Factors associated with vancomycin nephrotoxicity in the critically ill

Acute Kidney Injury in Relation to Nephrotoxic Medication Use Among Critically Ill Children in the Paediatric Intensive Care Unit

Background: Critically ill children are vulnerable to acute kidney injury (AKI) and are often exposed to nephrotoxic medications. Objectives: We aimed to investigate the association between nephrotoxic medications and the risk of AKI in critically ill children admitted to our paediatric intensive care unit (PICU). Methods: Patients aged > 1 month to ≤18 years old were prospectively recruited from 6/2020 to 6/2021. The medication records from 14 days prior to PICU admission to PICU discharge were reviewed. Medication-exposure intensity was defined as the number of concomitant nephrotoxic medications. The relative risk (RR) of nephrotoxic medication exposure indices and other potential predictors for AKI development were determined. Results: Altogether 253 episodes of admissions (median [IQR] age of 4.9 [9.6] years) were enrolled. The AKI incidence was 41.9% and 69.2% of the patients were exposed to ≥1 of the 47 nephrotoxic medications. The total nephrotoxic medication dose (RR: 1.01 [1.00, 1.02]) and medication-exposure intensity (RR: 1.381 [1.101, 1.732]) were significantly associated with AKI development. The risk of AKI increased when the medication-exposure intensity was ≥4 (RR: 3.687 (1.320, 10.301)). During their PICU stay, children with AKI received a higher number (P < .01), total dose (P < .01) and medication exposure intensity (P < .01) of nephrotoxic medications. Children with AKI who received nephrotoxic medications were more likely to have a persistently higher peak-to-baseline ratio (P = .046). Conclusion: Nephrotoxic medication exposure significantly increased the risk of AKI development among critically ill children. The use of nephrotoxic medications among critically ill children at risk for AKI should be monitored frequently.

Determination of a vancomycin nephrotoxicity threshold and assessment of target attainment in hematology patients

An area-under-the-curve (AUC24)-based approach is recommended to guide vancomycin therapeutic drug monitoring (TDM), yet trough concentrations are still commonly used despite associated risks. A definitive toxicity target is lacking, which is important for hematology patients who have a higher risk of nephrotoxicity. The aims were to (1) assess the impact of trough-based TDM on acute kidney injury (AKI) incidence, (2) establish a vancomycin nephrotoxicity threshold, and (3) evaluate the proportion of hematology patients achieving vancomycin therapeutic targets. Retrospective data was collected from 100 adult patients with a hematological malignancy or aplastic anemia who received vancomycin between April 2020 and January 2021. AKI occurrence was determined based on serum creatinine concentrations, and individual pharmacokinetic parameters were estimated using a Bayesian approach. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of pharmacokinetic indices to predict AKI occurrence. The proportion of patients who achieved target vancomycin exposure was evaluated based on an AUC24/MIC ≥400 and the determined toxicity threshold. The incidence of AKI was 37%. ROC curve analysis indicated a maximum AUC24 of 644 mg.h/L over the treatment period was an important predictor of AKI. By Day 4 of treatment, 29% of treatment courses had supratherapeutic vancomycin exposure, with only 62% of courses achieving AUC24 targets. The identified toxicity threshold supports an AUC24 target range of 400-650 mg.h/L, assuming an MIC of 1 mg/L, to optimize vancomycin efficacy and minimize toxicity. This study highlights high rates of AKI in this population and emphasizes the importance of transitioning from trough-based TDM to an AUC-based approach to improve clinical outcomes.

Is It Still Beneficial to Monitor the Trough Concentration of Vancomycin? A Quantitative Meta-Analysis of Nephrotoxicity and Efficacy

This study conducted a quantitative meta-analysis to investigate the association of vancomycin indicators, particularly area under the curve over 24 h (AUC24) and trough concentrations (Ctrough), and their relationship with both nephrotoxicity and efficacy. Literature research was performed in PubMed and Web of Science on vancomycin nephrotoxicity and efficacy in adult inpatients. Vancomycin Ctrough, AUC24, AUC24/minimum inhibitory concentration (MIC), nephrotoxicity evaluation and treatment outcomes were extracted. Logistic regression and Emax models were conducted, stratified by evaluation criterion for nephrotoxicity and primary outcomes for efficacy. Among 100 publications on nephrotoxicity, 29 focused on AUC24 and 97 on Ctrough, while of 74 publications on efficacy, 27 reported AUC24/MIC and 68 reported Ctrough. The logistic regression analysis indicated a significant association between nephrotoxicity and vancomycin Ctrough (odds ratio = 2.193; 95% CI 1.582-3.442, p < 0.001). The receiver operating characteristic curve had an area of 0.90, with a cut-off point of 14.55 mg/L. Additionally, 92.3% of the groups with a mean AUC24 within 400-600 mg·h/L showed a mean Ctrough of 10-20 mg/L. However, a subtle, non-statistically significant association was observed between the AUC24 and nephrotoxicity, as well as between AUC24/MIC and Ctrough concerning treatment outcomes. Our findings suggest that monitoring vancomycin Ctrough remains a beneficial and valuable approach to proactively identifying patients at risk of nephrotoxicity, particularly when Ctrough exceeds 15 mg/L. Ctrough can serve as a surrogate for AUC24 to some extent. However, no definitive cut-off values were identified for AUC24 concerning nephrotoxicity or for Ctrough and AUC24/MIC regarding efficacy.

The Influence of a Therapeutic Drug Monitoring Service on Vancomycin-Associated Nephrotoxicity

Vancomycin's widespread use as the mainstay antibiotic against methicillin-resistant Staphylococcus aureus infections is complicated by its narrow therapeutic index. Therapeutic drug monitoring using area under the concentration-time curve (AUC)-guided dosing is recommended to optimize therapy and prevent vancomycin-associated nephrotoxicity (VAN). In 2018, a consultative therapeutic drug monitoring Advisory Service (the Service) was piloted at an Australian hospital to enable AUC-guided vancomycin dosing. This study sought to compare the incidence of VAN pre- and post-Service implementation. A 4-year retrospective observational study of intravenous vancomycin therapy (greater than 48 hours) in adults (aged 18 years or older), spanning 3 years before and 1-year after implementation of the Service was undertaken. Nephrotoxicity was defined as an increase in serum creatinine concentrations of 26.5 μmol/L or greater or 50% or more from baseline, on 2 or more consecutive days. Univariate analysis was performed to compare patients before and after implementation, and with and without VAN. Independent factors associated with VAN were identified using a multivariate model. In total, 971 courses of vancomycin therapy, administered to 781 patients, were included: 764 courses (603 patients) before implementation and 207 courses (163 patients) after implementation. The incidence of VAN decreased by 5% after Service implementation (15% before implementation vs 10% after implementation; P = .075). Independent factors associated with VAN were sepsis, heart failure, solid-organ transplant, concomitant piperacillin-tazobactam, and average vancomycin AUC during therapy. In conclusion, there was a nonsignificant trend toward a reduced incidence of VAN after the Service. Larger prospective studies are needed to confirm the efficacy of the Service.

A Quasi-Experimental Evaluation of Single Trough-Based Area Under the Curve Guided Dosing on the Incidence of Vancomycin Associated Nephrotoxicity in Veteran Patients

Background: Two common dosing strategies for vancomycin are trough-based and area under the curve (AUC)-based dosing. Objective: To compare the incidence of nephrotoxicity in trough-based dosing group with the single trough-based AUC dosing at the Salem VA Medical Center. Methods: This retrospective study included patients who received trough-based dosing of vancomycin between January 1, 2017, and January 1, 2019 (preimplementation group) and AUC-based dosing (postimplementation) between October 1, 2019, and October 1, 2021, at the Salem VA Medical Center. The primary outcome was nephrotoxicity at 96 hours, 7 days, and entire hospital length of stay (LOS). Secondary outcomes included 30-day readmission and all-cause mortality rates, cumulative doses at 24, 48, and 72 hours, and percentage of patients considered at goal (AUC 400-600 or trough between 10 and 20 mg/L). Propensity score (PS) matching was utilized to adjust for confounding. Results: After PS matching 100 patients were included in preimplementation and 95 patients in the postimplementation group. The average study patient was a 68-year-old white male. There was significant reduction in the risk of nephrotoxicity in postimplementation cohort at 96 hours (adjusted (a)HR: 0.28, 95% CI (0.12-0.66); 7 days (aHR: 0.39, 95% CI (0.18-0.85); and entire hospital LOS (aHR: 0.46, 95% CI (0.22-0.95). Secondary outcomes showed no difference between the groups except significantly higher proportion of patients were considered at therapeutic goal in the postimplementation cohort compared with pre-implementation cohort. Conclusion: This hypothesis generating study shows that AUC-based dosing calculated using single trough concentration may result in reduced rate of nephrotoxicity than trough-based dosing.

Relationship between vancomycin-induced nephrotoxicity and vancomycin trough concentration in older adults: A retrospective observational study

OBJECTIVES

The objective of the study is to investigate the risk factors of vancomycin-induced renal toxicity in older adults, especially in those with chronic kidney disease (CKD) Stages 3-5.

METHODS

In this retrospective observational study, serum vancomycin trough concentrations (VTCs) in patients aged g65 years treated with vancomycin were analyzed, and independent risk factors of vancomycin-induced nephrotoxicity (VIN) were determined by logistic regression analysis.

RESULTS

In total, 321 patients were included in this study. Serum VTC was an independent risk factor for vancomycin-induced renal toxicity in total cohort (odds ratio [OR], 1.07; P = 0.004) as well as in the cohort with CKD Stages 3-5 (OR, 1.09; P = 0.010). A daily dose of vancomycin and Charlson comorbidity index was an independent risk factor for vancomycin-induced renal toxicity in total cohort (OR, 3.63; P = 0.006) and in the cohort with CKD Stage 3-5 (OR, 1.83; P = 0.002), respectively. In older adults with CKD Stages 3a and 3b-5, the VTCs associated with higher risk for vancomycin-induced renal toxicity were 21.5 mg/L and 16.5 mg/L, respectively.

CONCLUSIONS

In older adults, serum VTC is an independent risk factor for VIN. VTCs over 21.5 mg/L and 16.5 mg/L are associated with increased risk of VIN in this population with CKD Stage 3a and 3b-5, respectively.

The influence of vancomycin on renal functions, the predictors and associated factors for nephrotoxicity

BACKGROUND

Vancomycin has been widely used in the last six decades to treat methicillin-resistant S. aureus (MRSA) and other resistant gram-positive infections. The risk of vancomycin toxicity increases with the utilization of higher doses while treating the resistant form of bacterial infections. Nephrotoxicity is one of the major complications reported to be a hinderance in the prognosis of vancomycin therapy.

OBJECTIVES

This hospital-based study aimed to highlight the influence of vancomycin on renal function with special emphasis on identifying the predictors and augmenting factors for nephrotoxicity.

METHODOLOGY

A cross-sectional, unicentric, hospital-based study was conducted at King Fahad Specialist Hospital (KFSH) in Qassim region in Saudi Arabia (KSA). It included 319 hospitalized patients who received vancomycin at intermittent doses (15 to 30 mg/kg IV per day) based on the diseased state. Data regarding vancomycin dose, frequency, duration and data of renal function tests and type of admission were analysed to evaluate their influence on the renal function using parameters such as blood urea, serum creatinine levels and creatinine clearance. One-way ANOVA and Spearman correlation test were used in the analysis of data.

RESULTS

Both male and female patients treated with vancomycin had significantly (p<0.05) elevated blood urea and serum creatinine levels compared to baseline levels while creatinine clearance was non-significantly varied. Increasing age, increasing body weight, higher vancomycin dose and trough levels, increased vancomycin frequency and duration, critically ill patients and site of infection were factors associated with significant (p<0.05) increases in blood urea and serum creatinine levels with reduction in creatinine clearance.

CONCLUSION

Data suggested that vancomycin treatment reduced the renal function in patients and indicated its association with several predictors and confounding factors. The findings of the study might assist in identifying the patients under risk from the vancomycin-induced nephrotoxicity and in designing the preventive strategies to reduce such complications.

When and How to Use MIC in Clinical Practice?

Bacterial resistance to antibiotics continues to be a global public health problem. The choice of the most effective antibiotic and the use of an adapted dose in the initial phase of the infection are essential to limit the emergence of resistance. This will depend on (i) the isolated bacteria and its resistance profile, (ii) the pharmacodynamic (PD) profile of the antibiotic used and its level of toxicity, (iii) the site of infection, and (iv) the pharmacokinetic (PK) profile of the patient. In order to take account of both parameters to optimize the administered treatment, a minimal inhibitory concentration (MIC) determination associated with therapeutic drug monitoring (TDM) and their combined interpretation are required. The objective of this narrative review is thus to suggest microbiological, pharmacological, and/or clinical situations for which this approach could be useful. Regarding the microbiological aspect, such as the detection of antibiotic resistance and its level, the preservation of broad-spectrum β-lactams is particularly discussed. PK-PD profiles are relevant for difficult-to-reach infections and specific populations such as intensive care patients, cystic fibrosis patients, obese, or elderly patients. Finally, MIC and TDM are tools available to clinicians, who should not hesitate to use them to manage their patients.

Drug-induced kidney injury in Chinese critically ill pediatric patients

Background: Drug-induced acute kidney injury (DIKI) is a common adverse drug reaction event but is less known in pediatric patients. The study explored the DIKI in Chinese pediatric patients using the Pediatric Intensive Care database (PIC). Method: We screened pediatric patients with acute kidney injury (AKI) using the KDIGO criteria from the PIC and then assessed the relationship between their drugs and DIKI using the Naranjo scale. For the fifteen frequently used DIKI-suspected drugs, we divided patients into drug-exposed and non-exposed groups, using the outcome of whether DIKI was presented or not. Propensity score matching (PSM) was used to control for the effects of four confounders, age, gender, length of hospital stay, and major diagnosis. Unconditional logistic regression was used to identify statistically significant differences between the two groups. Results: A total of 238 drugs were used 1,863 times by the 81 patients with DIKI during their hospital stay. After screening the Naranjo scale to identify the top 15 suspected DIKI drugs with a high frequency of use, we found that furosemide injection (p = 0.001), midazolam injection (p = 0.001), 20% albumin prepared from human plasma injection (p = 0.004), fentanyl citrate injection (p = 0.001), compound glycyrrhizin injection (p = 0.026), vancomycin hydrochloride for intravenous (p = 0.010), and milrinone lactate injection (p = 0.009) were associated with DIKI. Conclusion: In critically ill pediatric patients, DIKI is more likely to occur after using furosemide injection, midazolam injection, 20% albumin prepared from human plasma injection, fentanyl citrate injection, compound glycyrrhizin injection, vancomycin hydrochloride for intravenous, milrinone lactate injection.

Pharmacokinetic assessment of vancomycin in critically ill patients and nephrotoxicity prediction using individualized pharmacokinetic parameters

Introduction: Therapeutic drug monitoring (TDM) and pharmacokinetic assessments of vancomycin would be essential to avoid vancomycin-associated nephrotoxicity and obtain optimal therapeutic and clinical responses. Different pharmacokinetic parameters, including trough concentration and area under the curve (AUC), have been proposed to assess the safety and efficacy of vancomycin administration. Methods: Critically ill patients receiving vancomycin at Nemazee Hospital were included in this prospective study. Four blood samples at various time intervals were taken from each participated patient. Vancomycin was extracted from plasma samples and analyzed using a validated HPLC method. Results: Fifty-three critically ill patients with a total of 212 blood samples from June 2019 to June 2021 were included in this study. There was a significant correlation between baseline GFR, baseline serum creatinine, trough and peak concentrations, AUCτ, AUC24h, Cl, and Vd values with vancomycin-induced AKI. Based on trough concentration values, 66% of patients were under-dosed (trough concentration <15 μg/ml) and 18.9% were over-dosed (trough concentration ≥20 μg/ml). Also, based on AUC24h values, about 52.2% were under-dosed (AUC24h < 400 μg h/ml), and 21.7% were over-dosed (AUC24h > 600 μg h/ml) that emphasizes on the superiority of AUC-based monitoring approach for TDM purposes to avoid nephrotoxicity occurrence. Conclusion: The AUC-based monitoring approach would be superior in terms of nephrotoxicity prediction. Also, to avoid vancomycin-induced AKI, trough concentration and AUCτ values should be maintained below the cut-off points.

Would they accept it? An interview study to identify barriers and facilitators to user acceptance of a prescribing advice service

Objectives

Few studies have explored the factors influencing user uptake of interventions designed to enhance therapeutic drug monitoring (TDM). This study aimed to identify barriers and facilitators to acceptance of a pilot intervention, the TDM Advisory Service (the Service), that provided prescribing advice for the antibiotic, vancomycin at an Australian public hospital.

Methods

A sample of prescribers and pharmacists who had interacted with the Service (n = 10), and a sample who had not (n = 13), participated in semi-structured interviews. Interviews were transcribed verbatim and analysed independently by two researchers for emerging themes. The Theoretical Domains Framework (TDF) was used to synthesise barriers and facilitators to Service acceptance.

Results

Key barriers reported by participants who had interacted with the Service aligned with two TDF domains: ‘Social Influences’ (prescribing hierarchy) and ‘Environmental Context and Resources’ (accessibility of dose advice). For participants who had not interacted with the Service, key barriers aligned with two TDF domains: ‘Knowledge’ (uncertainty of Service processes) and ‘Environmental Context and Resources’ (accessibility of dose advice). Key facilitators for both participant groups aligned with ‘Beliefs about Consequences’ (improved prescribing and patient outcomes) and ‘Environmental Context and Resources’ (accessibility of dose advice). A novel domain, ‘Trust’, was identified.

Conclusions

Independent of participant interaction with the Service, knowledge of Service processes, perceived beneficial outcomes, improved accessibility, and trust in Service capabilities were key determinants of acceptance. This evidence can be used to inform the adoption of strategies to adapt and enhance integration of the Service into clinical workflow.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07927-1.

Expression and 7-day time course of circulating microRNAs in septic patients treated with nephrotoxic antibiotic agents

Background

Through regulation of signaling pathways, microRNAs (miRNAs) can be involved in sepsis and associated organ dysfunction. The aims of this study were to track the 7-day time course of blood miRNAs in patients with sepsis treated with vancomycin, gentamicin, or a non-nephrotoxic antibiotic and miRNA associations with neutrophil gelatinase-associated lipokalin (NGAL), creatinine, procalcitonin, interleukin-6, and acute kidney injury (AKI) stage.

Methods

Of 46 adult patients, 7 were on vancomycin, 20 on gentamicin, and 19 on another antibiotic. Blood samples were collected on days 1, 4, and 7 of treatment, and miRNAs were identified using quantitative reverse transcription PCR.

Results

The results showed no relationship between miRNA levels and biochemical variables on day 1. By day 7 of gentamicin treatment miR-15a-5p provided good discrimination between AKI and non-AKI (area under curve, 0.828). In patients taking vancomycin, miR-155-5p and miR-192-5p positively correlated with creatinine and NGAL values, and miR-192-5p and miR-423-5p positively correlated with procalcitonin and interleukin-6 in patients treated with a non-nephrotoxic antibiotic. In patients together we found positive correlation between miR-155-5p and miR-423-5p and all biochemical markers.

Conclusion

The results suggest that these four miRNAs may serve as diagnostic or therapeutic tool in sepsis, renal injury and nephrotoxic treatment.

Trial registration

ClinicalTrials.gov, ID: NCT04991376. Registered on 27 July 2021.

Impact of ascorbic acid in reducing the incidence of vancomycin associated nephrotoxicity in critically ill patients: A preliminary randomized controlled trial

Background Antioxidants show nephroprotective effect against vancomycin associated nephrotoxicity (VAN) in animals. This study aimed to assess the ascorbic acid nephro-protective role against VAN clinically.

Methods Forty-one critically ill patients were randomly assigned to one of two groups: intervention group (vancomycin IV plus ascorbic acid, n=21) or control group (vancomycin IV only, n=20). Primary outcomes were the incidence of VAN and the absolute change in creatinine parameters, while mortality rate was the secondary outcome. Nephrotoxicity was defined as an increase in serum creatinine (S.cr) by at least 0.5 mg/dL or 50% of baseline for at least two successive measurements. This study is registered at Clinicaltrials.gov (NCT03921099), April 2019.

Results Mean absolute S.cr increase was significant when compared between both groups, P-value = 0.036, where S.cr increased by 0.05(0.12) and 0.34(0.55) mg/dL in the intervention and control groups, respectively. Mean absolute Cr.cl decline was significant when compared between both groups, P-value = 0.04, where Cr.cl was decreased by 5.9(17.8) and 22.3(30.4) ml/min in the intervention and control groups, respectively. Incidence of VAN was 1/21(4.7%) versus 5/20(25%) in the intervention and control groups, respectively (RR: 0.19; CI: 0.024–1.49; P-value = 0.093). Mortality was higher in the control group; however, it was not statistically significant, P-value = 0.141.

Conclusion Co-administration of ascorbic acid with vancomycin preserved renal function and reduced the absolute risk of VAN by 20.3%, however, the reduction in VAN incidence didn’t reach statistical significance level. Further large multicenter prospective trials are recommended.

Cardiorenal syndrome in COVID-19

SARS-CoV-2 preferentially targets the human's lungs, but it can affect multiple organ systems. We report a case of cardiorenal syndrome in a 37-year-old man who had symptoms of fever, myalgia and cough. He tested positive for COVID-19 and presented 5 days later with acute heart failure. Work up was done including echocardiography showing reduced ejection fraction. Later in the hospital course he developed acute renal failure and was treated with intermittent renal replacement therapy. No other definite cause of cardiorenal complications was identified during the course of the disease. A possible link with COVID-19 was considered with underlying mechanisms still needed to be explored. This case highlights the potential of SARS-CoV-2 affecting heart and kidneys. The disease not only involves the organs directly but can exacerbate the underlying comorbid illness.

Acute Kidney Injury in Septic Patients Treated by Selected Nephrotoxic Antibiotic Agents-Pathophysiology and Biomarkers-A Review

Acute kidney injury is a common complication in critically ill patients with sepsis and/or septic shock. Further, some essential antimicrobial treatment drugs are themselves nephrotoxic. For this reason, timely diagnosis and adequate therapeutic management are paramount. Of potential acute kidney injury (AKI) biomarkers, non-protein-coding RNAs are a subject of ongoing research. This review covers the pathophysiology of vancomycin and gentamicin nephrotoxicity in particular, septic AKI and the microRNAs involved in the pathophysiology of both syndromes. PubMED, UptoDate, MEDLINE and Cochrane databases were searched, using the terms: biomarkers, acute kidney injury, antibiotic nephrotoxicity, sepsis, miRNA and nephrotoxicity. A comprehensive review describing pathophysiology and potential biomarkers of septic and toxic acute kidney injury in septic patients was conducted. In addition, five miRNAs: miR-15a-5p, miR-192-5p, miR-155-5p, miR-486-5p and miR-423-5p specific to septic and toxic acute kidney injury in septic patients, treated by nephrotoxic antibiotic agents (vancomycin and gentamicin) were identified. However, while these are at the stage of clinical testing, preclinical and clinical trials are needed before they can be considered useful biomarkers or therapeutic targets of AKI in the context of antibiotic nephrotoxicity or septic injury.

Severe pulmonary injury leading to death during thoracic rod removal: a case report

PURPOSE

Removal of hardware procedures following posterior spinal fusion is most commonly performed for hardware irritation without overt infection. It is imperative that surgeons realize that serious complications may arise from this procedure. The purpose of this report is to report a case of a pneumothorax that developed in a thoracolumbar removal of hardware case that resulted in a patient death.

METHODS

Retrospective review of a patient's medical record and imaging.

RESULTS

A 74-year-old patient with a history of T4-10 anterior discectomy and fusion with rib autograft and T4-L2 posterior fusion underwent a removal of hardware procedure for delayed surgical site infection. During the procedure, the tip of the bolt cutter jaw broke and entered the pulmonary cavity leading to a pneumothorax. The patient developed pneumonia 1 month postoperatively and passed away.

CONCLUSIONS

This case report highlights one of the rare but potential complications of spinal removal of hardware surgery. It is essential that surgeons are aware of the possibility of pulmonary complications during thoracolumbar removal of hardware cases so that they may fully counsel their patients on the potential risks.

Relationship of vancomycin trough levels with acute kidney injury risk: an exposure–toxicity meta-analysis

Objectives

Nephrotoxicity represents a major complication of vancomycin administration, leading to high rates of morbidity and treatment failure. The aim of this meta-analysis was to evaluate the association between trough levels and risk of renal impairment, by defining an exposure–toxicity relationship and assessing its accuracy in predicting the development of acute kidney injury (AKI).

Methods

Medline, Scopus, CENTRAL, Clinicaltrials.gov and Google Scholar databases were systematically searched from inception. Studies examining the effects of trough levels on nephrotoxicity risk in adult patients were deemed eligible.

Results

The meta-analysis was based on 60 studies, including 13 304 patients. The development of AKI was significantly linked to both higher initial [standardized mean difference (SMD): 0.82; 95% CI: 0.65–0.98] and maximum (SMD: 1.06; 95% CI: 0.82–1.29) trough levels. Dose–response analysis indicated a curvilinear relationship between trough levels and nephrotoxicity risk (χ2 = 127.1; P value &lt; 0.0001). A cut-off of 15 mg/L detected AKI with a sensitivity of 62.6% (95% CI: 55.6–69.2) and a specificity of 65.5% (95% CI: 58.9–71.6), while applying a 20 mg/L threshold resulted in a sensitivity of 42.9% (95% CI: 34–52.2) and a specificity of 82.5% (95% CI: 73.9–88.8).

Conclusions

The present findings suggest that the development of vancomycin-induced AKI is significantly associated with higher initial and maximum trough levels. An exposure–response relationship was defined, indicating that increasing trough levels correlate with a significant rise of nephrotoxicity risk. Future studies should verify the effectiveness of individualized pharmacokinetic tools that would enable the attainment of trough level targets and minimize the risk of renal toxicity.

Calculated initial parenteral treatment of bacterial infections: Pharmacokinetics and pharmacodynamics

This is the third chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter features the pharmacokinetic and pharmacodynamics properties of the most frequently used antiinfective agents.

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

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

Association of Duration and Type of Surgical Prophylaxis With Antimicrobial-Associated Adverse Events

Importance

The benefits of antimicrobial prophylaxis are limited to the first 24 hours postoperatively. Little is known about the harms associated with continuing antimicrobial prophylaxis after skin closure.

Objective

To characterize the association of type and duration of prophylaxis with surgical site infection (SSI), acute kidney injury (AKI), and Clostridium difficile infection.

Design, Setting, and Participants

In this multicenter, national retrospective cohort study, all patients within the national Veterans Affairs health care system who underwent cardiac, orthopedic total joint replacement, colorectal, and vascular procedures and who received planned manual review by a trained nurse reviewer for type and duration of surgical prophylaxis and for SSI from October 1, 2008, to September 30, 2013, were included. Data were analyzed using multivariable logistic regression, with adjustments for covariates determined a priori to be associated with the outcomes of interest. Data were analyzed from December 2016 to December 2018.

Exposures

Duration of postoperative antimicrobial prophylaxis (<24 hours, 24-<48 hours, 48-<72 hours, and ≥72 hours).

Main Outcomes and Measures

Surgical site infection, AKI, and C difficile infection.

Results

Of the 79 058 included patients, 76 109 (96.3%) were men, and the mean (SD) age was 64.8 (9.4) years. Among 79 058 surgical procedures in the cohort, all had SSI and C difficile outcome data available; 71 344 (90.2%) had AKI outcome data. After stratification by type of surgery and adjustment for age, sex, race, diabetes, smoking, American Society of Anesthesiologists score greater than 2, methicillin-resistant Staphylococcus aureus colonization, mupirocin, type of prophylaxis, and facility factors, SSI was not associated with duration of prophylaxis. Adjusted odds of AKI increased with each additional day of prophylaxis (cardiac procedure: 24-<48 hours: adjusted odds ratio [aOR], 1.03; 95% CI, 0.95-1.12; 48-<72 hours: aOR, 1.22; 95% CI, 1.08-1.39; ≥72 hours: aOR, 1.82; 95% CI, 1.54-2.16; noncardiac procedure: 24-<48 hours: aOR, 1.31; 95% CI, 1.21-1.42; 48-<72 hours: aOR, 1.72; 95% CI, 1.47-2.01; ≥72 hours: aOR, 1.79; 95% CI, 1.27-2.53). The risk of postoperative C difficile infection demonstrated a similar duration-dependent association (24-<48 hours: aOR 1.08; 95% CI, 0.89-1.31; 48-<72 hours: aOR, 2.43; 95% CI, 1.80-3.27; ≥72 hours: aOR, 3.65; 95% CI, 2.40-5.53). The unadjusted numbers needed to harm for AKI after 24 to less than 48 hours, 48 to less than 72 hours, and 72 hours or more of postoperative prophylaxis were 9, 6, and 4, respectively; and 2000, 90, and 50 for C difficile infection, respectively. Vancomycin receipt was also a significant risk factor for AKI (cardiac procedure: aOR, 1.17; 95% CI, 1.10-1.25; noncardiac procedure: aOR, 1.21; 95% CI, 1.13-1.30).

Conclusions and Relevance

Increasing duration of antimicrobial prophylaxis was associated with higher odds of AKI and C difficile infection in a duration-dependent fashion; extended duration did not lead to additional SSI reduction. These findings highlight the notion that every day matters and suggest that stewardship efforts to limit duration of prophylaxis have the potential to reduce adverse events without increasing SSI.

Utilizing the Patient Care Process to Minimize the Risk of Vancomycin-Associated Nephrotoxicity

Vancomycin-associated acute kidney injury (AKI) is a popular topic in the medical literature with few clear answers. While many studies evaluate the risk of AKI associated with vancomycin, few data are high quality and/or long in duration of follow-up. This review takes the clinician through an approach to evaluate a patient for risk of AKI. This evaluation should include patient assessment, antibiotic prescription, duration, and monitoring. Patient assessment involves evaluating severity of illness, baseline renal function, hypotension/vasopressor use, and concomitant nephrotoxins. Evaluation of antibiotic prescription includes evaluating the need for methicillin-resistant Staphylococcus aureus (MRSA) coverage and/or vancomycin use. Duration of therapy has been shown to increase the risk of AKI. Efforts to de-escalate vancomycin from the antimicrobial regimen, including MRSA nasal swabs and rapid diagnostics, should be used to lessen the likelihood of AKI. Adequate monitoring includes therapeutic drug monitoring, ongoing fluid status evaluations, and a continual reassessment of AKI risk. The issues with serum creatinine make the timely evaluation of renal function and diagnosis of the cause of AKI problematic. Most notably, concomitant piperacillin-tazobactam can increase serum creatinine via tubular secretion, resulting in higher rates of AKI being reported. The few studies evaluating the long-term prognosis of AKI in patients receiving vancomycin have found that few patients require renal replacement therapy and that the long-term risk of death is unaffected for patients surviving after the initial 28-day period.

Atg7 mediates renal tubular cell apoptosis in vancomycin nephrotoxicity through activation of PKC-δ

Recent studies have shown that autophagy exhibits a renoprotective role in various models of acute kidney injury (AKI). However, its role in vancomycin (Van)-induced AKI remains largely unclarified. This study was the first to indicate that autophagy was rapidly activated in both human kidney-2 cells and renal tissues, and mammalian target of rapamycin (mTOR) was inactivated via the suppression of ERK1/2 and mTOR during Van treatment. Interestingly, for both in vitro and in vivo experiments, the suppression of autophagy via chloroquine and PT-Atg7-KO significantly ameliorated Van-induced kidney injury and renal tubular cell apoptosis. Global gene expression analysis indicated that the expression levels of 6159 genes were induced by Van treatment in the kidney cortical tissues of PT-Atg7 wild-type mice, and 18 of them were notably suppressed in PT-Atg7-KO mice. These 18 genes were further classified as programmed cell death, protein binding, signal transduction, E3 ubiquitin ligase, nucleoside diphosphate kinase activity, and E1-like activating enzyme. Unexpectedly, following Van treatment, PKC-δ expression was found to be highest among the 4 genes related to cell death, which was remarkably suppressed in vitro and in PT-Atg7-KO mice. In addition, Atg7 could induce renal cell apoptosis during Van treatment via binding to PKC-δ. Likewise, the inhibition of PKCδ ameliorated Van-induced apoptosis in human kidney-2 cells and kidney tissues. Furthermore, the data showed that PT-Atg7-KO exerted a renoprotective effect against Van-induced nephrotoxicity, but this effect was lost after injection with myc-tagged PKCδ. Taken altogether, these results indicate that Van induces autophagy by suppressing the activation of the ERK1/2 and mTOR signaling pathway. In addition, Atg7 mediates Van-induced AKI through the activation of PKCδ. In sum, autophagy inhibition may serve as a novel therapeutic target for treating nephrotoxic AKI induced by Van.-Xu, X., Pan, J., Li, H., Li, X., Fang, F., Wu, D., Zhou, Y., Zheng, P., Xiong, L., Zhang, D. Atg7 mediates renal tubular cell apoptosis in vancomycin nephrotoxicity through activation of PKC-δ.

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.

Postoperative Acute Kidney Injury in Young Adults With Congenital Heart Disease

BACKGROUND

There is an increasing number of young adults living with congenital heart disease (CHD). The goal of this study was to ascertain the frequency of acute kidney injury (AKI) as well as the risk factors and outcomes associated with AKI in young adults with CHD after a surgical procedure.

METHODS

This was a single-center retrospective cohort study including all patients 18 to 40 years of age with a diagnosis of CHD admitted to a quaternary care children's hospital cardiac intensive care unit postoperatively from 2004 to 2015. We defined AKI using the Kidney Disease Improving Global Outcomes criteria for serum creatinine. We explored potential susceptibilities and exposures for AKI using multivariable logistic regression and determined the association of AKI with duration of mechanical ventilation and length of stay using Poisson regression.

RESULTS

In 699 consecutively admitted patients AKI occurred in 13.2%. Suspected sepsis (odds ratio [OR], 2.87; 95% confidence interval [CI], 1.17 to 7.05), exposure to calcineurin inhibitors (OR, 5.80; 95% CI, 1.06 to 31.59), vancomycin (OR, 3.35; 95% CI, 1.11 to 10.14), and piperacillin-tazobactam (OR, 4.12; 95% CI, 1.23 to 13.78) increased the odds of AKI even after controlling for age, ejection fraction, recent cardiac catheterization, repeat cardiopulmonary bypass, bypass time, cross-clamp time, and other potential nephrotoxic medications. AKI was associated with a longer duration of mechanical ventilation (OR, 1.47; 95% CI, 1.15 to 1.89) and intensive care unit length of stay (OR, 1.50; 95% CI, 1.30 to 1.72).

CONCLUSIONS

AKI is common in young adults with CHD postoperatively and is associated with negative outcomes. The results highlight the importance future research and clinical efforts aimed at prevention and improved management of AKI in this patient group.

Relationship Between Initial Vancomycin Trough Levels and Early-Onset Vancomycin-Associated Nephrotoxicity in Critically Ill Patients

BACKGROUND

Appropriate initial dosing of vancomycin (VCM) is important in improving survival and in preventing nephrotoxicity in critically ill patients, but the potential relationship between initial VCM trough levels and early-onset nephrotoxicity remains unclear. We examined the relationship between initial VCM trough levels and early-onset VCM-associated nephrotoxicity.

METHODS

We performed a retrospective study of patients who had therapeutic drug monitoring of VCM with initial trough levels within 4 days after the beginning of VCM administration. We excluded patients who received renal replacement therapy from 2 days before to 7 days after the beginning of VCM administration, were younger than 18 years, or had renal dysfunction before the beginning of VCM administration. Early-onset VCM-associated nephrotoxicity was defined as an increase in serum creatinine level of ≥0.5 mg/dL (44.2 μmol/L) or 50% above baseline for 2 or more consecutive days within 7 days after the beginning of VCM administration.

RESULTS

Among 109 enrolled patients, 13 patients had early-onset VCM-associated nephrotoxicity. Its incidence rate was 31.3% in patients with initial trough levels of ≥20g/mL, which was significantly higher than 6.3% in patients with initial trough levels of <10 mg/L. Multiple logistic regression analysis demonstrated that early-onset VCM-associated nephrotoxicity was associated with initial trough levels of ≥20 mg/L (odds ratio, 5.0; 95% confidence interval, 1.3-19.1) and with vasopressor use (odds ratio, 5.0; 95% confidence interval, 1.3-19.1). Kaplan-Meier analysis showed that the probability of nonnephrotoxicity for patients with initial VCM trough levels of ≥20 mg/L was lower compared with patients with trough levels of <15 mg/L.

CONCLUSIONS

Initial trough levels of ≥20 mg/L but not ≥15 mg/L were associated with early-onset VCM-associated nephrotoxicity in critically ill patients. Future prospective studies are needed to examine outcomes in critically ill patients achieving initial VCM trough levels of 15-20 mg/L.

Vancomycin associated acute kidney injury in pediatric patients

INTRODUCTION

Vancomycin associated acute kidney injury (vAKI) is a well known complication in pediatric patients. Identification and characterization of the incidence and risk factors for vAKI in the pediatric population would assist clinicians in potentially preventing or mitigating vAKI.

METHODS AND MATERIALS

A 6 year retrospective cohort study was designed. Patients were included if they were < 19 years of age, received vancomycin as inpatients, and had a baseline SCr and one other SCr drawn during and up to 72 hours after the discontinuation of vancomycin. Data collection included patient demographics, vancomycin doses and length of therapy, vancomycin serum concentrations, and concomitant medications. The Kidney Disease Improving Global Outcomes (KDIGO) criteria were used to characterize acute kidney injury. Descriptive statistical methods were used and ordinal logistic regression was employed to determine variables significantly associated with vAKI.

RESULTS

A total of 7,095 patients met study criteria (55.4% male, median age 4.1 years (IQR 0.67-11.2 years)). Mechanical ventilation was used in 7.9% (n = 563) and mortality was 4.9% (n = 344). A total of 153 concomitant medications were identified. A median of 5 (IQR 3-7) SCr values were obtained and median SCr prior to vancomycin was 0.39 (IQR 0.28-0.57) mg/dL (CrCl 134±58 mL/min/1.73m2). Vancomycin was administered for a median of 2 (IQR 1-3) days (14.9±1.6 mg/kg/dose). vAKI was present in 12.2% (n = 862: KDIGO stage 1 (8.30%, n = 589), KDIGO stage 2 (1.94%, n = 138) KDIGO stage 3 (1.89%, n = 134)). Mean vancomycin serum concentration at 6-8 hours after a dose for patients with vAKI (10.7±8.9 mg/L) was significantly, but not clinically different for patients with no vAKI (7.5±6.3 mg/L). (p<0.05) Ordinal logistic regression identified total dose of vancomycin, vancomycin administration in the intensive care unit, and concomitant medication administration as significant for vAKI. In particular, concomitant administration of several different medications, including nafcillin, clindamycin, and acetazolamide, were noted for strong associations with vAKI. (p<0.05).

CONCLUSIONS

Moderate to severe acute kidney injury due to vancomycin is infrequent in children and associated with concomitant medication use and total dose of vancomycin. Serum vancomycin concentrations are not useful predictors of vAKI in the pediatric population.

Individualized Pharmacokinetic Dosing of Vancomycin Reduces Time to Therapeutic Trough Concentrations in Critically Ill Patients

Dosing vancomycin in critically ill patients often results in subtherapeutic and supratherapeutic trough concentrations. In this retrospective study, we compared the time to goal trough attainment and incidence of acute kidney injury in intensive care unit (ICU) patients whose vancomycin was dosed by a pharmacy pharmacokinetic (PK) dosing and monitoring service to the standard of care. Three-hundred fifty adult ICU patients at a Level 1 trauma, teaching hospital who received vancomycin for >24 hours from February 1, 2016, to November 30, 2016, were screened. Patients were included in the PK group if consecutive serum concentrations were used to calculate individualized PK and determine a dosing regimen. Patients who were dosed using troughs only were then matched 1-to-1 to the PK group by date of vancomycin initiation and included in the traditional group. Fifty patients were included in each group. Baseline characteristics were similar, except the PK group had more patients under the care of the neuromedical ICU service (42% vs 18%; P = .02) and fewer patients with a corrected creatinine clearance <30 mL/min/1.73 m² (22% vs 46%; P = .02). Attainment of goal trough concentrations for the PK and traditional groups were 84.4% and 29.4% by 48 hours (P = .0001), 88.4% and 60.7% by 72 hours (P = .009), and 92.9% and 77.8% by 96 hours (P = .1), respectively. Incidence of acute kidney injury between the PK and traditional groups was not statistically significant (8.3% vs 14%; P = .5). Utilization of individualized pharmacokinetic dosing of vancomycin in critically ill patients resulted in faster goal trough attainment without an increase in nephrotoxicity.

Multiple-Drug Resistance in Burn Patients: A Retrospective Study on the Impact of Antibiotic Resistance on Survival and Length of Stay

Despite improvements in early treatment, survival following burn injury remains challenged by sepsis and multiple organ dysfunction syndrome (MODS). Additionally, susceptibility to infections and growing antibiotic resistance places burn patients at increased risk for infections with multiple-drug resistant organisms (MDROs). We therefore aimed to evaluate the impact of MDRO infections on survival and hospital length of stay, as well as examine the role of these organisms in the development of complications, such as acute kidney injury, sepsis, and MODS. To study this, we included all burn patients with infections, admitted between January 1, 2012, and December 31, 2013. Patients were divided into two groups: patients with infections caused by MDROs and patients with infections caused by susceptible organisms. Data were collected on all available cultures, as well as demographic, injury, and treatment-related variables from the medical record. The number of operative procedures (median: 2 vs 1, P < .0001), ventilator days (21 vs 0 days, P < .0001), total antibiotic days (21 vs 7days, P < .0001), and length of hospitalization (39 vs 14 days, P < .0001) were significantly different in the MDRO group vs the nonresistant group. While MDRO infection was not associated with patient mortality, univariable logistic regression analyses demonstrated >20% TBSA (odds ratio [OR] = 4.30, 95% confidence interval [CI]: 1.14-16.29, P = .03), acute kidney injury (OR = 10.93, 95% CI: 2.74-43.57, P = .001), sepsis (OR = 19.20, 95% CI: 3.79-97.27, P < .001), and MODS (OR = 85.49, 95% CI: 12.97-563.28, P < .0001) significantly increased the odds of patient mortality. These findings suggest that infections with MDROs are associated with a greater number of surgical procedures, longer duration of mechanical ventilation, more antibiotic days, and longer hospitalization.

Identification of Vancomycin Exposure-Toxicity Thresholds in Hospitalized Patients Receiving Intravenous Vancomycin

Evidence supports vancomycin therapeutic-drug monitoring by area under the concentration-time curve (AUC), but data to establish an AUC upper limit are limited and published nephrotoxicity thresholds range widely. The objective of this analysis was to examine the association between initial vancomycin AUC and nephrotoxicity. This was a multicenter, retrospective cohort study of adult patients receiving intravenous vancomycin from 2014 to 2015. Nephrotoxicity was defined as a serum creatinine increase of 0.5 mg/liter and 50% from baseline on consecutive measurements. Vancomycin exposure profile during the initial 48 h of therapy was estimated using maximum a posteriori probability Bayesian estimation. Vancomycin AUC and minimum-concentration (Cmin) thresholds most strongly associated with nephrotoxicity were identified via classification and regression tree (CART) analysis. Predictive performances of CART-derived and other candidate AUC thresholds was assessed through positive and negative predictive value and receiver operating characteristic curves. Poisson regression was used to quantify the association between exposure thresholds and nephrotoxicity while adjusting for confounders. Among 323 patients included, nephrotoxicity was significantly higher in patients with AUCs from 0 to 48 h (AUC0-48) of ≥1,218 mg · h/liter, AUC0-24 of ≥677 mg · h/liter, AUC24-48 of ≥683 mg · h/liter, and day 1 Cmin (Cmin24) of ≥18.8 mg/liter. Vancomycin exposure in excess of these thresholds was associated with a 3- to 4-fold-increased risk of nephrotoxicity in Poisson regression. The predictive performance of AUC for nephrotoxicity was maximized at daily AUC values between 600 and 800 mg · h/liter. Although these data support an AUC range for vancomycin-associated nephrotoxity rather than a single threshold, available evidence suggests that a daily AUC limit of 700 mg · h/liter is reasonable.

Evaluation of the Risk for Acute Kidney Injury in Adult Cystic Fibrosis Patients Receiving Concomitant Vancomycin and Tobramycin

Background

The risk for acute kidney injury (AKI) has been associated with both tobramycin and vancomycin.

Objective

To determine whether the rate of drug therapy-related nephrotoxicity is greater in Cystic Fibrosis (CF) patients receiving concomitant vancomycin and tobramycin than patients receiving either agent alone.

Methods

Adult CF patients admitted for acute pulmonary exacerbation (APE) over a seven-year period (2008-2014), who received at least 72 hours of intravenous vancomycin, tobramycin or a combination of the two agents were evaluated for AKI. AKI was defined as a 1.5-fold increase in serum creatinine per RIFLE criteria. One hundred seventy-four hospital encounters from 72 unique patients were assessed in this single-center, cross-sectional study.

Results

AKI outcomes were not statistically different. AKI rates were 19% for vancomycin, 8.7% for tobramycin, and 19.7% for combination cohorts (p = 0.16).

Conclusion

Our data suggest there is no significant difference in AKI risk when vancomycin and tobramycin combination therapy is used.

A Quasi-Experiment To Study the Impact of Vancomycin Area under the Concentration-Time Curve-Guided Dosing on Vancomycin-Associated Nephrotoxicity

Evidence suggests that maintenance of vancomycin trough concentrations at between 15 and 20 mg/liter, as currently recommended, is frequently unnecessary to achieve the daily area under the concentration-time curve (AUC₂₄) target of ≥400 mg · h/liter. Many patients with trough concentrations in this range have AUC₂₄ values in excess of the therapeutic threshold and within the exposure range associated with nephrotoxicity. On the basis of this, the Detroit Medical Center switched from trough concentration-guided dosing to AUC-guided dosing to minimize potentially unnecessary vancomycin exposure. The primary objective of this analysis was to assess the impact of this intervention on vancomycin-associated nephrotoxicity in a single-center, retrospective quasi-experiment of hospitalized adult patients receiving intravenous vancomycin from 2014 to 2015. The primary analysis compared the incidence of nephrotoxicity between patients monitored by assessment of the AUC₂₄ and those monitored by assessment of the trough concentration. Multivariable logistic and Cox proportional hazards regression examined the independent association between the monitoring strategy and nephrotoxicity. Secondary analysis compared vancomycin exposures (total daily dose, AUC, and trough concentrations) between monitoring strategies. Overall, 1,280 patients were included in the analysis. After adjusting for severity of illness, comorbidity, duration of vancomycin therapy, and concomitant receipt of nephrotoxins, AUC-guided dosing was independently associated with lower nephrotoxicity by both logistic regression (odds ratio, 0.52; 95% confidence interval [CI], 0.34 to 0.80; P = 0.003) and Cox proportional hazards regression (hazard ratio, 0.53; 95% CI, 0.35 to 0.78; P = 0.002). AUC-guided dosing was associated with lower total daily vancomycin doses, AUC values, and trough concentrations. Vancomycin AUC-guided dosing was associated with reduced nephrotoxicity, which appeared to be a result of reduced vancomycin exposure.

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.

The Nephrotoxicity of Vancomycin

Vancomycin use is often associated with nephrotoxicity. It remains uncertain, however, to what extent vancomycin is directly responsible, as numerous potential risk factors for acute kidney injury frequently coexist. Herein, we critically examine available data in adult patients pertinent to this question. We review the pharmacokinetics/pharmacodynamics of vancomycin metabolism. Efficacy and safety data are discussed. The pathophysiology of vancomycin nephrotoxicity is considered. Risk factors for nephrotoxicity are enumerated, including the potential synergistic nephrotoxicity of vancomycin and piperacillin‐tazobactam. Suggestions for clinical practice and future research are given.

Vancomycin-associated acute kidney injury: A cross-sectional study from a single center in China

Objective

The objective of this study was to investigate the current situation of vancomycin (VAN)-associated acute kidney injury (VA-AKI) in China and identify the risk factors for VA-AKI, as well as to comprehensively examine the risk related to concurrent drug use. Further, we assessed the outcomes of patients who developed VA-AKI and the risk factors for these outcomes. Finally, we aimed to provide suggestions for improving the prevention and treatment of VA-AKI in China.

Methods

We conducted a retrospective observational study of inpatients who had been treated with VAN between January 2013 and December 2013 at Peking University First Hospital. AKI was defined as an increase in SCr of ≥0.3 mg/dl (≥26.5 μmol/l) within 48 hours or an increase to ≥1.5 times the baseline certainly or presumably within the past 7 days. VA-AKI was defined as the development of AKI during VAN therapy or within 7 days following the termination of VAN therapy. In addition, we compared patients with NO-AKI, who did not develop AKI during their hospitalization, with those with VA-AKI.

Results

Of the 934 patients treated with VAN during their hospital stay, 740 were included in this study. Among those excluded, 38.1% (74/194) were excluded because of a lack of data on serum creatinine (SCr). Among the included patients, 120 had confirmed VA-AKI, with an incidence of 16.2% (120/740). Multiple logistic regression analysis revealed that an elevated baseline estimated glomerular filtration rate (eGFR) (odds ratio [OR] = 1.009; p = 0.017) and concomitant vasopressor therapy (OR = 2.942; p = 0.009), nitrate use (OR = 2.869; p = 0.007), imipenem-cilastatin treatment (OR = 4.708; p = 0.000), and contrast medium administration (OR = 6.609 p = 0.005) were independent risk factors for VA-AKI; in addition, the receipt of orthopedic/trauma/burn surgery (OR = 0.3575; p = 0.011) and concomitant compound glycyrrhizin use (OR = 0.290; p = 0.017) were independent protective factors for VA-AKI. Multiple logistic regression analysis also demonstrated that among the patients who developed VA-AKI, coronary heart disease (CHD) (OR = 12.6; p = 0.006) and concomitant vasopressor therapy (OR = 15.4; p = 0.001) were independent risk factors for death. We also evaluated the factors influencing improvement of renal function. Multiple logistic regression analysis demonstrated that CHD (OR = 8.858, p = 0.019) and concomitant contrast medium administration (OR = 9.779, p = 0.005) were independent risk factors and that simultaneous β-blocker treatment (OR = 0.124, p = 0.001) was an independent protective factor for improvement of renal function.

Conclusion

Patients treated with VAN received insufficient monitoring of SCr and inadequate therapeutic drug monitoring. We recommend that hospitals increase their investment in clinical pharmacists. An elevated baseline eGFR and concomitant vasopressor therapy, nitrate use, imipenem-cilastatin treatment, and contrast medium administration were independent risk factors for VA-AKI; in addition, orthopedic/trauma/burn surgery and concomitant compound glycyrrhizin use were independent protective factors for VA-AKI.

[Therapeutic drug monitoring and individual dosing of antibiotics during sepsis : Modern or just "trendy"?]

Pharmacokinetic variability of anti-infective drugs due to pathophysiological changes by severe sepsis and septic shock is a well-known problem for critically ill patients resulting in suboptimal serum and most likely tissue concentrations of these agents.To cover a wide range of potential pathogens, high concentrations of broad spectrum anti-infectives have to reach the site of infection. Microbiological susceptibility testing (susceptible, intermediate, resistant) don't take the pharmacokinetic variability into account and are based on data generated by non-critically ill patients. But inter-patient variability in distribution and elimination of anti-infective drugs in ICU patients is extremely high and also highly unpredictable. Drug clearance of mainly renally eliminated drugs and thus the required dose can differ up to 10-fold due to the variability in renal function in patients with severe infections. To assure a timely and adequate anti-infective regime, individual dosing and therapeutic drug monitoring (TDM) seem to be appropriate tools in the setting of pathophysiological changes in pharmacokinetics (PK) and pharmakodynamics (PD) due to severe sepsis. In the case of known minimal inhibitory concentration, PK/PD indices (time or peak concentration dependent activity) and measured serum level can provide an optimal target concentration for the individual drug and patient.Modern anti-infective management for ICU patients includes more than the choice of drug and prompt application. Individual dosing, optimized prolonged infusion time and TDM give way to new and promising opportunities in infection control.

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.

Therapeutic drug monitoring of anti-infective agents in critically ill patients

Initial adequate anti-infective therapy is associated with significantly improved clinical outcomes for patients with severe infections. However, in critically ill patients, several pathophysiological and/or iatrogenic factors may affect the pharmacokinetics of anti-infective agents leading to suboptimal drug exposure, in particular during the early phase of therapy. Therapeutic drug monitoring (TDM) may assist to overcome this problem. We discuss the available evidence on the use of TDM in critically ill patient populations for a number of anti-infective agents, including aminoglycosides, β-lactams, glycopeptides, antifungals and antivirals. Also, we present the available evidence on the practices of anti-infective TDM and describe the potential utility of TDM to improve treatment outcome in critically ill patients with severe infections. For aminoglycosides, glycopeptides and voriconazole, beneficial effects of TDM have been established on both drug effectiveness and potential side effects. However, for other drugs, therapeutic ranges need to be further defined to optimize treatment prescription in this setting.

Augmentation of the Inotropic Effects of Dopamine Following Linezolid Administration in an Infant

Although generally safe and effective, one of the unique properties of linezolid is its weak inhibitory effect on monoamine oxidase. As such, it may interact with other medications that act through the adrenergic or serotonergic systems, including selective-serotonin reuptake inhibitors and vasoactive agents. We present a 3-month-old infant who was being treated with dopamine to maintain mean arterial pressure during mechanical ventilation following viral-induced respiratory failure. Hypertension and tachycardia developed during the administration of linezolid on two separate occasions. The physiology of catecholamine metabolism is reviewed including the role of the monoamine oxidase system. The potential interaction between linezolid and vasoactive agents such as dopamine is discussed.