Evolution of interventional vancomycin trials in light of new antibiotic development in the USA, 1999-2012

Is Use of Topical Vancomycin in Pediatric Spine Surgeries a Safe Option in the Prevention of Surgical Site Infections? A Meta-analysis and Systematic Review of the Literature

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To systematically review the available articles on topical vancomycin powder (TVP) use in pediatric spine surgeries exploring the usefulness and safety of such practice.

METHODS

We conducted an independent and duplicate electronic database search in PubMed, EMBASE, and Cochrane Library till March 2020 to identify all relevant literature on the use of TVP for pediatric spine surgeries. Surgical site infection (SSI) rate, specific reported complications, reoperation rate, microbial flora pattern in reported SSIs, and safety profile were the outcomes analyzed. Analysis was performed with the R platform using OpenMeta[Analyst] software.

RESULTS

No prospective studies were available to evaluate the use of TVP in pediatric spine surgeries for the prevention of SSIs. Neither standardized protocol, nor drug dosage, nor safety profile was established for pediatric use. Three retrospective cohort studies including 824 patients (TVP/control: 400/424) were included in the meta-analysis. There was low-quality evidence suggesting no significant difference between the 2 groups in SSI rate (RR = 0.474; 95% CI = [0.106,2.112]; P = .327) with significant heterogeneity (I² = 70.14; P = .035). The TVP group showed a significant benefit on cost analysis in one of the included studies. However, TVP did not prevent gram-negative coinfection on SSI in the TVP group.

CONCLUSION

From the literature available at present, TVP does not qualify to be recommended as a safe and useful option to prevent SSI following pediatric spine surgeries. High-quality prospective interventional studies are needed to arrive at a consensus on its use along with appropriate dosage and method of application.

Optimizing the detection of methicillin-resistant Staphylococcus aureus with elevated vancomycin minimum inhibitory concentrations within the susceptible range

Background

Determination of vancomycin minimum inhibitory concentration (MIC) can influence the agent used to treat methicillin-resistant Staphylococcus aureus (MRSA) infection. We studied diagnostic accuracy using E-test and VITEK^® 2 against a gold standard broth microdilution (BMD) methodology, the correlation between methods, and associations between vancomycin MIC and MRSA phenotype from clinical isolates.

Methods

MRSA isolates were obtained from April 2012 to December 2013. Vancomycin MIC values were determined prospectively on all isolates by gradient diffusion E-test and automated VITEK^® 2. The Clinical and Laboratory Standards Institute reference BMD method was performed retrospectively on thawed frozen isolates. Diagnostic accuracy for detecting less susceptible strains was calculated at each MIC cutoff point for E-Test and VITEK^® 2 using BMD ≥1 µg/mL as a standard. The correlation between methods was assessed using Spearman’s rho (ρ). The association between MRSA phenotype and MIC for the three methods was assessed using Fisher’s exact test.

Results

Of 148 MRSA isolates, all except one (E-test =3 µg/mL) were susceptible to vancomycin (MIC of ≤2 µg/mL) irrespective of methodology. MICs were ≥1.0 µg/mL for 9.5% of BMD, 50.0% for VITEK^® 2, and 27.7% for E-test. Spearman’s ρ showed weak correlations between methods: 0.29 E-test vs VITEK^® 2 (P=0.003), 0.27 E-test vs BMD (P=0.001), and 0.31 VITEK^® 2 vs BMD (P=0.002). The optimal cutoff points for detecting BMD-defined less susceptible strains were ≥1.0 µg/mL for E-test and VITEK^® 2. E-test sensitivity at this cutoff point was 0.85 and specificity 0.29, while VITEK^® 2 sensitivity and specificity were 0.62 and 0.51, respectively. Multiresistant MRSA strains tended to have higher MIC values compared to nonmultiresistant MRSA or epidemic MRSA 15 phenotypes by E-test (Fisher’s exact P<0.001) and VITEK^® 2 (Fisher’s exact P<0.001).

Conclusion

Overall diagnostic accuracy and correlations between MIC methods used in routine diagnostic laboratories and the gold standard BMD showed limited overall agreement. This study helps optimize guidance on the effective use of vancomycin.

The impact of a pilot continuing professional development module on hospital pharmacists' preparedness to provide contemporary advice on the clinical use of vancomycin

BACKGROUND

Revised international clinical guidelines for the antibiotic vancomycin have changed the advice pharmacists need to provide to medical and nursing colleagues.

OBJECTIVES

(1) To determine the self-reported confidence of hospital pharmacists to provide contemporary advice on vancomycin and (2) to evaluate hospital pharmacists' knowledge to provide contemporary advice on vancomycin following a pilot continuing professional development (CPD) module.

METHODS

The study was a prospective two-phase design in an Australian teaching hospital. Phase one: a survey of pharmacist self-reported confidence to eight questions on providing contemporary advice on vancomycin. Responses were recorded using a Likert scales. Phase two: The provision of a pilot online CPD module on vancomycin containing knowledge-based assessment based on a clinical vignette. Likert scales recorded self-reported confidence were reported as median and interquartile range (IQR). Knowledge assessment was reported using descriptive statistics. The main outcome measure were the self-reported confidence, and knowledge of pharmacists regarding provision of contemporary advice on clinical vancomycin use.

RESULTS

Response rates for surveys; confidence n = 35 (72.9 %) and knowledge n = 31 (58.5 %). Phase one: confidence was highest regarding vancomycin dosing and monitoring with 71.4-81.6 % of respondents agreeing or strongly agreeing that they were confident in these domains. Respondents agreeing or strongly agreeing were least confident regarding intravenous administration and infusion related reactions, 57.1 and 45.7 % respectively. Respondents who provided advice on vancomycin >10 times in the prior 12 months reported significantly higher confidence in; therapeutic range 1 (IQR 1-2) versus 2 (IQR 1-3) p = 0.02; amending dosage based on therapeutic drug monitoring results 2 (IQR 1-3) versus 3 (IQR 2-3) p = <0.001, and providing general advice to prescribers on vancomycin 2 (IQR 1-3) versus 2 (IQR 2-4) p = <0.009. Knowledge questions were answered correctly post CPD by >75 % of pharmacists.

CONCLUSION

Pharmacists' self-reported confidence to managing vancomycin was variable but generally high. Knowledge scores were consistently high after pharmacists completed a pilot CPD module on vancomycin. These data provides impetus for a randomised controlled study across multiple sites to determine the extent to which pharmacist knowledge on vancomycin can be attributed to completion of an online CPD.

Pharmacist-led implementation of a vancomycin guideline across medical and surgical units: impact on clinical behavior and therapeutic drug monitoring outcomes

Background

Vancomycin is the antibiotic of choice for the treatment of serious infections such as methicillin-resistant Staphylococcus aureus (MRSA). Inappropriate prescribing of vancomycin can lead to therapeutic failure, antibiotic resistance, and drug toxicity.

Objective

To examine the effectiveness of pharmacist-led implementation of a clinical practice guideline for vancomycin dosing and monitoring in a teaching hospital.

Methods

An observational pre–post study design was undertaken to evaluate the implementation of the vancomycin guideline. The implementation strategy principally involved education, clinical vignettes, and provision of pocket guidelines to accompany release of the guideline to the hospital Intranet. The target cohort for clinical behavioral change was junior medical officers, as they perform the majority of prescribing and monitoring of vancomycin in hospitals. Assessment measures were recorded for vancomycin prescribing, therapeutic drug monitoring, and patient outcomes.

Results

Ninety-nine patients, 53 pre- and 46 post-implementation, were included in the study. Prescribing of a loading dose increased from 9% to 28% (P=0.02), and guideline adherence to starting maintenance dosing increased from 53% to 63% (P=0.32). Dose adjustment by doctors when blood concentrations were outside target increased from 53% to 71% (P=0.12), and correct timing of initial concentration measurement increased from 43% to 57% (P=0.23). Appropriately timed trough concentrations improved from 73% to 81% (P=0.08). Pre-dose (trough) concentrations in target range rose from 33% to 44% (P=0.10), while potentially toxic concentrations decreased from 32% to 21% (P=0.05) post-implementation. Infection cure rates for patients increased from 85% to 96% (P=0.11) after the guideline was implemented.

Conclusion

The implementation strategy employed in this study demonstrated potential effectiveness, and should prompt additional larger studies to optimize strategies that will translate into improved clinical practice using vancomycin.

Risks for multidrug-resistant pathogens in the ICU

PURPOSE OF REVIEW

The impact of multidrug-resistant organisms (MDROs) is rising and often underestimated. The epidemiology of MDROs is extremely complex and multifactorial. There is increasing antibiotic resistance, mainly related to antibiotic pressure and patients' characteristics.

RECENT FINDINGS

Emphasis on MDRO epidemiology is needed to better understand current strategies of prevention and management. Among them, antibiotic stewardship has been one of the most successful strategies. It is important to note that there is a controversial issue when considering community and healthcare-related infections. In addition, different strategies have been determined to find the impact and optimal use of recently launched antibiotics for MDRO treatment.

SUMMARY

Infections with MDROs can prolong hospital stay, promote antibiotic use and prolong duration of mechanical ventilation. Some points should be further explored in clinical research such as the heterogeneity of healthcare-associated pneumonia and the need of new drug development. Resistance to non fermentative Gram-negative bacilli, rising minimum inhibitory concentration in methicillin-resistant Staphylococcus aureus and spread of MDROs in patients without known risk factors suggest a review of guideline validation, taking into account ecology and severity of patient illness to provide timely and appropriate empiric therapy.

The use of vancomycin powder in modern spine surgery: systematic review and meta-analysis of the clinical evidence

BACKGROUND

Surgical-site infections (SSIs) can lead to greater postoperative morbidity, mortality, and health care costs. Despite current prophylactic measures, rates of SSIs have been reported in up to 15% of patients undergoing spine surgery. The adjunctive local application of vancomycin powder in spine surgery is a low-cost strategy to help reduce SSIs. Vancomycin is active against skin pathogens that can potentially contaminate the wound during spinal surgery. The local application of vancomycin in its powder form ensures adequate surgical-site concentrations while minimizing adverse effects caused by undetectable systemic distribution. However, clinical studies have produced conflicting results, and the clinical evidence behind the use of vancomycin powder in modern spinal surgery practices is not clear.

PURPOSE

To examine the current clinical evidence on the use of vancomycin powder in spine surgery.

STUDY DESIGN

Systematic review and meta-analysis of literature.

METHODS

A comprehensive search of the English literature was conducted with PubMed (MEDLINE). The inclusion criteria consisted of intrawound vancomycin powder use in spine surgery as a prophylactic agent for SSIs. Studies that investigated nonspine surgeries, selected patients on the basis of clinical suspicion, or included patients with infections were excluded. Studies that compared intrawound vancomycin in spine surgery against their standard practice were pooled in the meta-analysis using a random-effects model.

RESULTS

A total of 671 abstracts were reviewed, and 18 papers met inclusion/exclusion criteria and were included in this review. These included 1 randomized controlled trial, 13 comparative studies, and 4 case series. The level of evidence in hierarchical order was as follows: 1 level II, 13 level III, and 4 level IV. Fourteen of the studies, 1 randomized controlled trial and 13 comparative studies, were eligible for the meta-analysis. The odds of developing a deep infection with intrawound vancomycin powder were 0.23 times the odds of experiencing an infection without intrawound vancomycin (95% confidence interval 0.11-0.50, P = 0.0002, I(2) = 47%). For combined superficial and deep infections the odds ratio was 0.43 (95% confidence interval 0.22-0.82, P = 0.01, I(2) = 36%).

CONCLUSIONS

Numerous clinical studies have confirmed the safety of using vancomycin powder in the surgical site. The pooled clinical data supports the use of vancomycin to prevent SSIs in adult spine surgeries. The majority of the supporting literature is class III evidence. Existing studies use different definitions for surgical site infections and different pre-, peri-, and postoperative antibiotic regimens. Further high-quality investigations should use standardized protocols to confirm these findings.