Systematic review and meta-analysis of vancomycin-induced nephrotoxicity associated with dosing schedules that maintain troughs between 15 and 20 milligrams per liter. Antimicrob Agents Chemother. 2013;57:734-744. [PMID: 23165462 DOI: 10.1128/aac.01568-12]

Nephrotoxic Risk Associated With Combination Therapy of Vancomycin and Piperacillin-Tazobactam in Critically Ill Patients With Chronic Kidney Disease

Background: The combination of vancomycin and piperacillin-tazobactam (VPT) has been associated with acute kidney injury (AKI) in hospitalized patients when compared to similar combinations. Additional studies examining this nephrotoxic risk in critically ill patients have not consistently demonstrated the aforementioned association. Furthermore, patients with baseline renal dysfunction have been excluded from almost all of these studies, creating a need to examine the risk in this patient population. Methods: This was a retrospective cohort analysis of critically ill adults with baseline chronic kidney disease (CKD) who received vancomycin plus an anti-pseudomonal beta-lactam at Emory University Hospital. The primary outcome was incidence of AKI. Secondary outcomes included stage of AKI, time to development of AKI, time to return to baseline renal function, new requirement for renal replacement therapy, intensive care unit and hospital length of stay, and in-hospital mortality. Results: A total of 109 patients were included. There was no difference observed in the primary outcome between the VPT (50%) and comparator (58%) group (P = .4), stage 2 or 3 AKI (15.9% vs 6%; P = .98), time to AKI development (1.7 vs 2 days; P = .5), time to return to baseline renal function (4 vs 3 days; P = .2), new requirement for RRT (4.5% vs 1.5%; P = .3), ICU length of stay (7.3 vs 7.4 days; P = .9), hospital length of stay (19.3 vs 20.1 days; P = .87), or in-hospital mortality (15.9% vs 10.8%; P = .4). A significant difference was observed in the duration of antibiotic exposure (3.32 vs 2.62 days; P = .045 days). Conclusion: VPT was not associated with an increased risk of AKI or adverse renal outcomes. Our findings suggest that the use of this antibiotic combination should not be avoided in this patient population. More robust prospective studies are warranted to confirm these findings.

Risk factors analysis and construction of predictive models for acute kidney injury in overweight patients receiving vancomycin treatment

BACKGROUND

Vancomycin induced acute kidney injury (VI-AKI) is one of its serious adverse reactions. The purpose of this study is to discuss the risk factors for VI-AKI in overweight patients and construct a clinical prediction model based on the results of the analysis.

METHODS

Multivariable logistic regression analysis was used to identify risk factors for VI-AKI and constructed nomogram models. The performance of the nomogram was evaluated based on the area under the receiver operating characteristic curve (AUC), calibration curves and decision curve analysis (DCA).

RESULT

Cancer (OR 4.186, 95% CI 1.473-11.896), vancomycin trough concentration >20.0 μg/mL (OR 6.251, 95% CI 2.275-17.180), concomitant furosemide (OR 2.722, 95% CI 1.071-6.919) and vasoactive agent (OR 2.824, 95% CI 1.086-7.340) were independent risk factors for VI-AKI. The AUC of the nomogram validation cohorts were 0.807 (95% CI 0.785-0.846). The calibration curve revealed that the predicted outcome was in agreement with the actual observations. Finally, the DCA curves showed that the nomogram had a good clinical applicability value.

CONCLUSION

There are four independent risk factors for the occurrence of VI-AKI in overweight patients, and the nomogram prediction model has good predictive ability, which can provide reference for clinical decision-making.

Serum and urinary biomarkers of vancomycin-induced acute kidney injury: A prospective, observational analysis

Vancomycin, a first-line drug for treating methicillin-resistant Staphylococcus aureus infections, is associated with acute kidney injury (AKI). This study involved an evaluation of biomarkers for AKI detection and their comparison with traditional serum creatinine (SCr). We prospectively enrolled patients scheduled to receive intravenous vancomycin for methicillin-resistant S aureus infection. Blood samples for pharmacokinetic assessment and SCr and cystatin C (CysC) measurements were collected at baseline and on days 3, 7, and 10 from the initiation of vancomycin administration (day 1). Urinary biomarkers, including kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin, and clusterin, were collected from days 1 to 7 and adjusted for urinary creatinine levels. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Of the 42 patients, 6 experienced vancomycin-induced AKI. On day 7, the change from baseline eGFR using CysC (ΔeGFRCysC) showed a stronger correlation with vancomycin area under the curve (r = -0.634, P < .001) than that using SCr (ΔeGFRSCr; r = -0.437, P = .020). ΔeGFRSCr showed no significant correlation with vancomycin pharmacokinetic in patients with body mass index ≥23. The median (interquartile range) level of KIM-1 (μg/mg) was significantly higher in the AKI group (0.006 [0.005-0.008]) than in the non-AKI group (0.004 [0.001-0.005]) (P = .039, Mann-Whitney U test), with area under the receiver operating characteristic curve (95% confidence interval) of 0.788 (0.587-0.990). Serum CysC, particularly in overweight individuals or those with obesity, along with urinary KIM-1 are important predictors of vancomycin-induced AKI. These results may aid in selecting better biomarkers than traditional SCr for detecting vancomycin-induced AKI.

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.

Determining steady-state trough range in vancomycin drug dosing using machine learning

BACKGROUND

Vancomycin is a renally eliminated, nephrotoxic, glycopeptide antibiotic with a narrow therapeutic window, widely used in intensive care units (ICU). We aimed to predict the risk of inappropriate vancomycin trough levels and appropriate dosing for each ICU patient.

METHODS

Observed vancomycin trough levels were categorized into sub-therapeutic, therapeutic, and supra-therapeutic levels to train and compare different classification models. We included adult ICU patients (≥ 18 years) with at least one vancomycin concentration measurement during hospitalization at Mayo Clinic, Rochester, MN, from January 2007 to December 2017.

RESULT

The final cohort consisted of 5337 vancomycin courses. The XGBoost models outperformed other machine learning models with the AUC-ROC of 0.85 and 0.83, specificity of 53% and 47%, and sensitivity of 94% and 94% for sub- and supra-therapeutic categories, respectively. Kinetic estimated glomerular filtration rate and other creatinine-based measurements, vancomycin regimen (dose and interval), comorbidities, body mass index, age, sex, and blood pressure were among the most important variables in the models.

CONCLUSION

We developed models to assess the risk of sub- and supra-therapeutic vancomycin trough levels to improve the accuracy of drug dosing in critically ill patients.

Evaluation of target area under the concentration-time curve of vancomycin in an initial dosing design: a retrospective cohort study

OBJECTIVES

Area under the concentration-time curve (AUC)-guided dosing of vancomycin was introduced in a clinical setting; however, the target range of non-steady-state AUCs, such as Day 1 AUC and Day 2 AUC, remains controversial. Therefore, we sought to determine pharmacokinetic parameter thresholds and identify independent risk factors associated with acute kidney injury (AKI) to establish a safe initial dosing design for vancomycin administration.

METHODS

A single-centre, retrospective, cohort study of hospitalized patients treated with vancomycin was conducted to determine the threshold of both non-steady-state AUCs (Day 1 and 2 AUCs) and trough levels at the first blood sampling point (therapeutic drug monitoring, TDM). In addition, independent risk factors associated with AKI were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

The thresholds for predicting AKI were estimated as 456.6 mg·h/L for AUC0-24h, 554.8 mg·h/L for AUC24-48h, 1080.8 mg·h/L for AUC0-48h and 14.0 μg/mL for measured trough levels, respectively. In a multivariate analysis, Day 2 AUC ≥ 554.8 mg·h/L [adjusted odds ratio (OR), 57.16; 95% confidence interval (CI), 11.95-504.05], piperacillin/tazobactam (adjusted OR, 15.84; 95% CI, 2.73-127.70) and diuretics (adjusted OR, 4.72; 95% CI, 1.13-21.01) were identified as risk factors for AKI.

CONCLUSIONS

We identified thresholds for both AUCs in the non-steady-state and trough levels at the first TDM. Our results highlight the importance of monitoring not only the AUC but also trough levels during vancomycin treatment to reduce the likelihood of AKI.

Time Series AI Model for Acute Kidney Injury Detection Based on a Multicenter Distributed Research Network: Development and Verification Study

Background

Acute kidney injury (AKI) is a marker of clinical deterioration and renal toxicity. While there are many studies offering prediction models for the early detection of AKI, those predicting AKI occurrence using distributed research network (DRN)-based time series data are rare.

Objective

In this study, we aimed to detect the early occurrence of AKI by applying an interpretable long short-term memory (LSTM)-based model to hospital electronic health record (EHR)-based time series data in patients who took nephrotoxic drugs using a DRN.

Methods

We conducted a multi-institutional retrospective cohort study of data from 6 hospitals using a DRN. For each institution, a patient-based data set was constructed using 5 drugs for AKI, and an interpretable multivariable LSTM (IMV-LSTM) model was used for training. This study used propensity score matching to mitigate differences in demographics and clinical characteristics. Additionally, the temporal attention values of the AKI prediction model's contribution variables were demonstrated for each institution and drug, with differences in highly important feature distributions between the case and control data confirmed using 1-way ANOVA.

Results

This study analyzed 8643 and 31,012 patients with and without AKI, respectively, across 6 hospitals. When analyzing the distribution of AKI onset, vancomycin showed an earlier onset (median 12, IQR 5-25 days), and acyclovir was the slowest compared to the other drugs (median 23, IQR 10-41 days). Our temporal deep learning model for AKI prediction performed well for most drugs. Acyclovir had the highest average area under the receiver operating characteristic curve score per drug (0.94), followed by acetaminophen (0.93), vancomycin (0.92), naproxen (0.90), and celecoxib (0.89). Based on the temporal attention values of the variables in the AKI prediction model, verified lymphocytes and calcvancomycin ium had the highest attention, whereas lymphocytes, albumin, and hemoglobin tended to decrease over time, and urine pH and prothrombin time tended to increase.

Conclusions

Early surveillance of AKI outbreaks can be achieved by applying an IMV-LSTM based on time series data through an EHR-based DRN. This approach can help identify risk factors and enable early detection of adverse drug reactions when prescribing drugs that cause renal toxicity before AKI occurs.

Relationship between nephrotoxicity and area under the concentration-time curve of vancomycin in critically ill patients: a multicenter retrospective study

We aimed to assess the frequency of acute kidney injury (AKI) in different areas under the concentration-time curve (AUC) values of vancomycin (VAN) using a two-point blood collection method, allowing for accurate AUC assessment in critically ill patients. This multicenter retrospective observational study was conducted in eight hospitals. We retrospectively analyzed the data of patients who had received VAN in an intensive care unit (ICU) between January 2020 and December 2022. The primary outcome was the incidence of AKI. Patients were classified into three groups according to the AUC24-48h at the initial therapeutic drug monitoring (TDM) as follows: <500, 500-600, and ≥600 µg·h/mL. The AUC24-48h values were calculated using the Bayesian estimation software Practical AUC-guided TDM. Among 146 patients [median age (interquartile range), 67 (56-78) years; 39% women], the AUC24-48h <500 µg·h/mL had an AKI rate of 6.5% (7/107), the AUC24-48h 500-600 µg·h/mL had an AKI rate of 28.0% (7/25), and the AUC24-48h ≥600 µg·h/mL had an AKI rate of 42.9% (6/14). In multivariate Cox proportional hazard analysis, the AUC24-48h 500-600 µg·h/mL [hazard ratio 5.4, 95% confidence interval (CI) 1.64-17.63] and the AUC24-48h ≥600 μg·h/mL (hazard ratio 7.0, 95% CI 2.31-21.18) significantly correlated with a higher incidence of AKI compared with the AUC24-48h <500 μg·h/mL. In conclusion, we identified an association between AUC on day 2 and the risk of AKI in ICU patients, suggesting that not only AUCs above 600 µg·h/mL but also those between 500 and 600 µg·h/mL pose a risk for AKI.

IMPORTANCE

Vancomycin (VAN) is a glycopeptide antibiotic and one of the most commonly used antibiotics for severe infections caused by methicillin-resistant Staphylococcus aureus. However, higher VAN concentrations have been associated with an increased risk of acute kidney injury (AKI). Herein, we aimed to assess the frequency of AKI in different areas under the concentration-time curve (AUC) values of VAN using a two-point blood collection method, allowing for accurate AUC assessment in critically ill patients. We identified an association between AUC on day 2 and the risk of AKI in intensive care unit patients, suggesting that not only AUCs above 600 µg·h/mL but also those between 500 and 600 µg·h/mL pose a risk for AKI. Therefore, individualized dosing is feasible, with pharmacists being able to optimize VAN doses to attain appropriate targets.

Swab Testing to Optimize Pneumonia treatment with empiric Vancomycin (STOP-Vanc): study protocol for a randomized controlled trial

Background

Vancomycin, an antibiotic with activity against Methicillin-resistant Staphylococcus aureus (MRSA), is frequently included in empiric treatment for community-acquired pneumonia (CAP) despite the fact that MRSA is rarely implicated in CAP. Conducting polymerase chain reaction (PCR) testing on nasal swabs to identify the presence of MRSA colonization has been proposed as an antimicrobial stewardship intervention to reduce the use of vancomycin. Observational studies have shown reductions in vancomycin use after implementation of MRSA colonization testing, and this approach has been adopted by CAP guidelines. However, the ability of this intervention to safely reduce vancomycin use has yet to be tested in a randomized controlled trial.

Methods

STOP-Vanc is a pragmatic, prospective, single center, non-blinded randomized trial. Adult patients with suspicion for CAP who are receiving vancomycin and admitted to the Medical Intensive Care Unit at Vanderbilt University Medical Center will be screened for eligibility. Eligible patients will be enrolled and randomized in a 1:1 ratio to either receive MRSA nasal swab PCR testing in addition to usual care (intervention group), or usual care alone (control group). PCR testing results will be transmitted through the electronic health record to the treating clinicians. Primary providers of intervention group patients with negative swab results will also receive a page providing clinical guidance recommending discontinuation of vancomycin. The primary outcome will be vancomycin-free hours alive, defined as the number of hours alive and free of the use of vancomycin within the first seven days following trial enrollment estimated using a proportional odds ratio model. Secondary outcomes include 30-day all-cause mortality and time alive off vancomycin.

Discussion

STOP-Vanc will provide the first randomized controlled trial data regarding the use of MRSA nasal swab PCR testing to guide antibiotic de-escalation. This study will provide important information regarding the effect of MRSA PCR testing and antimicrobial stewardship guidance on clinical outcomes in an intensive care unit setting.

Trial registration

This trial was registered on ClinicalTrials.gov on February 22, 2024. (ClinicalTrials.gov identifier: NCT06272994).

Optimizing vancomycin dosing in pediatrics: a machine learning approach to predict trough concentrations in children under four years of age

BACKGROUND

Vancomycin trough concentration is closely associated with clinical efficacy and toxicity. Predicting vancomycin trough concentrations in pediatric patients is challenging due to significant inter-individual variability and rapid physiological changes during maturation.

AIM

This study aimed to develop a machine learning model to predict vancomycin trough concentrations and determine optimal dosing regimens for pediatric patients < 4 years of age using ML algorithms.

METHOD

A single-center retrospective observational study was conducted from January 2017 to March 2020. Pediatric patients who received intravenous vancomycin and underwent therapeutic drug monitoring were enrolled. Seven ML models [linear regression, gradient boosted decision trees, support vector machine, decision tree, random forest, Bagging, and extreme gradient boosting (XGBoost)] were developed using 31 variables. Performance metrics including R-squared (R2), mean square error (MSE), root mean square error (RMSE), and mean absolute error (MAE) were compared, and important features were ranked.

RESULTS

The study included 120 eligible trough concentration measurements from 112 patients. Of these, 84 measurements were used for training and 36 for testing. Among the seven algorithms tested, XGBoost showed the best performance, with a low prediction error and high goodness of fit (MAE = 2.55, RMSE = 4.13, MSE = 17.12, and R2 = 0.59). Blood urea nitrogen, serum creatinine, and creatinine clearance rate were identified as the most important predictors of vancomycin trough concentration.

CONCLUSION

An XGBoost ML model was developed to predict vancomycin trough concentrations and aid in drug treatment predictions as a decision-support technology.

Comparing Actual and Rounded Serum Creatinine Concentration for Assessing the Accuracy of Vancomycin Dosing in Elderly Patients: A Single-Center Retrospective Study

Prescribers often face the challenge of predicting creatinine clearance (CrCl) in elderly patients who are 65 years or older and have serum creatinine (SCr) concentrations below 1 mg/dL. Studies have shown that utilizing rounded SCr would underestimate CrCl in this population, which could lead to the under-dosing of some medications like vancomycin. The current study aimed to compare the accuracy of vancomycin dosing using actual SCr versus rounded SCr to 1 mg/dL in elderly patients. A total of 245 patients were included. The therapeutic trough level (10-20 mg/L) was achieved in 138 (56.3%) patients using actual SCr. Sub-therapeutic (<10 mg/L) and supra-therapeutic (>20 mg/L) trough levels were observed in 32 (13.1%) and 75 (30.6%) patients, respectively. The predictive performance of different vancomycin doses based on actual SCr and rounded SCr compared to the targeted maintenance dose (TMD) showed a stronger correlation of dosing based on actual SCr with TMD (r = 0.55 vs. 0.31) compared to rounded SCr dosing; both doses showed similar precision, with ranges of ±552 mg/day for the dosing based on actual SCr and ±691 mg/day for the dosing based on rounded SCr. Furthermore, the dosing based on actual SCr showed a lower error percentage (69%) and a higher accuracy rate (57.6%) within ±10% of the TMD compared to the dosing based on rounded SCr, which had an error percentage of (92.3%) and an accuracy rate of (40%). The prevalence of vancomycin-associated nephrotoxicity (VAN) was seen in 44 (18%) patients. Patients between 75 and 84 years of age, those who were bedridden, and those with vancomycin trough concentrations greater than 20 mg/L had a higher risk of developing VAN. In conclusion, in elderly patients, estimating vancomycin dosing based on actual SCr was more accurate compared to rounded SCr to 1 mg/dL. The efficacy of vancomycin could be negatively affected by rounding up SCr, which could underestimate CrCl and result in the under-dosing of vancomycin.

Implementation of vancomycin AUC/MIC dosing vs traditional trough dosing and incidence of acute kidney injury at a rural community hospital

PURPOSE

Vancomycin treats methicillin-resistant Staphylococcus aureus infections in hospitalized patients, yet nephrotoxicity is a major risk. Dosing based on the ratio of vancomycin 24-hour area under the curve to minimum inhibitory concentration (AUC/MIC) is preferred over a trough-only vancomycin dosing approach to minimize the risk of acute kidney injury (AKI). This study compares the safety of AUC/MIC-guided and trough-only vancomycin dosing at a 255-bed hospital.

METHODS

A retrospective cohort study of adult patients with stable renal function who received at least 3 days of intravenous vancomycin via either AUC/MIC or trough-only dosing was conducted. The primary outcome was AKI occurrence during treatment. Secondary outcomes included the frequencies of therapeutic, subtherapeutic, and supratherapeutic vancomycin troughs. Relative risk calculations were performed for all outcomes.

RESULTS

600 patients from the trough-only group and 561 patients from the AUC/MIC group were included. 121 patients from the trough-only group and 87 patients from the AUC/MIC group experienced AKI during treatment (relative risk [RR], 0.769; 95% CI, 0.599-0.988; P = 0.0397). Compared with the trough-only group, the AUC/MIC group was significantly less likely to have supratherapeutic troughs (RR, 0.703; 95% CI, 0.611-0.809; P < 0.0001) and significantly more likely to have therapeutic troughs (RR, 1.14; 95% CI, 1.069-1.211; P < 0.0001), with no significant between-group difference in subtherapeutic troughs (RR, 1.03; 95% CI, 0.854-1.25; P = 0.74).

CONCLUSION

AUC/MIC dosing was associated with significantly lower risk of AKI, a lower risk of supratherapeutic trough levels, and a higher risk of therapeutic trough levels, with no significant difference in subtherapeutic troughs when compared to trough-only dosing. Limitations of this study included its retrospective nature and reliance on manual chart review.

Effect modification of dosing strategy (AUC or trough) on AKI associated with vancomycin in combination with piperacillin/tazobactam or cefepime and meropenem

Piperacillin-tazobactam (TZP), cefepime (FEP), or meropenem (MEM) and vancomycin (VAN) are commonly used in combination for sepsis. Studies have shown an increased risk of acute kidney injury (AKI) with TZP and VAN compared to FEP or MEM. VAN guidelines recommend area under the curve (AUC) monitoring over trough (Tr) to minimize the risk of AKI. We investigated the association of AKI and MAKE-30 with the two VAN monitoring strategies when used in combination with TZP or FEP/MEM. Adult patients between 2015 and 2019 with VAN > 72 hours were included. Patients with AKI prior to or within 48 hours of VAN or baseline CrCl of ≤30 mL/min were excluded. Four cohorts were defined: FEP/MEM/Tr, FEP/MEM/AUC, TZP/Tr, and TZP/AUC. A Cox Proportional Hazard Model was used to model AKI as a function of the incidence rate of at-risk days, testing monitoring strategy as a treatment effect modification. Multivariable logistic regression was used to model MAKE-30. Overall incidence of AKI was 18.6%; FEP/MEM/Tr = 115 (14.6%), FEP/MEM/AUC = 52 (14.9%), TZP/Tr = 189 (26%), and TZP/AUC = 96 (17.1%) (P < 0.001). Both drug group [(TZP; P = 0.0085)] and monitoring strategy [(Tr; P = 0.0007)] were highly associated with the development of AKI; however, the effect was not modified with interaction term [(TZP*Tr); 0.085)]. The odds of developing MAKE-30 were not different between any group and FEP/MEM/AUC. The effect of VAN/TZP on the development of AKI was not modified by the VAN monitoring strategy (AUC vs trough). MAKE-30 outcomes were not different among the four cohorts.

Effect of Different Local Antibiotic Regimens on Prevention of Postoperative Infection in Clean Surgical Wounds: A Systematic Review and Network Meta-analysis

OBJECTIVE

To compare the efficacy of several local antibiotic regimens in preventing surgical site infection (SSI) in clean surgical wounds.

DATA SOURCES

The authors searched CNKI (China National Knowledge Infrastructure), the VIP (VIP information resource integration service platform), Wanfang Data knowledge service platform (WANFANG), SinoMed, Cochrane Library, EMBASE, and PubMed.

STUDY SELECTION

A total of 20 randomized controlled trials published between January 1, 2000 and April 1, 2021 were included in this meta-analysis.

DATA EXTRACTION

Authors extracted the name of the first author, publication date, country, type of surgery, follow-up time, mean age of participants, sample size of each group, interventions, outcome indicators, and study type from each article.

DATA SYNTHESIS

The overall effectiveness of eight local managements in reducing the incidence of the SSI effect were compared through the SUCRA (surface under the cumulative ranking curve) probabilities. The results of a network meta-analysis demonstrated that gentamicin ointment (odds ratio [OR], 0.16; 95% CI, 0.04-0.60), mupirocin ointment (OR, 0.44; 95% CI, 0.21-0.94), and gentamicin soaking of the graft (OR, 0.63; 95% CI, 0.44-0.91) significantly reduced the incidence of SSI compared with control. Further, vancomycin soaking of the graft (86.7%) ranked first, followed by gentamicin ointment (81.1%), gentamicin irrigation (79.9%), mupirocin ointment (56.8%), triple antibiotic ointment (47.8%), gentamicin soaking of the graft (42.3%), and vancomycin powder (22.1%); ampicillin powder (17.8%) was the least effective drug.

CONCLUSIONS

The findings indicate that local antibiotics combined with conventional antibiotics in the wound before wound closure are effective in reducing the incidence of SSI in clean surgical wounds. Vancomycin inoculation of the graft exhibited the best effect.

Flucloxacillin worsens while imipenem-cilastatin protects against vancomycin-induced kidney injury in a translational rat model

BACKGROUND AND PURPOSE

Vancomycin is one of the most common clinical antibiotics, yet acute kidney injury is a major limiting factor. Common combinations of antibiotics with vancomycin have been reported to worsen and improve vancomycin-induced kidney injury. We aimed to study the impact of flucloxacillin and imipenem-cilastatin on kidney injury when combined with vancomycin in our translational rat model.

EXPERIMENTAL APPROACH

Male Sprague-Dawley rats received allometrically scaled (1) vancomycin, (2) flucloxacillin, (3) vancomycin + flucloxacillin, (4) vancomycin + imipenem-cilastatin or (5) saline for 4 days. Kidney injury was evaluated via drug accumulation and urinary biomarkers including urinary output, kidney injury molecule-1 (KIM-1), clusterin and osteopontin. Relationships between vancomycin accumulation in the kidney and urinary kidney injury biomarkers were explored.

KEY RESULTS

Urinary output increased every study day for vancomycin + flucloxacillin, but after the first dose only in the vancomycin group. In the vancomycin + flucloxacillin group, urinary KIM-1 increased on all days compared with vancomycin. In the vancomycin + imipenem-cilastatin group, urinary KIM-1 was decreased on Days 1 and 2 compared with vancomycin. Similar trends were observed for clusterin. More vancomycin accumulated in the kidney with vancomycin + flucloxacillin compared with vancomycin and vancomycin + imipenem-cilastatin. The accumulation of vancomycin in the kidney tissue correlated with increasing urinary KIM-1.

CONCLUSIONS AND IMPLICATIONS

Vancomycin + flucloxacillin caused more kidney injury compared with vancomycin alone and vancomycin + imipenem-cilastatin in a translational rat model. The combination of vancomycin + imipenem-cilastatin was nephroprotective.

Dosing and Exposure of Vancomycin With Continuous Infusion: A Retrospective Study

Vancomycin continuous infusion (CI) has suggested benefits over intermittent infusion: reduced nephrotoxicity, higher target attainment, and simpler therapeutic drug monitoring (TDM). Empiric dosing regimens range from 30-60 mg/kg/day and it is unclear which regimen results in optimal exposure. This study evaluates whether a dosing regimen of 45 mg/kg/day after a 20 mg/kg loading dose for patients with estimated glomerular filtration rate (eGFR) ≥ 50 mL/min results in adequate exposure. We retrospectively analyzed plasma concentrations from patients treated with vancomycin CI as routine clinical care between February and October 2021. Patients under 18 years old, with renal replacement therapy, reduced creatinine clearance (Chronic Kidney Disease Epidemiology Collaboration < 50 mL min/1.73 m2 ) or outpatient antibiotic therapy were excluded. Dose, renal function, and blood draw procedures were assessed for each measured vancomycin sample. Initially, 121 samples were included. Subsequently, 7 samples, 6 of which with concentrations ≥ 40 mg/L, were verified to be incorrectly drawn and excluded. With doses of 40-50 mg/kg/day concentrations ranged from 18.4-61.0 mg/L. Only 25% were within the target window of 17-25 mg/L and 15% were ≥ 40 mg/L. Supratherapeutic concentrations were observed in 89% of samples from patients dosed 40-60 mg/kg/day with eGFR 50-80 mL/min. Concluding, an empiric dosing regimen of 45 mg/kg results in too high vancomycin exposure and thus we recommend lower doses and differentiation according to renal function. Additionally, when measuring concentrations over 40 mg/L incorrect sampling must be excluded before dose adjustment and the large variability in exposure between patients, warrants the need for swift TDM.

Impact of Limiting Vancomycin Loading Doses in Patients With Methicillin-resistant Staphylococcus aureus Infections After Hospital Protocol Revision

Background: Vancomycin loading doses are commonly used to quickly attain target serum concentrations; however, data supporting their effect on clinical patient outcomes is limited. In April 2020, our institution revised our pharmacist-driven vancomycin dosing protocol to reserve loading doses for hemodynamically unstable patients with suspected serious methicillin-resistant Staphylococcus aureus (MRSA) infections. Prior to the protocol update, all patients treated with vancomycin at our institution received a weight-based loading dose. The purpose of this study is to assess clinical efficacy and safety outcomes related to the use of vancomycin loading doses. Methods: A retrospective, quasi-experimental study was performed to compare clinical outcomes in adult patients treated with vancomycin for laboratory-confirmed MRSA infections. Patients who received vancomycin therapy prior to our institution's vancomycin dosing protocol revisions (pre-intervention) were compared to patients who received vancomycin after the revisions (post-intervention). The primary outcome was all-cause, inpatient mortality. Secondary outcomes included persistent signs and symptoms of infection ≥5 days after vancomycin initiation, switch to alternative anti-MRSA therapy, and nephrotoxicity. Results: A total of 122 patients (63 pre-intervention patients and 59 post-intervention patients) were included. Receipt of a vancomycin loading dose did not impact the rate of inpatient mortality (4.76%vs 6.78%; OR 1.46, 95% CI [0.31, 6.79]). All secondary outcomes were similar between the two groups, including persistent signs and symptoms of infection, switch to alternative anti-MRSA therapy, and nephrotoxicity. Conclusions: Routine use of vancomycin loading doses is not associated with improved outcomes in hemodynamically stable patients with MRSA infections.

'The Year of Living Dangerously': Successful Rhodococcus Equi Therapy in an Immunosuppressed Patient with Minimal Toxicity by One Year of Continuous Intravenous Vancomycin Therapy Combined with Oral Levofloxacin And Rifampicin

Background

Rhodococcus equi is a Gram-positive microorganism that causes infections, particularly in immunocompromised patients. Treatment duration can be prolonged. While vancomycin is an effective drug in this scenario, its use may lead to renal damage. Studies have shown that continuous vancomycin infusion appears to be a safe strategy in terms of adverse effects compared to bolus administration.

Case description

We present the case of a 71-year-old female liver transplant recipient. After being diagnosed with a mediastinal infection caused by Rhodococcus equi with poor response to initial therapy, she required 12 months of continuous intravenous domiciliary infusion of vancomycin combined with oral levofloxacin and rifampicin. There was no drug-related complication throughout the follow-up.

Conclusions

The use of continuous vancomycin infusion has emerged as a safer, more efficient, and cost-effective alternative to intermittent administration. We want to emphasise the uniqueness of this case, where despite the unprecedented treatment duration, no adverse effects occurred.

LEARNING POINTS

Vancomycin therapy based on continuous infusion represents a safer and cheaper strategy than classic intermittent administration.The use of continuous infusion facilitates the management of complex infections with outpatient antimicrobial therapy.

Nut Cracked? Does the ACORN Trial End the Debate Surrounding Vancomycin and Piperacillin-Tazobactam Combination Therapy and Increased Risk for Acute Kidney Injury?

Observational data published over the past decade have suggested that concomitant receipt of piperacillin-tazobactam with vancomycin significantly increases the risk for vancomycin-associated acute kidney injury. Importantly, however, there is significant controversy surrounding this association, and debate continues about the veracity of the risk. Given this ongoing debate, the recently published "Cefepime vs Piperacillin-Tazobactam in Adults Hospitalized With Acute Infection: The ACORN Randomized Clinical Trial" is of tremendous interest to the infectious diseases community. In ACORN, the authors conclude that there was no association between receipt of cefepime or piperacillin-tazobactam and the primary outcome of acute kidney injury or death by day 14, despite the fact that >75% of the population received concomitant vancomycin. In this perspective, we provide a brief history on the controversy, provide a critical analysis of the ACORN findings, and ultimately discuss how these data help inform the ongoing debate.

Retrospective review of intermittent and continuous infusion vancomycin for methicillin-resistant Staphylococcus aureus bacteremia

PURPOSE

Vancomycin is commonly administered as an intermittent infusion (IIV), although vancomycin's stability at room temperature permits administration continuously over 24 h (CIV). At our institution, CIV has been the preferred infusion method for over 20 years due to ease of administration and simplicity of therapeutic drug monitoring. The purpose of this study was to examine the outcomes associated with IIV compared to CIV.

METHODS

This was a retrospective study of patients who received vancomycin for MRSA bacteremia. The primary outcomes were the time to therapeutic goal and frequency of adverse drug reactions on IIV compared to CIV. Secondary outcomes evaluated all-cause readmission, relapse, and mortality 30 days after completion of therapy.

RESULTS

Sixty-three patients were included. Significantly fewer patients were able to achieve a therapeutic goal on IIV compared to CIV (52.4% vs. 82.5%, p < 0.01). Patients on IIV took 3.6 days, on average, to reach the target goal, compared to 1.9 days when patients were switched to CIV (95% confidence interval, 0.48-3.04, p < 0.01). Six patients experienced adverse events on IIV, and 15 patients experienced adverse events on CIV (IIV 9.5%, CIV 23.8%, p = 0.035). One patient experienced relapse of infection, and six patients (9.5%) were readmitted 30 days after completion of therapy. There were no deaths in the cohort.

CONCLUSION

For MRSA bacteremia, CIV enabled patients to achieve the AUC/MIC goal significantly faster than when patients received IIV. Furthermore, patients who were unable to achieve a therapeutic trough on IIV became therapeutic once switched to CIV.

Risk factors for acute kidney injury associated with intravenous vancomycin in neurosurgical inpatients: a retrospective study

PURPOSE

Vancomycin (VAN) is widely used in neurosurgical patients for intracranial infections. We aimed to assess the incidence and risk factors for VAN-associated acute kidney injury (VA-AKI) in this population.

METHODS

A case-control study of patients who treated with vancomycin in neurosurgery from January 2020 to December 2022 was conducted. Demographics and potential risk factors were collected. Multivariate logistic regression analyses were performed to identify risk factors for VA-AKI. AKI was defined according to the Kidney Disease Improving Global Outcomes Guidelines (KDIGO).

RESULTS

A total of 345 patients participated with a VA-AKI incidence of 17.1% (59 cases). Among them, 15 patients had renal impairment (Stage 2 or higher), and 2 required dialysis. With univariate analysis and binary logistic regression analysis, we found that the use of mannitol (OR: 4.164; 95% CI: 1.606-10.792; P = 0.003), loop diuretics (OR: 3.371; 95% CI: 1.633-6.958; P = 0.001), three or more antimicrobial applications (OR: 3.623; 95% CI: 1.600-8.206; P = 0.002), diastolic blood pressure 80-89 mm Hg (OR: 5.532; 95% CI: 1.677-18.250; P = 0.005) and diastolic blood pressure ≥ 90 mm Hg (OR: 6.845; 95% CI: 1.518-30.866; P = 0.012) were independent risk factors for VA-AKI. In addition, according to the Youden Index, the trough concentration of vancomycin should not exceed 15.845 mg/L.

CONCLUSION

The incidence of VA-AKI in neurosurgical patients was 17.1%. The concomitant use of mannitol and loop diuretics, along with higher diastolic blood pressure and the combined use of more than three antimicrobial agents, were associated with an increased risk of neurosurgical VA-AKI.

Model-Informed Precision Dosing Improves Outcomes in Patients Receiving Vancomycin for Gram-Positive Infections

Background

Consensus guidelines for dosing and monitoring of vancomycin recommend collection of 2 serum concentrations to estimate an area under the curve/minimum inhibitory concentration ratio (AUC/MIC). Use of Bayesian software for AUC estimation and model-informed precision dosing (MIPD) enables pre-steady state therapeutic drug monitoring using a single serum concentration; however, data supporting this approach are limited.

Methods

Adult patients with culture-proven gram-positive infections treated with vancomycin ≥72 hours receiving either trough-guided or AUC-guided therapy were included in this retrospective study. AUC-guided therapy was provided using MIPD and single-concentration monitoring. Treatment success, vancomycin-associated acute kidney injury (VA-AKI), and inpatient mortality were compared using a desirability of outcome ranking analysis. The most desirable outcome was survival with treatment success and no VA-AKI, and the least desirable outcome was death.

Results

The study population (N = 300) was comprised of an equal number of patients receiving AUC-guided or trough-guided therapy. More patients experienced the most desirable outcome in the AUC-guided group compared to the trough-guided group (58.7% vs 46.7%, P = .037). Rates of VA-AKI were lower (21.3% vs 32.0%, P = .037) and median hospital length of stay was shorter (10 days [interquartile range {IQR}, 8-20] vs 12 days [IQR, 8-25]; P = .025) among patients receiving AUC-guided therapy.

Conclusions

AUC-guided vancomycin therapy using MIPD and single-concentration monitoring improved outcomes in patients with culture-proven gram-positive infections. Safety was improved with reduced incidence of VA-AKI, and no concerns for reduced efficacy were observed. Moreover, MIPD allowed for earlier assessment of AUC target attainment and greater flexibility in the collection of serum vancomycin concentrations.

Association of vancomycin-induced acute kidney injury with trough versus AUC monitoring in patients receiving extended durations of therapy

Objective

Vancomycin therapy is associated with an increased risk of acute kidney injury (AKI). Previous studies suggest that area under the curve (AUC) monitoring reduces the risk of AKI, but literature is lacking to support this in patients receiving longer durations of vancomycin therapy.

Design

Retrospective cohort study.

Method

Patients ≥18 years old, admitted between August 2015 and July 2017 or October 2017 and September 2019, and received at least 14 days of intravenous (IV) vancomycin therapy were included in the study. Our primary outcome was the incidence of AKI between trough monitoring and AUC monitoring groups using Kidney Disease Improving Global Outcomes criteria. Secondary outcomes included inpatient mortality, median inpatient length of stay, and median intensive care unit length of stay.

Results

Overall, 582 patients were included in the study, with 318 patients included in the trough monitoring group and 264 included in the AUC monitoring group. The median duration of vancomycin therapy was 23 days (interquartile range, 16-39). Patients within the trough monitoring group had a higher incidence of AKI compared to the AUC monitoring group (45.6% vs 28.4%, p < 0.001). Furthermore, logistic regression analysis showed that AUC monitoring was associated with a 54% lower incidence of AKI (OR 0.46, 95% CI [0.31-0.69]). All-cause inpatient mortality was numerically higher in the trough monitoring group (12.9% vs 8.3%, p = 0.078).

Conclusions

In patients who received at least 14 days of IV vancomycin therapy, AUC monitoring was associated with a lower incidence of AKI.

Correlation of Calculated Vancomycin Trough Concentrations and Exposure: A Monte Carlo Simulation

BACKGROUND

Current recommendations are to dose vancomycin to target 24-hour area under the curve (AUC) of 400-600 mg·h/L to optimize efficacy and safety. Limited data support AUC monitoring, and some centers continue to use trough concentrations. A target of 10-20 mg/L has been proposed to reduce nephrotoxicity risk.

OBJECTIVE

To use previously published pharmacokinetic equations in a Monte Carlo simulation relating AUC exposure to trough concentrations when targeting an AUC between 400 and 600 mg·h/L.

METHODS

Previously published pharmacokinetic data were used as input parameters for a Monte Carlo simulation using previously published formulae to correlate AUC to simulated trough concentrations. Pharmacokinetic parameters were assumed to occur in a normal distribution pattern. We excluded irrelevant simulated cases. Maintenance doses of 15 mg/kg were rounded to the nearest 250 mg. Calculated trough concentrations for AUCs of both 400 and 600 mg·h/L were evaluated in each simulation.

RESULTS

A total of 10 000 Monte Carlo simulations were performed. Targeting an AUC of 400 mg·h/L resulted in a mean trough concentration of 10.3 ± 0.8 mg/L. Targeting an AUC of 600 mg·h/L resulted in a mean trough concentration of 15.4 ± 1.2 mg/L.

CONCLUSION AND RELEVANCE

We demonstrate that a lower trough concentration range may be supported by an AUC of 400-600 mg·h/L, which may reduce risk and rates of nephrotoxicity without compromising previously established efficacious target trough concentrations.

Using Methicillin-Resistant Staphylococcus aureus Nasal Screens to Rule Out Methicillin-Resistant S aureus Pneumonia in Surgical Intensive Care Units

INTRODUCTION

The methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) has a high negative predictive value (NPV). We aimed to understand if there was a difference in the NPV of the MRSA screen in surgical intensive care units (ICUs) and to determine its role in antibiotic de-escalation.

METHODS

We performed a single-center, retrospective cohort study of adults with a positive respiratory culture and MRSA nasal PCR admitted to a surgical ICU from 2016 to 2019. Patients were stratified by surgical ICU: cardiothoracic/cardiovascular intensive care unit (CVICU) or transplant/acute care surgery intensive care unit (ACS-ICU). Our primary outcome was the NPV of MRSA screen. Secondary outcome was the duration of empiric MRSA-targeted therapy.

RESULTS

We analyzed 61 patients: 42.6% (n = 26) ACS-ICU and 57.4% (n = 35) CVICU. There were no differences in age, comorbidities, prior MRSA infection, recent antibiotic use, immunocompromised status, or renal replacement therapy. At pneumonia diagnosis, more patients in the ACS-ICU were hospitalized ≥5 d (65.4% versus 8.6%, P < 0.0001) and more patients in the CVICU were in septic shock (88.6% versus 34.5%, P < 0.0001) and thrombocytopenic (40% versus 11.5%, P = 0.02). NPV of the PCR was similar (ACS-ICU: 0.92 [0.75-0.98], CV-ICU 0.89 [0.73-0.96]). On multivariable linear regression, the CVICU was associated with longer empiric therapy (β 1.5, 95% CI 0.8-2.3, P < 0.0001), as was hospitalization for ≥5 d (β 0.73, 95% CI 0.06-1.39, P = 0.03).

CONCLUSIONS

The MRSA nasal PCR screen has a high NPV for ruling out MRSA pneumonia in critically ill surgical patients. However, patients in the CVICU and patients hospitalized ≥5 d had a longer time to de-escalation of MRSA-targeted therapy, potentially due to higher clinical risk profile.

The Effect of Vancomycin and Piperacillin-Tazobactam on Incidence of Acute Kidney Injury in Patients With Obesity

Background: Increasing evidence suggests that administration of combination vancomycin and piperacillin-tazobactam (VPT) increases the incidence of acute kidney injury (AKI) beyond that of vancomycin alone. But these investigations have not evaluated AKI risk specifically in an increasingly prevalent obese population in whom VPT pharmacokinetics are altered. Objective: To evaluate AKI risk with VPT administration to patients with obesity. Methods: We conducted a multicenter retrospective study of obese patients admitted to 2 separate academic teaching hospitals from January 2010 to December 2021, who received VPT, or vancomycin plus either cefepime, meropenem, or ceftazidime. The primary outcome evaluated AKI when patients were treated with or without VPT. Results: A total of 227 patients were evaluated (114 in VPT, vs 113 in control group). Overall, body mass index (35.6 kg/m2 ± 4.8vs 36.1 kg/m2 ± 5.2; P = .44) was similar between the VPT and control groups respectively. Total vancomycin dose on day 1 of antibiotic therapy (3,432 mg ± 935 vs 2,732 mg ± 912; P < .01) and nephrotoxin administration (75.4% vs 62.8%; P = .04) were higher in the VPT group. Incidence of AKI was higher in the VPT group (37.7%vs 14.2%; P = .01) and on regression analysis VPT was predictive of developing AKI (OR = 3.9; 95% CI = 2.0-7.7; P < .01). Conclusion and Relevance: In this retrospective study, the incidence of AKI was increased in obese patients receiving therapy with VPT. Vancomycin combination therapy with ceftazidime, cefepime, and meropenem appeared to be safe and was associated with less nephrotoxicity. Cautious use of VPT and further investigation with larger studies are warranted in this area.

Oritavancin vs Standard of Care for Treatment of Nonendovascular Gram-Positive Bloodstream Infections

Background

Data is limited comparing oritavancin (ORT) to the standard-of-care (SOC) for the treatment gram-positive blood stream infections (BSI).

Methods

This was a retrospective study of all patients in the Veteran's Affairs Health Care System treated with at least 1 dose of oritavancin or at least 5 days of vancomycin, daptomycin, ceftaroline, ampicillin, ampicillin-sulbactam, nafcillin, oxacillin, or cefazolin for a documented gram-positive BSI from 1 January 2015 to 30 June 2021. Patients with polymicrobial blood cultures or positive cultures from other sites were included if the organisms were sensitive to the incident antimicrobial; no concomitant antimicrobials could be used once the incident agent was started. Individuals were also excluded if they were diagnosed with endocarditis, had a neutrophil count 96-hours of treatment before the incident antimicrobial was started.The primary composite outcome was clinical failure, defined as all-cause mortality within 30-days from the end of therapy, or blood cultures positive for the incident organisms ≥72 hours after administration of the first dose and ≤30 days after the administration of the final dose of the study antimicrobial, or any drug or line-related readmissions within 30-days of hospital discharge.

Results

Two hundred-forty patients were identified for screening with 96 meeting criteria (27 in ORT and 69 in SOC groups). Baseline characteristics were generally balanced between groups except more patients in the ORT group received >96-hours of treatment before the incident antimicrobial was started (70.3% (19/27) vs 13.04% 9/69); P < .001). The pathogen most prevalent was methicillin susceptible Staphylococcus aureus (MSSA) (ORT 33.3% (9/27) vs SOC 46.4% (32/69)). Clinical failure occurred in 7.4% (2/27) in the ORT group and 17.4% (12/69) in SOC (P = .34). No components of the primary outcome were significantly different between groups, but AKI did occur more commonly in the SOC group (27.5% (19/69) vs 3.7% (1/27); P = .01).

Conclusions

ORT appears to be a safe and effective option when directly compared to the SOC for non-endocarditis BSIs.

Association between vancomycin therapeutic drug monitoring and clinical outcomes in treating neonatal sepsis

BACKGROUND

Neonatal sepsis is commonly treated with vancomycin in the neonatal intensive care unit. Therapeutic drug monitoring of vancomycin is routinely used to personalise dosing to optimise effectiveness and avoid toxicity.

OBJECTIVES

This study aimed to define a target range by evaluating associations between vancomycin trough concentrations or area under the concentration time curve over 24 hours (AUC24h) and clinical outcomes in neonates.

METHODS

Neonates, who were admitted to the neonatal intensive care unit and received intravenous vancomycin, were included in this retrospective cohort study. For evaluating effectiveness, patients who received vancomycin for < 5 days were excluded. The AUC24h was estimated based on a study-derived population pharmacokinetic model. Primary outcomes were persistent/recurrent infections and mortality within 30 days. Secondary outcomes, including acute kidney injury (AKI), were also assessed. Logistic regression and classification and regression tree analyses were performed.

RESULTS

A total of 448 patients (123 patients for effectiveness analysis) were included. A vancomycin trough > 10 mg/L was associated with 70% lower odds of persistent/recurrent infections (adjusted OR 0.30, 95% CI 0.09-0.86; P = 0.023). Patients who took more than a day to reach target range had 1.4 times higher odds of persistent/recurrent infections or death (P = 0.04). A vancomycin trough > 15 mg/L was associated with a three times higher risk of AKI (P = 0.003). An AUC24h of 420-650 mg*h/L was also associated with the lowest risk of composite outcomes (adjusted OR 0.29, 95% CI 0.08-0.86; P = 0.025).

CONCLUSION

A vancomycin trough target range of 10-15 mg/L and achievement of this target within a day of treatment initiation were associated with the most optimal clinical outcomes in treating neonatal sepsis.

Vancomycin dosing in high-intensity continuous renal replacement therapy: A retrospective cohort study

INTRODUCTION

An inverse relationship exists between vancomycin serum concentrations and the intensity of continuous renal replacement therapy (CRRT), reflected through the dialysate flow rate (DFR). There remains a lack of evidence to guide initial vancomycin dosing in the setting of high-intensity CRRT (i.e., DFR >30 mL/kg/h). Additionally, recommendations for pharmacokinetic monitoring of vancomycin have transitioned from a trough-based to area under the curve (AUC)-based dosing strategy to optimize efficacy and safety. Therefore, an improved understanding of the impact of CRRT intensity on AUC/MIC (minimum inhibitory concentration) has the potential to enhance vancomycin dosing in this patient population.

OBJECTIVES

The goal of this study is to evaluate current vancomycin dosing strategies and achievement of pharmacokinetic targets in patients on high-intensity CRRT.

METHODS

This was a single-center, retrospective cohort study of adult critically ill patients admitted to Houston Methodist Hospital between May 2019 and October 2021 and received vancomycin therapy while on high-intensity CRRT. High-intensity CRRT was defined by a DFR that was both ≥3 L/h and >30 mL/kg/h. Depending on the initial vancomycin dosing strategy, patients were stratified into either the traditional (15 mg/kg/day) or enhanced (≥15 mg/kg/day) dosing group. The primary outcome was the percent of patients who attained steady-state AUC24 /MIC ≥400 mg*h/L at the first obtained vancomycin level in the enhanced group compared with the traditional group.

RESULTS

A total of 125 patients were included in the final analysis, 56 in the traditional and 69 in the enhanced dosing group. The primary end point occurred in 74% and 54% of patients in the enhanced and traditional dosing groups, respectively (p = 0.029). Therapeutic vancomycin trough levels (10-20 μg/mL) were more commonly achieved in the enhanced dosing group compared with the traditional dosing group (66.7% vs. 45%, p = 0.013). As DFR rose, increasingly higher doses of vancomycin, up to 27 mg/kg/day, were required to achieve the therapeutic targets.

CONCLUSION

This is the first study to evaluate the influence of variable CRRT intensities on vancomycin AUC/MIC. Our findings suggest that vancomycin doses of ≥15 mg/kg/day are needed to achieve early therapeutic targets in patients on high-intensity CRRT.

Impact of implementing a vancomycin protocol to reduce kidney toxicity: A comparative study

Introduction: Vancomycin is a frequently used antibiotic for treating severe infections caused by multidrug-resistant, Gram-positive pathogens. To ensure its effectiveness and minimize the risk of nephrotoxicity, safe administration and dose monitoring are crucial. Understanding the impact of vancomycin serum levels on clinical outcomes is of paramount importance, necessitating improved knowledge on its use, dose monitoring, nephrotoxicity, and safe administration. Objective: This study aimed to evaluate the incidence of acute kidney injury (AKI) in patients receiving vancomycin before and after the implementation of an institutional protocol for vancomycin administration in a public tertiary hospital in southern Brazil. Materials and methods: A cross-sectional study design was employed, analyzing data from the electronic medical records of 422 patients who received vancomycin. The patient population was divided into two independent cohorts: those treated in 2016 (pre-protocol) and those treated in 2018 (post-protocol), following the implementation of the institutional vancomycin administration protocol. Results: The study included 211 patients in each year of assessment. Patients from both cohorts had a Charlson Comorbidity Index (CCI) score of 4. The post-protocol cohort consisted of older individuals, with a mean age of 62.8 years. In addition, patients in the post-protocol year had higher baseline creatinine levels, higher rates of intensive care unit (ICU) hospitalization, and increased use of vasopressors. In the pre-protocol year, patients received vancomycin therapy for a longer duration. When comparing the incidence of AKI between the two groups, an intervention study revealed rates of 38.4% in group 1 and 20.9% in group 2, indicating a significant reduction (p < 0.001) in the post-protocol group. A logistic regression model was developed to predict AKI, incorporating variables that demonstrated significance (p ≤ 0.250) in bivariate analysis and those recognized in the literature as important factors for AKI, such as the duration of therapy, vancomycin serum level, and ICU hospitalization. The logistic regression classification performance was assessed using a receiver operating characteristic (ROC) curve, yielding an area under the curve of 0.764, signifying acceptable discrimination of the regression model. Conclusion: Implementation of the institutional protocol for vancomycin administration resulted in a significant and cost-effective impact, ensuring appropriate therapeutic dosing, reducing adverse events (e.g., nephrotoxicity), and improving clinical outcomes for patients in the study population.

Effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit

OBJECTIVE

This study aimed to assess the effectiveness of a low trough serum concentration of vancomycin on acute kidney injury in infants and toddlers in the paediatric intensive care unit (PICU).

METHODS

A retrospective cohort study was performed of 126 infants and toddlers (aged between 29 days and 3 years) from the PICU of a tertiary care hospital who were administered intravenous vancomycin between January 2019 and December 2022. Information about their demographic factors, duration of PICU stay, time of administration and trough levels of vancomycin were retrieved. Descriptive statistics were used for demographic factors and multivariable logistic regression analyses were conducted to assess the determining factors.

RESULTS

Based on the trough concentration of vancomycin, the participants were divided into three groups as follows: 4-5 mg/L, 5-15 mg/L and >15 mg/L. The serum vancomycin concentration was significantly related to body weight, albumin, cystatin C, urea nitrogen in serum, serum creatinine and creatinine clearance (p<0.05) in these patients. Multivariate analysis showed that body weight, albumin, cystatin C, urea nitrogen in serum and creatinine clearance were independent contributors to the trough vancomycin concentration. There was no difference in the effectiveness of different trough concentrations on patients (p=0.241). The cumulative incidence of acute kidney injury was highest in the group with a trough concentration of vancomycin >15 mg/L (p<0.01).

CONCLUSIONS

Patients with a vancomycin trough concentration of 4-5 mg/L in the PICU had a high cure rate (79.4%) and a low incidence of acute kidney injury (HR 18.3, 95% CI 5.135 to 87.621; p<0.001). Therefore, the serum trough concentration should be considered but it should also be combined with the treatment effect to achieve individualised administration for the clinical application of vancomycin.

Evaluation of the initial timing of infection control pharmacist-driven audit and monitoring of vancomycin therapy in patients with infectious diseases: A retrospective observational study

BACKGROUND

Early monitoring and feedback on the treatment of infectious diseases are some of the methods for optimising antimicrobial treatment throughout the treatment period. Prospective audits and feedback interventions have also been shown to improve antimicrobial use and reduce antimicrobial resistance. We examined the appropriate use of antimicrobials by focusing on the initial timing for audits and feedback intervention of antimicrobial prescription by Infection Control Team pharmacists.

METHODS

We conducted a retrospective observational study in a university hospital in Tokyo, Japan from 1 January 2019 to 31 May 2021. We retrospectively enrolled patients with infections and those patients suspected of having an infection, who were administered vancomycin and assessed at our hospital. The definition of primary outcome was the maintenance of target vancomycin trough blood concentrations of 10-20 μg/ml during treatment. Multivariable logistic regression and multivariate linear regression analyses were performed to test the effectiveness of the initial timing of the intervention by Infection Control Team pharmacists as the explanatory variable.

RESULTS

A total of 638 patients were included in this study, with a median age of 69 years (interquartile range: 54-78 years). Multivariable logistic regression revealed that the maintenance of target vancomycin trough concentrations was not associated with the timing of the audit and the initiation of monitoring by Infection Control Team pharmacists (adjusted odds ratio: 0.99, 95% confidence interval: 0.99-1.00, p = 0.990). Multivariate linear regression revealed that the duration of vancomycin administration was significantly correlated with the timing of initiation of monitoring by Infection Control Team pharmacists (adjusted estimate: 0.0227, standard error: 0.0051, p = 0.012).

CONCLUSIONS

Our study showed that early initiation of a comprehensive audit and monitoring by Infection Control Team pharmacists did not affect the maintenance of the target vancomycin trough blood concentration. However, it reduced the duration of vancomycin administration.

Discrepancy between perceptions and acceptance of clinical decision support Systems: implementation of artificial intelligence for vancomycin dosing

BACKGROUND

Artificial intelligence (AI) tools are more effective if accepted by clinicians. We developed an AI-based clinical decision support system (CDSS) to facilitate vancomycin dosing. This qualitative study assesses clinicians' perceptions regarding CDSS implementation.

METHODS

Thirteen semi-structured interviews were conducted with critical care pharmacists, at Mayo Clinic (Rochester, MN), from March through April 2020. Eight clinical cases were discussed with each pharmacist (N = 104). Following initial responses, we revealed the CDSS recommendations to assess participants' reactions and feedback. Interviews were audio-recorded, transcribed, and summarized.

RESULTS

The participants reported considerable time and effort invested daily in individualizing vancomycin therapy for hospitalized patients. Most pharmacists agreed that such a CDSS could favorably affect (N = 8, 62%) or enhance (9, 69%) their ability to make vancomycin dosing decisions. In case-based evaluations, pharmacists' empiric doses differed from the CDSS recommendation in most cases (88/104, 85%). Following revealing the CDSS recommendations, we noted 78% (69/88) discrepant doses. In discrepant cases, pharmacists indicated they would not alter their recommendations. The reasons for declining the CDSS recommendation were general distrust of CDSS, lack of dynamic evaluation and in-depth analysis, inability to integrate all clinical data, and lack of a risk index.

CONCLUSION

While pharmacists acknowledged enthusiasm about the advantages of AI-based models to improve drug dosing, they were reluctant to integrate the tool into clinical practice. Additional research is necessary to determine the optimal approach to implementing CDSS at the point of care acceptable to clinicians and effective at improving patient outcomes.

Vancomycin Hydrochloride as a Risk Factor for Acute Kidney Injury: A Retrospective Study

INTRODUCTION

The incidence of acute kidney injury (AKI) caused by vancomycin hydrochloride (VCM) was reported to be 5-43%. VCM-induced AKI was reported to be more likely to occur 4-17 days after initiating VCM treatment; however, it may occur earlier. The aim of this study was therefore to investigate risk factors for the development of AKI within two (AKI2days) and seven (AKI7days) days of VCM administration.

METHODS

This was a single-center, retrospective study including patients who underwent VCM therapy between April 1, 2013, and December 31, 2019. AKI was evaluated based on the Kidney Disease: Improving Global Outcomes criteria.

RESULTS

In total, 287 patients were enrolled. The incidence of VCM-induced AKI within 7 days was 10.8% (31/286 cases), and the incidence of AKI within 2 days was 5.9% (15/252 cases). Serum VCM trough concentrations and tazobactam-piperacillin (TZP) were shown to be a risk factor for VCM-induced AKI. The serum VCM trough concentration was 12.67 μg/mL within the 48 h threshold (AKI2days) and 19.03 μg/mL within the 7-day threshold (AKI7days).

CONCLUSION

Our study demonstrated that high serum VCM trough concentrations and the combination of VCM and TZP were independent risk factors for VCM-induced AKI. Avoiding the concomitant use of TZP, or thorough monitoring of renal function with the concomitant use of TZP, may be helpful in reducing the occurrence of AKI. Furthermore, monitoring serum VCM trough concentrations within 2 days may effectively reduce the incidence of AKI.

Efficacy and Safety of Vancomycin Bayesian-Estimated Area Under the Curve Versus Trough-Based Dosing

BACKGROUND

Vancomycin guidelines by the Infectious Diseases Society of America and American Society of Health-System Pharmacists endorse Bayesian-software-assisted area under the curve (AUC_24h) in their 2020 update. At this time, there are limited clinical data that support its use.

OBJECTIVES

The purpose of this study is to evaluate the safety benefits and efficacy outcomes of using Bayesian-assisted AUC_24h dosing compared to trough dosing.

METHODS

Hospitalized patients from before February 1, 2020, (preimplementation of AUC_24h dosing) and after August 1, 2020, (postimplementation) were reviewed. Patients with confirmed or suspected methicillin-resistant Staphylococcus aureus (MRSA) infection of the lungs, heart, bones, prosthetic joint, or blood receiving vancomycin for at least 72 hours were included. The primary endpoint was the percentage of patients experiencing an acute kidney injury (AKI) in the trough-based group versus those experiencing AKI in the AUC_24h group. The composite of all-cause mortality, 30-day readmission, or change in antibiotic therapy due to clinical worsening in patients with confirmed MRSA infections was included as a secondary endpoint. Data were analyzed with statistical testing methods as appropriate.

RESULTS

There was a significant reduction in AKI between the AUC_24h dosing and trough dosing groups (3% vs 12%; P < 0.01). The efficacy for MRSA infections was also similar between groups (11% vs 14%; P = 0.72).

CONCLUSION AND RELEVANCE

Bayesian-assisted AUC_24h dosing was associated with a significant reduction in incidence of AKI when compared to trough-based dosing. There was no difference in the composite efficacy endpoint for patients with confirmed MRSA infection, although the study was not powered for this analysis. These data may provide evidence for more institutions to adopt the Bayesian software to assist in dosing of vancomycin.

Drug induced nephrotoxicity- A mechanistic approach

The main goal of the treatment of patients is its effectiveness and safety. However, all currently prescribed drugs being used also have certain adverse effects, which might be seen as an unavoidable but necessary cost of pharmacotherapy. The kidney is the primary organ for xenobiotics elimination, making it particularly susceptible to the harmful effects of drugs and their metabolites during their excretion from the body. Moreover, certain medications have a preferential nephrotoxicity potential, which means that using them increases the risk of kidney injury. Drug nephrotoxicity is, therefore, both a significant problem and a complication of pharmacotherapy. It should be noted that, there is presently no accepted definition of drug-induced nephrotoxicity and no established diagnostic criteria. The current review briefly describes the pathogenic mechanism of drug-induced nephrotoxicity, the various basic drugs with nephrotoxicity potential and the renal biomarkers for the treatment of the drug-related kidney damage.

Evaluation of the Effectiveness and Use of Anti-Methicillin-Resistant Staphylococcus aureus Agents for Aspiration Pneumonia in Older Patients Using a Nationwide Japanese Administrative Database

Studies indicated potential harm from empirical broad-spectrum therapy. A recent study of hospitalizations for community-acquired pneumonia suggested that empirical anti-methicillin-resistant Staphylococcus aureus (MRSA) therapy was associated with an increased risk of death and other complications. However, limited evidence supports empirical anti-MRSA therapy for older patients with aspiration pneumonia. In a nationwide Japanese database, patients aged ≥65 years on admission with aspiration pneumonia were analyzed. Patients were divided based on presence of respiratory failure and further sub-categorized based on their condition within 3 days of hospital admission, either receiving a combination of anti-MRSA agents and other antibiotics, or not using MRSA agents. An inverse probability weighting method with estimated propensity scores was used. Out of 81,306 eligible patients, 55,098 had respiratory failure, and 26,208 did not. In the group with and without respiratory failure, 0.93% and 0.42% of the patients, respectively, received anti-MRSA agents. In patients with respiratory failure, in-hospital mortality (31.38% vs. 19.03%, p < 0.001), 30-day mortality, and 90-day mortality were significantly higher, and oxygen administration length was significantly longer in the anti-MRSA agent combination group. Anti-MRSA agent combination use did not improve the outcomes in older patients with aspiration pneumonia and respiratory failure, and should be carefully and comprehensively considered.

Vancomycin Therapeutic Drug Monitoring: A Cross-Sectional Survey of Canadian Hospitals

Background

Little is known about the current landscape of vancomycin therapeutic drug monitoring (TDM) in Canadian hospitals, which operate within publicly funded health care systems.

Objectives

To determine current TDM practices for vancomycin and associated challenges and to gather perceptions about TDM based on area under the concentration-time curve (AUC) in Canadian hospitals.

Methods

An electronic survey was distributed to hospital pharmacists in spring 2021 through multiple national and provincial antimicrobial stewardship, public health, and pharmacy organizations. The survey gathered data about hospital characteristics, TDM methods, inclusion criteria for patient selection, pharmacokinetic and pharmacodynamic targets, vancomycin susceptibility testing and reporting, and perceived barriers and challenges.

Results

In total, 120 pharmacists from 10 of the 13 provincial and territorial jurisdictions in Canada, representing 12.5% of Canadian acute care hospitals (n = 962), completed at least 90% of survey questions. The predominant TDM method was trough-based (107/119, 89.9%); another 10.1% of respondents (12/119) reported performing AUC-based TDM (with or without trough-based TDM), and 17.9% (19/106) of those not already using AUC-based TDM were considering implementing it within 1 to 2 years. Among hospitals performing trough-based TDM, 60.5% (66/109) targeted trough levels between 15 and 20 mg/L for serious infections with methicillin-resistant Staphylococcus aureus. One-quarter of the respondents using this method (27/109, 24.8%) agreed that trough-based TDM was of uncertain benefit, and about one-third (33/109, 30.3%) were neutral on this question. Multiple challenges were identified for trough-based TDM, including sub- or supra-therapeutic concentrations and collection of specimens at inappropriate times. Overall, 40.5% (47/116) of respondents agreed that AUC-based TDM was likely safer than trough-based TDM, whereas 23.3% (27/116) agreed that AUC-based TDM was likely more effective.

Conclusions

This survey represents a first step in developing evidence-based, standardized best practices for vancomycin TDM that are uniquely suited to the Canadian health care system.

Medication-Related Adverse Events and Discordancies in Cystatin C-Based vs Serum Creatinine-Based Estimated Glomerular Filtration Rate in Patients With Cancer

Importance

Serum creatinine-based estimated glomerular filtration rate (eGFRcr) may overestimate the glomerular filtration rate (GFR) in patients with cancer. Cystatin C-based eGFR (eGFRcys) is an alternative marker of GFR.

Objective

To determine whether the therapeutic drug levels and adverse events (AEs) associated with renally cleared medications were higher in patients with cancer whose eGFRcys was more than 30% lower than their eGFRcr.

Design, Setting, and Participants

This cohort study analyzed adult patients with cancer at 2 major academic cancer centers in Boston, Massachusetts. These patients had their creatinine and cystatin C measured on the same day between May 2010 and January 2022. The date of the first simultaneous eGFRcr and eGFRcys measurement was considered to be the baseline date.

Exposure

The primary exposure was eGFR discordance, defined as an eGFRcys that was more than 30% lower than the eGFRcr.

Main Outcomes and Measures

The primary outcome was risk of the following medication-related AEs within 90 days of the baseline date: (1) supratherapeutic vancomycin trough level greater than 30 μg/mL, (2) trimethoprim-sulfamethoxazole-related hyperkalemia (>5.5 mEq/L), (3) baclofen toxic effect, and (4) supratherapeutic digoxin level (>2.0 ng/mL). For the secondary outcome, a multivariable Cox proportional hazards regression model was used to compare 30-day survival of those with vs without eGFR discordance.

Results

A total of 1869 adult patients with cancer (mean [SD] age, 66 [14] years; 948 males [51%]) had simultaneous eGFRcys and eGFRcr measurement. There were 543 patients (29%) with an eGFRcys that was more than 30% lower than their eGFRcr. Patients with an eGFRcys that was more than 30% lower than their eGFRcr were more likely to experience medication-related AEs compared with patients with concordant eGFRs (defined as eGFRcys within 30% of eGFRcr), including vancomycin levels greater than 30 μg/mL (43 of 179 [24%] vs 7 of 77 [9%]; P = .01), trimethoprim-sulfamethoxazole-related hyperkalemia (29 of 129 [22%] vs 11 of 92 [12%]; P = .07), baclofen toxic effects (5 of 19 [26%] vs 0 of 11; P = .19), and supratherapeutic digoxin levels (7 of 24 [29%] vs 0 of 10; P = .08). The adjusted odds ratio for vancomycin levels more than 30 μg/mL was 2.59 (95% CI, 1.08-7.03; P = .04). Patients with an eGFRcys more than 30% lower than their eGFRcr had an increased 30-day mortality (adjusted hazard ratio, 1.98; 95% CI, 1.26-3.11; P = .003).

Conclusions and relevance

Results of this study suggest that among patients with cancer with simultaneous assessment of eGFRcys and eGFRcr, supratherapeutic drug levels and medication-related AEs occurred more commonly in those with an eGFRcys more than 30% lower than their eGFRcr. Future prospective studies are needed to improve and personalize GFR estimation and medication dosing in patients with cancer.

Contemporary pharmacologic treatments of MRSA for hospitalized adults: rationale for vancomycin versus non-vancomycin therapies as first line agents

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) remains an important pathogen in the hospital setting and causes significant morbidity and mortality each year. Since the initial discovery over 60 years ago, vancomycin has remained a first-line treatment for many different types of MRSA infections. However, significant concerns related to target attainment and nephrotoxicity have spurred efforts to develop more effective agents in the last two decades.

AREAS COVERED

Newer anti-MRSA antibiotics that have been approved since 2000 include linezolid, daptomycin, and ceftaroline. As clinical evidence has accumulated, these newer agents have become more frequently used, and some are now recommended as co-first-line options (along with vancomycin) in clinical practice guidelines. For this review, a scoping review of the literature was conducted to support our findings and recommendations.

EXPERT OPINION

Vancomycin remains an important standard of care for MRSA infections but is limited with respect to nephrotoxicity and rapid target attainment. Newer agents such as linezolid, daptomycin, and ceftaroline have specific indications for treating different types of MRSA infections; however, newer agents also have unique attributes which require consideration during therapy.

Evaluation of Real-World Vancomycin Dosing and Attainment of Therapeutic Drug Monitoring Targets

In 2020, the Infectious Diseases Society of America (IDSA) recommended a change in vancomycin therapeutic drug monitoring from trough-based to AUC/MIC-based to optimize vancomycin's efficacy and reduce nephrotoxicity. Many hospitals have not implemented this change due to barriers such as the cost of AUC/MIC software and lack of provider familiarity. The purpose of this study was to determine the rate of AUC/MIC ratio target attainment using current trough-based vancomycin dosing practices at a city hospital. The rates of acute kidney injury (AKI) were also evaluated. Vancomycin orders were reviewed retrospectively to determine the expected AUC/MIC ratios using first-order pharmacokinetic equations over a 7-month period. Orders were excluded if they were written for a one-time dose, for individuals less than 18 years of age, or for those on hemodialysis. A total of 305 vancomycin orders were included in this review. Overall, 27.9% (85/305) of vancomycin orders attained the AUC/MIC ratio target of 400-600 mg·h/L as recommended by the guidelines. Nearly 35% (106/305) achieved AUC/MIC ratios below 400 mg·h/L and 37.4% (114/305) achieved AUC/MIC ratios above 600 mg·h/L. Orders for obese patients were significantly more likely to have below the target AUC/MIC ratios (68% vs. 23.9%, X² 48.48, p < 0.00001) and non-obese patients were significantly more likely to have above the target AUC/MIC ratios (45.7% vs. 12%, X² 27.36, p < 0.00001). The overall rate of acute kidney injury observed was 2.6%. Most vancomycin orders did not attain therapeutic drug monitoring targets, reflecting the ongoing clinical challenge of optimizing vancomycin doses and implementing new guideline recommendations.

An Electronic Algorithm to Identify Vancomycin-Associated Acute Kidney Injury

Background

The burden of vancomycin-associated acute kidney injury (V-AKI) is unclear because it is not systematically monitored. The objective of this study was to develop and validate an electronic algorithm to identify cases of V-AKI and to determine its incidence.

Methods

Adults and children admitted to 1 of 5 health system hospitals from January 2018 to December 2019 who received at least 1 dose of intravenous (IV) vancomycin were included. A subset of charts was reviewed using a V-AKI assessment framework to classify cases as unlikely, possible, or probable events. Based on review, an electronic algorithm was developed and then validated using another subset of charts. Percentage agreement and kappa coefficients were calculated. Sensitivity and specificity were determined at various cutoffs, using chart review as the reference standard. For courses ≥48 hours, the incidence of possible or probable V-AKI events was assessed.

Results

The algorithm was developed using 494 cases and validated using 200 cases. The percentage agreement between the electronic algorithm and chart review was 92.5% and the weighted kappa was 0.95. The electronic algorithm was 89.7% sensitive and 98.2% specific in detecting possible or probable V-AKI events. For the 11 073 courses of ≥48 hours of vancomycin among 8963 patients, the incidence of possible or probable V-AKI events was 14.0%; the V-AKI incidence rate was 22.8 per 1000 days of IV vancomycin therapy.

Conclusions

An electronic algorithm demonstrated substantial agreement with chart review and had excellent sensitivity and specificity in detecting possible or probable V-AKI events. The electronic algorithm may be useful for informing future interventions to reduce V-AKI.

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.

Association Between Vancomycin AUC and Clinical Failure in Patients with Streptococcal Bacteremia

Background: Monitoring of vancomycin using the area under the curve (AUC) to minimum inhibitory concentration (MIC) ratio is now preferred for serious methicillin-resistant Staphylococcus aureus infections. Vancomycin AUC/MIC monitoring is being investigated but is not yet well elucidated with other bacterial pathogens. Methods: A retrospective cross-sectional study was conducted assessing patients with streptococcal bacteremia treated with vancomycin definitive therapy. AUC was calculated using a Bayesian approach, and classification and regression tree analysis was used to identify a vancomycin AUC threshold predictive of clinical failure. Results: Eleven patients had a vancomycin AUC < 329 of which 8 (73%) experienced clinical failure, while 35 patients had a vancomycin AUC ≥ 329 of which 12 (34%) experienced clinical failure (P = .04). Hospital length of stay was longer in the AUC ≥ 329 group (15 vs 8 days, P = .05), whereas time to bacteremia clearance (29 [22-45] vs 25 [20-29] hours, P = .15) and toxicity incidence (13% vs 4%, P = 1) were similar between groups. Conclusions: This study identified a VAN AUC threshold of <329 to be predictive of clinical failure in patients with streptococcal bacteremia which should be interpreted as hypothesis-generating. Studies evaluating VAN AUC-based monitoring for streptococcal bloodstream infections along with other infection types are needed before implementation into clinical practice can be recommended.

Altered Pharmacokinetics Parameters of Vancomycin in Patients with Hematological Malignancy with Febrile Neutropenia, a Bayesian Software Estimation

The pharmacokinetics of vancomycin vary significantly between specific groups of patients, such as critically ill patients and patients with hematological malignancy (HM) with febrile neutropenia (FN). Recent evidence suggests that the use of the usual standard dose of antibiotics in patients with FN may not offer adequate exposure due to pharmacokinetic variability (PK). Therefore, the purpose of this study is to assess the effect of FN on AUC_0-24 as a key parameter for vancomycin monitoring, as well as to determine which vancomycin PK parameters are affected by the presence of FN using Bayesian software PrecisePK in HM with FN. This study was carried out in King Abdulaziz Medical City. All adult patients who were admitted to the Princess Norah Oncology Center PNOC between 1 January and 2017 and 31 December 2020, hospitalized and received vancomycin with a steady-state trough concentration measured before the fourth dose, were included. During the trial period, 297 patients received vancomycin during their stay at the oncology center, 217 of them meeting the inclusion criteria. Pharmacokinetic parameters were estimated for the neutropenic and non-FN patients using the precise PK Bayesian platform. The result showed that there was a significant difference (p < 0.05) in vancomycin clearance Cl_van, the volume of distribution at a steady-state V_dss, the volume of distribution for peripheral compartment V_dp, half-life for the elimination phase t½_β, and the first-order rate constant for the elimination process β in FN compared to non-FN patients. Furthermore, AUC_0-24 was lower for FN patients compared to non-FN patients, p < 0.05. FN has a significant effect on the PK parameters of vancomycin and AUC_0-24, which may require specific consideration during the treatment initiation.

Necessity of vancomycin trough concentrations to manage uncomplicated acute bacterial skin and skin structure infections: a laboratory stewardship analysis

Background

Recent recommendations by the American Society of Health System Pharmacists and Infectious Disease Society of America have provided guidance regarding vancomycin dosing and monitoring in serious infections (including methicillin-resistant Staphylococcus aureus); however, trough monitoring for uncomplicated acute bacterial skin and skin structure infections (ABSSSI) were not addressed. Vancomycin use appears to lead to a low incidence of acute kidney injury with short durations and a low trough goal (10-15 mg/L). Nevertheless, clinical studies have found no difference in clinical outcomes for ABSSSI regardless of vancomycin level. Therefore, it can be posed whether trough monitoring is necessary in this patient population.

Methods

This is a retrospective cohort study comparing vancomycin therapy duration for ABSSSI in adult, general medicine patients who received scheduled vancomycin with an initial creatinine clearance rate of ≥50 mL/minute and had at least one vancomycin trough. The objective of this study was to determine if vancomycin treatment duration differs for patients with ABSSSI with a sub-therapeutic vancomycin trough (ST; <10 mg/L) compared with therapeutic trough (TT; ≥10 mg/L).

Results

There were 39 (67.2%) patients with ST compared with 19 (32.8%) with TT. A similar median vancomycin treatment duration for ST (48.25 hours) and TT (59.5 hours; p=0.65) was found. There was no statistical difference for hospital duration, time from last trough to vancomycin discontinuation, or incidence of acute kidney injury (p>0.05 for all).

Conclusion

Patients with ST and TT had similar vancomycin durations and clinical outcomes. It may be prudent for institutions to address vancomycin trough laboratory stewardship and associated costs.

Methicillin-Resistant Staphylococcus aureus Nasal Swab Is Insufficient to Withhold Empiric Methicillin-Resistant Staphylococcus aureus Pneumonia Coverage in a Trauma Population

INTRODUCTION

Methicillin-resistant staphylococcus aureus (MRSA) nasal colonization is a predictor of MRSA pneumonia in intensive care unit (ICU) patients. Negative nasal swabs have shown up to a 97% negative predictive value for MRSA pneumonia in nontrauma populations, though little investigation has been pursued in trauma patients.

MATERIALS AND METHODS

All trauma patients admitted to the ICU from April 2018 to February 2019 were screened for MRSA colonization by nasal swab. Patients with suspicion for pneumonia underwent bronchoalveolar lavage or quantitative sputum culture and were started on empiric antibiotic therapy based on the swab result. Swab-positive patients were started on empiric MRSA coverage and swab-negative patients were not.

RESULTS

MRSA nasal swab screening was performed in 601 trauma ICU patients. Ninety-six patients subsequently underwent pneumonia workup and were started on an empiric antibiotic regimen based on nasal swab results. Seventeen (17.7%) patients were MRSA nasal swab positive on screening, and 22 (22.9%) patients subsequently had significant growth of MRSA on quantitative respiratory culture. The sensitivity of nasal swab was 50.0% and the specificity was 91.9%. Eleven patients had a negative MRSA nasal swab but a positive MRSA pneumonia (11.5%). Patients with inadequate antibiotic coverage had statistically longer hospital length of stay, ICU length of stay, ventilator days, and rates of unplanned intubation compared to patients with adequate antibiotic coverage.

CONCLUSIONS

Nasal swab screening was not sensitive enough in a trauma population with a high endemic incidence of MRSA colonization to warrant withholding empiric antibiotic MRSA coverage in patients with suspected pneumonia.

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.

Enzyme-responsive biomimetic solid lipid nanoparticles for antibiotic delivery against hyaluronidase-secreting bacteria

In this work, a potent hyaluronidase inhibitor (ascorbyl stearate (AS)) was successfully employed to design vancomycin-loaded solid lipid nanoparticles (VCM-AS-SLNs) with biomimetic and enzyme-responsive features, to enhance the antibacterial efficacy of vancomycin against bacterial-induced sepsis. The VCM-AS-SLNs prepared were biocompatible and had appropriate physicochemical parameters. The VCM-AS-SLNs showed an excellent binding affinity to the bacterial lipase. The in vitro drug release study showed that the release of the loaded vancomycin was significantly accelerated by the bacterial lipase. The in silico simulations and MST studies confirmed the strong binding affinity of AS and VCM-AS-SLNs to bacterial hyaluronidase compared to its natural substrate. This binding superiority indicates that AS and VCM-AS-SLNs could competitively inhibit the effect of hyaluronidase enzyme, and thus block its virulence action. This hypothesis was further confirmed using the hyaluronidase inhibition assay. The in vitro antibacterial studies against sensitive and resistant Staphylococcus aureus revealed that the VCM-AS-SLNs had a 2-fold lower minimum inhibitory concentration, and a 5-fold MRSA biofilm elimination compared to the free vancomycin. Furthermore, the bactericidal-kinetic showed a 100% bacterial clearance rate within 12 hours of treatment with VCM-AS-SLNs, and less than 50 % eradication after 24 hours for the bare VCM. Therefore, the VCM-AS-SLN shows potential as an innovative multi-functional nanosystem for effective and targeted delivery of antibiotics.

Evaluation of Vancomycin TDM Strategies: Prediction and Prevention of Kidney Injuries Based on Vancomycin TDM Results

The current guidelines for therapeutic drug monitoring (TDM) of vancomycin suggest a target 24-hour area under the curve (AUC_0-24) of 400 to 600 mg*h/L for serious methicillin-resistant Staphylococcus aureus infections. In this study, the predictabilities of acute kidney injury (AKI) of various TDM target parameters, target levels, and sampling methods were evaluated in patients who underwent TDM from January 2020 to December 2020. The AUC_0-24 and trough values were calculated by both one- and two-point sampling methods, and were evaluated for the predictability of AKI. Among the AUC_0-24 cutoff comparisons, the threshold value of 500 mg*h/L in the two sampling methods was statistically significant (P = 0.042) when evaluated for the predictability of AKI. Analysis by an receiver operating characteristic curve estimated an AUC_0-24 cutoff value of 563.45 mg*h/L as a predictor of AKI, and was proposed as the upper limit of TDM target.