Acute Kidney Injury During Vancomycin Therapy in Critically Ill Children

Urinary biomarkers as indicators of acute kidney injury in critically ill children exposed to vancomycin

STUDY OBJECTIVE

The standard of care for detecting acute kidney injury (AKI) is change in serum creatinine (SCr) and urine output, which are limited. This study aimed to compare urinary biomarkers neutrophil gelatinase-associated lipocalin (uNGAL) with kidney injury molecule-1 (uKIM-1) in critically ill children exposed to vancomycin who did and did not develop AKI as defined by changes in SCr.

DESIGN

Single-center, prospective, clinical, observational cohort study.

SETTING

Tertiary care children's hospital in an urban setting.

PATIENTS

Children aged 0 (corrected gestational age 42 weeks) to 18 years admitted to the intensive care unit who received vancomycin were included.

INTERVENTION

None.

MEASUREMENTS

The primary outcome was mean change in uNGAL and uKIM-1 between AKI and no-AKI groups. AKI was defined as a minimum 50% increase in SCr from baseline over a 48 h period, within 7 days of first vancomycin exposure. Three urine samples were collected: baseline (between 0 and 6 h of first vancomycin dose), second (18-24 h after the "baseline"), and third (18-24 h after the second sample). Concentrations of uKIM-1 and uNGAL were measured in each sample.

MAIN RESULTS

Forty-eight children (52% male; median age 6 years) were included. Eight (16.7%) children developed AKI. Mean changes in uNGAL (713.196 ± 1,216,474 vs. 16.101 ± 37.812 pg/mL; p = 0.0004) and uKIM-1 (6060 ± 11.165 vs. 340 ± 542 pg/mL; p = 0.0015) were greater in children with AKI versus no-AKI, respectively.

CONCLUSIONS

uNGAL and uKIM-1 concentrations increased significantly more in critically ill children with AKI compared with those with no-AKI during the first 48-72 h of vancomycin exposure and may be useful as prospective biomarkers of AKI.

Epidemiology of Vancomycin in Combination With Piperacillin/Tazobactam-Associated Acute Kidney Injury in Children: A Systematic Review and Meta-analysis

BACKGROUND

Several studies have shown that vancomycin combined with piperacillin/tazobactam (VPT) increased the risk of acute kidney injury (AKI) compared with other antibiotics in children. However, the epidemiology of VPT-associated AKI in children is unknown.

OBJECTIVE

To evaluate the incidence and risk factors of VPT-associated AKI in children.

DATA SOURCES

Literature databases of PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP Database, WanFang Database, and China Biology Medicine Disc were searched from inception to November 2023. References of included studies were also manually checked.

STUDY SELECTION AND DATA EXTRACTION

Two independent reviewers selected studies, extracted data, and quality assessment. Meta-analyses were performed to quantify the incidence and risk factors of VPT-associated AKI in children.

DATA SYNTHESIS

Sixteen cohort studies were identified. Overall, the incidence of VPT-associated AKI in children was 24.3% (95% CI: 17.9%-30.6%). The incidence of VPT-associated AKI in critically ill children (26.6%) was higher than that in noncritically ill children (10.9%). Moreover, higher serum vancomycin trough concentration (>15 mg/L), use of vasopressors, combination of nephrotoxins and intensive care unit admission were risk factors for VPT-associated AKI in children (P < 0.05).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Identifying high-risk groups and determining safer treatments is critical to reducing the incidence of VPT-associated AKI in children.

CONCLUSIONS

The incidence of VPT-associated AKI in children is high, especially in critically ill children. Medication regimens should be personalized based on the presence of individual risk factors. Moreover, renal function was regularly assessed throughout treatment with VPT.

Incidence of Antimicrobial-Associated Acute Kidney Injury in Children: A Structured Review

Acute kidney injury (AKI) is a commonly reported adverse effect of administration of antimicrobials. While AKI can be associated with poorer outcomes, there is little information available to understand rates of AKI in children exposed to various antimicrobials. We performed a structured review using the PubMed and Embase databases. Articles were included if they provided an AKI definition in patients who were < 19 years of age receiving an antimicrobial and reported the frequency of AKI. Author-defined AKI rates were calculated for each study and mean pooled estimates for each antimicrobial were derived from among all study participants. Pooled estimates were also derived for those studies that reported AKI according to pRIFLE (pediatric risk, injury, failure, loss, end stage criteria), AKIN (acute kidney injury network), or KDIGO (kidney disease improving global outcomes) creatinine criteria. A total of 122 studies evaluating 28 antimicrobials met the inclusion criteria. Vancomycin was the most commonly studied drug: 11,514 courses across 44 included studies. Among the 27,285 antimicrobial exposures, the overall AKI rate was 13.2% (range 0-42.1% by drug), but the rate of AKI varied widely across studies (range 0-68.8%). Cidofovir (42.1%) and conventional amphotericin B (37.0%) had the highest pooled rates of author-defined AKI. Eighty-one studies used pRIFLE, AKIN, or KDIGO AKI criteria and the pooled rates of AKI were similar to author-defined AKI rates. In conclusion, antimicrobial-associated AKI is reported to occur frequently in children, but the rates of AKI varies widely across studies and drugs. Most published studies examined hospitalized patients and heterogeneity in study populations and in author definitions of AKI are barriers to a comparison of nephrotoxicity risk among antimicrobials in children.

Late-Onset Sepsis Evaluation and Empiric Therapy in Extremely Low Gestational Age Newborns

BACKGROUND

Little is known about late-onset sepsis (LOS) evaluations in extremely low gestational age newborns (ELGANs). We describe frequencies of LOS evaluation in ELGANs, infant characteristics, and empiric therapy choices during evaluations.

METHODS

Cohort study of infants 22-28 weeks gestational age (GA) discharged from 243 centers from 2009 to 2018, excluding infants with congenital anomalies, discharged or deceased prior to postnatal day (PND) 2, or admitted after PND 2. A new LOS evaluation was defined as the first blood culture obtained between PND 3 and 90, or one obtained ≥1 day following a negative culture and ≥10 days from prior positive cultures. We determined numbers of evaluations and percentage positive by GA, center, and over time. We described characteristics associated with positive evaluations, infants with LOS, and empiric antimicrobials. We calculated descriptive and comparative statistics using Wilcoxon rank sum, Fisher's exact, or Pearson chi-square tests, as appropriate.

RESULTS

Of 47,187 included infants, 67% had ≥1 LOS evaluation and 21% of evaluated infants had ≥1 LOS (culture positive) episode; 1.6 evaluations occurred per infant and 10% were positive. The percentage of infants evaluated and positive for LOS was higher at earlier GA. LOS was associated with inotrope support (15% vs. 9%; p < .001) and invasive mechanical ventilation (66% vs. 51%; p < .001). Infants with positive cultures were more likely than infants with negative cultures to receive empiric antimicrobials during the LOS evaluation (95% vs. 73%; p < .001).

CONCLUSIONS

Among ELGANs, earlier GA and postnatal age were associated with LOS evaluation and positive cultures. Most infants undergoing evaluation were started on empiric antimicrobials.

Incidence and risk factors of drug-induced kidney injury in children: a systematic review and meta-analysis

PURPOSE

To comprehensively summarize the incidence and risk factors of drug-induced kidney injury (DIKI) in children.

METHODS

We systematically searched seven databases from inception to November 2022. Two independent reviewers selected studies, extracted data, and assessed the risk of bias. Meta-analyses were conducted to quantify the incidence and risk factors of DIKI in children.

RESULTS

A total of 69 studies comprising 195,894 pediatric patients were included. Overall, the incidence of DIKI in children was 18.2% (95%CI: 16.4%-20.1%). The incidence of DIKI in critically ill children (19.6%, 95%CI: 15.9%-23.3%) was higher than that in non-critically ill children (16.1%, 95%CI: 12.9%-19.4%). Moreover, the risk factors for DIKI in children were intensive care unit (ICU) admission (OR = 1.59, 95% CI: 1.42-1.78, P = 0.000), treatment days (OR = 1.04, 95% CI: 1.03-1.05, P = 0.000), surgical intervention (OR = 1.43, 95% CI: 1.00-2.02, P = 0.048), infection (OR = 2.30, 95% CI: 1.44-3.66, P = 0.000), patent ductus arteriosus (OR = 4.78, 95% CI: 1.82-12.57, P = 0.002), chronic kidney disease (OR = 2.78, 95% CI: 1.92-4.02, P = 0.000), combination with antibacterial agents (OR = 1.98, 95% CI: 1.54-2.55, P = 0.000), diuretics (OR = 1.97, 95% CI: 1.51-2.56, P = 0.000), combination with antiviral agents (OR = 1.50, 95% CI: 1.11-2.04, P = 0.008), combination with non-steroidal anti-inflammatory drugs (OR = 1.79, 95% CI: 1.40-2.28, P = 0.000), and combination with immunosuppressive agents (OR = 2.84, 95% CI: 1.47-5.47, P = 0.002).

CONCLUSION

The incidence of DIKI in children is high, especially in critically ill children. Identifying high-risk groups and determining safer treatments is critical to reducing the incidence of DIKI in children. In clinical practice, clinicians should adjust medication regimens for high-risk pediatric groups, such as ICU admission, some underlying diseases, combination with nephrotoxic drugs, etc., and regularly evaluate kidney function throughout treatment.

Factors associated with acute kidney injury among preterm infants administered vancomycin: a retrospective cohort study

BACKGROUND

Vancomycin (VCM) is a widely used antibiotic for the treatment of gram-positive microorganisms, with some nephrotoxic effects. Recent studies have suggested that piperacillin-tazobactam (TZP) aggravates VCM-induced nephrotoxicity in adults and adolescents. However, there is a lack of research investigating these effects in the newborn population. Therefore, this study investigates whether the concomitant use of TZP with VCM use increases the risk of acute kidney injury (AKI) and to explore the factors associated with AKI in preterm infants treated with VCM.

METHODS

This retrospective study included preterm infants with birth weight < 1,500 g in a single tertiary center who were born between 2018 and 2021 and received VCM for a minimum of 3 days. AKI was defined as an increase in serum creatinine (SCr) of at least 0.3 mg/dL and an increase in SCr of at least 1.5 times baseline during and up to 1 week after discontinuation of VCM. The study population was categorized as those with or without concomitant use of TZP. Data on perinatal and postnatal factors associated with AKI were collected and analyzed.

RESULTS

Of the 70 infants, 17 died before 7 postnatal days or antecedent AKI and were excluded, while among the remaining participants, 25 received VCM with TZP (VCM + TZP) and 28 VCM without TZP (VCM-TZP). Gestational age (GA) at birth (26.4 ± 2.8 weeks vs. 26.5 ± 2.6 weeks, p = 0.859) and birthweight (750.4 ± 232.2 g vs. 838.1 ± 268.7 g, p = 0.212) were comparable between the two groups. There were no significant differences in the incidence of AKI between groups. Multivariate analysis showed that GA (adjusted OR: 0.58, 95% CI: 0.35-0.98, p = 0.042), patent ductus arteriosus (PDA) (adjusted OR: 5.23, 95% CI: 0.67-41.05, p = 0.115), and necrotizing enterocolitis (NEC) (adjusted OR: 37.65, 95% CI: 3.08-459.96, p = 0.005) were associated with AKI in the study population.

CONCLUSIONS

In very low birthweight infants, concomitant use of TZP did not increase the risk of AKI during VCM administration. Instead, a lower GA, and NEC were associated with AKI in this population.

Vancomycin-associated acute kidney injury epidemiology in children: a systematic review

INTRODUCTION

Vancomycin is a recognised cause of drug-induced acute kidney injury (AKI).

OBJECTIVE

The aim of this systematic review was to summarise the incidence of, and the risk factors for, vancomycin-associated AKI (v-AKI) in children.

DESIGN

A systematic search was performed in November 2020 on the search engines PubMed, Web of Science and Medline, using predefined search terms. The inclusion criteria were primary paediatric studies, intervention with vancomycin and studies that included AKI as an outcome. Study quality was assessed using the relevant Critical Appraisal Skills Programme checklist. The data are reported using descriptive statistics.

RESULTS

890 studies were identified and screened with 25 studies suitable for inclusion. A cohort of 12 730 patients with v-AKI were included and the incidence of v-AKI in children was found to be 11.8% (1.6%-27.2%). The median age of the cohort was 2.5 years (range 0-23) and 57% were male patients. Risk factors that increased the likelihood of v-AKI were concomitant use of nephrotoxic medications, increased trough concentrations and, to a lesser extent, increased dose, longer duration of treatment, impaired renal function and if the patient required paediatric intensive care.

CONCLUSIONS

The incidence of v-AKI in children is significant and methods to reduce this risk should be considered. Further prospective interventional studies to understand the mechanisms of nephrotoxicity from vancomycin are needed and targeting risk factors may make vancomycin administration safer.

Implementation of a Pharmacist-Driven Vancomycin and Aminoglycoside Dosing Service in a Pediatric Hospital

OBJECTIVE

Pharmacy-driven antibiotic dosing services have been shown to improve clinical outcomes in adult patients. This study evaluated the effect of a pharmacist-driven antimicrobial dosing service on the percentage of therapeutic serum concentrations achieved following initial vancomycin or aminoglycoside dosing regimens. A secondary objective was to determine the effect of the dosing service on nephrotoxicity in pediatric patients.

METHODS

This single-center, retrospective study used data obtained from an electronic medical record to evaluate the utility of a pharmacist-driven vancomycin or aminoglycoside dosing protocol. Assessments of target, subtherapeutic, and supratherapeutic serum concentrations were evaluated. The occurrence of changes in serum creatinine and presentation of acute kidney injury (AKI) were also determined.

RESULTS

The incidence (n [%]) of a therapeutic initial serum concentration was not statistically significant between pre-protocol and post-protocol groups (21 [46.7%] vs 22 [48.9%], respectively; p = 0.834). The incidence of initial supratherapeutic concentrations (19 [42.2%] vs 7 [15.6%]; p = 0.005) and the average number of supratherapeutic concentrations per antibiotic course (0.76 vs 0.26; p = 0.01) were higher in the pre-protocol group compared with the post-protocol group. The incidence of AKI was significantly lower in the post-protocol group (2.2% vs 13.3%; p = 0.049).

CONCLUSIONS

Implementation of a pharmacist-driven dosing service did not affect the likelihood of achieving an initial therapeutic concentration. However, it did reduce the likelihood of both supratherapeutic concentrations and AKI. Additional studies in pediatric patients are needed to affirm the use of pharmacist dosing services.

Pharmacokinetics of Vancomycin in Critically Ill Children: A Systematic Review

Background and Objective

Vancomycin is often used in the ICU for the treatment of Gram-positive bacterial infection. In critically ill children, there are pathophysiologic changes that affect the pharmacokinetics of vancomycin. A systematic review of vancomycin pharmacokinetics and pharmacodynamics in critically ill children was performed.

Methods

Pharmacokinetic studies of vancomycin in critically ill children published up to May 2021 were included in the review provided they included children aged > 1 month. Studies including neonates were excluded. A search was performed using the PubMed, Scopus, and Google Scholar databases. The Risk of Bias Assessment Tool for Systematic Reviews (ROBIS) was used to check for quality and reduce bias. Data on study characteristics, patient demographics, clinical parameters, pharmacokinetic parameters, outcomes, and study limitations were collected.

Results

Thirteen studies were included in this review. A wide variety of dosing and sampling strategies were used in the studies. Methods for estimating vancomycin pharmacokinetics, especially the area under the curve over 24 h, varied. Vancomycin doses of 20–60 mg/kg were given daily. This resulted in high variability in pharmacokinetic parameters. Vancomycin trough level was less than 15 μg/mL in most of the studies. Vancomycin clearance ranged from 0.05 to 0.38 L/h/kg. Volume of distribution ranged from 0.1 to 1.16 L/kg. Half-life was between 2.4 and 23.6 h. Patients in the study receiving continuous vancomycin infusion had AUC₂₄ < 400 µg·h/mL.

Conclusion

There is large variability in the pharmacokinetics of vancomycin among critically ill patients. Studies to assess the factors responsible for this variability in vancomycin pharmacokinetics are needed.

Pharmacokinetics of Antibiotics in Pediatric Intensive Care: Fostering Variability to Attain Precision Medicine

Children show important developmental and maturational changes, which may contribute greatly to pharmacokinetic (PK) variability observed in pediatric patients. These PK alterations are further enhanced by disease-related, non-maturational factors. Specific to the intensive care setting, such factors include critical illness, inflammatory status, augmented renal clearance (ARC), as well as therapeutic interventions (e.g., extracorporeal organ support systems or whole-body hypothermia [WBH]). This narrative review illustrates the relevance of both maturational and non-maturational changes in absorption, distribution, metabolism, and excretion (ADME) applied to antibiotics. It hereby provides a focused assessment of the available literature on the impact of critical illness—in general, and in specific subpopulations (ARC, extracorporeal organ support systems, WBH)—on PK and potential underexposure in children and neonates. Overall, literature discussing antibiotic PK alterations in pediatric intensive care is scarce. Most studies describe antibiotics commonly monitored in clinical practice such as vancomycin and aminoglycosides. Because of the large PK variability, therapeutic drug monitoring, further extended to other antibiotics, and integration of model-informed precision dosing in clinical practice are suggested to optimise antibiotic dose and exposure in each newborn, infant, or child during intensive care.

Incidence and Risk Factors for Acute Kidney Injury in Hospitalized Children Receiving Piperacillin-Tazobactam

OBJECTIVE

Drug-induced kidney injury contributes to morbidity and mortality in hospitalized children. Antibiotics such as TZP have been implicated in the development of acute kidney injury (AKI) in adults; however, data are limited in children. The purpose of this study was to determine the incidence of AKI in hospitalized children receiving TZP.

METHODS

This was a retrospective cohort study of hospitalized children between 2 months and 19 years of age who received TZP for at least 48 hours. Acute kidney injury was defined as a 50% increase from the initial serum creatinine (SCr) prior to TZP initiation. Serum creatinine values were adjusted for fluid balance using a validated approach. Severity of AKI was characterized using the Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease (pRIFLE) criteria. Descriptive and inferential statistics were used to describe the incidence and risk factors of AKI, with an alpha = 0.05.

RESULTS

A total of 65 subjects were included. Twenty-five (38.5%) required PICU admission. The incidence of AKI was 7.7% (n = 5) using adjusted SCr (13.37 cases/1000 patient-days). According to pRIFLE, 6.15% (n = 4) subjects met criteria for Risk (n = 3) or Injury (n = 1), and none developed Failure, Loss, or End-Stage (10.70 cases/1000 patient-days for Risk and Injury categories). No risk factors were identified. Hospital length of stay was longer in subjects who experienced AKI compared with those who did not (p = 0.04).

CONCLUSIONS

The incidence of AKI in hospitalized children exposed to TZP was low. In those who did develop AKI, peak SCr occurred approximately 1 week after TZP initiation.

Pharmacokinetics and Target Attainment of Antibiotics in Critically Ill Children: A Systematic Review of Current Literature

BACKGROUND

Pharmacokinetics (PK) are severely altered in critically ill patients due to changes in volume of distribution (Vd) and/or drug clearance (Cl). This affects the target attainment of antibiotics in critically ill children. We aimed to identify gaps in current knowledge and to compare published PK parameters and target attainment of antibiotics in critically ill children to healthy children and critically ill adults.

METHODS

Systematic literature search in PubMed, EMBASE and Web of Science. Articles were labelled as relevant when they included information on PK of antibiotics in critically ill, non-neonatal, pediatric patients. Extracted PK-parameters included Vd, Cl, (trough) concentrations, AUC, probability of target attainment, and elimination half-life.

RESULTS

50 relevant articles were identified. Studies focusing on vancomycin were most prevalent (17/50). Other studies included data on penicillins, cephalosporins, carbapenems and aminoglycosides, but data on ceftriaxone, ceftazidime, penicillin and metronidazole could not be found. Critically ill children generally show a higher Cl and larger Vd than healthy children and critically ill adults. Reduced target-attainment was described in critically ill children for multiple antibiotics, including amoxicillin, piperacillin, cefotaxime, vancomycin, gentamicin, teicoplanin, amikacin and daptomycin. 38/50 articles included information on both Vd and Cl, but a dosing advice was given in only 22 articles.

CONCLUSION

The majority of studies focus on agents where TDM is applied, while other antibiotics lack data altogether. The larger Vd and higher Cl in critically ill children might warrant a higher dose or extended infusions of antibiotics in this patient population to increase target-attainment. Studies frequently fail to provide a dosing advice for this patient population, even if the necessary information is available. Our study shows gaps in current knowledge and encourages future researchers to provide dosing advice for special populations whenever possible.

Baseline kidney function is associated with vancomycin-induced acute kidney injury in children: a prospective nested case-control study

BACKGROUND

Children with kidney insufficiency are susceptible to vancomycin-induced acute kidney injury (VIAKI), but there is a lack of compelling clinical data. We conducted a nested case-control study to evaluate the relationship between kidney insufficiency and incidence of VIAKI in children.

METHODS

Patients were considered to have VIAKI if they met the criteria for eGFR change according to pRIFLE-I or p-RIFLE-F. Case group comprised patients who developed VIAKI. Case-control ratio was 1:3; patients were matched for age, severity, and nature of illness and initial vancomycin dose. Primary endpoint was incidence of VIAKI at three levels of kidney function, calculated using Kaplan-Meier curve and log-rank test. Secondary endpoint was treatment-related in-hospital mortality amongst case and control groups.

RESULTS

Amongst 386 children who fit study criteria, 31 developed VIAKI (8.03%). Thirty-one cases and 93 controls were selected from the observed cohort. Three risk factors were identified for VIAKI: moderate kidney insufficiency (OR 8.8, 2.4-32.8), vancomycin trough concentration ≥ 15 μg/mL (OR 7.7, 1.7-34.4), and furosemide use (OR 24.8, 6.4-98.2). A significant difference in time to VIAKI was noted between patients with moderate kidney insufficiency and patients with mild kidney insufficiency or normal kidney function (p < 0.001). In-hospital mortality rate in case group was 45.2%, compared to 18.3% in control group (p < 0.01).

CONCLUSIONS

Children with moderate kidney insufficiency are more likely to develop VIAKI than those with normal and mild kidney insufficiency. Patients who develop VIAKI have higher in-hospital mortality than those who do not develop VIAKI.

Impact of the Implementation of a Vancomycin Protocol on Trough Serum Vancomycin Concentrations in a Pediatric Intensive Care Unit

BACKGROUND

Vancomycin is an antibiotic that is widely used in pediatric intensive care, but the safe and effective use of this drug is challenging.

OBJECTIVE

This study aimed to assess the impact of a vancomycin protocol on trough serum concentrations.

METHODS

We conducted a retrospective quasiexperimental study in patients aged ≤ 18 years in intensive care who received vancomycin for at least 5 days. Patients were divided into two groups: before and after a protocol implemented in 2017 that suggested an initial vancomycin dose of 60 mg/kg/day, target serum levels of 15-20 μg/mL, and dose adjustments. We compared patient characteristics, target serum level achievement, and vancomycin levels over time.

RESULTS

Each group contained 65 patients; most were male infants with heart disease as the main reason for hospitalization. Only 29.2% of the patients had pretreatment cultures for bacteria identification recorded, with 1.5% identified as methicillin-resistant Staphylococcus aureus. For the first serum levels, 10.8% of patients in the pre-protocol group and 21.5% in the post-protocol group achieved the 15-20 μg/mL target (p = 0.153); during the first 5 days of treatment, this proportion significantly increased from 52.3 to 73.8% (p = 0.018). We observed a difference between the first and fifth levels: 8.9 μg/mL (95% confidence interval [CI] - 3.1 to 21) pre-protocol and 0.4 μg/mL (95% CI - 6.1 to 6.9) post-protocol (p = 0.175).

CONCLUSIONS

Reaching adequate trough vancomycin concentrations in critically ill pediatric patients remains a challenge, and clinical practice protocols allow better dose adjustment and control even when monitoring technologies are unavailable.

Impact of the use of nephrotoxic drugs in critically ill pediatric patients

OBJECTIVE

To evaluate the association between the use of nephrotoxic drugs and acute kidney injury in critically ill pediatric patients.

METHODS

This was a retrospective cohort study involving all children admitted to the intensive care unit of a pediatric hospital during a 1-year period. Acute kidney injury was defined according to the KDIGO classification. Patients with a length of hospital stay longer than 48 hours and an age between 1 month and 14 years were included. Patients with acute or chronic nephropathy, uropathy, congenital or acquired heart disease, chronic use of nephrotoxic drugs, rhabdomyolysis and tumor lysis syndrome were excluded. Patients were classified according to the use of nephrotoxic drugs during their stay at the pediatric intensive care unit.

RESULTS

The sample consisted of 226 children, of whom 37.1% used nephrotoxic drugs, 42.4% developed acute kidney injury, and 7.5% died. The following drugs, when used alone, were associated with acute kidney injury: acyclovir (p < 0.001), vancomycin (p < 0.001), furosemide (p < 0.001) and ganciclovir (p = 0.008). The concomitant use of two or more nephrotoxic drugs was characterized as an independent marker of renal dysfunction (p < 0.001). After discharge from the pediatric intensive care unit, renal function monitoring in the ward was inadequate in 19.8% of cases.

CONCLUSION

It is necessary for intensivist physicians to have knowledge of the main nephrotoxic drugs to predict, reduce or avoid damage to their patients.

Frequency of Exposure of Nephrotoxic Drugs and Drug-Induced Acute Kidney Injury in Pediatric Intensive Care Unit: A Retrospective Review From a Tertiary Care Centre in Pakistan

Introduction

Acute kidney injury (AKI) is one of the most common problems seen in the pediatric intensive care unit (PICU), with an overall 27% incidence. Besides many other factors, nephrotoxic medications (Nephrotoxins; Ntx) are also responsible for a large proportion of potentially avoidable pediatric AKI, directly accounting for 16% of AKI events.

Objective

To assess potential associations between nephrotoxic drugs and the risk of developing AKI in children admitted in PICU.

Material and methods

This is a retrospective cross-sectional study. Children (aged 1 month - 18 years) admitted to the PICU, with a length of stay >24 hours, were included. AKI was defined as according to KDIGO (Kidney Disease Improving Global Outcomes) criteria. Mild AKI was defined as a rise in creatinine value of 0.3 mg/dl from presenting value at a 24-hour interval. Patients were grouped according to the presence or absence of AKI. All medications administered in the ICU were assessed for nephrotoxicity through a review of adverse reactions mentioned in the Pediatric Dosage Handbook, along with consultation with a clinical pharmacist.

Results

Among 752 patients, the mean age was 4.8 years ± 4.37. There were 57.3% male and 42.7% female children. Among the exposed children, 37.4% received one drug, 32.4% received two drugs and 12.1% had high nephrotoxin exposure. The most commonly used drug was vancomycin (16.8%), as a single Ntx; vancomycin/colistin (12.9%), in dual nephrotoxic combination; and vancomycin/colistin/amphotericin (2.9%) in highly exposed children (i.e., with equal or more than three). Overall, the incidence of AKI was 14.9%.

Conclusion

Nephrotoxins are potentially avoidable risk factors in critically ill children. Whenever a combination of medications is required, it’s advisable to review all medications for better protection of kidneys and preventing of acute kidney injury.

Effect of Cystatin C on Vancomycin Clearance Estimation in Critically Ill Children Using a Population Pharmacokinetic Modeling Approach

BACKGROUND

Vancomycin is eliminated by glomerular filtration, but current approaches to estimate kidney function in children are unreliable. The authors sought to compare the suitability of cystatin C (CysC)-based glomerular filtration rate equations with the most commonly used creatinine-based equation, bedside Schwartz, to estimate vancomycin clearance (CL).

METHODS

This prospective observational study enrolled critically ill patients (2-18 years) receiving intravenous vancomycin at the Children's Hospital of Philadelphia during December 2015-November 2017. Vancomycin levels were collected during clinical care and at 3 times during a single dosing interval. Plasma CysC was measured within 24 hours before intravenous vancomycin (baseline) initiation or immediately after enrollment and along with the third pharmacokinetic sample. Nonlinear mixed effects modeling was performed using NONMEM software. Covariate selection was used to test model fit with inclusion of the estimated glomerular filtration rate (eGFR) on CL using bedside Schwartz versus various published CysC-based equations.

RESULTS

In total, 83 vancomycin levels were obtained from 20 children. The median age was 12.7 years; 6 patients were women. A 1-compartment model best described the data; CL was allometrically scaled to 0.75. During covariate selection, inclusion of the eGFR calculated using a CysC-based equation significantly improved model fit [reduction in objective function value (OFV) range: -17.191 to -18.704] than bedside Schwartz ([INCREMENT]OFV -12.820). Including the full age spectrum equation, an eGFR equation based on both creatinine and CysC, led to the largest OFV reduction (-22.913); female sex was also a significant covariate of CL in the model. Final model pharmacokinetic indices were CL = 0.29 L/h/kg and volume of distribution = 0.48 L/kg.

CONCLUSIONS

CysC-based equations help better estimate vancomycin CL than bedside Schwartz in critically ill children.

A whole blood microsampling assay for vancomycin: development, validation and application for pediatric clinical study

Background: Vancomycin is a commonly used antibiotic, which requires therapeutic drug monitoring to ensure optimal treatment. Microsampling assays are attractive tools for pediatric clinical research and therapeutic drug monitoring. Results: A LC-MS/MS method for the quantification of vancomycin in human whole blood employing volumetric absorptive microsampling (VAMS^®) devices (20 μl) was developed and validated. Vancomycin was stable in human whole blood VAMS under assay conditions. Stability for vancomycin was established for at least 160 days as dried microsamples at -78°C. Conclusion: This method is currently being utilized for the quantitation of vancomycin in whole blood VAMS for an ongoing pediatric clinical study and representative clinical data are reported.

Vancomycin Therapeutic Drug Monitoring in Children: New Recommendations, Similar Challenges

The American Society of Health-System Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists have recently published revised guidelines for the therapeutic monitoring of vancomycin. Previous iterations of the guideline largely focused on targeting vancomycin trough concentrations (VTCs) in the range of 15 to 20 mg/L for therapeutic efficacy. The revised guidelines shift the focus of therapeutic monitoring directly to AUC/MIC-based therapeutic monitoring for children, with a suggestion of a goal AUC/MIC 400 to 800. The primary hesitation in applying these recommendations to children stems from the absence of pediatric clinical data demonstrating correlations with clinical outcomes and either VTC or AUC and no benefit in other secondary outcomes (e.g., recurrence, duration of bacteremia). One can glean indirectly from this that such aggressive dosing and monitoring strategies are unnecessary to achieve therapeutic success in the majority of children with serious methicillin-resistant Staphylococcus aureus infections. Providers should carefully weigh the potential unknown benefits of targeting vancomycin AUC 400 to 800 mg*hr/L in children with the known risks of acute kidney injury associated with increasing the dose of vancomycin as well as the substantial time, effort, and costs of this process.

Incidence of Acute Kidney Injury Among Infants in the Neonatal Intensive Care Unit Receiving Vancomycin With Either Piperacillin/Tazobactam or Cefepime

OBJECTIVES

To determine whether combination therapy with vancomycin and TZP is associated with a higher incidence of acute kidney injury (AKI) compared with vancomycin with cefepime in infants admitted to the NICU.

METHODS

This retrospective cohort study included infants in the NICU who received vancomycin/cefepime or vancomycin/TZP for at least 48 hours. The primary outcome was incidence of AKI, which was defined by the neonatal modified Kidney Disease Improving Global Outcomes AKI criteria.

RESULTS

Forty-two infants who received vancomycin with cefepime and 58 infants who received vancomycin with TZP were included in the analysis. The median gestational age at birth, birth weight, and dosing weight were lower in the TZP group, but other baseline characteristics were comparable, including corrected gestational age. Two patients (3%) receiving vancomycin/TZP versus 2 patients (5%) receiving vancomycin/cefepime met criteria for AKI during their antibiotic course (p = 1.00). There were no clinically significant changes in serum creatinine or urine output from baseline to the end of combination antibiotic treatment in either group.

CONCLUSIONS

Among infants admitted to our NICU, AKI incidence associated with vancomycin and either TZP or cefepime therapy was low and did not differ by antibiotic combination.

Vancomycin-associated Nephrotoxicity and Risk Factors in Critically Ill Children Without Preexisting Renal Injury

BACKGROUND

A recent systematic review concluded that critically ill pediatric patients have higher odds of vancomycin-related nephrotoxicity [odds ratio (OR): 3.61, 95% CI: 1.21-10.74]. We aimed to assess the incidence and risk factors for vancomycin-associated nephrotoxicity in critically ill children without preexisting renal injury.

METHODS

A cohort of children admitted to a pediatric intensive care unit, from 2011 to 2016 treated with vancomycin without preexisting renal injury. The main diagnosis, therapeutic interventions and medications administered in this period were evaluated. Generalized estimating equation models were used to assess the association between clinical covariates and the dependent variable pediatric risk, injury, failure, loss, end-stage renal disease (pRIFLE).

RESULTS

Hundred ten patients, representing 1177 vancomycin days, were analyzed. Vancomycin-associated nephrotoxicity was seen in 11.8%. In a multivariate model, higher vancomycin doses were not associated with poorer renal function (P = 0.08). Higher serum vancomycin levels were weakly associated with pRIFLE classification (OR: 1.05, 95% CI: 1.02-1.07). Furosemide or amphotericin B in addition to the vancomycin treatment was associated with impaired renal function (OR: 2.56, 95% CI: 1.38-4.8 and OR: 7.7 95% CI: 2.55-23, respectively).

CONCLUSIONS

Vancomycin-associated nephrotoxicity in acute ill children without preexisting renal injury, measured with pRIFLE, is close to 11.8%. Furosemide and amphotericin B in addition to the vancomycin treatment are strong predictors of worse pRIFLE scores. The influence of acute kidney injury status at pediatric intensive care unit admission and the method used for renal function assessment might influence the incidence of vancomycin-associated nephrotoxicity and its associated risk factors.

Vancomycin-Associated Acute Kidney Injury in Critically Ill Adolescent and Young Adult Patients

BACKGROUND

Risk factors for the development of vancomycin-associated acute kidney injury (AKI) have been evaluated in both pediatric and adult populations; however, no previous studies exist evaluating this in the critically ill adolescent and young adult patients.

OBJECTIVE

Identify the incidence of AKI and examine risk factors for the development of AKI in critically ill adolescents and young adults on vancomycin.

METHODS

This retrospective review evaluated the incidence of AKI in patients 15 to 25 years of age who received vancomycin, while admitted to an intensive care unit. Acute kidney injury in this population was defined as an increase in serum creatinine by 0.5 mg/dL or 50% from baseline. Patients who developed AKI were evaluated for specific risk factors compared to those who did not develop AKI.

RESULTS

A total of 50 patients (20 developed AKI) were included in the study. There was no difference in vancomycin daily dose or duration of vancomycin therapy. Maximum vancomycin trough (31.15 mg/dL vs 12.5 mg/dL, P = .006), percentage of patients with concurrent nephrotoxic medication (95% vs 60%, P = .012) and concurrent vasopressor (55% vs 23%, P = .029) were higher in those who developed AKI. Percentage of patients who underwent a procedure while on vancomycin (35% vs 6.7%, P = .021) was also higher within the AKI group.

CONCLUSIONS

Vancomycin-associated AKI occurred in 40% of critically ill adolescent and young adult patients. These patients may be more likely to develop vancomycin-associated AKI if they had undergone a procedure, as well as in the presence of high vancomycin trough levels, concurrent nephrotoxic agents, and concurrent vasopressor therapy.

Nephrotoxicity With Vancomycin in the Pediatric Population: A Systematic Review and Meta-Analysis

BACKGROUND

Vancomycin is frequently used to treat methicillin-resistant Staphylococcus aureus infections in pediatric patients. Vancomycin exposure may lead to an increase in frequency of nephrotoxicity. Our aim was to conduct a systematic review to describe predictors of nephrotoxicity associated with vancomycin, including documented trough concentrations ≥15 mg/L. We also aimed to use a meta-analysis to assess the impact of a vancomycin trough ≥15 mg/L on nephrotoxicity.

METHODS

A literature search was performed using PubMed, Cochrane Library, Embase and Web of Sciences database. We included randomized clinical trials and observational studies evaluating the relationship between vancomycin troughs and nephrotoxicity in pediatric-age patients. Studies not measuring troughs or defining a different cut-off point than 15 mg/L were excluded. Data on age, exclusion criteria, nephrotoxicity definition, risk factors for nephrotoxicity and vancomycin trough levels were extracted from selected papers.

RESULTS

Ten studies were identified for meta-analysis. All subjects had comparatively normal baseline serum creatinine values. Common risk factors identified included elevated (≥15 mg/L) trough levels, renal impairment, hypovolemia and concurrent use of nephrotoxic medications. Troughs ≥15 mg/L increased nephrotoxicity by 2.7-fold (odds ratio (OR), 2.71; 95% confidence interval: 1.82-4.05; I(2) = 40%; Q = 0.09). These odds were further increased among patients in the pediatric intensive care unit (OR, 3.61; 95% confidence interval: 1.21-10.74; I(2) = 45%; Q = 0.18).

CONCLUSIONS

Though the rate of vancomycin-induced nephrotoxicity is increased in pediatric patients with higher vancomycin troughs, other factors such as intensive care unit admission, hypovolemia and concurrent nephrotoxic drug use appear to contribute to the development of nephrotoxicity.

Ceftaroline for Suspected or Confirmed Invasive Methicillin-Resistant Staphylococcus aureus: A Pharmacokinetic Case Series

OBJECTIVES

To describe the ceftaroline pharmacokinetics in critically ill children treated for suspected or confirmed methicillin-resistant Staphylococcus aureus infections, including blood stream infection and describe the microbiological and clinical outcomes.

DESIGN

Retrospective electronic medical record review.

SETTINGS

Free-standing tertiary/quaternary pediatric children's hospital.

PATIENTS

Critically ill children receiving ceftaroline monotherapy or combination therapy for suspected or confirmed methicillin-resistant S. aureus infections in the PICU.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Seven patients, three females (43%), and four males (57%), accounted for 33 ceftaroline samples for therapeutic drug management. A median of four samples for therapeutic drug management was collected per patient (range, 2-9 samples). The median age was 7 years (range, 1-13 yr) with a median weight of 25.5 kg (range, 12.6-40.1 kg). Six of seven patients (86%) demonstrated an increase in volume of distribution, five of seven patients (71%) demonstrated an increase in clearance, and 100% of patients demonstrated a shorter half-life estimate as compared with the package insert estimate. Six of seven patients (85.7%) had documented methicillin-resistant S. aureus growth from a normally sterile site with five of six (83.3%) having documented BSI, allowing six total patients to be evaluated for the secondary objective of microbiological and clinical response. All six patients achieved a positive microbiological and clinical response for a response rate of 100%.

CONCLUSIONS

These data suggest the pharmacokinetics of ceftaroline in PICU patients is different than healthy pediatric and adult patients, most notably a faster clearance and larger volume of distribution. A higher mg/kg dose and a more frequent dosing interval for ceftaroline may be needed in PICU patients to provide appropriate pharmacodynamic exposures. Larger pharmacokinetic, pharmacodynamic, and interventional treatment trials in the PICU population are warranted.

Incidence and Risk Factors for Vancomycin Nephrotoxicity in Acutely Ill Pediatric Patients

Background: Particularly with the current increased vancomycin dosing trends, the true risk of the agent's nephrotoxicity is not well characterized and remains of concern. Objective: To determine the incidence of vancomycin nephrotoxicity in acutely ill hospitalized children and to secondarily characterize the risk factors for this complication. Methods: A single-center retrospective cohort study conducted at UCSF Benioff Children's Hospital from June 2012 to June 2015. Inpatients 3 months to <19 years who received intravenous vancomycin for ≥48 hours were included. The primary outcome was incidence of nephrotoxicity, defined as an increase in serum creatinine by ≥50% from baseline. Univariate and multivariate analyses were conducted to identify risk factors for vancomycin nephrotoxicity. Results: A total of 291 patients (272 nonnephrotoxic and 19 nephrotoxic) were included in the analysis. Of the 19 patients, 12 (4.1%) were found to have moderate to severe toxicity. The median duration of therapy was 3 (3-5) and 4 (3-6) days for the group with "no nephrotoxicity" and "nephrotoxicity," respectively. The mean time for the serum creatinine to return to normal in patients with nephrotoxicity was 5.1 days. In the multivariate analysis, only final trough concentration ≥15mg/dL (odds ratio = 3.49, 95% confidence interval = 1.2-10.1; P = .021) and receipt of piperacillin/tazobactam (odds ratio = 3.14, 95% confidence interval = 1.02-9.6; P = .046) were significantly associated with nephrotoxicity. Conclusion: The rate of moderate to severe vancomycin-associated nephrotoxicity in acutely ill children is relatively uncommon and reversible. Kidney injury is associated with increased vancomycin trough concentrations and concomitant receipt of nephrotoxins, particularly piperacillin/tazobactam.

Pediatric acute kidney injury induced by concomitant vancomycin and piperacillin-tazobactam

BACKGROUND

Vancomycin is very commonly used in combination with piperacillin-tazobactam (PTZ) as the initial empiric treatment for moderate-severe infection, whenever coverage for both methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa is required. The combination of vancomycin and PTZ in adults has recently been reported to significantly increase the risk of acute kidney injury (AKI) relative to vancomycin monotherapy; such reports in pediatrics, however, are sparse.

METHODS

A retrospective chart review was conducted of pediatric patients, aged 0-14 years, who were admitted to the general wards or intensive care unit and developed AKI after receiving vancomycin and PTZ concomitantly for >48 h. AKI is defined as a decrease in estimated glomerular filtration rate ≥50% from baseline. Cases were identified by reviewing the Adverse Drug Reaction program database at King Saud University Medical City in Saudi Arabia from January 2015 to June 2016.

RESULTS

Eight children admitted to the present hospital and who received concomitant vancomycin and PTZ treatment for pneumonia (n = 7) or febrile neutropenia (n = 1) developed drug-induced nephrotoxicity. Drug Interaction Probability Scale (DIPS) score for causation assessment was 9 in all cases (highly probable).

CONCLUSION

Caution in utilizing the combination of vancomycin and PTZ is warranted in pediatric patients. Health-care professionals should be vigilant if this combination is to be initiated, and ensure close monitoring of renal function. Antibiotic therapy de-escalation should be considered as soon as culture results are available.

Association of Acute Kidney Injury With Concomitant Vancomycin and Piperacillin/Tazobactam Treatment Among Hospitalized Children

IMPORTANCE

β-Lactam antibiotics are often coadministered with intravenous (IV) vancomycin hydrochloride for children with suspected serious infections. For adults, the combination of IV vancomycin plus piperacillin sodium/tazobactam sodium is associated with a higher risk of acute kidney injury (AKI) compared with vancomycin plus 1 other β-lactam antibiotic. However, few studies have evaluated the safety of this combination for children.

OBJECTIVE

To assess the risk of AKI in children during concomitant therapy with vancomycin and 1 antipseudomonal β-lactam antibiotic throughout the first week of hospitalization.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study focused on children hospitalized for 3 or more days who received IV vancomycin plus 1 other antipseudomonal β-lactam combination therapy at 1 of 6 large children's hospitals from January 1, 2007, through December 31, 2012. The study used the Pediatric Health Information System Plus database, which contains administrative and laboratory data from 6 pediatric hospitals in the United States. Patients with underlying kidney disease or abnormal serum creatinine levels on hospital days 0 to 2 were among those excluded. Patients 6 months to 18 years of age who were admitted through the emergency department of the hospital were included. Data were collected from July 2015 to March 2016. Data analysis took place from April 2016 through July 2017. (Exact dates are not available because the data collection and analysis processes were iterative.).

MAIN OUTCOMES AND MEASURES

The primary outcome was AKI on hospital days 3 to 7 and within 2 days of receiving combination therapy. Acute kidney injury was defined using KDIGO criteria and was based on changes in serum creatinine level from hospital days 0 to 2 through hospital days 3 to 7. Multiple logistic regression was performed using a discrete-time failure model to test the association between AKI and receipt of IV vancomycin plus piperacillin/tazobactam or vancomycin plus 1 other antipseudomonal β-lactam antibiotic.

RESULTS

A total of 1915 hospitalized children who received combination therapy were identified. Of the 1915 patients, a total of 866 (45.2%) were female and 1049 (54.8%) were male, 1049 (54.8%) were identified as white in race/ethnicity, and the median (interquartile range) age was 5.6 (2.1-12.7) years. Among the cohort who received IV vancomycin plus 1 other antipseudomonal β-lactam antibiotic, 157 patients (8.2%) had antibiotic-associated AKI. This number included 117 of 1009 patients (11.7%) who received IV vancomycin plus piperacillin/tazobactam combination therapy. After adjustment for age, intensive care unit level of care, receipt of nephrotoxins, and hospital, IV vancomycin plus piperacillin/tazobactam combination therapy was associated with higher odds of AKI each hospital day compared with vancomycin plus 1 other antipseudomonal β-lactam antibiotic combination (adjusted odds ratio, 3.40; 95% CI, 2.26-5.14).

CONCLUSIONS AND RELEVANCE

Coadministration of IV vancomycin and piperacillin/tazobactam may increase the risk of AKI in hospitalized children. Pediatricians must be cognizant of the potential added risk of this combination therapy when making empirical antibiotic choices.

MBD2 upregulates miR-301a-5p to induce kidney cell apoptosis during vancomycin-induced AKI

Despite DNA methylation occurred in acute kidney injury (AKI), how it influenced progression of AKI remains unclear. Methyl-CpG-binding domain protein 2 (MBD2), a protein readers of methylation, was used to analyze the impact of DNA methylation on vancomycin (VAN)-induced AKI. Here, in cultured human kidney tubular epithelial cells (HK-2), we show that knockdown of MBD2 by siRNA attenuated VAN-induced apoptosis, caspase activity, and the expression of BAX and cleaved caspase 3. Interestingly, knockdown of MBD2 by siRNA was associated with the suppression of miR-301a-5p. Mechanistic studies confirmed MBD2 binds to these methylated CpG elements of miR-301a-5p promoter, and then activates miR-301a-5p promoter by suppressing methylation. Furthermore, anti-miR-301a-5p significantly blocked VAN-induced apoptosis and caspase activity in HK-2 cells, which was accompanied by downregulation of p53, and upregulation of MITF, HDGF and MDM-4 together. The latter genes were further identified as target genes of miR-301a-5p, and silencing of MDM-4 promoted p53 accumulation. In vivo, mice with MBD2 knockout (MBD2-KO) were counteracted to VAN-induced AKI, indicated by the analysis of renal function, histology, apoptosis and inflammation. MBD2-KO also significantly suppressed the expression of miR-301a-5p, p53, BAX and cleaved caspase 3, and restored the expression of MDM-4, MITF and HDGF. Finally, in vivo inhibition of miR-301a-5p also ameliorated VAN-induced AKI. Together, these results show the novel MBD2/miR-301a-5p/MITF, HDGF and MDM-4/p53 pathway in VAN-induced AKI.

Piperacillin-tazobactam versus cefepime incidence of acute kidney injury in combination with vancomycin and tobramycin in pediatric cystic fibrosis patients

BACKGROUND

Cystic fibrosis (CF) patients often receive prolonged courses of broad spectrum antibiotics, such as piperacillin-tazobactam or cefepime in combination with vancomycin and tobramycin. The objective of this study was to determine the difference in AKI for pediatric CF patients receiving piperacillin-tazobactam or cefepime in combination with vancomycin and tobramycin.

METHODS

IRB approval from a single CF center was obtained for this retrospective cohort study. Charts were evaluated from December 1, 2008 to June 30,2015. Patients were included if they had a diagnosis of CF, age 30 days to 18 years, and received intravenous vancomycin, tobramycin, and piperacillin-tazobactam or cefepime. The primary outcome was difference of AKI incidence in patients receiving piperacillin-tazobactam or cefepime, as defined by modified pediatric risk, injury, failure, loss, end stage renal disease (pRIFLE) criteria.

RESULTS

Seventy-one patients were included with a median (interquartile range) age 11 years (7-16) and weight 36.2 kg (22.7-50). AKI was identified in 54.5% (18/33) of patients receiving piperacillin-tazobactam and 13.2% (5/38) of patients receiving cefepime (P ≤ 0.0001). One patient receiving piperacillin-tazobactam experienced acute renal failure. There was a slight difference in length of admission (13 vs 10 days, P = 0.042), but no difference in days to maximum SCr (6 vs 3, P = 0.127) nor FEV1 percent predicted on admission (69% vs 65%, P = 1.00).

CONCLUSIONS

AKI occurred in nearly 55% of patients with piperacillin-tazobactam therapy versus 13% of patients with cefepime therapy, which suggests cefepime may be preferred in combination with vancomycin and tobramycin for pediatric CF patients.

Identifying High-Risk Medications Associated with Acute Kidney Injury in Critically Ill Patients: A Pharmacoepidemiologic Evaluation

BACKGROUND

Nephrotoxic medications are a common cause of acute kidney injury (AKI). Critically ill children receive more medication than other inpatients; however, the risk of nephrotoxic medication-induced AKI in these children is not well understood.

OBJECTIVE

The aim of this study was to determine the association between exposure to nephrotoxic medications in the intensive care unit (ICU) and the development of AKI amongst critically ill children, adjusting for differences in underlying risk.

METHODS

We conducted a nested case-control study among a cohort of patients admitted to a paediatric intensive care unit between January 2006 and June 2009. Cases were identified according to the RIFLE criteria. Using incidence density sampling, controls were matched 1:1 according to pre-ICU nephrotoxic drug exposure. Administration of nephrotoxic medications and other known risk factors of AKI were evaluated during the ICU stay prior to the diagnosis of AKI.

RESULTS

A total of 914 patients in the cohort developed AKI and had an identifiable matched control. Eighty-seven percent of cases and 74% of controls were exposed to one or more nephrotoxic medications in the ICU during the study period. Furosemide (administered to 67.8% of patients), vancomycin (28.7%), and gentamicin (21.4%) were the most frequently administered nephrotoxic drugs. Patients who developed AKI were more likely to be exposed to at least one nephrotoxic medication and risk increased with increasing number of nephrotoxic medications. Ganciclovir (adjusted odds ratio [AOR] 4.7; 95% CI 1.7-13.0), furosemide (AOR 1.9; 95% CI 1.4-2.4), and gentamicin (AOR 1.8; 95% CI 1.4-2.4) significantly increased the odds of developing AKI after adjusting for underlying differences in risk factors of AKI.

CONCLUSION

This is the first study to assess the association between risk-adjusted nephrotoxic medication exposure and the development of AKI in critically ill children. Nephrotoxic medication exposure was common amongst children in the ICU and we found AKI was associated with the administration of specific drugs after adjustment for important risk factors.

Drug-associated acute kidney injury: who's at risk?

The contribution of nephrotoxic medications to the development of acute kidney injury (AKI) is becoming better understood concomitant with the increased incidence of AKI in children. Treatment of AKI is not yet available, so prevention continues to be the most effective approach. There is an opportunity to mitigate severity and prevent the occurrence of AKI if children at increased risk are identified early and nephrotoxins are used judiciously. Early detection of AKI is limited by the dependence of nephrologists on serum creatinine as an indicator. Promising new biomarkers may offer early detection of AKI prior to the rise in serum creatinine. Early detection of evolving AKI is improving and offers opportunities for better management of nephrotoxins. However, the identification of patients at increased risk will remain an important first step, with a focus on the use of biomarker testing and interpretation of the results.

Frequency of and Risk Factors for Acute Kidney Injury Associated With Vancomycin Use in the Pediatric Intensive Care Unit

BACKGROUND: Published information evaluating frequency of and risk factors for vancomycin-induced acute kidney injury (AKI) in the pediatric intensive care unit (PICU) population is conflicting. OBJECTIVES: The primary objective was to describe the proportion of our PICU patients who developed AKI with intravenous (IV) vancomycin. The secondary objective was to describe the associated potential risk factors. METHODS: Pediatric patients (0-18 years) who received their first IV vancomycin dose in the PICU were evaluated in this retrospective chart review. AKI was defined based on Pediatric-Modified RIFLE (pRIFLE) criteria. Patient demographics, vancomycin trough concentrations, concomitant nephrotoxins, and estimated creatinine clearance changes were analyzed. RESULTS: Of 265 patients included, the primary outcome of AKI (defined by meeting any pRIFLE criteria) occurred in 62 (23.4%) patients (48 category R, 11 category I, 3 category F). Patients who received vancomycin treatment for = 5 days were more likely to develop AKI (unadjusted odds ratio [uOR]: 2.52; 95% confidence interval [CI]: 1.11-5.73), as were patients with a maximum vancomycin trough level = 20 mg/L (OR: 2.99; 95% CI: 1.54-5.78) and patients on 1 (uOR: 2.29; 95% CI: 1.12-4.66) or more concurrent nephrotoxin (uOR: 3.11; 95% CI: 1.43-6.77). Among nephrotoxins, patients receiving furosemide concomitantly with vancomycin were more likely to develop AKI (uOR: 3.47; 95% CI: 1.92-6.27). After adjustment, only furosemide was a significant predictor of risk of AKI/AKI (adjusted OR: 3.52; 95% CI: 1.88-6.62). The study was limited by its retrospective and observational design, and confounding variables. CONCLUSIONS: Patients who were receiving vancomycin with concurrent furosemide were at highest risk of developing AKI.

Drug Class Combination–Associated Acute Kidney Injury

Objective: To evaluate the quality of available evidence of drug class combinations and their association with the development of acute kidney injury (AKI). Data Sources: A search of MEDLINE and Embase databases was completed using the following terms: “risk factor AND (acute kidney injury or acute kidney failure) AND (drug or medication).” Study Selection and Data Extraction: Inclusion criteria were the following: English language, full-text availability, and at least 1 drug-combination. Each citation was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria. The literature was evaluated using the quality of evidence component of GRADE. No standardized definition of AKI was applied throughout.. Data Synthesis: Out of 2139 total citations, 151 were assessed for full-text review, with 121 citations (6%) meeting inclusion criteria, producing76 unique drug class combinations. Overall, 56 combinations (73.7%) were considered very low quality; 12 (15.8%) were considered low quality. There were 8 (10.5%) of moderate quality, and no combination was considered high quality. 58 (76%) combinations that had a single citation,with a mean of 1.6 citations per drug class combination. The combination of nonsteroidal anti-inflammatory drugs (NSAIDs) and diuretics was reported in 10 citations, the largest number of citations. Conclusions: Our study demonstrates a lack of well-designed studies addressing drug class combination–associated AKI. The combination of NSAIDs and diuretics with or without additional renin-angiotensin aldosterone agents had the strongest level of evidence. Despite limitations, the information included in this review may result in additional scrutiny about combining certain individual nephrotoxic drugs.

Review of vancomycin-induced renal toxicity: an update

In recent times the use of larger doses of vancomycin aimed at curbing the increasing incidence of resistant strains of Staphylococcus aureus has led to a wider report of acute kidney injury (AKI). Apart from biological plausibility, causality is implied by the predictive association of AKI with larger doses, longer duration, and graded plasma concentrations of vancomycin. AKI is more likely to occur with the concurrent use of nephrotoxic agents, and in critically ill patients who are susceptible to poor renal perfusion. Although most vancomycin-induced AKI cases are mild and therefore reversible, their occurrence may be associated with greater incidence of end-stage kidney disease and higher mortality rate. The strategy for its prevention includes adequate renal perfusion and therapeutic drug monitoring in high-risk individuals. In the near future, there is feasibility of renoprotective use of antioxidative substances in the delivery of vancomycin.

Vancomycin Dosing and Pharmacokinetics in Postoperative Pediatric Cardiothoracic Surgery Patients

OBJECTIVES

This study compared vancomycin trough concentrations and pharmacokinetic parameters in pediatric cardiothoracic surgery (CTS) patients versus those in controls receiving 20 mg/kg/dose, intravenously, every 8 hours.

METHODS

A retrospective study was conducted in children <18 years of age, following CTS, versus an age-and sex-matched control group. The primary objective was to determine differences in trough concentrations between groups. Secondary objectives included comparisons of pharmacokinetics between groups and development of vancomycin-associated acute kidney injury (AKI), defined as a doubling in serum creatinine from baseline. Also dosing projections were developed to target an area-under-the-curve-to-minimum inhibitory concentration (AUC:MIC) ratio of ≥400.

RESULTS

Twenty-seven patients in each group were evaluated. Mean trough concentrations were significantly different between groups (CTS: 18.4 mg/L; control: 8.8 mg/L; p < 0.01). Vancomycin-associated acute kidney injury AKI was significantly higher in the CTS group than in controls (25.9% versus 0%, respectively, p<0.01). There were significant differences in vancomycin elimination rates, with a high degree of variability, but no statistical differences in other parameters. Based on dosing projections, CTS patients would require 21 to 88 mg/kg/day, with a dosage interval determined by the child's glomerular filtration rate to achieve the target AUC:MIC ≥400.

CONCLUSIONS

Vancomycin dosage of 20 mg/kg/dose intravenously every 8 hours achieved significantly higher trough concentrations in CTS patients than in controls. Pharmacokinetic parameters were highly variable in CTS patients, indicating more individualization of dosage is needed. A future prospective study is needed to determine whether the revised dosage projections achieve the AUC:MIC target and to determine whether these regimens are associated with less vancomycin-associated AKI.

Healthcare-associated Staphylococcus aureus Bacteremia in Children: Evidence for Reverse Vancomycin Creep and Impact of Vancomycin Trough Values on Outcome

INTRODUCTION

Elevated vancomycin minimum inhibitory concentrations (MICs) in Staphylococcus aureus have been associated with worse clinical outcomes in adults. For invasive meticillin-resistant S. aureus (MRSA) infections in adults, the Infectious Diseases Society of America recommends targeting vancomycin serum trough concentrations between 15 and 20 μg/mL. We evaluated trends in vancomycin MICs from healthcare-associated (HCA) S. aureus bacteremia isolates in children in addition to correlating vancomycin serum trough levels with clinical outcomes.

METHODS

Patients and isolates were identified from a prospective S. aureus surveillance study at Texas Children's Hospital (TCH). HCA S. aureus bacteremia isolates from 2003 to 2013 were selected. Vancomycin MICs by E-test were determined and medical records were reviewed. Acute kidney injury (AKI) was defined as doubling of the baseline serum creatinine.

RESULTS

Three hundred forty-one isolates met inclusion criteria. We observed a reverse vancomycin creep among MRSA isolates in the study period with a decline in the proportion of isolates with vancomycin MIC ≥ 2 μg/mL (from 32.7% to 5.6%; P < 0.001). However, the proportion of MSSA isolates with MIC ≥ 2 μg/mL increased (from 2.9% to 9%; P = 0.04). Among patients who had vancomycin troughs performed, there was no difference in duration of bacteremia or fever with vancomycin trough >15 versus <15 μg/mL. A vancomycin trough >15 μg/mL was, however, an independent risk factor for AKI.

CONCLUSIONS

Vancomycin MICs are shifting among HCA S. aureus bacteremia isolates with significant differences between MRSA and MSSA at TCH. Higher vancomycin troughs did not improve outcomes in pediatric HCA S. aureus bacteremia but were associated with increased nephrotoxicity. Further studies are needed to better understand optimal management of children with S. aureus bacteremia.

Drugs as risk factors of acute kidney injury in critically ill children

BACKGROUND

Acute kidney injury (AKI) is a serious condition in critically ill children. Nephrotoxic medication exposure is a common contributing factor to AKI, but little literature is available in pediatrics. The aim of the present study was to assess potential associations between drugs and the risk of developing AKI.

METHODS

We performed a retrospective case-control study in a pediatric intensive care unit (PICU). Cases were patients who developed AKI during PICU stay. Patients without AKI served as controls and were matched to cases by age and gender in a one-to-one ratio.

RESULTS

One hundred case-control pairs were included. Cases were not statistically different from controls with regard to median weight and main diagnoses, but differed with regard to the need for mechanical ventilation, severity of illness, and median length of PICU stay. Multivariate models revealed a statistically significant higher risk of developing AKI for patients treated with metamizole, morphine, paracetamol, and tropisetron. A similar risk could be shown for medication groups, namely glucocorticoids, betalactam antibiotics, opioids, and non-steroidal anti-inflammatory drugs.

CONCLUSIONS

The results suggest that drugs are associated with acute renal dysfunction in critically ill children, but the multifactorial causes of AKI should be kept in mind.

Pharmacodynamic Characteristics of Nephrotoxicity Associated With Vancomycin Use in Children

BACKGROUND

Limited studies incorporating population-based pharmacokinetic modeling have been conducted to determine pharmacodynamic indices associated with nephrotoxicity during vancomycin exposure in children.

METHODS

A retrospective cohort analysis was conducted from September 2003 to December 2011 at 2 hospitals. Nephrotoxicity was defined as an increase in serum creatinine concentration (SCr) by ≥0.5 mg/dL, or ≥50% increase in baseline SCr, either persisting for ≥2 consecutive days. A 1-compartment model with first-order kinetics was used in NONMEM 7.2 to estimate trough concentrations (Cmin) and area under the curve over 24 hours (AUC). Univariate, classification and regression tree (CART), and multivariate analyses were conducted to identify factors contributing to nephrotoxicity.

RESULTS

The analyses included 680 pediatric subjects with 1576 vancomycin serum concentrations. Based on univariate analysis, median Cmin (14.2 [interquartile range, IQR, 7.1-25.4] vs 8.4 [IQR, 5.5-12.4] mcg/mL; P = .001) and AUC (544 [IQR, 359-801] vs 378 [IQR, 304-494]; P < .001) were significantly higher in the nephrotoxic group compared with the non-nephrotoxic group. Using CART, we discovered that subjects with doses ≥60 mg/kg per day and AUC >1063 mg-h/L had a significantly higher occurrence of nephrotoxicity (P = .005). Adjusting for intensive care unit stay and concomitant nephrotoxic drugs, steady-state vancomycin Cmin ≥15 mcg/mL (adjusted odds ratio [aOR], 2.5; 95% confidence interval [CI], 1.1-5.8; P = .028) and AUC ≥800 mg-h/L (aOR, 3.7; 95% CI, 1.2-11.0; P = .018) were associated with increased risk of nephrotoxicity.

CONCLUSIONS

Our study describes the pediatric exposure-nephrotoxicity relationships for vancomycin. Vancomycin Cmin ≥15 mcg/mL and AUC ≥800 mg-h/L in children are independently associated with a > 2.5-fold increased risk of nephrotoxicity and may provide justification for use of alternative antibiotics in selected situations.

Evaluation of Target Attainment of Vancomycin Area Under the Curve in Children With Methicillin-Resistant Staphylococcus Aureus Bacteremia

BACKGROUND

Vancomycin is often required to treat methicillin-resistant Staphylococcus aureus bacteremia in children. Treatment failure occurs in up to 50% of adults and is associated with a 24-hour area under the curve/minimum inhibitory concentration (AUC24h/MIC) <400. We sought to identify patient factors associated with vancomycin AUC and whether AUC24h/MIC <400 was predictive of treatment failure in children.

METHODS

Hospitalized children younger than 18 years with methicillin-resistant Staphylococcus aureus bacteremia receiving vancomycin were included in a retrospective cohort study. AUC24h was calculated using a validated pharmacokinetic model. Factors such as age, sex, underlying conditions, presence of foreign bodies, patient site of infection, and markers of illness severity were examined for an association with vancomycin AUC, and AUC24h/MIC was evaluated for an association with treatment failure.

RESULTS

Subjects requiring intensive care unit support were significantly more likely to have higher vancomycin AUC24h and AUCavg than those subjects not needing intensive care unit support. Although vancomycin serum trough concentrations are predictive of vancomycin AUC, suboptimal exposure of vancomycin occurred in almost 20% of subjects despite trough concentrations within the target range. A relationship between vancomycin AUC24h/MIC and treatment failure could not be established.

CONCLUSIONS

To ensure optimal AUC/MIC pharmacodynamic index, especially in critically ill patients, estimation of the AUC is critical.

Late-Occurring Vancomycin-Associated Acute Kidney Injury in Children Receiving Prolonged Therapy

Background: Acute kidney injury (AKI) in patients receiving vancomycin has been associated with trough concentrations ≥15 mg/L and longer therapy duration. The objective of this study was to determine the incidence and factors associated with late AKI in children receiving ≥8 days of vancomycin therapy. Methods: Children aged 30 days to 17 years who were admitted to our institution and received intravenous vancomycin for at least 8 days during January to December of 2007 and 2010 and had a suspected or proven gram-positive infection were included. Late AKI was categorized as AKI occurring after the first 7 days of therapy and within 48 hours following vancomycin discontinuation. The primary outcome was incidence of late AKI as determined by modified pRIFLE criteria. Results: One-hundred sixty-seven patients were included, with a median (interquartile range) age (years) and weight (kg) of 2 (1-7) and 12.5 (8.9-23.8). Late AKI was identified in 12.6% (21/167). A higher percentage of late AKI patients received concomitant treatment with intravenous acyclovir, amphotericin products, or piperacillin-tazobactam. Age <1 year was the only factor independently associated with late AKI development (odds ratio = 4.4; 95% confidence interval = 1.3-15.4). Conclusions: Late AKI occurred in nearly 13% of children receiving ≥8 days of vancomycin therapy. This study suggests that vancomycin trough concentrations are not associated with late AKI, but that age <1 year and concomitant administration of certain nephrotoxins may be factors associated with increased risk.

Balancing vancomycin efficacy and nephrotoxicity: should we be aiming for trough or AUC/MIC?

Sixty years later, the question that still remains is how to appropriately utilize vancomycin in the pediatric population. The Infectious Diseases Society of America published guidelines in 2011 that provide guidance for dosing and monitoring of vancomycin in adults and pediatrics. However, goal vancomycin trough concentrations of 15-20 μg/mL for invasive infections caused by methicillin-resistant Staphylococcus aureus were based primarily on adult pharmacokinetic and pharmacodynamic data that achieved an area under the curve to minimum inhibitory concentration ratio (AUC/MIC) of ≥400. Recent pediatric literature shows that vancomycin trough concentrations needed to achieve the target AUC/MIC are different than the adult goal troughs cited in the guidelines. This paper addresses several thoughts, including the role of vancomycin AUC/MIC in dosing strategies and safety monitoring, consistency in laboratory reporting, and future directions for calculating AUC/MIC in pediatrics.

Factors Associated With Acute Kidney Injury in Children Receiving Vancomycin

Background: As higher vancomycin doses have been used in children, concern for acute kidney injury (AKI) has increased. Data describing factors associated with AKI, particularly dose-related factors, are limited. Objective: To determine the incidence of AKI in children receiving intravenous vancomycin and to identify factors associated with increased odds of AKI. Methods: A retrospective review of patients admitted to a tertiary academic pediatric hospital from February 2009 to September 2010 was performed. Patients 3 months to <19 years old with normal kidney function, receiving vancomycin for at least 48 hours were included. Incidence of AKI was assessed as defined by the Pediatric-Modified RIFLE criteria. Patients with and without AKI were compared to determine factors associated with increased odds of AKI, focusing on vancomycin dose. Results: Of 175 patients included, 24 (13.7%) met AKI criteria. In a multivariate regression, likelihood of AKI increased with each 5 mg/kg increase in vancomycin dose (odds ratio [OR] = 1.16; 95% CI = 1.01-1.33). Odds of AKI increased with each additional day of therapy (OR = 1.11; 95% CI = 1.01-1.22) and use of concomitant nephrotoxic medications (OR = 5.02; 95% CI = 1.09-23.19). The study was limited by small sample size and retrospective design. Conclusions: AKI was common in children receiving vancomycin. Higher doses of vancomycin were associated with increased odds of AKI. The risks and benefits of higher vancomycin dosing should be considered for each patient. Patients should be monitored closely for AKI, especially with higher doses, extended durations of therapy, or concomitant use of nephrotoxic medications.

Vancomycin monitoring in children using bayesian estimation

BACKGROUND

Optimal monitoring of vancomycin in children needs evaluation using the exposure target with area under the curve (AUC) of the serum concentrations versus time over 24 hours. Our study objectives were to: (1) compare the accuracy and precision of vancomycin AUC estimations using 2 sampling strategies-1 serum concentration sample (1S, near trough) versus 2 samples (2S, near peak and trough) against the rich sample (RS) method; and (2) determine the performance of these strategies in predicting future AUC against an internal validation sample (VS).

METHODS

This was a retrospective cohort study using population-based pharmacokinetic modeling with Bayesian post hoc individual estimations in nonlinear mixed effects modeling (version 7.2). Pediatric subjects 3 months-21 years of age who received vancomycin ≥48 hours and had more than 3 drug samples within the first ≤96 hours of therapy were enrolled. Outcome measures were the accuracy, precision, and internal predictive performance of AUC estimations using 2 monitoring strategies (ie, 1S versus 2S) against the RS (which was derived from modeling all serum vancomycin concentrations obtained anytime during therapy) and VS (from serum concentrations obtained after 96 hours of therapy).

RESULTS

Analysis included 138 subjects with 712 vancomycin serum concentrations. Median age was 6.1 (interquartile range, 2.2-12.2) years, weight 22 (13-38) kg, and baseline serum creatinine 0.37 (0.30-0.50) mg/dL. Both accuracy and precision were improved with the 2S, compared with 1S, for AUC estimations (-2.0% versus -7.6% and 10.3% versus 12.8%, respectively) against the RS. Improved accuracy and precision were also observed for 2S when evaluated against VS in predicting future AUC.

CONCLUSIONS

Compared with 1S, the 2S sampling strategy for vancomycin monitoring improved accuracy and precision in estimating and predicting future AUC. Evaluating 2 drug concentrations in children may be prudent to ensure adequate drug exposure.