The Nephrotoxicity of Vancomycin

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.

Usefulness of vancomycin treatment individualization via Bayesian algorithms: a 5-year study in critical patients

Aim: Compare two vancomycin dosing strategies in critical patients with methicillin-resistant Staphylococcus aureus (MRSA) infections, considering the heterogeneity of the dosing regimens administered and their implications for toxicity and efficacy. Materials & methods: Longitudinal retrospective observational study in two patient cohorts (standard dosing vs dosing via Bayesian algorithms). Results: The group of Bayesian algorithms received substantially higher and significantly heterogeneous doses, with an absence of nephrotoxicity. The speed of decrease observed in CRP and PCT was greater for the Bayesian strategy (p = 0.045 and 0.0009, respectively). Conclusion: Applying Bayesian algorithms to vancomycin dosage individualization allows for administering much higher doses than with standard regimens, facilitating a quicker clinical response in the absence of nephrotoxicity.

Obstructive Sleep Apnea and Acute Lower Respiratory Tract Infections: A Narrative Literature Review

Both obstructive sleep apnea (OSA) and acute lower respiratory tract infections (LRTIs) are important global health issues. The pathophysiological links between OSA and LRTIs include altered immune responses due to chronic intermittent hypoxia and sleep fragmentation, increased aspiration risk, and a high burden of comorbidities. In this narrative review, we evaluated the current evidence on the association between OSA and the incidence and outcomes of acute LRTIs in adults, specifically community-acquired pneumonia and viral pneumonia caused by influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Studies have demonstrated that OSA patients are more likely to develop bacterial pneumonia and exhibit a higher risk of invasive pneumococcal disease. The risk intensifies with the severity of OSA, influencing hospitalization rates and the need for intensive care. OSA is also associated with an increased risk of contracting influenza and suffering more severe disease, potentially necessitating hospitalization. Similarly, OSA contributes to increased COVID-19 disease severity, reflected by higher rates of hospitalization, longer hospital stays, and a higher incidence of acute respiratory failure. The effect of OSA on mortality rates from these infections is, however, somewhat ambiguous. Finally, we explored antibiotic therapy for OSA patients with LRTIs, addressing care settings, empirical regimens, risks, and pharmacokinetic considerations. Given the substantial burden of OSA and its significant interplay with acute LRTIs, enhanced screening, targeted vaccinations, and optimized management strategies for OSA patients should be prioritized.

In Vitro Performance of a Long-Range Surface Plasmon Hydrogel Aptasensor for Continuous and Real-Time Vancomycin Measurement in Human Serum

This study investigated the suitability of surface modification for a long-range surface plasmon (LRSP) aptasensor using two different hydrogels, aiming at real-time monitoring of vancomycin (VCM) in undiluted serum and blood. Three different layer structures were formed on a gold surface of LRSP sensor chip using poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-N-methacryloyl-(L)-tyrosinemethylester (MAT)] (PMM) and poly[MPC-co-2-ethylhexyl methacrylate (EHMA)-co-MAT] (PMEM). The peptide aptamer for VCM was immobilized in PMM and PMEM via MAT. Among four differently prepared sensor chips, the LRSP hydrogel aptasensor with PMM, referred to as the PMM hydrogel, exhibited the highest sensor output and superior antifouling properties. Following the optimization of the PMM hydrogel preparation conditions, the shelf life of the PMM hydrogel was determined to exceed 2 weeks, and the same sensor chip could be used for 102 days without significant performance deterioration. The PMM hydrogel was then applied for VCM measurement in undiluted serum in vitro, where it demonstrated a limit of detection of 0.098 μM and a dynamic range of 0.18-100 μM, covering the therapeutic range. Additionally, the PMM hydrogel enabled the continuous measurement of various VCM concentrations in serum without rinsing and showed a concentration-dependent output in undiluted blood. These findings underscore the potential of the PMM hydrogel for real-time and direct monitoring of VCM in body fluids.

Applications of model simulation in pharmacological fields and the problems of theoretical reliability

The use of mathematical models has become increasingly prevalent in pharmacological fields, particularly in drug development processes. These models are instrumental in tasks such as designing clinical trials and assessing factors like efficacy, toxicity, and clinical practice. Various types of models have been developed and documented. Nevertheless, emphasizing the reliability of parameter values is crucial, as they play a pivotal role in shaping the behavior of the system. In some instances, parameter values reported previously are treated as fixed values, which can lead to convergence towards values that deviate substantially from those found in actual biological systems. This is especially true when parameter values are determined through fitting to limited observations. To mitigate this risk, the reuse of parameter values from previous reports should be approached with a critical evaluation of their validity. Currently, there is a proposal for a simultaneous search for plausible values for all parameters using comprehensive search algorithms in both pharmacokinetic and pharmacodynamic or systems pharmacological models. Implementing these methodologies can help address issues related to parameter determination. Furthermore, integrating these approaches with methods developed in the field of machine-learning field has the potential to enhance the reliability of parameter values and the resulting model outputs.

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

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

Therapeutic Potential of Chlorogenic Acid in Chemoresistance and Chemoprotection in Cancer Treatment

Chemotherapeutic drugs are indispensable in cancer treatment, but their effectiveness is often lessened because of non-selective toxicity to healthy tissues, which triggers inflammatory pathways that are harmful to vital organs. In addition, tumors' resistance to drugs causes failures in treatment. Chlorogenic acid (5-caffeoylquinic acid, CGA), found in plants and vegetables, is promising in anticancer mechanisms. In vitro and animal studies have indicated that CGA can overcome resistance to conventional chemotherapeutics and alleviate chemotherapy-induced toxicity by scavenging free radicals effectively. This review is a summary of current information about CGA, including its natural sources, biosynthesis, metabolism, toxicology, role in combatting chemoresistance, and protective effects against chemotherapy-induced toxicity. It also emphasizes the potential of CGA as a pharmacological adjuvant in cancer treatment with drugs such as 5-fluorouracil, cisplatin, oxaliplatin, doxorubicin, regorafenib, and radiotherapy. By analyzing more than 140 papers from PubMed, Google Scholar, and SciFinder, we hope to find the therapeutic potential of CGA in improving cancer therapy.

Development of an on-site therapeutic drug monitoring method using a portable spectrometer

We report on the development of an on-site therapeutic drug monitoring (TDM) method for vancomycin (VCM) utilizing a portable spectrometer and commercially available immunoturbidimetric assay reagents designed for automated clinical chemistry analyzers. The method enables the quantification of VCM in plasma samples within 10 min, with a good correlation between the measured values and the theoretical values (r2 = 0.995). The intra and inter-day precisions were found to be below 12.5% and 17.7%, respectively. Moreover, we established a correlation between the quantitative values using this method and those measured through HPLC-UV and automated clinical chemistry analyzers, showing good reliability (R2 = 0.970 and 0.951, respectively). This method allows anyone to rapidly perform TDM at the bedside and is expected to be used to evaluate appropriate drug therapy.

Hospital-Acquired Acute Kidney Injury in Non-Critical Medical Patients in a Developing Country Tertiary Hospital: Incidence and Predictors

Background

Acute kidney injury (AKI) is a frequent complication in critical patients, leading to a worse prognosis. Although its consequences are worse among critical patients, AKI is also associated with less favorable outcomes in non-critical patients. Therefore, understanding the magnitude of the problem in these patients is crucial, yet there is a scarcity of evidence in non-critical settings, especially in resource limited countries. Hence, the study aimed at determining the incidence and predictors of hospital acquired acute kidney injury (HAAKI) in non-critical medical patients who were admitted at a large tertiary hospital in Ethiopia.

Methods

A retrospective chart review study was conducted from September 25, 2022 to January 20, 2023 among 232 hospitalized non-critical medical patients admitted to St. Paul's Hospital Millennium Medical College between January 2020 and January 2022. The incidence of HAAKI was estimated using incidence density per total person day (PD) observation of the study participants. To identify predictors of HAAKI, a log binomial regression model was fitted at a p value of ≤0.05. The magnitude of association was measured using adjusted relative risk (ARR) with its 95% CI.

Results

During the median follow-up duration of 11 days (IQR, 6-19 days), the incidence of HAAKI was estimated to be 6.0 per 100 PD (95% CI = 5.5 to 7.2). Significant predictors of HAAKI were found to be having type 2 diabetes mellitus (ARR = 2.36, 95% CI = 1.03, 5.39, p-value=0.042), and taking vancomycin (ARR = 3.04, 95% CI = 1.38, 6.72, p-value=0.006) and proton pump inhibitors (ARR = 3.80, 95% CI = 1.34,10.82, p-value=0.012).

Conclusion

HAAKI is a common complication in hospitalized non-critical medical patients, and is associated with a common medical condition and commonly prescribed medications. Therefore, it is important to remain vigilant in the prevention and timely identification of these cases and to establish a system of rational prescribing habits.

Leonurine alleviates vancomycin nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α pathway

Vancomycin (VCM) is the first-line antibiotic for severe infections, but nephrotoxicity limits its use. Leonurine (Leo) has shown protective effects against kidney damage. However, the effect and mechanism of Leo on VCM nephrotoxicity remain unclear. In this study, mice and HK-2 cells exposed to VCM were treated with Leo. Biochemical and pathological analysis and fluorescence probe methods were performed to examine the role of Leo in VCM nephrotoxicity. Immunohistochemistry, q-PCR, western blot, FACS, and Autodock software were used to verify the mechanism. The present results indicate that Leo significantly alleviates VCM-induced renal injury, morphological damage, and oxidative stress. Increased intracellular and mitochondrial ROS in HK-2 cells and decreased mitochondrial numbers in mouse renal tubular epithelial cells were reversed in Leo-administrated groups. In addition, molecular docking analysis using Autodock software revealed that Leo binds to the PPARγ protein with high affinity. Mechanistic exploration indicated that Leo inhibited VCM nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α inflammation pathway. Taken together, our results indicate that the PPARγ inhibition and inflammation reactions were implicated in the VCM nephrotoxicity and provide a promising therapeutic strategy for renal injury.

Proximal tubular MBD2 promotes autophagy to drive the progression of AKI caused by vancomycin via regulation of miR-597-5p/S1PR1 axis

Our recent investigation has indicated that the global deletion of MBD2 can mitigate the progression of AKI induced by VAN. Nevertheless, the role and regulatory mechanisms of proximal tubular MBD2 in this pathophysiological process have yet to be elucidated. Our preceding investigation revealed that autophagy played a crucial role in advancing AKI induced by VAN. Consequently, we postulated that MBD2 present in the proximal tubule could upregulate the autophagic process to expedite the onset of AKI. In the present study, we found for the first time that MBD2 mediated the autophagy production induced by VAN. Through the utilization of miRNA chip analysis, we have mechanistically demonstrated that MBD2 initiates the activation of miR-597-5p through promoter demethylation. This process leads to the suppression of S1PR1, which results in the induction of autophagy and apoptosis in renal tubular cells. Besides, PT-MBD2-KO reduced autophagy to attenuate VAN-induced AKI via regulation of the miR-597-5p/S1PR1 axis, which was reversed by rapamycin. Finally, the overexpression of MBD2 aggravated the diminished VAN-induced AKI in autophagy-deficient mice (PT-Atg7-KO). These data demonstrate that proximal tubular MBD2 facilitated the process of autophagy via the miR-597-5p/S1PR1 axis and subsequently instigated VAN-induced AKI through the induction of apoptosis. The potentiality of MBD2 being a target for AKI was established.

Age-Related Differences in Vancomycin-Associated Nephrotoxicity and Efficacy in Methicillin-Resistant Staphylococcus aureus Infection: A Comparative Study between Elderly and Adult Patients

Elderly patients (age ≥ 65 years) are susceptible to methicillin-resistant Staphylococcus aureus (MRSA) infections, with potential for more adverse treatment outcomes or complications compared to younger adults (18-64 years). This study compared vancomycin-associated nephrotoxicity and efficacy in elderly and adult patients and investigated the correlation between vancomycin pharmacokinetic/pharmacodynamic (PK/PD) indices and clinical outcomes. A prospective study was conducted in 10 hospitals in Shanghai from October 2012 to November 2019. A total of 164 patients with MRSA infections were enrolled, including 83 elderly and 81 adult patients. Vancomycin therapeutic drug monitoring (TDM) was performed in all patients, indicating significantly higher vancomycin trough concentrations (Ctrough), 24-h area under the curve (AUC24) values, and AUC24/minimum inhibitory concentration (AUC24/MIC) values in elderly patients compared to adult patients. The incidence of vancomycin-associated nephrotoxicity was nearly three times higher in elderly patients (18.1% vs. 6.2%, p = 0.020), despite similar clinical and microbiological efficacy. Of particular importance, a Ctrough > 20 mg/L was found as an independent factor of nephrotoxicity in elderly patients. Further analysis of patients with an estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m2 also revealed that elderly patients had significantly higher vancomycin-related PK/PD indices and more nephrotoxicity than adult patients. In conclusion, elderly patients receiving vancomycin therapy face a higher risk of nephrotoxicity, which requires close vancomycin TDM, especially when the Ctrough exceeds 20 mg/L.

Association between trough serum vancomycin concentration and vancomycin-associated acute kidney injury and 30-day mortality in critically ill elderly adults

BACKGROUND

Vancomycin-associated acute kidney injury (VA-AKI) is the most clinically relevant side effect of vancomycin. The objective of this study was to investigate the association between VTC and VA-AKI as well as 30-day mortality in critically ill elderly adults.

METHOD

Elderly patients with trough serum vancomycin concentration records(VTC) in the Medical Information Mart-IV (MIMIC-IV) and eICU databases were retrospectively studied.

RESULTS

A total of 3,146 critically ill elderly adults were finally enrolled. The incidence of VA-AKI in the elderly population was 76.5%. Logistic regression analysis revealed significant relationships between VA-AKI and various factors, including VTC, comorbidities, and laboratory indicators, and SOFA, and GCS score. For each mg/L increase, the OR for VA-AKI increased by 2.5%. The association between VTC and 30-day mortality was found to be statistically significant (odds ratio (OR): 1.021, 95% CI: 1.010-1.031), P < 0.001). The Restricted cubic splines (RCS) curves revealed that VTC ranged of 19.67 to 35.72 mg/l for AKI and 19.17 to 42.86 mg/l for 30-day mortality exhibit OR with 95% CI above 1, indicating statistically significant associations with an increased risk of AKI and 30-day mortality, respectively. In the subgroup analysis, VTC was identified as a risk factor for VA-AKI in specific patient groups, including white individuals, female patients, those with shock, patients with SOFA > 6, patients with baseline creatinine > 1.2 mg/dl and patients with or without exposed to other nephrotoxic medications.

CONCLUSION

This study found the significant association between VTC and the incidence of VA-AKI and 30-day mortality in critically ill elderly adults. The RCS curves indicated concentration ranges for AKI (19.67-35.72 mg/L) and 30-day mortality (19.17-42.86 mg/L), signifying increased risk.

Plasma Microbial Cell-Free DNA Sequencing for Pathogen Detection and Quantification in Children With Musculoskeletal Infections

BACKGROUND

Nearly half of all pediatric musculoskeletal infections (MSKIs) are culture negative. Plasma microbial cell-free DNA (mcfDNA) sequencing is noninvasive and not prone to the barriers of culture. We evaluated the performance of plasma mcfDNA sequencing in identifying a pathogen, and examined the duration of pathogen detection in children with MSKIs.

METHODS

We conducted a prospective study of children, aged 6 months to 18 years, hospitalized from July 2019 to May 2022 with MSKIs, in whom we obtained serial plasma mcfDNA sequencing samples and compared the results with cultures.

RESULTS

A pathogen was recovered by culture in 23 of 34 (68%) participants, and by initial mcfDNA sequencing in 25 of 31 (81%) participants. Multiple pathogens were detected in the majority (56%) of positive initial samples. Complete concordance with culture (all organisms accounted for by both methods) was 32%, partial concordance (at least one of the same organism(s) identified by both methods) was 36%, and discordance was 32%. mcfDNA sequencing was more likely to show concordance (complete or partial) if obtained prior to a surgical procedure (82%), compared with after (20%), (RR 4.12 [95% CI 1.25, 22.93], p = .02). There was no difference in concordance based on timing of antibiotics (presample antibiotics 60% vs no antibiotics 75%, RR 0.8 [95% CI 0.40, 1.46], p = .65]). mcfDNA sequencing was positive in 67% of culture-negative infections and detected a pathogen for a longer interval than blood culture (median 2 days [IQR 1, 6 days] vs 1 day [1, 1 day], p < .01).

CONCLUSIONS

Plasma mcfDNA sequencing may be useful in culture-negative pediatric MSKIs if the sample is obtained prior to surgery. However, results must be interpreted in the appropriate clinical context as multiple pathogens are frequently detected supporting the need for diagnostic stewardship.

[Potential Nephrotoxicity of Combination of Vancomycin and Piperacillin-Tazobactam: Recommendations from the AG ABS of the DGPI supported by experts of the GPN]

The combination of vancomycin and piperacillin/tazobactam (V+P/T) is used for empirical antibiotic treatment of severe infections, especially in immunocompromised patients and those colonized with multidrug-resistant bacteria. Nephrotoxicity is a frequently observed adverse effect of vancomycin. Its risk can be reduced by therapeutic drug monitoring and adjusted dosing. Piperacillin/tazobactam (P/T) rarely causes interstitial nephritis. The results of retrospective cohort studies in children predominantly show a low, clinically irrelevant, additive nephrotoxicity (defined as an increase in creatinine in the serum) of both substances. Due to the limitations of the existing publications, the ABS working group of the DGPI and experts of the GPN do not recommend against the use of P/T plus vancomycin. Preclinical studies and a prospective study with adult patients, which evaluated different renal function tests as well as clinical outcomes, do not support previous findings of additive nephrotoxicity. Time-restricted use of V+P/T can minimize exposure and the potential risk of nephrotoxicity. Local guidelines, developed in collaboration with the antibiotic stewardship team, should define the indications for empirical and targeted use of P/T and V+P/T. When using combination therapy with V+P/T, kidney function should be monitored through clinical parameters (volume status, balancing, blood pressure) as well as additional laboratory tests such as serum creatinine and cystatin C.

Anti-Microbial Activities of Mussel-Derived Recombinant Proteins against Gram-Negative Bacteria

Many anti-microbial peptides (AMPs) and pro-apoptotic peptides are considered as novel anti-microbial agents, distinguished by their different characteristics. Nevertheless, AMPs exhibit certain limitations, including poor stability and potential toxicity, which hinder their suitability for applications in pharmaceutics and medical devices. In this study, we used recombinant mussel adhesive protein (MAP) as a robust scaffold to overcome these limitations associated with AMPs. Mussel adhesive protein fused with functional peptides (MAP-FPs) was used to evaluate anti-microbial activities, minimal inhibitory concentration (MIC), and time-kill kinetics (TKK) assays against six of bacteria strains. MAP and MAP-FPs were proved to have an anti-microbial effect with MIC of 4 or 8 µM against only Gram-negative bacteria strains. All tested MAP-FPs killed four different Gram-negative bacteria strains within 180 min. Especially, MAP-FP-2 and -5 killed three Gram-negative bacteria strain, including E. coli, S. typhimurium, and K. pneumoniae, within 10 min. A cytotoxicity study using Vero and HEK293T cells indicated the safety of MAP and MAP-FP-2 and -3. Thermal stability of MAP-FP-2 was also validated by HPLC analysis at an accelerated condition for 4 weeks. This study identified that MAP-FPs have novel anti-microbial activity, inhibiting the growth and rapidly killing Gram-negative bacteria strains with high thermal stability and safety.

Dalbavancin real-life utilization among diabetic patients suffering from infections in Italy and Spain: The DALBADIA retrospective cohort study

OBJECTIVES

To retrospectively describe the patterns of use of dalbavancin for treating infections in diabetic patients in Italian and Spanish standard clinical practice.

METHODS

DALBADIA [NCT04959799] was a multicentre, observational, retrospective cohort study, conducted in Italy and Spain. The study enrolled 97 adults with type 1 or 2 diabetes mellitus, treated with dalbavancin as per standard clinical practice for a Gram-positive bacterial infection or the Gram-positive component of a mixed infection.

RESULTS

Dalbavancin was used to treat cellulitis (18/92 patients, 19.6%), followed by prosthetic joint infection (14 patients, 15.2%), endocarditis (13 patients, 14.1%), and primary bacteraemia (10 patients, 10.9%); 78/92 (84.8%) patients had Gram-positive infections only, and 14 (15.2%) had mixed infections. The most frequently isolated microorganisms were Staphylococcus aureus in 43 (55.8% of the patients with microbial isolation), 25.6% of which methicillin-resistant; Staphylococcus epidermidis in 13 (16.9%), 53.8% of which methicillin-resistant; Enterococcus faecalis in 11 (14.3%). The main reason for the dalbavancin choice was the intent to simplify the antibiotic regimen (81.5% of cases). A multidisciplinary team participated in the treatment choice process for 53 (57.6%) patients. Dalbavancin was given as first-line antibiotic in 34 (37.0%) patients and administered as one infusion in 32 (34.8%), and as two infusions in 39 (42.4%). In total, 57/62 (91.9%) eligible patients with available assessment were judged clinically cured or improved at the end of observation.

CONCLUSION

In clinical practice, dalbavancin was used in diabetic patients to treat ABSSSIs and other difficult-to-treat infections with a favourable safety profile and a high rate of positive clinical responses.

The effects of antibiotic therapy on neonatal sepsis-associated acute kidney injury

AIM

Neonatal sepsis remains one of the most dangerous conditions in the neonatal intensive care units. One of the organs affected by sepsis is the kidney, making acute kidney injury (AKI) a common complication of sepsis. Treatment of sepsis almost always involves antibiotic therapy, which by itself may cause some adverse effects, including nephrotoxicity. We analyzed the mutual effect of antibiotic therapy and sepsis on AKI in an experimental and clinical study in infants and neonatal rats.

MATERIALS AND METHODS

We evaluated the influence of therapy with different antibiotics on the appearance of AKI markers (blood urea nitrogen (BUN), neutrophil gelatinase-associated lipocalin (NGAL), clusterin, interleukin-18 (IL-18), kidney injury molecule-1 (KIM-1), monocyte chemoattractant protein 1 (MCP-1), calbindin, glutation-S-transferase subtype π (GST-π)) and liver injury markers in newborns with or without clinical signs of sepsis in the intensive care unit. In parallel, we analyzed the development of AKI in experimental lipopolysaccharide (LPS)-induced systemic inflammation in newborn rats accompanied by antibiotic therapy.

KEY FINDINGS

We showed that therapy with metronidazole or ampicillin in combination with sulbactam had a beneficial effect in children with suspected sepsis, resulting in a decrease in AKI markers levels. However, treatment of newborns with netilmicin, cefepime, linezolid, or imipenem in combination with cilastatin worsened kidney function in these patients.

SIGNIFICANCE

This prospective study indicates which antibiotics are preferable in neonatal sepsis and which should be used with caution in view of the risk of AKI development.

Association of piperacillin and vancomycin exposure on acute kidney injury during combination therapy

Objectives

Acute kidney injury (AKI) is a well-documented adverse effect observed with piperacillin/tazobactam in combination with vancomycin. The pharmacokinetics of these antibiotics when given in combination have not been previously evaluated. The purpose of this study was to compare the exposure of vancomycin + piperacillin/tazobactam in patients with and without AKI.

Methods

Ninety adult patients, who received at least 72 h of vancomycin + piperacillin/tazobactam combination therapy and had available serum concentrations of vancomycin and piperacillin were included in the study. Nephrotoxicity was defined as a 1.5-fold increase in serum creatinine within 7 days from baseline. Median daily AUCs were calculated in those with nephrotoxicity (vancomycin + piperacillin/tazobactam 'N') versus those without nephrotoxicity (vancomycin + piperacillin/tazobactam 'WN') during the first 7 days of combination therapy.

Results

The overall incidence of AKI in those receiving vancomycin + piperacillin/tazobactam was 20% (18/90). The median daily vancomycin AUCs did not differ between the vancomycin + piperacillin/tazobactam 'WN' and vancomycin + piperacillin/tazobactam 'N' groups. Although not statistically significant, the median daily vancomycin AUCs in the vancomycin + piperacillin/tazobactam 'N' group were numerically greater on Day 5 and trended downwards thereafter. For the piperacillin group, the median daily AUCs did not vary between groups, except on Day 7 where the vancomycin + piperacillin/tazobactam 'WN' group had statistically greater median piperacillin AUC than the vancomycin + piperacillin/tazobactam 'N' group (P = 0.046).

Conclusions

Utilizing serum creatinine-defined AKI, our study did not find any significant differences in vancomycin and piperacillin/tazobactam exposure between the groups with and without nephrotoxicity. These data indicate that vancomycin + piperacillin/tazobactam should not be avoided due to the risk of overexposure; instead, clinicians should continue to use these therapies cautiously.

Risk of Acute Kidney Injury Based on Vancomycin Target Trough Attainment Strategy: Area-Under-the-Curve-Guided Bayesian Software, Nomogram, or Trough-Guided Dosing

BACKGROUND

Guidelines support area-under-the-curve (AUC) monitoring for vancomycin dosing which may lower overall doses and reduce acute kidney injury (AKI).

OBJECTIVE

The aim of this study was to compare incidence of AKI across 3 vancomycin dosing modalities: AUC-targeted Bayesian pharmacokinetic software, AUC-targeted empiric dosing nomogram, and trough-guided dosing using clinical pharmacists' judgment.

METHODS

This retrospective study included adult patients with a pharmacy dosing consult who received ≥1 dose of vancomycin and ≥1 serum vancomycin level documented between January 1, 2018, and December 31, 2019. Patients with baseline serum creatinine ≥2 mg/dL, weight ≥100 kg, receiving renal replacement therapy, AKI prior to vancomycin therapy, or vancomycin ordered only for surgical prophylaxis were excluded. The primary analysis was incidence of AKI adjusted for baseline serum creatinine, age, and intensive care unit admission. A secondary outcome was adjusted incidence of an abnormal trough value (<10 or >20 μg/mL).

RESULTS

The study included 3459 encounters. Incidence of AKI was 21% for Bayesian software (n = 659), 22% for the nomogram (n = 303), and 32% for trough-guided dosing (n = 2497). Compared with trough-guided dosing, incidence of AKI was lower in the Bayesian (adjusted odds ratio [OR] = 0.72, 95% confidence interval [CI]: 0.58-0.89) and the nomogram (adjusted OR = 0.71, 95% CI: 0.53-0.95) groups. Compared with trough-guided dosing, abnormal trough values were less common in the Bayesian group (adjusted OR = 0.83, 95% CI: 0.69-0.98).

CONCLUSION AND RELEVANCE

Study results suggest that use of AUC-guided Bayesian software reduces the incidence of AKI and abnormal trough values compared with trough-guided dosing.

Development of Antibacterial Peptides with Membrane Disruption and Folate Pathway Inhibitory Activities against Methicillin-Resistant Staphylococcus aureus

Antimicrobial peptides (AMPs) offer an opportunity to overcome multidrug resistance. Here, novel peptides were designed based on AMP fragments derived from sea cucumber hemolytic lectin to enhance anti-methicillin-resistant Staphylococcus aureus (MRSA) activity with less side effects. Two designed peptides, CGS19 (LARVARRVIRFIRRAW-NH2) and CGS20 (RRRLARRLIFFIRRAW-NH2), exhibited strong antibacterial activities against clinically isolated MRSA with MICs of 3-6 μM, but no obvious cytotoxicity was observed. Consistently, CGS19 and CGS20 exerted rapid bactericidal activity and effectively induced 5.9 and 5.8 log reduction of MRSA counts in mouse subeschar, respectively. Further, CGS19 and CGS20 kill bacteria not only through disturbing membrane integrity but also by binding formate-tetrahydrofolate ligase, a key enzyme in the folate metabolism pathway, thereby inhibiting the folate pathway of MRSA. CGS19 and CGS20 are promising lead candidates for drug development against MRSA infection. The dual mechanisms on the identical peptide sequence or scaffold might be an underappreciated manner of treating life-threatening pathogens.

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.

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.

Prevalence, risk factors, and outcomes of acute kidney injury in a pediatric cardiac intensive care unit: A cross-sectional study

Background and Aims

Acute kidney injury (AKI) is a common complication in pediatric cardiac intensive care unit (CICU). This study aims to identify the prevalence, risk factors, and outcomes of AKI in pediatrics admitted to a CICU unit of a tertiary hospital.

Methods

We retrospectively gathered the data of 253 randomly selected patients admitted to the CICU unit from March 2018 to March 2022. Data were collected from EHRs. We used the Kidney Disease Improving Global Outcomes (KDIGO) criteria for identifying AKI in patients.

Results

Overall, AKI prevalence was 22.9% in our population. In the multivariable analysis, vancomycin intake (odds ratio [OR]: 2.109, 95% confidence interval [CI]: 1.15-3.84), angiography (OR: 4.38, 95% CI: 1.28-14.93), and mechanical ventilation (OR: 2.08, 95% CI: 1.02-4.23) were independent risk factors of AKI development and patients with AKI had a higher in-hospital mortality rate (OR: 5.81, 95% CI: 2.55-13.19), higher need for cardiopulmonary resuscitation (OR: 3.08, 95% CI: 1.17-8.09), and longer ICU length of stay (OR: 6.49, 95% CI: 3.31-9.67). Furthermore, furosemide administration was associated with lower risk of developing AKI (OR: 0.52, 95% CI: 0.27-0.97).

Conclusion

AKI is common and is associated with worse outcomes in patients with congenital heart disease. Our results emphasize the importance of early identification and monitoring of AKI in the pediatric CICU setting.

Pathogens and their resistance behavior in necrotizing fasciitis

BACKGROUND

Necrotizing fasciitis (NF) is a rare but life-threatening condition in which extensive soft tissue destruction can occur very quickly if left untreated. Therefore, timely broad-spectrum antibiotic administration is of prognostic importance in addition to radical surgical debridement.

AIM

This study evaluates the cases of NF in our hospital during the last ten years retrospectively with respect to the pathogens involved and their antimicrobial resistance. This approach aims to provide guidance regarding the most targeted initial antibiotic therapy.

METHODS

We performed a retrospective microbiological study evaluating pathogen detection and resistance patterns including susceptibility testing of 42 patients with NF.

RESULTS

Type 1 NF (polymicrobial infection) occurred in 45% of the patients; 31% presented type 2 NF (monomicrobial infection). The most common pathogens detected were E. coli, staphylococci such as Staphylococcus aureus and Staphylococcus epidermidis, Proteus mirabilis, enterococci, and streptococci such as Streptococcus pyogenes. Twelve percent presented an additional fungus infection (type 4). Ten percent showed no cultivation. Two percent (one patient) presented cocci without specification.

CONCLUSION

Most pathogens were sensitive to antibiotics recommended by guidelines. This confirms the targeting accuracy of the guidelines. Further studies are necessary to identify risk factors associated with multidrug resistant infections requiring early vancomycin/meropenem administration.

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

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

A Review of the Clinical Utilization of Oral Antibacterial Therapy in the Treatment of Bone Infections in Adults

Chronic osteomyelitis in adults is managed with prolonged courses of intravenous antibiotics in conjunction with surgical debridement of necrotic bone. Over the past 40 years, there has been no paradigm shift in this approach, as randomized controlled trials of this standard of care compared to alternatives such as prolonged oral antibiotics are scarce. However, there have been many small trials, case reports, and review papers evaluating the effectiveness of oral treatment for chronic osteomyelitis. The oral route for infections requiring prolonged treatment is intuitively and practically more favorable due to several advantages, the most important of which is the avoidance of long-term IV antimicrobial therapy with its complications, inconvenience, and cost. In this paper, we review the literature evaluating oral antibiotic therapy in the management of chronic bone infections since 1975. The majority of osteomyelitis infections are caused by Staphylococcus aureus, hence we focus on its treatment using oral antibiotics; however, we also emphasize subpopulations of patients with diabetes, implanted hardware, and with less common bacterial organisms. The primary objective of this review is to promulgate clinical recommendations on the use of oral antibiotics in bone infections in the context of initial therapy, transition from intravenous therapy, and the role of chronic suppression. The secondary objective is to summarize current knowledge of the specific oral antimicrobial agents that are commonly utilized, together with a synopsis of the available literature pertaining to their pharmacokinetic/pharmacodynamic properties and duration of therapy in bone infection.

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.

Vancomycin associated acute kidney injury in patients with infectious endocarditis: a large retrospective cohort study

Background: Vancomycin remains the cornerstone antibiotic for the treatment of infective endocarditis (IE). Vancomycin has been associated with significant nephrotoxicity. However, vancomycin associated acute kidney injury (AKI) has not been evaluated in patients with IE. We conducted this large retrospective cohort study to reveal the incidence, risk factors, and prognosis of vancomycin-associated acute kidney injury (VA-AKI) in patients with IE. Methods: Adult patients diagnosed with IE and receiving vancomycin were included. The primary outcome was VA-AKI. Results: In total, 435 of the 600 patients were enrolled. Of these, 73.6% were male, and the median age was 52 years. The incidence of VA-AKI was 17.01% (74). Only 37.2% (162) of the patients received therapeutic monitoring of vancomycin, and 30 (18.5%) patients had reached the target vancomycin trough concentration. Multiple logistic regression analysis revealed that body mass index [odds ratio (OR) 1.088, 95% CI 1.004, 1.179], duration of vancomycin therapy (OR 1.030, 95% CI 1.003, 1.058), preexisting chronic kidney disease (OR 2.291, 95% CI 1.018, 5.516), admission to the intensive care unit (OR 2.291, 95% CI 1.289, 3.963) and concomitant radiocontrast agents (OR 2.085, 95% CI 1.093, 3.978) were independent risk factors for VA-AKI. Vancomycin variety (Lai Kexin vs. Wen Kexin, OR 0.498, 95% CI 0.281, 0.885) were determined to be an independent protective factor for VI-AKI. Receiver operator characteristic curve analysis revealed that duration of therapy longer than 10.75 days was associated with a significantly increased risk of VA-AKI (HR 1.927). Kidney function was fully or partially recovered in 73.0% (54) of patients with VA-AKI. Conclusion: The incidence of VA-AKI in patients with IE was slightly higher than in general adult patients. Concomitant contrast agents were the most alarmingly nephrotoxic in patients with IE, adding a 2-fold risk of VA-AKI. In patients with IE, a course of vancomycin therapy longer than 10.75 days was associated with a significantly increased risk of AKI. Thus, closer monitoring of kidney function and vancomycin trough concentrations was recommended in patients with concurrent contrast or courses of vancomycin longer than 10.75 days.

The AKI-to-CKD Transition: The Role of Uremic Toxins

After acute kidney injury (AKI), renal function continues to deteriorate in some patients. In a pro-inflammatory and profibrotic environment, the proximal tubules are subject to maladaptive repair. In the AKI-to-CKD transition, impaired recovery from AKI reduces tubular and glomerular filtration and leads to chronic kidney disease (CKD). Reduced kidney secretion capacity is characterized by the plasma accumulation of biologically active molecules, referred to as uremic toxins (UTs). These toxins have a role in the development of neurological, cardiovascular, bone, and renal complications of CKD. However, UTs might also cause CKD as well as be the consequence. Recent studies have shown that these molecules accumulate early in AKI and contribute to the establishment of this pro-inflammatory and profibrotic environment in the kidney. The objective of the present work was to review the mechanisms of UT toxicity that potentially contribute to the AKI-to-CKD transition in each renal compartment.

Recombinant Klotho alleviates vancomycin-induced acute kidney injury by upregulating anti-oxidative capacity via JAK2/STAT3/GPx3 axis

Emerging studies support that Klotho protects against different kidney diseases. However, the role of Klotho in vancomycin induced acute kidney injury (Van-AKI) is largely unclear. Hence this study aimed to explore the regulatory mechanism of Klotho in Van-AKI. The mRNA expression of Klotho and the JAK2/STAT3/GPx3 in renal tissue were assessed by RNA sequence analysis after 600 mg/kg Van daily for seven days; Small interfering RNA and recombinant protein are applied to examine the mechanism action of Klotho in vitro and in vivo respectively. Flow cytometry and spectrophotometry detected the expression of reactive oxygen species and antioxidant enzymes. Transmission electron microscopy scanned the structural damage of mitochondria. Western blotting, qPCR, and immunofluorescence were employed to explore the JAK2/STAT3/GPx3 expression. RNA sequence analysis found that Van challenging reduced Klotho and GPx3 expression but increased JAK2/STAT3 in renal tissue. In HK-2 cells, Klotho were decreased by Van in a dose-dependent manner. Klotho siRNA enhanced the production of reactive oxygen species and the cell apoptosis ratio by regulating the JAK2/STAT3, and JAK2/STAT3 inhibitors prevented the decrease of GPx3. Meanwhile, 1 μg/ml recombinant human Klotho showed the opposite function to 120 pmol Klotho siRNA. In Van-AKI BALB/c mice, 20 μg/kg recombinant mouse Klotho once every two days improved the anti-oxidative enzyme expression, mitochondria structure, renal dysfunction, and histological damage. In conclusion, Klotho enhances antioxidant capacity through the JAK2/STAT3/GPx3 axis, which in turn improves Van-AKI.

Model-informed precision dosing of vancomycin for rapid achievement of target area under the concentration-time curve: A simulation study

In this study, we aimed to evaluate limited sampling strategies for achieving the therapeutic ranges of the area under the concentration-time curve (AUC) of vancomycin on the first and second day (AUC0-24 , AUC24-48 , respectively) of therapy. A virtual population of 1000 individuals was created using a population pharmacokinetic (PopPK) model, which was validated and incorporated into our model-informed precision dosing tool. The results were evaluated using six additional PopPK models selected based on a study design of prospective or retrospective data collection with sufficient concentrations. Bayesian forecasting was performed to evaluate the probability of achieving the therapeutic range of AUC, defined as a ratio of estimated/reference AUC within 0.8-1.2. The Bayesian posterior probability of achieving the AUC24-48 range increased from 51.3% (a priori probability) to 77.5% after using two-point sampling at the trough and peak on the first day. Sampling on the first day also yielded a higher Bayesian posterior probability (86.1%) of achieving the AUC0-24 range compared to the a priori probability of 60.1%. The Bayesian posterior probability of achieving the AUC at steady-state (AUCSS ) range by sampling on the first or second day decreased with decreased kidney function. We demonstrated that second-day trough and peak sampling provided accurate AUC24-48 , and first-day sampling may assist in rapidly achieving therapeutic AUC24-48 , although the AUCSS should be re-estimated in patients with reduced kidney function owing to its unreliable predictive performance.

Kidney function changes in acute heart failure: a practical approach to interpretation and management

Worsening kidney function (WKF) is common in patients with acute heart failure (AHF) syndromes. Although WKF has traditionally been associated with worse outcomes on a population level, serum creatinine concentrations vary greatly during episodes of worsening heart failure, with substantial individual heterogeneity in terms of their clinical meaning. Consequently, interpreting such changes within the appropriate clinical context is essential to unravel the pathophysiology of kidney function changes and appropriately interpret their clinical meaning. This article aims to provide a critical overview of WKF in AHF, aiming to provide physicians with some tips and tricks to appropriately interpret kidney function changes in the context of AHF.

Optimizing Dynamic Antibiotic Treatment Strategies against Invasive Methicillin-Resistant Staphylococcus Aureus Infections using Causal Survival Forests and G-Formula on Statewide Electronic Health Record Data

Developing models for individualized, time-varying treatment optimization from observational data with large variable spaces, e.g., electronic health records (EHR), is problematic because of inherent, complex bias that can change over time. Traditional methods such as the g-formula are robust, but must identify critical subsets of variables due to combinatorial issues. Machine learning approaches such as causal survival forests have fewer constraints and can provide fine-tuned, individualized counterfactual predictions. In this study, we aimed to optimize time-varying antibiotic treatment -identifying treatment heterogeneity and conditional treatment effects- against invasive methicillin-resistant Staphylococcus Aureus (MRSA) infections, using statewide EHR data collected in Florida, USA. While many previous studies focused on measuring the effects of the first empiric treatment (i.e., usually vancomycin), our study focuses on dynamic sequential treatment changes, comparing possible vancomycin switches with other antibiotics at clinically relevant time points, e.g., after obtaining a bacterial culture and susceptibility testing. Our study population included adult individuals admitted to the hospital with invasive MRSA. We collected demographic, clinical, medication, and laboratory information from the EHR for these patients. Then, we followed three sequential antibiotic choices (i.e., their empiric treatment, subsequent directed treatment, and final sustaining treatment), evaluating 30-day mortality as the outcome. We applied both causal survival forests and g-formula using different clinical intervention policies. We found that switching from vancomycin to another antibiotic improved survival probability, yet there was a benefit from initiating vancomycin compared to not using it at any time point. These findings show consistency with the empiric choice of vancomycin before confirmation of MRSA and shed light on how to manage switches on course. In conclusion, this application of causal machine learning on EHR demonstrates utility in modeling dynamic, heterogeneous treatment effects that cannot be evaluated precisely using randomized clinical trials.

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.

Vancomycin-loaded silk fibroin microspheres in an injectable hydrogel for chronic osteomyelitis therapy

Introduction: Chronic osteomyelitis remains a clinical challenge in orthopedics. Methods: In this study, silk fibroin microspheres (SFMPs) loaded with vancomycin are entrapped in an injectable silk hydrogel to form a vancomycin delivery system for treatment of chronic osteomyelitis. Results and Discussion: Vancomycin showed continuous release from the hydrogel for up to 25 days. The hydrogel shows strong antibacterial activity against both Escherichia coli and Staphylococcus aureus and a long antibacterial duration of 10 days without a decrease in the antibacterial effect. The injection of vancomycin-loaded silk fibroin microspheres entrapped in the hydrogel into the infected site of rat tibia reduced bone infection and improved bone regeneration compared with other treatment groups. Conclusion: Thus, the composite SF hydrogel features a sustained-release profile and good biocompatibility, making it promising for application in osteomyelitis treatment.

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.

Acute Kidney Injury in Kidney Transplant Patients in Intensive Care Unit: From Pathogenesis to Clinical Management

Kidney transplantation is the first-choice treatment for end-stage renal disease (ESRD). Kidney transplant recipients (KTRs) are at higher risk of experiencing a life-threatening event requiring intensive care unit (ICU) admission, mainly in the late post-transplant period (more than 6 months after transplantation). Urosepsis and bloodstream infections account for almost half of ICU admissions in this population; in addition, potential side effects related to immunosuppressive treatment should be accounted for cytotoxic and ischemic changes induced by calcineurin inhibitor (CNI), sirolimus/CNI-induced thrombotic microangiopathy and posterior reversible encephalopathy syndrome. Throughout the ICU stay, Acute Kidney Injury (AKI) incidence is common and ranges from 10% to 80%, and up to 40% will require renal replacement therapy. In-hospital mortality can reach 30% and correlates with acute illness severity and admission diagnosis. Graft survival is subordinated to baseline estimated glomerular filtration rate (eGFR), clinical presentation, disease severity and potential drug nephrotoxicity. The present review aims to define the impact of AKI events on short- and long-term outcomes in KTRs, focusing on the epidemiologic data regarding AKI incidence in this subpopulation; the pathophysiological mechanisms underlying AKI development and potential AKI biomarkers in kidney transplantation, graft and patients' outcomes; the current diagnostic work up and management of AKI; and the modulation of immunosuppression in ICU-admitted KTRs.

Retrospective review of antimicrobial use for gastroschisis patients in Kigali, Rwanda: can improved stewardship reduce late inpatient deaths?

Gastroschisis mortality is 75-100% in low-resource settings. In Rwanda, late deaths are often due to sepsis. We aimed to understand the effect of antimicrobial use on survival. We conducted a retrospective review of gastroschisis patients at a tertiary hospital in Kigali, Rwanda between January 2016-June 2019. Demographics, antimicrobial use, microbiology, and outcomes were abstracted. Descriptive and univariate analyses were conducted to assess factors associated with improved survival. Among 92 gastroschisis patients, mortality was 77%(n = 71); 23%(n = 21) died within 48 h. 98%(n = 90) of patients received antibiotics on arrival. Positive blood cultures were obtained in 41%(n = 38). Patients spent 86%(SD = 20%) of their hospital stay on antibiotics and 38%(n = 35) received second-line agents. There was no difference in age at arrival, birth weight, gestational age, silo complications, or antimicrobial selection between survivors and non-survivors. Late death patients spent more total hospital days and post-abdominal closure days on antibiotics (p < 0.001) compared to survivors. There was no difference in the proportion of hospital stay on second-line antibiotics (p = 0.1).

CONCLUSION

We identified frequent late deaths, prolonged antibiotic courses, and regular use of second-line antibiotic agents in this retrospective cohort of Rwandan gastroschisis patients. Future studies are needed to evaluate antimicrobial resistance in pediatric surgical patients in Rwanda.

WHAT IS KNOWN

• Global disparities in gastroschisis outcomes are extreme, with <4% mortality in high-income settings and 75-100% mortality in low-income settings. • Antimicrobial surveillance data is sparse across Africa, but existing evidence suggests high levels of resistance to first-line antibiotics in Rwanda.

WHAT IS NEW

• In-hospital survival for gastroschisis was 23% from 2016-2019 and most deaths occurred late (>48hrs after admission) due to sepsis. • Rwandan gastroschisis patients received prolonged courses of antibiotics and second-line antibiotics were frequently used without culture data, raising concern for antimicrobial resistance.

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.

Evaluation of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia: Epidemiology, clinical characteristics, and outcomes in the older patients in a tertiary teaching hospital in Malaysia

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a major concern in the global healthcare system. However, data from Asian regions dealing with the singularity of this infection in older persons is lacking. We aimed to identify the differences in the clinical characteristics and outcomes of MRSA bacteremia between adults aged 18-64 and ≥ 65 years.

METHODS

A retrospective study cohort was conducted at the University Malaya Medical Centre (UMMC) on cases of MRSA bacteremia from 2012 to 2016. Patient demographic and clinical data were collected for risk factors analyses.

RESULTS

New cases of MRSA bacteremia showed a trend of increase from 0.12 to 100 admissions in 2012 to 0.17 per 100 admissions in 2016 but a drop was observed in 2014 (0.07 per 100 admissions). Out of the 275 patients with MRSA bacteremia, 139 (50.5%) patients were aged ≥ 65 years old. Co-morbidities and severity at presentation were significantly higher among older adults, including diabetes mellitus (p = 0.035), hypertension (p = 0.001), and ischemic heart disease (p < 0.001), as well as higher Charlson Comorbidity Index (p < 0.001) and Pitt bacteremia scores (p = 0.016). Central line-associated bloodstream infections were more common among younger patients (37.5% vs. 17.3% in older patients, p < 0.001), while skin and soft tissue infections are more frequent among older adults (20.9% vs. 10.3% in younger patients, p = 0.016). All-cause mortality and in-hospital mortality were significantly higher in older patients (82.7% and 56.1% vs. 63.2% and 28.7% in younger patients, p < 0.001). Multivariate analysis revealed age ≥ 65 years (adjusted odds ratio: 3.36; 95% confidence interval: 1.24-9.13), Pitt score ≥ 3 (2.15; 1.54-3.01), hospital (6.12; 1.81-20.72) and healthcare (3.19; 1.30-7.81) acquisition of MRSA, indwelling urinary catheters (5.43; 1.39-21.23), inappropriate targeted treatment (8.08; 1.15-56.86), lack of infectious disease team consultation (2.90; 1.04-8.11) and hypoalbuminemia (3.31; 1.25-8.79), were significant risk factors for 30-day mortality.

CONCLUSION

Older patients' risk of mortality from MRSA bacteremia was three times higher than younger patients. Our data will contribute to developing and validating a robust scoring system for risk-stratifying patients to achieve better management and improved clinical outcomes.

Shapeshifting bullvalene-linked vancomycin dimers as effective antibiotics against multidrug-resistant gram-positive bacteria

The alarming rise in superbugs that are resistant to drugs of last resort, including vancomycin-resistant enterococci and staphylococci, has become a significant global health hazard. Here, we report the click chemistry synthesis of an unprecedented class of shapeshifting vancomycin dimers (SVDs) that display potent activity against bacteria that are resistant to the parent drug, including the ESKAPE pathogens, vancomycin-resistant Enterococcus (VRE), methicillin-resistant Staphylococcus aureus (MRSA), as well as vancomycin-resistant S. aureus (VRSA). The shapeshifting modality of the dimers is powered by a triazole-linked bullvalene core, exploiting the dynamic covalent rearrangements of the fluxional carbon cage and creating ligands with the capacity to inhibit bacterial cell wall biosynthesis. The new shapeshifting antibiotics are not disadvantaged by the common mechanism of vancomycin resistance resulting from the alteration of the C-terminal dipeptide with the corresponding d-Ala-d-Lac depsipeptide. Further, evidence suggests that the shapeshifting ligands destabilize the complex formed between the flippase MurJ and lipid II, implying the potential for a new mode of action for polyvalent glycopeptides. The SVDs show little propensity for acquired resistance by enterococci, suggesting that this new class of shapeshifting antibiotic will display durable antimicrobial activity not prone to rapidly acquired clinical resistance.

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.

Exploring the Past to Inform the Future to Optimize the Pharmacokinetics of Vancomycin in Children With Severe Burn Injuries

Sepsis remains one of the leading causes of death among pediatric patients with burn injuries. Despite limited vancomycin pharmacokinetic (PK) information within this population, it is widely used to treat severe burn injuries. Those with severe burns are at risk of nephrotoxicity, with an incidence of acute kidney injury (AKI) over 50%. Delivering an effective vancomycin dose and avoiding unnecessary toxicity is essential for improved patient outcomes. This was a retrospective analysis of 115 children aged 0.2 months to 18 years with severe burns, >10% total body surface area. Vancomycin was given via intravenous infusion; blood samples were drawn between 6- and 12-hour postinfusion. A population pharmacokinetic model was developed using nonlinear mixed-effect modeling (Monolix, version 2016R1). A one-compartment model described a steady-state volume of distribution (V), dependent on weight. Vancomycin clearance (CL) was influenced by age and estimated creatinine clearance (CrCL). The study population's (median age = 4 years, median weight = 20 kg, median total body surface area (%TBSA) = 40%) median V and CL were calculated to be 1.25 L/kg (95% CI, 1.04-1.46) and 0.15 L/h/kg (95% CI, 0.126-0.165), respectively. The PK model was explicitly developed to characterize the impact of physiological changes in children under 18 years of age and the percentage of the burn surface area using limited data. The analysis determined that weight, age, and estimated CrCL were important covariates in predicting vancomycin PK with high variability in CL and V.

Daptomycin for the treatment of acute bacterial meningitis: a narrative review

BACKGROUND

There is a growing interest in the utilization of daptomycin for the treatment of multi-drug resistant, Gram-positive infections. Pharmacokinetic studies suggest that daptomycin could penetrate into the cerebrospinal fluid, albeit to a small extent. The objective of this review was to evaluate the available clinical evidence for daptomycin use in acute bacterial meningitis of both pediatric and adult patients.

METHODS

Electronic databases were searched up to June 2022 for studies published on the topic. The inclusion criteria were met if the study reported the use of intravenous daptomycin (more than a single dose) for the treatment of diagnosed acute bacterial meningitis.

RESULTS

A total of 21 case reports were identified that met the inclusion criteria. These suggest that daptomycin could be safe and effective alternative in achieving clinical cure of meningitis. In these studies, daptomycin was used in the event of treatment failure, patient intolerance, or bacterial resistance to first-line agents.

CONCLUSIONS

Daptomycin has potential to be an alternative to standard care for meningitis caused by Gram-positive bacteria in the future; however, more robust research is required to establish an optimal dosing regimen, duration of therapy, and place in therapy for the management of meningitis.

Post-operative complications of total knee arthroplasty in patients with hypertension

BACKGROUND

Hypertension is one of the most common comorbidities among patients undergoing surgery. However, few studies have focused on patients undergoing knee arthroplasty, and most of them had small sample sizes. This study aimed to analyze post-operative complications associated with hypertension in patients who underwent knee replacement surgery.

METHODS

Data from the 2019 National Inpatient Sample (NIS) database were used. Patients who underwent primary total knee arthroplasty (pTKA) and those who underwent aseptic revision total knee arthroplasty (rTKA) were analyzed separately. Propensity score matching was performed to reduce the effects of demographic factors and comorbidities other than hypertension on post-operative complications. A multinomial logistic regression that included all significantly different demographics and comorbidities was performed to verify the results and evaluate the odds ratios.

RESULTS

A total of 107,981 patients who underwent pTKA and 6571 who underwent rTKA owing to mechanical complications were identified in the 2019 NIS database. Compared with the non-hypertension group, patients with hypertension had a higher risk of developing acute renal failure and electrolyte disorders after TKA. Further analysis revealed that hyponatraemia and hypokalaemia were associated with hypertension.

CONCLUSIONS

Hypertension was associated with the incidence of acute renal failure after TKA. It is important to identify patients with risk factors for acute renal failure (in addition to hypertension) and take careful measures to prevent acute renal failure in them.

Determination of vancomycin exposure target and individualized dosing recommendations for critically ill patients undergoing continuous renal replacement therapy

STUDY OBJECTIVE

Few studies have been conducted to quantify the exposure target of vancomycin in intensive care unit (ICU) patients undergoing continuous renal replacement therapy (CRRT) and provide optimized dosage regimens. We aimed to determine vancomycin exposure target and dosing recommendations using data from an open database in critically ill patients undergoing CRRT.

DESIGN

A retrospective observational cohort study.

DATA SOURCE

A large public database.

PATIENTS

The adult patients who received intravenous vancomycin and CRRT treatment in the database between 2017 and 2019 were reviewed to determine eligibility. A total of 180 patients with 1186 observations were included in the population pharmacokinetic (PPK) model development. The clinical efficacy of vancomycin was analyzed in 159 eligible patients.

METHODS

A PPK model was developed to estimate individual pharmacokinetic (PK) parameters. The area under the concentration-time curve (AUC) was estimated by a Bayesian approach based on individual vancomycin concentrations. Multivariate logistic regression analyses were performed to identify the factors of clinical outcomes. Threshold of vancomycin exposure in predicting efficacy was identified via receiver operating characteristic (ROC) curve. Dosing recommendations were designed using Monte Carlo Simulations (MCS) based on the optimized exposure target.

MEASUREMENTS AND MAIN RESULTS

On covariate analysis, CRRT intensity significantly affected vancomycin PK. The AUC above 427 mg*h/L was the only significant predictor of clinical efficacy (adjusted odds ratio (aOR): 1.008, 95% confidence interval (CI): 1.004-1.011, p = 0.000). MCS indicated that vancomycin dosage regimens of 5 mg/kg q12h or 7.5 mg/kg q12h were recommended for patients with CRRT intensities of 20-25 mL/kg/h or 25.1-45 mL/kg/h, respectively.

CONCLUSIONS

An AUC threshold of 427 mg*h/L (assuming the minimal inhibitory concentration (MIC) = 1 mg/L) was a recommended efficacy exposure target of vancomycin for critically ill patients undergoing CRRT. Vancomycin 5-7.5 mg/kg q12h is recommended as the initial dosage regimens for ICU patients undergoing CRRT.

Safety and Feasibility Assessment of a Pharmacy-Driven AUC/MIC Vancomycin Dosing Protocol in a Multicenter Hospital System

Vancomycin is used for Gram-positive infections, including methicillin-resistant Staphylococcus aureus. The 2020 vancomycin guidelines described by M. J. Rybak, J. Le, T. P. Lodise, D. P. Levine, et al. (Am J Health Syst Pharm 77:835-864, 2020, https://doi.org/10.1093/ajhp/zxaa036) provided an update on vancomycin dosing, which recommended an optimal area under the concentration-time curve over 24 h to MIC (AUC/MIC) target of 400 to 600. In 2021, a pharmacy-driven AUC/MIC vancomycin dosing protocol was implemented across 12 Sentara Health System hospitals. The primary objective of this study was to assess if the pharmacy-driven AUC/MIC vancomycin dosing protocol led to fewer acute kidney injury (AKI) events than trough-based dosing. Secondary objectives included vancomycin duration, hospital length of stay, administered vancomycin dose during admission, vancomycin labs drawn during standard lab times, and cost. AKI was assessed in two separate ways: (i) modified AKIN (Acute Kidney Injury Network) criteria and (ii) a modified version from the vancomycin guidelines. Inferential statistics were used to analyze the results of this retrospective study. Per the AKIN definition, the rates of AKI were 13.9% (349/2,507) in the trough-based group and 14.9% (369/2,471) in the AUC/MIC-based group (P = 0.309). Per the definition of the vancomycin guidelines, the rates of AKI were 6.7% (169/2,507) in the trough-based group and 7.6% (187/2,471) in the AUC/MIC-based group (P = 0.258). A total of 52% (2,679/5,151) of vancomycin labs were obtained during standard lab times in the AUC group and 24% (1,144/4,766) in the trough group (P < 0.05). There was no difference in AKI events between AUC and trough dosing. Use of contrast dye may confound these results. AUC/MIC dosing was associated with more lab draws during standard times, a larger number of labs drawn per person, and less total use of vancomycin. IMPORTANCE In this article, we report that there were no differences in rates of acute kidney injury between trough-based vancomycin dosing and AUC/MIC-based vancomycin dosing across 12 hospitals. AUC/MIC dosing resulted in more vancomycin lab draws during standard lab draw times compared to trough dosing, thus making it more convenient for health care personnel. This study includes all uses for vancomycin, including empirical use, and all patient severity levels. Therefore, this research reflects real-world use of vancomycin in hospitals. AUC/MIC dosing is supported by various infectious disease societies. However, the feasibility of incorporating AUC/MIC dosing in hospitals is undetermined. This study is unique in that it includes hospitals of various sizes (small community hospitals and an academic teaching hospital), and it includes a feasibility component. Therefore, this study has broad applicability to other hospitals across the United States. This original research includes the clinical application of vancomycin in a multicenter health system.

Long-range surface plasmon aptasensor for label-free monitoring of vancomycin

Vancomycin (VCM) causes poisoning symptoms at high concentrations; thus, therapeutic drug monitoring is recommended to measure and control blood levels regularly. However, blood analysis at regular intervals does not allow knowing the detailed temporal change in concentration. To address this challenge, we developed a long-range surface plasmon (LRSP) aptasensor for measuring VCM label-free and real-time by combining a sensitive LRSP sensor and a peptide aptamer with a VCM recognition site. First, three different biosensors for VCM were compared. One was prepared by immobilizing the peptide aptamer directly on (Direct-Apt) or via a self-assembled monolayer (SAM) on a gold surface (SAM-Apt). The other used anti-VCM antibodies immobilized on a gold surface via the SAM (SAM-Ab). The Direct-Apt showed larger sensor output to VCM than the other biosensors. The dynamic range for VCM was 0.78-100 μM, including the therapeutic range (6.9-13.8 μM). The Direct-Apt also showed the sensor output only from VCM among four different antibiotics, demonstrating the high selectivity for VCM. The VCM captured by the aptamer could be removed by rinsing with phosphate-buffered saline. The measurement was rapid, with 72- and 77-sec response and recovery times, allowing not only repeated but also real-time measurements. Finally, the Direct-Apt in 20% serum solutions showed comparable sensitivity to VCM in the buffer solution, indicating high capability for real-sample.