Clinical outcomes of linezolid and vancomycin in patients with nosocomial pneumonia caused by methicillin-resistant Staphylococcus aureus stratified by baseline renal function: a retrospective, cohort analysis

Molecular Characterization and Antibiotic Susceptibility Pattern of Bacterial Strains Isolated From Wound of Patients With Diabetes

BACKGROUND

 Diabetic wound infections are susceptible to various pathogens, particularly bacteria, due to the immunocompromised state of diabetic patients. Staphylococcus aureus is frequently implicated in diabetic wounds. To ascertain the presence of multiple antibiotic resistance in bacterial pathogens derived from diabetic wound infections, a comprehensive analysis is required.

MATERIALS AND METHODS

The present cross-sectional investigation was carried out at a tertiary care facility. The samples were collected in aseptic conditions from the Endocrinology unit, specifically from local in-hospital patients (n=140). These samples were then assessed for their susceptibility to the commonly used antibacterial medications within the study area. The specimens were obtained from the lesions of individuals diagnosed with diabetes. The subjects were subjected to inoculation using various media and cultures.

RESULTS

The findings of this study revealed that a collective sum of 122 bacterial isolates was acquired. The conclusions of the antibiotic susceptibility analysis revealed that the gram-positive isolates had a higher level of resistance to penicillin G (93.18%). However, they demonstrated sensitivity to vancomycin (100%) and linezolid (LZD) (95%). The gram-negative isolates exhibited complete resistance, at a rate of 100%, to penicillin, specifically amoxicillin (AMC), as well as to sulfonamides, such as sulfamethoxazole/trimethoprim (SXT), which belong to the antibiotic classes mentioned.

CONCLUSION

In conclusion, there has been a notable rise in antibiotic resistance.

A 600 mg of fixed-dose linezolid in renally impaired patients versus 15 mg/kg intermittent dose-optimized vancomycin in renally non-impaired patients: A single centre retrospective analysis for adult patients with hospital-acquired pneumonia due to methicillin-resistant Staphylococcus aureus

OBJECTIVES

Both linezolid and vancomycin are approved by USFDA and IDSA guidelines for the management of nosocomial pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) in clinical practice. Baseline creatinine clearance is the criterion for prescribing vancomycin or linezolid for hospital-acquired pneumonia in our institution. However, patients with renal function impairment are far more difficult to manage in intensive care. Thus, the objectives of the study were to compare the clinical efficacy and safety of 600 mg of fixed-dose linezolid with intermittent dose-optimised vancomycin in hospital-acquired pneumonia due to MRSA and to evaluate parameters of clinical cure.

METHODS

Analysis of a review of patients' charts. Patients with creatinine clearance <80 ml/min received 600 mg linezolid/12 h (n = 139, LN cohort), and patients with creatinine clearance ≥80 ml/min received intravenous 15 mg/kg vancomycin/12 h for 1-2 weeks consecutively or 3 weeks in case of bacteremia (n = 152, VC cohort) for management of hospital-acquired pneumonia due to MRSA.

RESULTS

A 59% of patients from the LN cohort and 47% of patients from the VC cohort were clinically cured. Administration of systemic steroids (p = 0.0412) and ≥ 80 ml/min creatinine clearance (p = 0.0498) were the independent parameters for the clinical cure of patients. Nephrotoxicity was higher among patients of the VC cohort than the LN cohort (p = 0.0464). Treatment failed in 41% of patients from the LN cohort and in 53% of patients from the VC cohort (p = 0.0200).

CONCLUSIONS

A 600 mg of fixed-dose linezolid is an ideal alternative to intermittent dose-optimised vancomycin for better clinical outcomes for patients with hospital-acquired pneumonia due to MRSA, especially for patients with renal impairment.

Area-Under-Curve-Guided Versus Trough-Guided Monitoring of Vancomycin and Its Impact on Nephrotoxicity: A Systematic Review and Meta-Analysis

BACKGROUND

Conventionally, vancomycin trough levels have been used for therapeutic drug monitoring (TDM). Owing to the increasing evidence of trough levels being poor surrogates of area under the curve (AUC) and the advent of advanced pharmacokinetics software, a paradigm shift has been made toward AUC-guided dosing. This study aims to evaluate the impact of AUC-guided versus trough-guided TDM on vancomycin-associated nephrotoxicity.

METHODS

A systematic review was conducted using PubMed, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Google scholar, and Cochrane library databases; articles published from January 01, 2009, to January 01, 2021, were retrieved and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Studies that evaluated trough-guided or AUC-guided vancomycin TDM and vancomycin-associated nephrotoxicity were included. Random-effects models were used to compare the differences in nephrotoxicity.

RESULTS

Of the 1191 retrieved studies, 57 were included. Most studies included adults and older adults (n = 47, 82.45%). The pooled prevalence of nephrotoxicity was lower in AUC-guided TDM [6.2%; 95% confidence interval (CI): 2.9%-9.5%] than in trough-guided TDM (17.0%; 95% CI: 14.7%-19.2%). Compared with the trough-guided approach, the AUC-guided approach had a lower risk of nephrotoxicity (odds ratio: 0.53; 95% CI: 0.32-0.89). The risk of nephrotoxicity was unaffected by the AUC derivation method. AUC thresholds correlated with nephrotoxicity only within the first 96 hours of therapy.

CONCLUSIONS

The AUC-guided approach had a lower risk of nephrotoxicity, supporting the updated American Society of Health-System Pharmacists guidelines. Further studies are needed to evaluate the optimal AUC-derivation methods and clinical utility of repeated measurements of the AUC and trough levels of vancomycin.

Changes in regional oxygen saturation of the kidney and brain of infants during hospitalization

BACKGROUND

In pre-term infants, the postnatal changes in the regional oxygen saturation (rSO₂) of the brain and kidney are unclear.

METHODS

We performed a prospective observational study. We measured the cerebral/renal rSO₂ ratio and recorded the associated clinical features of infants born at 23 to 41 weeks of gestation weekly from the early postnatal period to discharge.

RESULTS

The median cerebral/renal rSO₂ ratios (interquartile ranges) between birth and the expected date of birth were 1.13 (1.06-1.26) at 23-24 weeks (n = 7), 1.18 (1.10-1.32) at 25-26 weeks (n = 11), 1.24 (1.11-1.37) at 27-28 weeks (n = 9), 1.12 (1.05-1.19) at 29-30 weeks (n = 4), 1.11 (1.03-1.15) at 31-32 weeks (n = 5), 1.02 (0.98-1.06) at 33-34 weeks (n = 9), 0.98 (0.94-1.06) at 35-36 weeks (n = 19), and 0.95 (0.86-0.99) at 37-41 weeks of gestation (n = 22). The median cerebral/renal rSO₂ ratio did not significantly change after birth, but with increasing gestational age, the cerebral/renal rSO₂ ratio at the expected date of birth decreased (r = - 0.74, p < 0.001). Nephrotoxic drugs did not affect cerebral/renal rSO₂ at the expected date of birth, after adjustment for clinical factors.

CONCLUSIONS

Unlike in most infants born after the late pre-term period, the renal rSO₂ remained lower than the cerebral rSO₂ on the expected date of birth in infants born very pre-term.

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

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

Medicine Dose Adjustment Practice and Associated Factors among Renally Impaired Patients in Amhara Regional State, Ethiopia

Background

Kidney disease affects absorption, distribution, metabolism, and excretion of medicines and their metabolites. Therefore, when prescribing medicines for patients with kidney disease, dose adjustment is an accepted standard of practice.

Objective

This study aimed to assess medicine dose adjustment practice and associated factors among adult patients with renal impairment admitted to medical wards at Amhara region referral hospitals.

Method

Multicenter, institution-based, cross-sectional study was conducted from March 28, 2020, to August 30, 2020. The data was collected by using a pretested interviewer-administered structured questionnaire. Data were entered into Epi-Data version 4.6 and transferred into SPSS version 25 for further data processing and analysis. Descriptive statistics such as frequencies and percentages were computed. Both bivariable and multivariable binary logistic regression analyses were fitted to identify factors associated with dose adjustment practice. A 95% confidence interval and a p value less than 0.05 were used to declare statistical significance.

Result

Among 815 medicines' prescriptions that needed dose adjustment, 417 (51.2%) of them were dosed inappropriately. Number of medicines, number of comorbidities, and being unemployed were significantly associated with inappropriate dose adjustment.

Conclusion

Our study revealed that there was a considerable rate of inappropriate dose adjustment in patients with renal impairment. Training for health care providers, use of guidelines, and communication with clinical pharmacists should be encouraged for good prescription practice.

Impact of an interactive, clinical decision-making workshop on student learning of antimicrobial stewardship principles

BACKGROUND AND PURPOSE

Educational escape room activities are being implemented in various classroom environments to augment learning. These games are structured in a linear pathway, and all participants must complete riddles to arrive at the same answer and "escape the room."

EDUCATIONAL ACTIVITY AND SETTING

Investigators created a multi-directional interactive learning activity where students were presented with a patient case. The activity required students to identify the presented infectious disease, interpret microbiology results, and select antibiotic treatment options. Students were required to provide dosing and antimicrobial stewardship metrics based on their treatment selection along with rationale. Upon completion of the activity, students participated in group discussions explaining the reasoning behind their selected treatment option. They also completed a satisfaction survey. Knowledge of antimicrobial stewardship principles was assessed via a multiple-choice exam. Exam performance was compared to the prior year when a traditional lecture format was utilized to teach the topic.

FINDINGS

Of 194 students enrolled in the course, 138 completed the satisfaction survey. The majority (86.9%) indicated that they would recommend the activity and 88.2% considered it an effective tool for learning antimicrobial stewardship. There was a mean decline of 6.38% (P = .3) in correctly answered exam questions with the implementation of the activity compared to results from the previous academic year (N = 185).

SUMMARY

Students perceived the game as a valuable learning experience, but it did not result in an improvement in knowledge of antimicrobial stewardship as assessed by multiple-choice exams.

AUCs and 123s: a critical appraisal of vancomycin therapeutic drug monitoring in paediatrics

The revised vancomycin guidelines recommend implementing AUC24-based therapeutic drug monitoring (TDM) using Bayesian methods in both adults and paediatrics. The motivation for this change was accumulating evidence showing aggressive dosing to achieve high troughs, as recommended in the first guidelines for adults and extrapolated to paediatrics, is associated with increased nephrotoxicity without improving clinical outcomes. AUC24-based TDM requires substantial resources that may need to be diverted from other valuable interventions. It can therefore be justified only after certain assumptions are shown to be true: (i) there is a clear relationship between vancomycin efficacy and/or toxicity and the proposed therapeutic range; and (ii) maintaining exposure within the target range with AUC24-based TDM improves clinical outcomes and/or decreases toxicity. In this review, we critically appraise the scientific basis for these assumptions. We find studies evaluating the relationship between vancomycin AUC24/MIC and efficacy in adults and children do not offer strong support for the recommended lower limit of the proposed therapeutic range (i.e. AUC24/MIC ≥400). Nephrotoxicity in children increases in a stepwise manner along the vancomycin exposure continuum but it is unclear if one parameter (AUC24 versus trough) is a superior predictor. Overall, evidence in children suggests good-to-excellent correlation between AUC24 and trough. Most importantly, there is no convincing evidence that the method of vancomycin TDM has a causal role in improving efficacy or reducing toxicity. These findings question the need to transition to resource-intensive AUC24-based TDM over retaining trough-based TDM with lower targets to minimize nephrotoxicity in paediatrics.

Augmented Renal Clearance and How to Augment Antibiotic Dosing

Augmented renal clearance (ARC) refers to the state of heightened renal filtration commonly observed in the critically ill. Its prevalence in this patient population is a consequence of the body’s natural response to serious disease, as well as the administration of fluids and pharmacologic therapies necessary to maintain sufficient blood pressure. ARC is objectively defined as a creatinine clearance of more than 130 mL/min/1.73 m² and is thus a crucial condition to consider when administering antibiotics, many of which are cleared renally. Using conventional dosing regimens risks the possibility of subtherapeutic concentrations or clinical failure. Over the past decade, research has been conducted in patients with ARC who received a number of antibacterials frequently used in the critically ill, such as piperacillin-tazobactam or vancomycin. Strategies to contend with this condition have also been explored, though further investigations remain necessary.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Vancomycin area under the curve to minimum inhibitory concentration ratio predicting clinical outcome: a systematic review and meta-analysis with pooled sensitivity and specificity

BACKGROUND

Vancomycin is a first-line antibiotic for methicillin-resistant Staphylococcus aureus infections or other Gram-positive infections. The area under the curve (AUC) to minimum inhibitory concentration (MIC) ratio is proposed as a therapeutic drug-monitoring parameter. How well clinical efficacy is predicted by this measure has not been established.

OBJECTIVE

Determine the test performance characteristics (TPC) of AUC:MIC of vancomycin for prediction of positive outcome.

DATA SOURCES

PubMed and Ovid Medline (1946 to 2018) and EMBASE (1974 to 2018). Study Eligibility Criteria and Participants: Studies of patients treated with vancomycin for any type of infection in peer reviewed publications. All patient populations were included.

INTERVENTIONS

Vancomycin AUC:MIC or AUC was related to patient clinical outcome.

METHODS

Searches of medical databases using relevant terms were performed. Screening, study reviewing, data extracting and assessing data quality was performed independently by two reviewers. Studies were stratified by type of primary outcome for calculation of pooled sensitivity, specificity and construction of hierarchical summary receiver operating characteristic (HSROC) curves.

RESULTS

Nineteen studies including 1699 patients were meta-analysed. Pooled sensitivity and specificity were 0.77 (95% CI 0.67-0.84) and 0.62 (95% CI 0.53-0.71) respectively for the seven studies with primary outcome of mortality and 0.65 (95% CI 0.53-0.75), 0.58 (95% CI 0.48-0.67) for studies with composite or clinical cure outcome (n = 12). HSROC curves suggested considerable heterogeneity. An additional 11 studies were described but could not be included for meta-analysis because data were not available. The majority of these studies (9/11) failed to demonstrate a relationship between AUC:MIC and positive clinical outcome.

CONCLUSIONS

Vancomycin AUC:MIC performance was modest and inconsistent. Analysis was limited by studies without sufficient data; therefore, meta-analytic results may overestimate TPC values. Given this, as well as the lack of standardization of methods, widespread adoption of AUC:MIC as the preferred vancomycin monitoring parameter may be premature.