Bacteraemia in emergency departments: effective antibiotic reassessment is associated with a better outcome

Impact of Implementing an Antimicrobial Stewardship Program for Optimizing Antibiotic Treatment in Gram-negative Bacilli Bacteremia

BACKGROUND

Antibiotic Stewardship Programs (ASP) have improved empirical and directed antibiotic treatment in Gram-negative Bacilli (GNB) bloodstream infections. A decrease in mortality, readmission, and length of hospitalization has been reported.

MATERIALS AND METHODS

A pre-post-quasi-experimental study was conducted between November and April 2015-2016 (pre-intervention period), 2016-2017, 2017-2018, and 2018-2019 (post-intervention periods), to analyse the impact of ASP on empirical, directed, and entire treatment optimization, as well as mortality, readmission, and length of hospitalization, in hospitalized patients with Gram-negative bacilli (GNB) bloodstream infections.

RESULTS

One hundred seventy-four patients were included (41 in the pre-intervention group, 38 in the first-year post-intervention group, 50 in the second-year post-intervention group, and 45 in the third-year post-intervention group). There was a significant improvement in directed treatment optimization (43.9% in the pre-intervention group, 68.4% in the first-year post-intervention group, 74% in the second-year post-intervention group, and 88.9% in the third-year post-intervention group, P <0.001), as well as in entire treatment optimization (19.5%, 34.2%, 40.0%, and 46.7%, respectively, P=0.013), with increased optimal directed (adjusted odds ratio [aOR], 3.71; 95% confidence interval [CI], 1.60-8.58) and entire treatment (aOR, 3.31; 95% CI, 1.27-8.58). Although a tendency toward improvement was observed in empirical treatment after ASP implementation, it did not reach statistical significance (41.5% vs. 57.9%, P=0.065). No changes in mortality, readmission, or length of hospitalization were detected.

CONCLUSION

ASP implementation improved both directed and entire treatment optimization in patients with GNB bloodstream infections over time. Nevertheless, no improvement was found in clinical outcomes such as mortality, readmission, or length of hospitalization.

Diagnostic uncertainty in infectious diseases: Advocacy for a nosological framework

Diagnostic uncertainty (DU) is frequent in infectious diseases (ID), being recorded in 10% to over 50% of patients. Herein, we show that in several fields of clinical practice, high rates of DU are constant over time. DUs are not taken into account in guidelines, as therapeutic propositions are based on an established diagnosis. Moreover, while other guidelines underline the need for rapid broad-spectrum antibiotic therapy for patients with sepsis, many clinical conditions mimic sepsis and lead to unnecessary antibiotic therapy. Considering DU, many studies have been carried out to look for relevant biomarkers of infections, which also attest to non-infectious diseases mimicking infections. Therefore, diagnosis is often primarily a hypothesis, and empirical antibiotic therapy should be reassessed when microbiological data are available. However, other than for urinary tract infections or unexpected primary bacteremia, the high frequency of sterile microbiological samples implies that DU remains central in follow-up, which does not facilitate clinical management or antibiotic optimization. The main way to resolve the therapeutic challenge of DU could be to precisely describe the latter through a consensual definition that would facilitate consideration of DU and its mandatory therapeutic implications. A consensual definition of DU would also clarify responsibility and accountability for physicians in the antimicrobial approval process and l provide an opportunity to instruct their students in this large field of medical practices and to productively conduct relevant research.

Analytical Performance and Potential Clinical Utility of EUCAST Rapid Antimicrobial Susceptibility Testing in Blood Cultures after Four Hours of Incubation

EUCAST rapid antimicrobial susceptibility testing (RAST) provides antibiotic susceptibility results after 4 to 8 h of incubation. This study assessed the diagnostic performance and clinical usefulness of EUCAST RAST after 4 h. This was a retrospective clinical study performed on blood cultures with Escherichia coli and Klebsiella pneumoniae complex (K. pneumoniae and Klebsiella variicola) at Karolinska University Laboratory (Stockholm, Sweden). The rate of categorized RAST results and the categorical agreement (CA) of RAST with the standard EUCAST 16-to-20-h disk diffusion (DD) method for piperacillin-tazobactam, cefotaxime, ceftazidime, meropenem, and ciprofloxacin were analyzed, as well as the utility of RAST for adjusting the empirical antibiotic therapy (EAT) and the combination of RAST with a lateral flow assay (LFA) for extended-spectrum β-lactamase (ESBL) detection. A total of 530 E. coli and 112 K. pneumoniae complex strains were analyzed, generating 2,641 and 558 readable RAST zones, respectively. RAST results categorized according to antimicrobial sensitivity/resistance (S/R) were obtained for 83.1% (2,194/2,641) and 87.5% (488/558) of E. coli and K. pneumoniae complex strains, respectively. The RAST result categorization to S/R for piperacillin-tazobactam was poor (37.2% for E. coli and 66.1% for K. pneumoniae complex). CA with the standard DD method was over 97% for all tested antibiotics. Using RAST, we detected 15/26 and 1/10 of the E. coli and K. pneumoniae complex strains that were resistant to the EAT. For patients treated with cefotaxime, RAST was used to detect 13/14 cefotaxime-resistant E. coli strains and 1/1 cefotaxime-resistant K. pneumoniae complex strain. ESBL positivity was reported the same day as blood culture positivity with RAST and LFA. EUCAST RAST provides accurate and clinically relevant susceptibility results after 4 h of incubation and can accelerate the assessment of resistance patterns. IMPORTANCE Early effective antimicrobial treatment has been shown to be crucial for improving the outcome of bloodstream infections (BSI) and sepsis. In combination with the rise of antibiotic resistance, this calls for accelerated methods for antibiotic susceptibility testing (AST) for effective treatment of BSI. This study assesses EUCAST RAST, an AST method that yields results in 4, 6, or 8 h after blood culture positivity. We analyzed a high number of clinical samples of Escherichia coli and Klebsiella pneumoniae complex strains and confirm that the method delivers reliable results after 4 h of incubation for the relevant antibiotics for treating E. coli and K. pneumoniae complex bacteremia. Furthermore, we conclude that it is an important tool for antibiotic treatment decision-making and early detection of ESBL-producing isolates.

Epidemiology and outcome of occult bacteremia in patients discharged from emergency departments or ambulatory units: one-year study

Microbiological diagnosis of bloodstream infection (BSI) is made several hours after blood culture sampling. This delay could be critical in ambulatory clinics, emergency departments, and hospital day care units, as the patient may be discharged prior to blood culture positivity. Our aim was to evaluate the clinical outcome (including the number of readmissions) of patients diagnosed with BSI after discharge. We prospectively included all adult patients with positive blood culture for BSI that was confirmed after discharge from our center (Grenoble-Alpes University Hospital) in 2016. Patients were contacted about their blood culture results, and their clinical status was controlled via an external consultation or their family physician, with hospital readmission if necessary. Clinical outcome, accuracy of initial diagnosis, microbiological epidemiology, and antibiotic prescription were assessed. In 2016, 1433 episodes of positive blood culture were detected in our hospital, with 50 (3.5%) occurring after patient discharge. Clinically relevant bacteria were determined in 32/50 cases (64%), while other positive blood culture results were considered to be contaminants. Clinical reevaluation was performed in 45 patients (90%). The diagnosis was changed during the clinical reassessment of 24/49 patients (49%). Antibiotics were prescribed prior to discharge for 24/50 patients (48%), modified during follow-up for 15/45 (33%), and initiated for 13/45 (29%) at the reevaluation. Overall, 24/45 (53%) patients were readmitted to hospital units after reevaluation. The clinical follow-up of patients with positive blood culture after discharge led to diagnostic changes and hospital readmission in around half of patients.

Simplified therapeutic guidelines: the main tool of antimicrobial stewardship programs associated with optimal antibiotic therapy V3

Hospitals regularly seek to upgrade their antimicrobial stewardship program (ASP). Our aim was to evaluate the impact of simplified therapeutic guidelines (STGs) compared to various established tools for ASP on the rate of optimal antibiotic therapy (OAT) and antibiotic consumption. Audits of antibiotic prescriptions were carried out over a 24-month period. Feedback information led to STGs (e.g., ≤ 15 drugs). The impact of STGs was based on the rate of OAT, defined as a diagnosis of the infectious disease in the patient's medical records associated with the corresponding therapy indicated in the STGs or in other guidelines. STGs were compared to five other means of ASP: internal or national guidelines, audit, information regarding antibiotic consumption and bacterial resistance, and restricted access to targeted antibiotics. Antibiotic consumption was measured in defined daily doses/1000 days of hospital stay, focusing on third-generation cephalosporins (TGC) and fluoroquinolones (FQ). Twenty-six hospitals were audited from April 2017 to June 2019. A total of 1,028 antibiotic prescriptions were analyzed, including 204 (20%) after STG implementation in seven hospitals. In multivariate analysis, OAT (n = 176, 17%) was associated with STGs, AOR 2.21 [1.51-3.22], and with three tools in place, 1.75 [1.24-2.48]. The relative variations of consumption of TGC and FQ for hospitals with or without STGs were - 13.1 vs. + 9.4% and - 18.5 vs. - 2.7%, respectively, from 2018 to 2019. STGs were more likely than other ASP tools to improve the rate of OAT and to reduce the consumption of antibiotics.

Precise magnetic resonance imaging-guided sonodynamic therapy for drug-resistant bacterial deep infection

The precise treatment of drug-resistant deep bacterial infections remains a huge challenge in clinic. Herein, a polymer-peptide-porphyrin conjugate (PPPC), which can be real-time monitored in infectious site, is developed for accurate and deep sonodynamic therapy (SDT) based on "in vivo self-assembly" strategy. The PPPC contains four moieties, i.e., a hyperbranched polymer backbone, a self-assembled peptide linked with an enzyme-cleavable peptide-poly (ethylene glycol) terminal, a bacterial targeting peptide, and a porphyrin sonosensitizer (MnTCPP) segment. Once PPPC nanoparticles reach the infectious area, the protecting PEG layers are removed due to the over-expressed gelatinase, leading to the secondary assembly into large nanoaggregates and resultant enhanced accumulation of sonosensitizer. The nanoaggregates exhibit enhanced interaction with bacterial membrane and decrease the minimum inhibitory concentration (MIC) significantly. Meanwhile, compared with free MnTCPP, the concentration of which can not be accurately quantified, the accumulation amount of MnTCPP in PPPCs at infectious site can be in situ monitored by magnetic resonance imaging (MRI) using T₁ combined with T₂. When the concentration of PPPC-1 reaches MIC, the drug-resistant bacterial infection area is exposed to ultrasound irradiation, causing the precise and efficient elimination of bacteria. Therefore, the MRI-guided SDT system shows extraordinary tissue penetration depth, drug concentration monitoring, morphology-transformation induced accumulation and improved treatment capacity toward drug-resistant bacteria.

Risk Factors for Unnecessary Antibiotic Therapy: A Major Role for Clinical Management

BACKGROUND

Assessment of antimicrobial use places an emphasis on therapeutic aspects of infected patients. Our aim was to determine the risk factors for unnecessary antibiotic therapy (UAT).

METHODS

This was a prospective, multicenter study evaluating all curative antibiotic therapies prescribed over 2 consecutive days through the same electronic medical records. Each item that could participate in these prescriptions was collected from the computerized file (reason for hospitalization, comorbid conditions, suspected or definitive diagnosis of infection, microbial analyses). UAT was defined as the recognition of noninfectious sydromes (NIS), nonbacterial infections, use of redundant antimicrobials, and continuation of empirical broad-spectrum antimicrobials.

RESULTS

Four hundred fifty-three antibiotic therapies were analyzed at 17 institutions. An infectious disease was the reason for hospitalization in 201 cases (44%). An unspecified diagnosis of infection was observed in 104 cases (23%). Microbial samples were taken in 296 cases (65%), allowing isolation of a pathogen in 156 cases (53%). Unspecified diagnosis was associated with the absence of a microbial sample compared to patients with a diagnosis: (56/104 [54%] vs 240/349 [69%]; P = .005). A total of 158 NIS were observed (35%). UAT was observed in 169 cases (37%), due to NIS in 106 cases. In multivariate analysis, the modifiable risk factors for UAT were unspecified diagnosis (adjusted odds ratio [AOR], 1.83; 95% confidence interval [CI], 1.04-3.20) and absence of a blood culture (AOR, 5.26; 95% CI, 2.56-10.00).

CONCLUSIONS

UAT is associated with an unspecified diagnosis and the absence of microbial testing. Antimicrobial stewardship programs should focus on diagnostic difficulties and microbial testing, the latter facilitating antibiotic reassessment and therapeutic interruption.

Identifying targets for antibiotic stewardship interventions through analysis of the antibiotic prescribing process in hospitals - a multicentre observational cohort study

Background

In order to change antibiotic prescribing behaviour, we need to understand the prescribing process. The aim of this study was to identify targets for antibiotic stewardship interventions in hospitals through analysis of the antibiotic prescribing process from admission to discharge across five groups of infectious diseases.

Methods

We conducted a multi-centre, observational cohort study, including patients with lower respiratory tract infections, exacerbation of chronic obstructive pulmonary disease, skin- and soft tissue infections, urinary tract infections or sepsis, admitted to wards of infectious diseases, pulmonary medicine and gastroenterology at three teaching hospitals in Western Norway. Data was collected over a 5-month period and included antibiotics prescribed and administered during admission, antibiotics prescribed at discharge, length of antibiotic therapy, indication for treatment and discharge diagnoses, estimated glomerular filtration rate (eGFR) on admission, antibiotic allergies, place of initiation of therapy, admittance from an institution, patient demographics and outcome data. Primary outcome measure was antibiotic use throughout the hospital stay, analysed by WHO AWaRe-categories and adherence to guideline. Secondary outcome measures were a) antibiotic prescribing patterns by groups of diagnoses, which were analysed using descriptive statistics and b) non-adherence to the national antibiotic guidelines, analysed using multivariate logistic regression.

Results

Through analysis of 1235 patient admissions, we identified five key targets for antibiotic stewardship interventions in our population of hospital inpatients; 1) adherence to guideline on initiation of treatment, as this increases the use of WHO Access-group antibiotics, 2) antibiotic prescribing in the emergency room (ER), as 83.6% of antibiotic therapy was initiated there, 3) understanding prescribing for patients admitted from other institutions, as this was significantly associated with non-adherence to guideline (OR = 1.44 95% CI 1.04, 2.00), 4) understanding cultural and contextual drives of antibiotic prescribing, as non-adherent prescribing differed significantly between the sites of initiation of therapy (between hospitals and ER versus ward) and 5) length of therapy, as days of antibiotic therapy was similar across a wide range of diagnoses and with prolonged therapy after discharge.

Conclusions

Analysing the process of antibiotic prescribing in hospitals with patient-level data identified important targets for antibiotic stewardship interventions in hospitals.

Urinary tract infection and antibiotic use around ureteral stent insertion for urolithiasis

Urolithiasis is the main indication for a ureteral JJ stent. Our aim was to determine the incidence of urinary tract infections (UTIs) after a JJ stent for urolithiasis, with an emphasis on antibiotic use. Prospective, multicenter, cohort study over a 4-month period including all of the patients with urolithiasis requiring JJ stent insertion. The clinical and microbiological data and therapeutic information were recorded until removal of the JJ stent. Two hundred twenty-three patients at five French private hospitals were included. A urine culture was performed for 187 patients (84%) prior to insertion of a JJ stent, 36 (19%) of which were positive. One hundred thirty patients (58%) received an antibiotic therapy during surgery: 74 (33%) prophylaxis and 56 (25%) empirical antibiotic therapy, comprising 17 different regimens. The rate of prophylaxis varied according to the center, from 0 to 70%. A total of 208 patients were followed-up until removal of the first stent. The rate of UTIs was 6.3% (13/208); 8.1% of the patients who did not receive a prophylaxis had a UTI versus 1.4% of those who did receive a prophylaxis (p = 0.057). Seven empirical antibiotic regimens were used to treat these 13 patients. Another large panel of antibiotic prescriptions was observed at the time of JJ stent removal. The incidence of a UTI after JJ stent insertion for urolithiasis was 6.3%, in part due to a lack of prophylaxis. An unwarranted diversity of antibiotic use was observed at each step of care.

Antibiotic guidelines coupled with selective reporting of antibiograms

OBJECTIVES

We reported the impact of internal guidelines coupled with selective reporting of antibiotic susceptibility tests (srAST) on antibiotic adequacy in healthcare facilities.

METHODS

This prospective study involved clinicians from three clinics with medical and surgical activities employing a full-time infectious disease (ID) specialist. Internal guidelines were updated in 2016. The clinics were working with the same laboratory, which delivered the srAST introduced in March 2017. Two weeks per month over a 6-month period, all isolated bacterial specimens, empirical antibiotic therapies (EAT) and the documented ones were analyzed. An EAT listed in the guidelines and a documented therapy mentioned in the srAST defined their adequacy.

RESULTS

A total of 257 positive bacterial samples were analyzed in 199 patients, for which 106 infections were studied. Of these, 32% were urinary tract infections, 15% were primary bloodstream infections, 11% were bone infections, and 42% were other types of infection. The three main bacteria were Escherichia coli (27%), Staphylococcus aureus (24%), and Enterococcus faecalis (14%). The total number of antibiotic prescriptions was 168, with 75 (45%) EATs and 93 (55%) documented therapies. There were 35/75 (47%) adequate EATs and 86/93 (92%) adequate documented therapies. The ID specialist was not involved in 90/168 (53.5%) prescriptions, of which 43/90 (48%) were adequate, with 21/35 (60%) EATs and 22/86 (25%) documented therapies. There was a statistical correlation between compliance of the EATs with guidelines and of the documented therapy with srAST (p=0.02).

CONCLUSION

Combining internal guidelines and srAST led to a high rate of antibiotic adequacy.

Impact of simplified therapeutic guidelines on antibiotic prescriptions: a prospective multicentre comparative study

OBJECTIVES

We studied the impact of simplified therapeutic guidelines (STGs) associated with accompanied self-antibiotic reassessment (ASAR) on antibiotic use.

METHODS

Prospective antibiotic audits and feedback took place at 15 hospitals for 12 months, allowing STGs with ≤15 drugs to be devised. STGs were explained to prescribers through sessions referred to as ASAR. Optimal therapy was defined by the conjunction of a diagnosis and the drug specified in the STGs. Analysis of consumption focused on critical drugs: amoxicillin/clavulanic acid, third-generation cephalosporins and fluoroquinolones.

RESULTS

We compared prescriptions in five hospitals before (n = 179) and after (n = 168) the implementation of STGs + ASAR. These tools were associated with optimal therapies and amoxicillin/clavulanic acid prescriptions [adjusted odds ratio (AOR) 3.28, 95% CI 1.82-5.92 and 2.18, 95% CI 1.38-3.44, respectively] and fewer prescriptions for urine colonization [AOR 0.20 (95% CI 0.06-0.61)]. Comparison of prescriptions (n = 1221) from 10 departments of three clinics with STGs + ASAR for the first quarters of 2018 and 2019 revealed that the prescriptions by 23 ASAR participants more often complied with STGs than those by 28 other doctors (71% versus 60%, P = 0.003). STGs alone were adopted by 10 clinics; comparing the prescriptions (n = 311) with the 5 clinics with both tools, we observed fewer unnecessary therapies in the latter [AOR 0.52 (95% CI 0.34-0.80)]. The variation in critical antibiotic consumption between 2017 and 2018 was -16% for the 5 clinics with both tools and +20% for the other 10 (P = 0.020).

CONCLUSIONS

STGs + ASAR promote optimal antibiotic therapy and reduce antibiotic use.

Pasteurella bacteraemia: Impact of comorbidities on outcome, based on a case series and literature review

OBJECTIVES

Pasteurella bacteraemia is rare, but has been associated with a high mortality rate. The aim of this study was to estimate the impact of comorbidities on patients with Pasteurella bacteraemia.

METHODS

All cases of Pasteurella bacteraemia in adults treated in our centre between January 2008 and December 2017 were included retrospectively and compared with cases identified in a systematic review of the literature via MEDLINE covering the years 1951-2017. The epidemiological, bacteriological, and clinical data were collected, as well as the instances of death after 30 days.

RESULTS

Twenty cases of Pasteurella bacteraemia identified in our centre and 99 cases from the literature review were included. A major comorbidity was found in 80/119 (67.2%) patients. The death rate at 30 days was 31.1%. The most common comorbidities were cirrhosis, immunosuppressive therapy, and malignant diseases. Age was not associated with mortality. On multivariate analysis, the only factor associated with mortality was a major comorbidity (odds ratio 2.78, 95% confidence interval 1.01-7.70; p = 0.04).

CONCLUSIONS

This study confirms the high mortality rate and highlights the importance of the host background, independent of age, in Pasteurella bacteraemia. Clinicians should be aware of the comorbidities in cases of Pasteurella infection, due to the poor prognosis of bacteraemia.

Early Infectious Disease Consultation Is Associated With Lower Mortality in Patients With Severe Sepsis or Septic Shock Who Complete the 3-Hour Sepsis Treatment Bundle

Objective

Severe sepsis and septic shock (SS/SS) treatment bundles reduce mortality, and early infectious diseases (ID) consultation also improves patient outcomes. We retrospectively examined whether early ID consultation further improves outcomes in Emergency Department (ED) patients with SS/SS who complete the sepsis bundle.

Method

We included 248 adult ED patients with SS/SS who completed the 3-hour bundle. Patients with ID consultation within 12 hours of ED triage (n = 111; early ID) were compared with patients who received standard care (n = 137) for in-hospital mortality, 30-day readmission, length of hospital stay (LOS), and antibiotic management. A competing risk survival analysis model compared risks of in-hospital mortality and discharge alive between groups.

Results

In-hospital mortality was lower in the early ID group unadjusted (24.3% vs 38.0%, P = .02) and adjusted for covariates (odds ratio, 0.47; 95% confidence interval (CI), 0.25–0.89; P = .02). There was no significant difference in 30-day readmission (22.6% vs 23.5%, P = .89) or median LOS (10.2 vs 12.1 days, P = .15) among patients who survived. A trend toward shorter time to antibiotic de-escalation in the early ID group (log-rank test P = .07) was observed. Early ID consultation was protective of in-hospital mortality (adjusted subdistribution hazard ratio (asHR), 0.60; 95% CI 0.36–1.00, P = .0497) and predictive of discharge alive (asHR 1.58, 95% CI, 1.11–2.23; P-value .01) after adjustment.

Conclusions

Among patients receiving the SS/SS bundle, early ID consultation was associated with a 40% risk reduction for in-hospital mortality. The impact of team-based care and de-escalation on SS/SS outcomes warrants further study.