Impact of a Rapid Blood Culture Diagnostic Panel on Time to Optimal Antimicrobial Therapy at a Veterans Affairs Medical Center

Early detection of bacteremia pathogens with rapid molecular diagnostic tests and evaluation of effect on intensive care patient management

İNTRODUCTION: The BioFire FilmArray Blood Culture Identification panel (BCID2), a rapid molecular blood culture identification test based on multiplex nested polymerase chain reaction. The aim of this study was to evaluate clinical outcomes between the period before (pre-BCID2 group) and after (post-BCID2 group) the introduction of the BCID2 panel into our routine practice.

METHODS

The primary endpoint was time to optimal antibiotherapy, and the secondary endpoints were duration of hospital and intensive care unit stay, 7-day, 14-day and 28-day mortality rates after bacteremia.

RESULTS

The median time from empirical antibiotherapy to optimal antimicrobial therapy was 4560 (IQR;3060-7140) minutes in the pre-BCID2 group and 1715 (IQR;1362- 2776.25) minutes (in the post-BCID2 group (p<0.05).

CONCLUSION

Adding the BCID2 panel may improve antibiotic management in critically ill bacteremia patients.

Rapid Diagnostic Tests and Antimicrobial Stewardship Programs for the Management of Bloodstream Infection: What Is Their Relative Contribution to Improving Clinical Outcomes? A Systematic Review and Network Meta-analysis

BACKGROUND

Evidence about the clinical impact of rapid diagnostic tests (RDTs) for the diagnosis of bloodstream infections is limited, and whether RDT are superior to conventional blood cultures (BCs) embedded within antimicrobial stewardship programs (ASPs) is unknown.

METHODS

We performed network meta-analyses using results from studies of patients with bloodstream infection with the aim of comparing the clinical impact of RDT (applied on positive BC broth or whole blood) to conventional BC, both assessed with and without ASP with respect to mortality, length of stay (LOS), and time to optimal therapy.

RESULTS

Eighty-eight papers were selected, including 25 682 patient encounters. There was an appreciable amount of statistical heterogeneity within each meta-analysis. The network meta-analyses showed a significant reduction in mortality associated with the use of RDT + ASP versus BC alone (odds ratio [OR], 0.72; 95% confidence interval [CI], .59-.87) and with the use of RDT + ASP versus BC + ASP (OR, 0.78; 95% CI, .63-.96). No benefit in survival was found associated with the use of RDT alone nor with BC + ASP compared to BC alone. A reduction in LOS was associated with RDT + ASP versus BC alone (OR, 0.91; 95% CI, .84-.98) whereas no difference in LOS was shown between any other groups. A reduced time to optimal therapy was shown when RDT + ASP was compared to BC alone (-29 hours; 95% CI, -35 to -23), BC + ASP (-18 hours; 95% CI, -27 to -10), and to RDT alone (-12 hours; 95% CI, -20 to -3).

CONCLUSIONS

The use of RDT + ASP may lead to a survival benefit even when introduced in settings already adopting effective ASP in association with conventional BC.

Misidentification and misreporting of antibiotic resistance in Kluyvera bacteremia by blood culture molecular identification panels

The use of molecular identification panels has advanced the diagnosis for blood stream infections with fast turnaround time and high accuracy. Yet, this technology cannot completely replace conventional blood culture and standardized antibiotic susceptibility testing (AST) given its limitations and occasional false results. Here we present two cases of bacteremia caused by Kluyvera. Its identification and antibiotic resistance were at least partially mispresented by blood culture molecular identification panels on ePlex, Verigene, and Biofire. The detection of CTX-M resistance marker did not align with the susceptibility to the third generation cephalosporins among a wide range of antibiotics for this organism. Conventional extended-spectrum beta-lactamase (ESBL) testing was used to confirm the absence of ESBL. Caution should be taken when managing cases with CTX-M or ESBL detection in blood culture caused by uncommon pathogens. Conventional culture with microbial identification and standardized AST should continue to be the gold standard for routine patient care.

IMPORTANCE

This is the first report that highlights the limitations of blood culture molecular identification panels on identifying Kluyvera and its associated antibiotic resistance patterns. Both the false identification and overreporting of antibiotic resistance could mislead the treatment for bacteremia caused by this pathogen. Patient isolation could have been avoided due to the lack of extended-spectrum beta-lactamase (ESBL) activity of the organism. This report emphasizes the importance of confirming rapid identification and antibiotic resistance by molecular technologies with standardized methods. It also provides insight into the development of new diagnostic panels.

The impact of implementation of rapid blood culture identification panels on antimicrobial optimization: a retrospective cohort study

Objective

Determine the impact of limited implementation of a rapid blood culture identification (BCID) panel.

Design

Retrospective cohort study.

Methods

From February to April 2022, positive blood cultures identified via e-Plex BCID (Roche, Carlsbad, CA) were compared to those identified using standard microbial identification techniques. The primary outcomes assessed were time to optimal therapy, time to de-escalation of anti-MRSA (methicillin-resistant Staphylococcus aureus) agents, and time to de-escalation of anti-pseudomonal agents. Additional analysis investigated the impact of the availability of antimicrobial stewardship program support. This study was conducted at Grady Health System, a large metropolitan safety-net hospital in the southeastern United States.

Results

A total of 253 blood cultures were included in this study (153 BCID and 100 standard). Blood culture identification use was associated with a reduction in median time to optimal antimicrobial therapy (43.4 vs 72.1 h, P < .001) and median time to de-escalation of anti-MRSA agents (27.7 vs 46.7 h, P = .006), and a trend towards reduction of median time to de-escalation of anti-pseudomonal agents (38.8 vs 54.8 h, P = .07). These reductions persisted when controlling for patient age, sex, intensive care unit status, Charlson Comorbidity Index, and antimicrobial stewardship program availability.

Conclusions

Despite restricted use and lack of 24/7 antimicrobial stewardship program availability, BCID panel utilization was associated with earlier initiation of optimal therapy and pathogen identification with subsequent de-escalation of broad-spectrum antimicrobials, as compared to standard antimicrobial techniques. This suggests the potential for benefit from adopting novel diagnostic technologies outside of idealized fully-resourced settings.

Approaches to Reduce Use and Duration of Anti-MRSA Agents for Antimicrobial Stewardship Programs: A Review of Recent Literature

Antimicrobial stewardship programs (ASPs) have the potential to effectively deescalate unnecessary methicillin-resistant Staphylococcus aureus (MRSA) coverage. This review summarizes literature published from 2014 through 2021 describing contemporary ASP methods and their resulting effectiveness at reducing anti-MRSA agent use (ie vancomycin, linezolid, daptomycin, ceftaroline, and clindamycin). This review of the literature examined the following strategies, which had reports of success in either decreasing the use or duration of anti-MRSA agents: prospective review and feedback, antibiotic timeouts, health system or department protocol changes, polymerase chain reaction (PCR) and rapid testing of patient samples. Most of the current literature continue to support most ASP interventions including antibiotic timeouts, pathways, and molecular testing including MRSA nasal PCRs and rapid diagnostic testing can be successful at reducing unnecessary anti-MRSA use.

Clinical impact of a multiplex rapid diagnostic pneumonia panel in critically ill patients

Objective

To evaluate the clinical impact of the BioFire FilmArray Pneumonia Panel (PNA panel) in critically ill patients.

Design

Single-center, preintervention and postintervention retrospective cohort study.

Setting

Tertiary-care academic medical center.

Patients

Adult ICU patients.

Methods

Patients with quantitative bacterial cultures obtained by bronchoalveolar lavage or tracheal aspirate either before (January-March 2021, preintervention period) or after (January-March 2022, postintervention period) implementation of the PNA panel were randomly screened until 25 patients per study month (75 in each cohort) who met the study criteria were included. Antibiotic use from the day of culture collection through day 5 was compared.

Results

The primary outcome of median time to first antibiotic change based on microbiologic data was 50 hours before the intervention versus 21 hours after the intervention (P = .0006). Also, 56 postintervention regimens (75%) were eligible for change based on PNA panel results; actual change occurred in 30 regimens (54%). Median antibiotic days of therapy (DOTs) were 8 before the intervention versus 6 after the intervention (P = .07). For the patients with antibiotic changes made based on PNA panel results, the median time to first antibiotic change was 10 hours. For patients who were initially on inadequate therapy, time to adequate therapy was 67 hours before the intervention versus 37 hours after the intervention (P = .27).

Conclusions

The PNA panel was associated with decreased time to first antibiotic change and fewer antibiotic DOTs. Its impact may have been larger if a higher percentage of potential antibiotic changes had been implemented. The PNA panel is a promising tool to enhance antibiotic stewardship.

Examining the clinical impact of rapid multiplex polymerase chain reaction-based diagnostic testing for bloodstream infections in a national cohort of the Veterans Health Administration

STUDY OBJECTIVE

Bloodstream infections (BSIs) are a significant cause of mortality. Use of a rapid multiplex polymerase chain reaction-based blood culture identification panel (BCID) may improve antimicrobial utilization and clinical outcomes by shortening the time to appropriate therapy and de-escalating antibiotics among patients on overly broad-spectrum empiric therapy. The effect of BCID on clinical outcomes across varying institutional antimicrobial stewardship program (ASP) practices is unclear. This study evaluated clinical outcomes associated with the "real-world" implementation of BCID in a national health system with varying ASP practices.

DESIGN

National, multicenter, retrospective, pre-post quasi-experimental study of hospitalized patients admitted from 2015 to 2020 to VHA facilities, which introduced the BCID for ≥1 year.

SETTING

United States Veterans Health Administration (VHA) hospitals with BCID.

PATIENTS

Hospitalized VHA patients with ≥1 blood culture positive for bacteria featured on the BCID panel.

INTERVENTION

Comparison of outcomes between the pre- and post-BCID implementation groups.

MEASUREMENTS

Outcomes evaluated included early antimicrobial de-escalation within 48 h, defined as reduction in antimicrobial spectrum scores, time to appropriate therapy, and 30-day mortality.

MAIN RESULTS

A total of 4138 patients (pre-BCID, n = 2100; post-BCID, n = 2038) met the study criteria. Implementation of BCID was associated with significant improvements in early antimicrobial de-escalation (34.6%: pre-BCID vs. 38.1%: post-BCID; p = 0.022), which persisted after adjusting for other covariates (adjusted risk ratio [aRR], 1.11; 95% confidence interval [CI], 1.02-1.20; p = 0.011). Median time to appropriate therapy was shorter in the post-BCID implementation group relative to the pre-BCID group (9 h: pre-BCID vs. 8 h: post-BCID, respectively, p = 0.005), and a greater percentage of patients received early appropriate antimicrobial therapy within 48 h in the post-BCID implementation group (91.7%: pre-BCID vs. 93.8%: post-BCID; p = 0.008). In the multivariable regression analysis, BCID implementation was significantly associated with a higher likelihood of appropriate therapy within 48 h (aRR, 1.02; 95% CI, 1.01-1.08; p = 0.020). There was no difference in 30-day mortality between groups overall (12.6% pre-BCID vs. 11.2% post-BCID; p = 0.211).

CONCLUSIONS

In a "real-world" clinical setting, the implementation of BCID was associated with clinical improvements in antimicrobial utilization. The BCID platform may serve as a useful adjunct for BSI management in facilities with ASP.