Empiric antimicrobial therapy for bacteremia: get it right from the start or get a call from infectious disease

A Closer Look at the Laboratory Impact of Utilizing ePlex Blood Culture Identification Panels: a Workflow Analysis Using Rapid Molecular Detection for Positive Blood Cultures

Rapid identification of pathogens is critical in bloodstream infections. We evaluated the diagnostic performance of the GenMark Dx ePlex blood culture identification (BCID) panels and the adoption of the ePlex system into the clinical laboratory workflow. Nonduplicate remnant specimens of positive blood cultures were prospectively tested using ePlex panels between January and March 2020. A total of 313 unique positive blood culture specimens were tested. The identified organisms consisted of 98 Gram-negative rods (GNR), 90 Gram-positive cocci (GPC) in clusters, 62 GPC in chains, 21 Gram-positive rods, and 20 yeasts; 22 organisms were off panel. The positive percent agreement was 100% across all organisms tested after discordancy resolution, while the negative percent agreement was 100% across all targets except Corynebacterium spp., where it was 99.7%. The ePlex BCID panels accurately detected 5 pan targets and 42 antimicrobial resistance gene markers, including 31 mecA, 4 vanA, 6 CTX-M, and 1 KPC gene. The median times to result were calculated as 2.5 h for Xpert MRSA/SA in GPC in clusters, 9.5 h for Accelerate Pheno (identification and susceptibility) in GNR, 6 h for peptide nucleic acid fluorescent in situ hybridization [PNA-FISH] in yeasts, 27 h for the latex agglutination test in S. aureus, 29 h for Lancefield serotyping in GPC in chains, and 29 h for Vitek-MS in GNR. In our laboratory, the ePlex panels could substantially reduce the time to result for bloodstream infection (BSI) caused by Streptococcus spp., Enterococcus spp., and Candida spp. The highly accurate ePlex panels can help streamline laboratory efficiency in the blood bench workflow, reducing the time to result for identification of BSI pathogens. IMPORTANCE Sepsis is a leading cause of morbidity and mortality worldwide. Rapid identification of the causative agent is of critical importance for the prompt initiation of the appropriate antibiotic treatment. In this study, we evaluated the diagnostic performance of the GenMark Dx ePlex blood culture identification (BCID) panels and their adoption into the clinical laboratory workflow. We prospectively tested 313 blood culture isolates and found that ePlex BCID panels had a positive percent agreement of 100% across all organisms tested after discordancy resolution. The negative percent agreement was 100% across all targets except Corynebacterium spp., where it was 99.7%. This new rapid technology (turnaround time of ~90 min) can help streamline laboratory efficiency in the blood bench workflow, reducing the time to result for identification of BSI pathogens. Adoption should be individualized based on the needs of the patient population and capabilities of the laboratory.

Selected Biomarkers Correlate with the Origin and Severity of Sepsis

The microbial etiology and source of sepsis influence the inflammatory response. Therefore, the plasma levels of cytokines (IL-6, IL-8, and IL-10), chemokines (CCL2/MCP-1, MIP-1β), heparin-binding protein (HBP), soluble CD14 (sCD14), and cortisol were analyzed in blood from septic patients obtained during the first 96 hours of intensive care unit hospitalization. The etiology was established in 56 out of a total of 62 patients enrolled in the study. Plasma concentrations of MCP-1, sCD14, IL-6, and IL-10 were significantly higher in patients with community-acquired pneumonia (CAP; n = 10) and infective endocarditis (IE; n = 11) compared to those with bacterial meningitis (BM; n = 18). Next, cortisol levels were higher in IE patients than in those with BM and CAP, and at one time point, cortisol was also higher in patients with gram-negative sepsis when compared to those with gram-positive infections. Furthermore, cortisol and MCP-1 levels correlated positively with the daily measured SOFA score. In addition, HBP levels were significantly higher in patients with IE than in those with BM. Our findings suggest that MCP-1, sCD14, IL-6, IL-10, cortisol, and HBP are modulated by the source of sepsis and that elevated MCP-1 and cortisol plasma levels are associated with sepsis-induced organ dysfunction.

Comparison of warfarin therapy clinical outcomes following implementation of an automated mobile phone-based critical laboratory value text alert system

BACKGROUND

Computerized alert and reminder systems have been widely accepted and applied to various patient care settings, with increasing numbers of clinical laboratories communicating critical laboratory test values to professionals via either manual notification or automated alerting systems/computerized reminders. Warfarin, an oral anticoagulant, exhibits narrow therapeutic range between treatment response and adverse events. It requires close monitoring of prothrombin time (PT)/international normalized ratio (INR) to ensure patient safety. This study was aimed to evaluate clinical outcomes of patients on warfarin therapy following implementation of a Personal Handy-phone System-based (PHS) alert system capable of generating and delivering text messages to communicate critical PT/INR laboratory results to practitioners' mobile phones in a large tertiary teaching hospital.

METHODS

A retrospective analysis was performed comparing patient clinical outcomes and physician prescribing behavior following conversion from a manual laboratory result alert system to an automated system. Clinical outcomes and practitioner responses to both alert systems were compared. Complications to warfarin therapy, warfarin utilization, and PT/INR results were evaluated for both systems, as well as clinician time to read alert messages, time to warfarin therapy modification, and monitoring frequency.

RESULTS

No significant differences were detected in major hemorrhage and thromboembolism, warfarin prescribing patterns, PT/INR results, warfarin therapy modification, or monitoring frequency following implementation of the PHS text alert system. In both study periods, approximately 80% of critical results led to warfarin discontinuation or dose reduction. Senior physicians' follow-up response time to critical results was significantly decreased in the PHS alert study period (46.3% responded within 1 day) compared to the manual notification study period (24.7%; P = 0.015). No difference in follow-up response time was detected for junior physicians.

CONCLUSIONS

Implementation of an automated PHS-based text alert system did not adversely impact clinical or safety outcomes of patients on warfarin therapy. Approximately 80% immediate recognition of text alerts was achieved. The potential benefits of an automated PHS alert for senior physicians were demonstrated.

Improving antibiotic use in the hospital: Focusing on positive blood cultures is an effective option

OBJECTIVES

The unsolicited and systematic evaluation of positive blood cultures (pBC) after laboratory report by a single infectious disease specialist (IDS) was evaluated during one year, using a computer-generated alert by the laboratory. The main objectives of IDS counselling were to improve antibiotic use for bloodstream infection (i.e., initiating or modifying therapy) and to stop unjustified therapy for contaminated pBC.

METHODS

During the first part of the study (4 months), all pBC in patients from ICUs, medical and surgical wards were analyzed. After an interim analysis, only pBC from medical and surgical wards were evaluated during the second part (8 months).

RESULTS

Overall, 1090 episodes of pBC (representing 866 patients) were evaluated and classified as bloodstream infection (65.5%), contamination (29%) or undetermined (5.5%). Forty-three percent of episodes prompted IDS counselling, including initiation (5%), modification (27.5%), withdrawal (3.5%) and diagnosis workup (5%). Restricting the evaluation to medical and surgical wards increased the rate of counselling (61.2% vs. 27.7%, P<0.0001), notably for de-escalating (20% vs. 8%, P<0.0001), initiating (9% vs. 2%, P<0.0001), oral switch (6% vs. 2%, P<0.0001), withdrawing (5% vs. 2%, P=0.002) or reducing the duration of therapy (5% vs. 2%, P=0.002).

DISCUSSION AND CONCLUSIONS

In complement to the laboratory report, a computer-generated alert used by the IDS was useful for the management of pBC in hospital. The impact of IDS counselling was more effective when the evaluation was restricted to medical and surgical wards.

Effects of a pharmacist-to-dose computerized request on promptness of antimicrobial therapy

OBJECTIVES

To examine the effects of computerized requests for pharmacist-to-dose (PTD), an advanced clinical decision support tool for dosing guidance, on antimicrobial therapy with vancomycin and aminoglycosides, describe PTD request utilization, and identify factors that may prolong this process.

DESIGN

A retrospective review was conducted of patients hospitalized from Jan 2004 to Jun 2006 with suspected pneumonia who received vancomycin, tobramycin, or gentamicin via PTD (study) or routine provider order entry (control).

MEASUREMENTS

The primary endpoint was time to pharmacist completion of PTD request. Secondary data points included medication turn-around times for first doses of vancomycin or aminoglycosides and for first doses of any antibiotic, dose adjustment for renal dysfunction, medication errors, and time of order entry. Multivariate analysis was conducted to identify predictors of total time to pharmacist verification and time to administration of first doses of vancomycin or aminoglycosides.

RESULTS

Median time for pharmacist completion of PTD requests was 29 minutes. Delays were noted in the study group (n = 49) by comparison with the control group (n = 48) for median time to first dose of vancomycin or aminoglycoside (185 vs. 138 min, p = 0.45) and for any antibiotic (134 vs. 118 min, p = 0.42), respectively. Fewer medication errors were reported in the study group (5 vs. 18 errors, p = 0.002). In a multivariate model, PTD was not significantly predictive of time to pharmacy verification or medication turn-around time.

CONCLUSIONS

Pharmacists completed pharmacist-to-dose consultations for dosing guidance of vancomycin and aminoglycosides within a median of 30 minutes. Implementation of a computerized request for clinical pharmacists to provide medication-related clinical decision support increased medication turn-around time of vancomycin and aminoglycosides and reduced medication errors. Consultation of clinical pharmacists by computerized request for initial antibiotic dosing of medications with narrow therapeutic windows is an option for medication-related clinical decision support but providers should be aware that consultation may delay medication turn-around time.