0.006), baseline eGFR (RR 1.22 (1.04-1.43), p = 0.011), and use of aminoglycosides (RR 3.92 (1.06-14.44), p = 0.041) were the risk factors for AKI associated with autologous HSCT. During hospitalization for HSCT, AKI was a common problem. The use of a low dose of methotrexate to prevent graft versus host disease was associated with its occurrence.