Duration of Antimicrobial Treatment for Bacteremia in Canadian Critically Ill Patients

Challenging management dogma where evidence is non-existent, weak, or outdated: part II

Many dogmas influence daily clinical practice, and critical care medicine is no exception. We previously highlighted the weak, questionable, and often contrary evidence base underpinning four established medical managements-loop diuretics for acute heart failure, routine use of heparin thromboprophylaxis, rate of sodium correction for hyponatremia, and 'every hour counts' for treating bacterial meningitis. We now provide four further examples in this "Dogma II" piece (a week's course of antibiotics, diabetic ketoacidosis algorithms, sodium bicarbonate to improve ventricular contractility during severe metabolic acidosis, and phosphate replacement for hypophosphatemia) where routine practice warrants re-appraisal.

Antibiotic duration and route for treatment of adults with uncomplicated streptococcal bloodstream infections: a retrospective study in a large healthcare system

Data guiding the duration and route of streptococcal bloodstream infection (BSI) treatment are lacking. We conducted a retrospective cohort study of adults hospitalized with uncomplicated streptococcal BSI in a large integrated healthcare system from 2013 to 2020. The exposures of interest were antibiotic duration (5-10 days vs. 11-15 days) and antibiotic route (oral switch vs. entirely intravenous). The primary outcome was a composite 90-day outcome comprised of all-cause mortality, recurrent streptococcal BSI, or readmission. We performed non-inferiority analyses for each exposure. Separate multivariable Cox proportional hazards regression models were constructed for each exposure. The antibiotic duration analysis included 1,407 patients (5-10 days, n = 246; 11-15 days, n = 1,161). We found that 5-10-day courses were non-inferior to 11-15-day courses (P = 0.047). The antibiotic route analysis included 1,461 patients (oral switch, n = 1,112; entirely intravenous, n = 349). Oral step-down therapy did not meet the criteria for non-inferiority (P = 0.06). In the adjusted models, no significant difference was found in the primary outcome rate by antibiotic duration or antibiotic route at discharge. We found that 5-10-day courses were non-inferior to longer courses, and thus may be a safe and effective treatment option in the treatment of uncomplicated streptococcal bacteremia. Randomized controlled trials are needed to confirm the equivalent outcomes with shorter regimens and to definitively determine the optimal antibiotic route on discharge.

Awareness Regarding Antimicrobial Resistance and Antibiotic Prescribing Behavior among Physicians: Results from a Nationwide Cross-Sectional Survey in India

(1) Background: Understanding the physicians' knowledge, attitudes, and antimicrobial prescribing behavior is a crucial step towards designing strategies for the optimal use of these agents. (2) Methods: A cross-sectional online survey was conducted among clinicians across India between May and July 2022 using a self-administered questionnaire in English comprising 35 questions pertaining to demographic characteristics, knowledge, attitude, and practices domains. (3) Results: A total of 544 responses were received from 710 physicians contacted. Sixty percent of participants were males, with mean age of 34.7 years. Mean ± Standard Deviation scores for knowledge, attitude, and practices domains were 8 ± 1.6, 20.2 ± 3.5, and 15.3 ± 2.1, respectively. Higher scores were associated with basic [odds ratio (95% Confidence Interval), p value: 2.95 (1.21, 7.2), 0.02], medical and allied sciences [2.71 (1.09, 6.67), 0.03], and central zone [3.75 (1.39, 10.12), 0.009]. A substantial proportion of dissatisfactory responses were found regarding hospital antibiograms, antibiotics effective against anaerobes, WHO AWaRe (access, watch, and reserve) classification of antibiotics, and the role of infection prevention and control (IPC) measures in the containment of antimicrobial resistance (AMR). (4) Conclusions: There is a need to sensitize and educate clinicians on various issues related to antimicrobial use, such as antibiograms, double anaerobic cover, IPC practices, and guideline-based recommendations, to curb the AMR pandemic.

Short versus long course of colistin treatment for carbapenem-resistant A. baumannii in critically ill patients: A propensity score matching study

BACKGROUND

Carbapenem-resistant Acinetobacter baumannii (CRAB) is one of the most commonly found nosocomial infections in critically ill patients. However, the appropriate treatment period for a specific group of critically ill patients with CRAB infection is currently being debated. Therefore, our study aimed to evaluate the optimal courses of therapy for critically ill patients with CRAB infection by comparing the outcomes of colistin therapy of short duration (< 14 days) versus long duration (≥ 14 days).

METHODS

A retrospective cohort study was conducted at Nakornping Hospital on critically ill patients with CRAB infection who received either a short or long course of colistin treatment between 2015 and 2022. The primary outcome was the 30-day mortality rate while secondary outcomes were clinical response, microbiological response, and nephrotoxicity. Propensity score matching with a 1: 1 ratio was performed to reduce potential biases. Furthermore, a logistic regression model was used to estimate the odds ratio (OR).

RESULTS

A total of 374 patients met the inclusion criteria. Two hundred and forty-eight patients were recruited after utilizing propensity scores to match patients at a 1: 1 ratio. The results from the propensity score matching analysis demonstrated that the long-course therapy group had a lower 30-day mortality rate compared to the short-course therapy group (adjusted OR (aOR) = 0.46, 95% CI: 0.26-0.83, p = 0.009). The clinical response and microbiological response rates were higher in patients who received the long course of colistin therapy compared to those receiving the short course (aOR = 3.24, 95% CI: 1.78-5.92, p = 0.001; aOR = 3.01, 95% CI: 1.63-5.57, p = 0.001). There was no significant different in the occurrence of nephrotoxicity (aOR = 1.28, 95% CI: 0.74-2.22, p = 0.368) between the two treatment groups.

CONCLUSION

A long course of colistin therapy resulted in a lower 30-day mortality rate in critically ill patients, and better clinical and microbiological outcomes, but similar nephrotoxicity as compared to a short course of colistin therapy. Therefore, a specific subset of critically ill patients who had CRAB infection needed to be considered for a long course of therapy.

The effect of duration of antimicrobial treatment for bacteremia in critically ill patients on in-hospital mortality - Retrospective double center analysis

PURPOSE

Excessive duration of antibiotic treatment is a major factor for inappropriate antibiotic consumption. Although in some instances shorter antibiotic courses are as efficient as longer ones, no specific recommendations as to the duration of antimicrobial treatment for bloodstream infections currently exist. In the present study, we investigated the effect of antibiotic treatment duration on in-hospital mortality using retrospective data from two cohorts that included patients with bacteremia at two Swiss tertiary Intensive Care Units (ICUs).

MATERIALS AND METHODS

Overall 8227 consecutive patients requiring ICU admission were screened for bacteremia between 01/2012-12/2013 in Lausanne and between 07/2016-05/2017 in Bern. Patients with an infection known to require prolonged treatment or having single positive blood culture with common contaminant pathogens were excluded. The primary outcome of interest was the time from start of antimicrobial treatment to in-hospital death or hospital discharge, whichever comes first. The predictor of interest was adequate antimicrobial treatment duration, further divided into shorter (≤10 days) and longer (>10 days) durations. A time-dependent Cox model and a cloning approach were used to address immortality bias. The secondary outcomes were the median duration of antimicrobial treatment for patients with bacteremia overall and stratified by underlying infectious syndrome and pathogens in the case of secondary bacteremia.

RESULTS

Out of the 707 patients with positive blood cultures, 382 were included into the primary analysis. Median duration of antibiotic therapy was 14 days (IQR, 7-20). Most bacteremia (84%) were monomicrobial; 18% of all episodes were primary bacteremia. Respiratory (28%), intra-abdominal (23%) and catheter infections (17%) were the most common sources of secondary bacteremia. Using methods to mitigate the risk of confounding associated with antibiotic treatment durations, shorter versus longer treatment groups showed no differences in in-hospital survival (time-dependent Cox-model: HR 1.5, 95% CI (0.8, 2.7), p = 0.20; Cloning approach: HR 1.0, 95% CI (0.7,1.5) p = 0.83). Sensitivity analyses showed that the interpretation did not change when using a 7 days cut-off.

CONCLUSIONS

In this restrospective study, we found no evidence for a survival benefit of longer (>10 days) versus shorter treatment course in ICU patients with bacteremia.

TRIAL REGISTRATION

The study was retrospectively registered on clinicatrials.gov (NCT05236283), 11 February 2022. The respective cantonal ethics commission (KEK Bern # 2021-02302) has approved the study.

Use of Fluoroquinolones or Sulfamethoxazole-Trimethoprim Compared to Β-Lactams for Oral Step-Down Therapy in Hospitalized Patients With Uncomplicated Enterobacterales Bacteremia

BACKGROUND

Antibiotic therapy for uncomplicated Enterobacterales bacteremia from a urinary source has traditionally consisted of fluoroquinolones (FQs) and sulfamethoxazole-trimethoprim (SXT). However, adverse events associated with FQs and emerging antimicrobial resistance have led to alternative agents, specifically oral Β-lactams (OBLs), being utilized despite concern of subtherapeutic serum concentrations related to their low relative bioavailability.

OBJECTIVE

To compare efficacy of antibiotic therapies with bioavailability differences in patients with uncomplicated bacteremia from a urinary source.

METHODS

This was a retrospective study comparing clinical efficacy in hospitalized adult patients receiving OBL or FQ/SXT. Patients were required to receive at least 48 hours of appropriate intravenous antibiotic therapy and at least one dose of oral therapy. The primary outcome was all-cause hospital readmission within 30 days of discharge. Secondary outcomes included readmission with recurrent infectious etiology and readmission due to Clostridioides difficile infection.

RESULTS

Of 210 eligible patients, 91 received FQ/SXT and 119 received OBL. There was no difference between the groups in all-cause hospital readmission (FQ/SXT: 16.5%; OBL: 14.3%) (P = 0.660 [95% confidence interval, CI = -0.076, 0.120]) or readmission with recurrent bacteremia (FQ/SXT: 0%; OBL: 3.4%) (P = 0.135). There was a significant difference in repeat hospital admission with recurrent urinary tract infection (UTI) (FQ/SXT: 0%, OBL: 5.0%) (P = 0.037).

CONCLUSION AND RELEVANCE

OBLs appear to be non-inferior to FQ/SXT in the rate of all-cause hospital readmission within 30 days. However, OBLs may be associated with increased readmissions with recurrent UTI.

Antibiotic treatment duration for bloodstream infections in critically ill children—A survey of pediatric infectious diseases and critical care clinicians for clinical equipoise

Objective

To describe antibiotic treatment durations that pediatric infectious diseases (ID) and critical care clinicians usually recommend for bloodstream infections in critically ill children.

Design

Anonymous, online practice survey using five common pediatric-based case scenarios of bloodstream infections.

Setting

Pediatric intensive care units in Canada, Australia and New Zealand.

Participants

Pediatric intensivists, nurse practitioners, ID physicians and pharmacists.

Main outcome measures

Recommended treatment durations for common infectious syndromes associated with bloodstream infections and willingness to enrol patients into a trial to study treatment duration.

Results

Among 136 survey respondents, most recommended at least 10 days antibiotics for bloodstream infections associated with: pneumonia (65%), skin/soft tissue (74%), urinary tract (64%) and intra-abdominal infections (drained: 90%; undrained: 99%). For central vascular catheter-associated infections without catheter removal, over 90% clinicians recommended at least 10 days antibiotics, except for infections caused by coagulase negative staphylococci (79%). Recommendations for at least 10 days antibiotics were less common with catheter removal. In multivariable linear regression analyses, lack of source control was significantly associated with longer treatment durations (+5.2 days [95% CI: 4.4–6.1 days] for intra-abdominal infections and +4.1 days [95% CI: 3.8–4.4 days] for central vascular catheter-associated infections). Most clinicians (73–95%, depending on the source of bloodstream infection) would be willing to enrol patients into a trial of shorter versus longer antibiotic treatment duration.

Conclusions

The majority of clinicians currently recommend at least 10 days of antibiotics for most scenarios of bloodstream infections in critically ill children. There is practice heterogeneity in self-reported treatment duration recommendations among clinicians. Treatment durations were similar across different infectious syndromes. Under appropriate clinical conditions, most clinicians would be willing to enrol patients into a trial of shorter versus longer treatment for common syndromes associated with bloodstream infections.

Antimicrobial treatment duration for uncomplicated bloodstream infections in critically ill children: a multicentre observational study

Background

Bloodstream infections (BSIs) cause significant morbidity and mortality in critically ill children but treatment duration is understudied. We describe the durations of antimicrobial treatment that critically ill children receive and explore factors associated with treatment duration.

Methods

We conducted a retrospective observational cohort study in six pediatric intensive care units (PICUs) across Canada. Associations between treatment duration and patient-, infection- and pathogen-related characteristics were explored using multivariable regression analyses.

Results

Among 187 critically ill children with BSIs, the median duration of antimicrobial treatment was 15 (IQR 11–25) days. Median treatment durations were longer than two weeks for all subjects with known sources of infection: catheter-related 16 (IQR 11–24), respiratory 15 (IQR 11–26), intra-abdominal 20 (IQR 14–26), skin/soft tissue 17 (IQR 15–33), urinary 17 (IQR 15–35), central nervous system 33 (IQR 15–46) and other sources 29.5 (IQR 15–55) days. When sources of infection were unclear, the median duration was 13 (IQR 10–16) days. Treatment durations varied widely within and across PICUs. In multivariable linear regression, longer treatment durations were associated with severity of illness (+ 0.4 days longer [95% confidence interval (CI), 0.1 to 0.7, p = 0.007] per unit increase in PRISM-IV) and central nervous system infection (+ 17 days [95% CI, 6.7 to 27.4], p = 0.001). Age and pathogen type were not associated with treatment duration.

Conclusions

Most critically ill children with BSIs received at least two weeks of antimicrobial treatment. Further study is needed to determine whether shorter duration therapy would be effective for selected critically ill children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03219-z.

How Antibiotics Stewardship Can Be Safely Implemented in Patients with Septic Shock?

In critically ill patients with sepsis and septic shock, the need for prompt and adequate antibiotic therapy is balanced by the risk of excessive antibiotic exposure that leads to emergence of multidrug-resistant pathogens. As such, antibiotic stewardship programs propose a set of operating rules from antibiotic treatment initiation to de-escalation and finally cessation. In this review, we will describe the rationale for early antibiotic treatment in septic patients, how to optimize initial antibiotic treatment, rules for early treatment discontinuation in pathogen-negative sepsis, and optimal duration of antimicrobial therapy.

Impact of a restrictive antibiotic policy on the acquisition of extended-spectrum beta-lactamase-producing Enterobacteriaceae in an endemic region: a before-and-after, propensity-matched cohort study in a Caribbean intensive care unit

BACKGROUND

High-level antibiotic consumption plays a critical role in the selection and spread of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) in the ICU. Implementation of a stewardship program including a restrictive antibiotic policy was evaluated with respect to ESBL-E acquisition (carriage and infection).

METHODS

We implemented a 2-year, before-and-after intervention study including all consecutive adult patients admitted for > 48 h in the medical-surgical 26-bed ICU of Guadeloupe University Hospital (French West Indies). A conventional strategy period (CSP) including a broad-spectrum antibiotic as initial empirical treatment, followed by de-escalation (period before), was compared to a restrictive strategy period (RSP) limiting broad-spectrum antibiotics and shortening their duration. Antibiotic therapy was delayed and initiated only after microbiological identification, except for septic shock, severe acute respiratory distress syndrome and meningitis (period after). A multivariate Cox proportional hazard regression model adjusted on propensity score values was performed. The main outcome was the median time of being ESBL-E-free in the ICU. Secondary outcome included all-cause ICU mortality.

RESULTS

The study included 1541 patients: 738 in the CSP and 803 in the RSP. During the RSP, less patients were treated with antibiotics (46.8% vs. 57.9%; p < 0.01), treatment duration was shorter (5 vs. 6 days; p < 0.01), and administration of antibiotics targeting anaerobic pathogens significantly decreased (65.3% vs. 33.5%; p < 0.01) compared to the CSP. The incidence of ICU-acquired ESBL-E was lower (12.1% vs. 19%; p < 0.01) during the RSP. The median time of being ESBL-E-free was 22 days (95% CI 16-NA) in the RSP and 18 days (95% CI 16-21) in the CSP. After propensity score weighting and adjusted analysis, the median time of being ESBL-E-free was independently associated with the RSP (hazard ratio, 0.746 [95% CI 0.575-0.968]; p = 0.02, and hazard ratio 0.751 [95% CI 0.578-0.977]; p = 0.03, respectively). All-cause ICU mortality was lower in the RSP than in the CSP (22.5% vs. 28.6%; p < 0.01).

CONCLUSIONS

Implementation of a program including a restrictive antibiotic strategy is feasible and is associated with less ESBL-E acquisition in the ICU without any worsening of patient outcome.

Antibiotic treatment of common infections: more evidence to support shorter durations

PURPOSE OF REVIEW

Although there is increasing recognition of the link between antibiotic overuse and antimicrobial resistance, clinician prescribing is often unnecessarily long and motivated by fear of clinical relapse. High-quality evidence supporting shorter treatment durations is needed to give clinicians confidence to change prescribing habits. Here we summarize recent randomized controlled trials investigating antibiotic short courses for common infections in adult patients.

RECENT FINDINGS

Randomized trials in the last five years have demonstrated noninferiority of short-course therapy for a range of conditions including community acquired pneumonia, intraabdominal sepsis, gram-negative bacteraemia and vertebral osteomyelitis.

SUMMARY

Treatment durations for many common infections have been based on expert opinion rather than randomized trials. There is now evidence to support shorter courses of antibiotic therapy for many conditions.

Duration of antimicrobial therapy for Gram-negative infections

PURPOSE OF REVIEW

The potential benefits on antimicrobial resistance emergence, incidence of antibiotic-related adverse effects, and health costs have pushed to shorten therapeutic courses for Gram-negative bacilli (GNB) infections. However, the safety of this approach is still under investigation. This review gathers recent contributions to the evaluation of the impact on antimicrobial resistance and clinical outcome of shorter therapeutic courses against GNB infections, and highlights data on the modern approach of adjustable antibiotic duration.

RECENT FINDINGS

Recent advances include data on the safety of 7-day treatment of uncomplicated Enterobacteriaceae bloodstream infections with favorable early 48-h evolution. A promising innovative approach with individualized treatment duration arises, supported by recently published results on GNB bacteremia evaluating fixed antibiotic durations and an adaptive antibiotic duration driven by blood levels of C-reactive protein.

SUMMARY

Recent literature illustrates a strong trend towards shortened antibiotic durations in GNB infections, illustrated by lately published data in GNB bacteremia and ongoing studies in GNB ventilator-associated pneumonia. However, short antibiotic course for specific situations, such as immunodeficiency, drug-resistance, and inadequate source control should be handled with caution because of lack of supportive data.

Effectiveness of Shorter Versus Longer Durations of Therapy for Common Inpatient Infections Associated With Bacteremia: A Multicenter, Propensity-Weighted Cohort Study

BACKGROUND

National guidelines for pneumonia (PNA), urinary tract infection (UTI), and acute bacterial skin and skin structure infection (ABSSSI) do not address treatment duration for infections associated with bacteremia. We evaluated clinical outcomes of patients receiving shorter (5-9 days) versus longer (10-15 days) duration of antibiotics.

METHODS

This was a multicenter retrospective cohort study of inpatients with uncomplicated PNA, UTI, or ABSSSI and associated bacteremia. The primary outcome was clinical failure, a composite of rehospitalization, reinitiation of antibiotics, or all-cause mortality within 30 days of antibiotic completion. Secondary outcomes included individual components of the primary outcome, Clostridioides difficile infection, and antibiotic-related adverse effects necessitating change in therapy. A propensity score-weighted logistic regression model was used to mitigate potential bias associated with nonrandom assignment of treatment duration.

RESULTS

Of 408 patients included, 123 received a shorter treatment duration (median 8 days) and 285 received a longer duration (median 13 days). In the propensity-weighted analysis, the probability of the primary outcome was 13.5% in the shorter group and 11.1% in the longer group (average treatment effect, 2.4%; odds ratio [OR], 1.25; 95% confidence interval [CI], .65-2.40; P = .505). However, shorter courses were associated with higher probability of restarting antibiotics (OR, 1.62; 95% CI, 1.01-2.61; P = .046) and C. difficile infection (OR, 4.01; 95% CI, 2.21-7.59; P < .0001).

CONCLUSIONS

Shorter courses of antibiotic treatment for PNA, UTI, and ABSSSI with bacteremia were not associated with increased overall risk of clinical failure; however, prospective studies are needed to further evaluate the effectiveness of shorter treatment durations.

To give or not to give antibiotics is not the only question

In a 1945 Nobel Lecture, Sir Alexander Fleming warned against the overuse of antibiotics, particularly in response to public pressure. In the subsequent decades, evidence has shown that bacteria can become resistant to almost any available molecule. One key question is how the emergence and dissemination of resistant bacteria or resistance genes can be delayed. Although some clinicians remain sceptical, in this Personal View, we argue that the prescription of fewer antibiotics and shorter treatment duration is just as effective as longer regimens that remain the current guideline. Additionally, we discuss the fact that shorter antibiotic treatments exert less selective pressure on microorganisms, preventing the development of resistance. By contrast, longer treatments associated with a strong selective pressure favour the emergence of resistant clones within commensal organisms. We also emphasise that more studies are needed to identify the optimal duration of antibiotic therapy for common infections, which is important for making changes to the current guidelines, and to identify clinical biomarkers to guide antibiotic treatment in both hospital and ambulatory settings.

The Changing Landscape of Uncomplicated Gram-Negative Bacteremia: A Narrative Review to Guide Inpatient Management

Gram-negative bacteremia secondary to focal infection such as skin and soft-tissue infection, pneumonia, pyelonephritis, or urinary tract infection is commonly encountered in hospital care. Current practice guidelines lack sufficient detail to inform evidence-based practices. Specifically, antimicrobial duration, criteria to transition from intravenous to oral step-down therapy, choice of oral antimicrobials, and reassessment of follow-up blood cultures are not addressed. The presence of bacteremia is often used as a justification for a prolonged course of antimicrobial therapy regardless of infection source or clinical response. Antimicrobials are lifesaving but not benign. Prolonged antimicrobial exposure is associated with adverse effects, increased rates of Clostridioides difficile infection, antimicrobial resistance, and longer hospital length of stay. Emerging evidence supports shorter overall duration of antimicrobial treatment and earlier transition to oral agents among patients with uncomplicated Enterobacteriaceae bacteremia who have achieved adequate source control and demonstrated clinical stability and improvement. After appropriate initial treatment with an intravenous antimicrobial, transition to highly bioavailable oral agents should be considered for total treatment duration of 7 days. Routine follow-up blood cultures are not cost-effective and may result in unnecessary healthcare resource utilization and inappropriate use of antimicrobials. Clinicians should incorporate these principles into the management of gram-negative bacteremia in the hospital.

Seven Versus 14 Days of Antibiotic Therapy for Uncomplicated Gram-negative Bacteremia: A Noninferiority Randomized Controlled Trial

BACKGROUND

Gram-negative bacteremia is a major cause of morbidity and mortality in hospitalized patients. Data to guide the duration of antibiotic therapy are limited.

METHODS

This was a randomized, multicenter, open-label, noninferiority trial. Inpatients with gram-negative bacteremia, who were afebrile and hemodynamically stable for at least 48 hours, were randomized to receive 7 days (intervention) or 14 days (control) of covering antibiotic therapy. Patients with uncontrolled focus of infection were excluded. The primary outcome at 90 days was a composite of all-cause mortality; relapse, suppurative, or distant complications; and readmission or extended hospitalization (>14 days). The noninferiority margin was set at 10%.

RESULTS

We included 604 patients (306 intervention, 298 control) between January 2013 and August 2017 in 3 centers in Israel and Italy. The source of the infection was urinary in 411 of 604 patients (68%); causative pathogens were mainly Enterobacteriaceae (543/604 [90%]). A 7-day difference in the median duration of covering antibiotics was achieved. The primary outcome occurred in 140 of 306 patients (45.8%) in the 7-day group vs 144 of 298 (48.3%) in the 14-day group (risk difference, -2.6% [95% confidence interval, -10.5% to 5.3%]). No significant differences were observed in all other outcomes and adverse events, except for a shorter time to return to baseline functional status in the short-course therapy arm.

CONCLUSIONS

In patients hospitalized with gram-negative bacteremia achieving clinical stability before day 7, an antibiotic course of 7 days was noninferior to 14 days. Reducing antibiotic treatment for uncomplicated gram-negative bacteremia to 7 days is an important antibiotic stewardship intervention.

CLINICAL TRIALS REGISTRATION

NCT01737320.

Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) randomised clinical trial: study protocol

INTRODUCTION

Bloodstream infections are a leading cause of mortality and morbidity; the duration of treatment for these infections is understudied.

METHODS AND ANALYSIS

We will conduct an international, multicentre randomised clinical trial of shorter (7 days) versus longer (14 days) antibiotic treatment among hospitalised patients with bloodstream infections. The trial will include 3626 patients across 60 hospitals and 6 countries. We will include patients with blood cultures confirming a pathogenic bacterium after hospital admission. Exclusion criteria will include patient factors (severe immunosuppression), infection site factors (endocarditis, osteomyelitis, undrained abscesses, infected prosthetic material) and pathogen factors (Staphylococcus aureus, Staphylococcus lugdunensis, Candida and contaminant organisms). We will leave the selection of specific antibiotics, doses and route of delivery to the discretion of treating physicians; no placebo control will be used given the diversity of pathogens and sources of bacteraemia. The intervention will be assignment of treatment duration to be 7 versus 14 days. We will minimise selection bias via central randomisation with variable block sizes, with concealed allocation until day 7 of adequate antibiotic treatment. The primary outcome is 90-day survival; we will test whether 7 days is non-inferior to 14 days of treatment, with a non-inferiority margin of 4% absolute mortality. Secondary outcomes include hospital and intensive care unit (ICU) mortality, relapse rates of bacteraemia, hospital and ICU length of stay, mechanical ventilation and vasopressor duration, antibiotic-free days, Clostridium difficile infection, antibiotic allergy and adverse events and colonisation/infection with antibiotic-resistant organisms.

ETHICS AND DISSEMINATION

The study has been approved by the ethics review board at each participating site. Sunnybrook Health Sciences Centre is the central ethics committee. We will disseminate study results via the Canadian Critical Care Trials Group and other collaborating networks to set the global paradigm for antibiotic treatment duration for non-staphylococcal Gram-positive, Gram-negative and anaerobic bacteraemia, among patients admitted to hospital.

TRIAL REGISTRATION NUMBER

The BALANCE (Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness) trial was registered at www.clinicaltrials.gov (registration number: NCT03005145).

Bloodstream infections in critically ill patients: an expert statement

Bloodstream infection (BSI) is defined by positive blood cultures in a patient with systemic signs of infection and may be either secondary to a documented source or primary—that is, without identified origin. Community-acquired BSIs in immunocompetent adults usually involve drug-susceptible bacteria, while healthcare-associated BSIs are frequently due to multidrug-resistant (MDR) strains. Early adequate antimicrobial therapy is a key to improve patient outcomes, especially in those with criteria for sepsis or septic shock, and should be based on guidelines and direct examination of available samples. Local epidemiology, suspected source, immune status, previous antimicrobial exposure, and documented colonization with MDR bacteria must be considered for the choice of first-line antimicrobials in healthcare-associated and hospital-acquired BSIs. Early genotypic or phenotypic tests are now available for bacterial identification and early detection of resistance mechanisms and may help, though their clinical impact warrants further investigations. Initial antimicrobial dosing should take into account the pharmacokinetic alterations commonly observed in ICU patients, with a loading dose in case of sepsis or septic shock. Initial antimicrobial combination attempting to increase the antimicrobial spectrum should be discussed when MDR bacteria are suspected and/or in the most severely ill patients. Source identification and control should be performed as soon as the hemodynamic status is stabilized. De-escalation from a broad-spectrum to a narrow-spectrum antimicrobial may reduce antibiotic selection pressure without negative impact on mortality. The duration of therapy is usually 5–8 days though longer durations may be discussed depending on the underlying illness and the source of infection. This narrative review covers the epidemiology, diagnostic workflow and therapeutic aspects of BSI in ICU patients and proposed up-to-date expert statements.

A pilot randomized controlled trial of 7 versus 14 days of antibiotic treatment for bloodstream infection on non-intensive care versus intensive care wards

BACKGROUND

The optimal treatment duration for patients with bloodstream infection is understudied. The Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness (BALANCE) pilot randomized clinical trial (RCT) determined that it was feasible to enroll and randomize intensive care unit (ICU) patients with bloodstream infection to 7 versus 14 days of treatment, and served as the vanguard for the ongoing BALANCE main RCT. We performed this BALANCE-Ward pilot RCT to examine the feasibility and impact of potentially extending the BALANCE main RCT to include patients hospitalized on non-ICU wards.

METHODS

We conducted an open pilot RCT among a subset of six sites participating in the ongoing BALANCE RCT, randomizing patients with positive non-Staphylococcus aureus blood cultures on non-ICU wards to 7 versus 14 days of antibiotic treatment. The co-primary feasibility outcomes were recruitment rate and adherence to treatment duration protocol. We compared feasibility outcomes, patient/pathogen characteristics, and overall outcomes among those enrolled in this BALANCE-Ward and prior BALANCE-ICU pilot RCTs. We estimated the sample size and non-inferiority margin impacts of expanding the BALANCE main RCT to include non-ICU patients.

RESULTS

A total of 134 patients were recruited over 47 site-months (mean 2.9 patients/site-month, median 1.0, range 0.1-4.4 patients/site-month). The overall recruitment rate exceeded the BALANCE-ICU pilot RCT (mean 1.10 patients/site-month, p < 0.0001). Overall protocol adherence also exceeded the adherence in the BALANCE-ICU pilot RCT (125/134, 93% vs 89/115, 77%, p = 0.0003). BALANCE-Ward patients were older, with lower Sequential Organ Failure Assessment scores, and higher proportions of infections caused by Escherichia coli and genito-urinary sources of bloodstream infection. The BALANCE-Ward pilot RCT patients had an overall 90-day mortality rate of 17/133 (12.8%), which was comparable to the 90-day mortality rate in the ICU pilot RCT (17/115, 14.8%) (p = 0.65). Simulation models indicated there would be minimal sample size and non-inferiority margin implications of expanding enrolment to increasing proportions of non-ICU versus ICU patients.

CONCLUSION

It is feasible to enroll non-ICU patients in a trial of 7 versus 14 days of antibiotics for bloodstream infection, and expanding the BALANCE RCT hospital-wide has the potential to improve the timeliness and generalizability of trial results.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02917551. Registered on September 28, 2016.

A Systematic Review and Meta-analysis of Antibiotic Treatment Duration for Bacteremia Due to Enterobacteriaceae

The duration of antibiotic therapy for bacteremia due to Enterobacteriaceae is not well defined. We sought to evaluate the clinical outcomes with shorter- versus longer-course treatment. We performed a systematic search of the PubMed and EMBASE databases through May 2018. Studies presenting comparative outcomes between patients receiving antibiotic treatment for ≤10 days ("short-course") and those treated for >10 days ("long-course") were considered eligible. Four retrospective cohort studies and one randomized controlled trial comprising 2,865 patients met the inclusion criteria. The short- and long-course antibiotic treatments did not differ in 30-day all-cause mortality (1,374 patients; risk ratio [RR] = 0.99; 95% confidence interval [CI], 0.69 to 1.43), 90-day all-cause mortality (1,750 patients; RR = 1.16; 95% CI, 0.81 to 1.66), clinical cure (1,080 patients; RR = 1.02; 95% CI, 0.96 to 1.08), or relapse at 90 days (1,750 patients; RR = 1.08; 95% CI, 0.69 to 1.67). In patients with bacteremia due to Enterobacteriaceae, the short- and long-course antibiotic treatments did not differ significantly in terms of clinical outcomes. Further well-designed studies are needed before treatment for 10 days or less is adopted in clinical practice.

Chlorhexidine versus saline in reducing the risk of catheter associated urinary tract infection: A cost-effectiveness analysis

BACKGROUND

Catheter associated urinary tract infections are one of the most common infections acquired in hospital. A recent randomised control study demonstrated the benefit of using chlorhexidine (0.1%) for meatal cleaning prior to urinary catheter insertion, by reducing both catheter associated asymptomatic bacteriuria and infection. These findings raise the important question of whether a decision to switch from saline to chlorhexidine was likely to be cost-effective. The aim of this paper was to evaluate the cost-effectiveness of adopting routine use of chlorhexidine for meatal cleaning prior to urinary catheter insertion METHODS: The outcomes of this cost-effectiveness study are changes to health service costs in $AUD and changes to quality adjusted life years from a decision to adopt 0.1% chlorhexidine for meatal cleaning prior to urinary catheter insertion as compared to saline. Effectiveness outcomes for this study were taken from a 32 week stepped wedge randomised controlled study conducted in three Australian hospitals.

RESULTS

The changes in health costs from switching from saline to 0.1% chlorhexidine per 100,000 catheterisations would save hospitals AUD$387,909 per 100,000 catherisations, prevent 70 cases of catheter associated urinary tract infections, release 282 bed days and provide a small improvement in health benefits of 1.43 quality adjusted life years. Using a maximum willingness to pay for a marginal quality adjusted life year threshold of AUD$28,000 per 100,000 catherisations, suggests that adopting chlorhexidine would be cost effective and potentially cost-saving.

CONCLUSION

The findings from our work provide evidence to health system administrators and those responsible for drafting catheter associated urinary tract infections prevention guidelines that investing in switching from saline to chlorhexidine is not only clinically effective but also a sensible decision in the context of allocating finite healthcare resources.

Top Questions in Uncomplicated, Non-Staphylococcus aureus Bacteremia

The Infectious Diseases Society of America infection-specific guidelines provide limited guidance on the management of focal infections complicated by secondary bacteremias. We address the following 3 commonly encountered questions and management considerations regarding uncomplicated bacteremia not due to Staphylococcus aureus: the role and choice of oral antibiotics focusing on oral beta-lactams, the shortest effective duration of therapy, and the role of repeat blood cultures.

7 versus 14 days of antibiotic treatment for critically ill patients with bloodstream infection: a pilot randomized clinical trial

Background

Shorter-duration antibiotic treatment is sufficient for a range of bacterial infections, but has not been adequately studied for bloodstream infections. Our systematic review, survey, and observational study indicated equipoise for a trial of 7 versus 14 days of antibiotic treatment for bloodstream infections; a pilot randomized clinical trial (RCT) was a necessary next step to assess feasibility of a larger trial.

Methods

We conducted an open, pilot RCT of antibiotic treatment duration among critically ill patients with bloodstream infection across 11 intensive care units (ICUs). Antibiotic selection, dosing and route were at the discretion of the treating team; patients were randomized 1:1 to intervention arms consisting of two fixed durations of treatment – 7 versus 14 days. We recruited adults with a positive blood culture yielding pathogenic bacteria identified while in ICU. We excluded patients with severe immunosuppression, foci of infection with an established requirement for prolonged treatment, single cultures with potential contaminants, or cultures yielding Staphylococcus aureus or fungi. The primary feasibility outcomes were recruitment rate and adherence to treatment duration protocol. Secondary outcomes included 90-day, ICU and hospital mortality, relapse of bacteremia, lengths of stay, mechanical ventilation and vasopressor duration, antibiotic-free days, Clostridium difficile, antibiotic adverse events, and secondary infection with antimicrobial-resistant organisms.

Results

We successfully achieved our target sample size (n = 115) and average recruitment rate of 1 (interquartile range (IQR) 0.3–1.5) patient/ICU/month. Adherence to treatment duration was achieved in 89/115 (77%) patients. Adherence differed by underlying source of infection: 26/31 (84%) lung; 18/29 (62%) intra-abdominal; 20/26 (77%) urinary tract; 8/9 (89%) vascular-catheter; 4/4 (100%) skin/soft tissue; 2/4 (50%) other; and 11/12 (92%) unknown sources. Patients experienced a median (IQR) 14 (8–17) antibiotic-free days (of the 28 days after blood culture collection). Antimicrobial-related adverse events included hepatitis in 1 (1%) patient, Clostridium difficile infection in 4 (4%), and secondary infection with highly resistant microorganisms in 10 (9%). Ascertainment was complete for all study outcomes in ICU, in hospital and at 90 days.

Conclusion

It is feasible to conduct a RCT to determine whether 7 versus 14 days of antibiotic treatment is associated with comparable 90-day survival.

Trial registration

ClinicalTrials.gov, identifier: NCT02261506. Registered on 26 September 2014.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2474-1) contains supplementary material, which is available to authorized users.

Multiple-Drug Resistance in Burn Patients: A Retrospective Study on the Impact of Antibiotic Resistance on Survival and Length of Stay

Despite improvements in early treatment, survival following burn injury remains challenged by sepsis and multiple organ dysfunction syndrome (MODS). Additionally, susceptibility to infections and growing antibiotic resistance places burn patients at increased risk for infections with multiple-drug resistant organisms (MDROs). We therefore aimed to evaluate the impact of MDRO infections on survival and hospital length of stay, as well as examine the role of these organisms in the development of complications, such as acute kidney injury, sepsis, and MODS. To study this, we included all burn patients with infections, admitted between January 1, 2012, and December 31, 2013. Patients were divided into two groups: patients with infections caused by MDROs and patients with infections caused by susceptible organisms. Data were collected on all available cultures, as well as demographic, injury, and treatment-related variables from the medical record. The number of operative procedures (median: 2 vs 1, P < .0001), ventilator days (21 vs 0 days, P < .0001), total antibiotic days (21 vs 7days, P < .0001), and length of hospitalization (39 vs 14 days, P < .0001) were significantly different in the MDRO group vs the nonresistant group. While MDRO infection was not associated with patient mortality, univariable logistic regression analyses demonstrated >20% TBSA (odds ratio [OR] = 4.30, 95% confidence interval [CI]: 1.14-16.29, P = .03), acute kidney injury (OR = 10.93, 95% CI: 2.74-43.57, P = .001), sepsis (OR = 19.20, 95% CI: 3.79-97.27, P < .001), and MODS (OR = 85.49, 95% CI: 12.97-563.28, P < .0001) significantly increased the odds of patient mortality. These findings suggest that infections with MDROs are associated with a greater number of surgical procedures, longer duration of mechanical ventilation, more antibiotic days, and longer hospitalization.

Treatment duration for Escherichia coli bloodstream infection and outcomes: retrospective single-centre study

OBJECTIVES

To investigate the impact of treatment duration on mortality and on relapse in patients with Escherichia coli bloodstream infection (BSI).

METHODS

Retrospective single-centre study of patients diagnosed with E. coli BSI at our centre over a 4-year period.

EXCLUSION CRITERIA

age <18 years, clinical data not available, polymicrobial BSI, failure to receive in vitro active therapy, and death while receiving antibiotic therapy. Exposure variable was treatment duration dichotomized into short (≤10 days) and long (>10 days) therapy. Primary end point was all-cause mortality within 90 days after index BSI. Secondary end point was relapse, defined as repeat isolation of E. coli from blood cultures within 90 days after index BSI, in patients with documented clinical cure and completion of therapy for the initial episode.

RESULTS

Of the 856 analysed patients: 426 received short and 430 received long therapy. All-cause mortality at day 90 occurred in 47 patients; on multivariate analysis, short therapy was not associated with a higher risk of mortality, also after adjusting the model for the propensity score of receiving short therapy. Relapse occurred in 42 patients. Independent risk factors for relapse using death as competing risk were immunosuppression (subhazard ratio 4.67, p < 0.001), and end-stage liver disease (subhazard ratio 2.58, p 0.013). The propensity-weighted estimation of the average treatment effect for relapse reduction with long therapy (>10 days) was -1.6% (p 0.26) in the total population, and -7.1% (p 0.18) in immunocompromised patients.

CONCLUSIONS

We could not identify shorter treatment duration as a risk factor for mortality and for relapse in patients with E. coli BSI.

To which extent can we decrease antibiotic duration in critically ill patients?

INTRODUCTION

Inadequate empirical antibiotic therapy is associated with higher mortality in critically ill patients with severe infections. Nevertheless, prolonged duration of antibiotic treatment is also potentially harmful. Development of new infections with more resistant pathogens is one of the arguments against the administration of prolonged courses of antibiotics. Areas covered: We aim to describe the optimal duration of antimicrobial therapy in the most common infections affecting critically ill patients. A literature search was performed to identify all clinical trials, observational studies, meta-analysis, and reviews about this topic from PubMed. Expert commentary: Diverse observational studies have reported a poor outcome in critically ill patients without a documented infection who receive prolonged antibiotic therapy. We summarize the available information about the optimal duration of antimicrobial therapy in critically ill patients with severe infections including community-acquired pneumonia, intra-abdominal infections, bacteremia, meningitis and urinary-tract infections as well as the clinical consequences of short antimicrobial courses in certain severe infections. The utility of procalcitonin to reduce the duration of antibiotics is also discussed. Finally, we give clear recommendations about the length of treatment for the most common infections in critically ill patients.

Optimal duration of antimicrobial therapy for uncomplicated Gram-negative bloodstream infections

PURPOSE

Optimal antimicrobial treatment duration for Gram-negative bloodstream infection (BSI) remains unclear. This retrospective cohort study examined effectiveness of short (7-10 days) and long (>10 days) courses of antimicrobial therapy for uncomplicated Gram-negative BSI.

METHODS

Hospitalized adults with uncomplicated Gram-negative BSI at Palmetto Health hospitals in Columbia SC, USA from January 1, 2010 to December 31, 2013 were identified. Multivariate Cox proportional hazards regression with propensity score adjustment was used to examine risk of treatment failure in the two groups.

RESULTS

During the study period, 117 and 294 patients received short and long courses of antimicrobial therapy for uncomplicated Gram-negative BSI, respectively. Overall, the median age was 67 years, 258 (63%) were women, 282 (69%) had urinary source of infection, and 271 (66%) had BSI due to Escherichia coli. The median duration of antimicrobial therapy was 8.5 and 13.3 days in the short and long treatment groups, respectively. After adjustment for the propensity to use a short course of therapy, risk of treatment failure was higher in patients receiving short compared to long courses of antimicrobial agents (HR 2.60, 95% CI: 1.20-5.53, p = 0.02). Other risk factors for treatment failure included liver cirrhosis (HR 5.83, 95% CI: 1.89-15.02, p = 0.004) and immune compromised status (HR 4.30, 95% CI: 1.57-10.80, p = 0.006). Definitive antimicrobial therapy with intravenous or highly bioavailable oral agents was associated with reduced risk of treatment failure (HR 0.33, 95% CI: 0.14-0.73, p = 0.006).

CONCLUSIONS

The current results support common clinical practice of 2 weeks of antimicrobial therapy for uncomplicated Gram-negative BSI.

Pathogens and antimicrobial susceptibility profiles in critically ill patients with bloodstream infections: a descriptive study

BACKGROUND

Surveillance of antimicrobial resistance is vital to guiding empirical treatment of infections. Collating and reporting routine data on clinical isolate testing may offer more timely information about resistance patterns than traditional surveillance network methods.

METHODS

Using routine microbiology testing data collected from the Bacteremia Antibiotic Length Actually Needed for Clinical Effectiveness retrospective cohort study, we conducted a descriptive secondary analysis among critically ill patients in whom bloodstream infections had been diagnosed in 14 intensive care units (ICUs) in Canada. The participating sites were located within tertiary care teaching hospitals and represented 6 provinces and 10 cities. More than 80% of the study population was accrued from 2011-2013. We assessed the epidemiologic features of the infections and corresponding antimicrobial susceptibility profiles. Susceptibility testing was done according to Clinical Laboratory Standards Institute guidelines at accredited laboratories.

RESULTS

A total of 1416 pathogens were isolated from 1202 patients. The most common organisms were Escherichia coli (217 isolates [15.3%]), Staphylococcus aureus (175 [12.4%]), coagulase-negative staphylococci (117 [8.3%]), Klebsiella pneumoniae (86 [6.1%]) and Streptococcus pneumoniae (85 [6.0%]). The contribution of individual pathogens varied by site. For 13 ICUs, gram-negative susceptibility rates were high for carbapenems (95.4%), tobramycin (91.2%) and piperacillin-tazobactam (90.0%); however, the proportion of specimens susceptible to these agents ranged from 75.0%-100%, 66.7%-100% and 75.0%-100%, respectively, across sites. Fewer gram-negative bacteria were susceptible to fluoroquinolones (84.5% [range 64.1%-97.2%]). A total of 145 patients (12.1%) had infections caused by highly resistant microorganisms, with significant intersite variation (range 2.6%-24.0%, χ2 = 57.50, p < 0.001).

INTERPRETATION

We assessed the epidemiologic features of bloodstream infections in a geographically diverse cohort of critically ill Canadian patients using routine pathogen and susceptibility data extracted from readily available microbiology testing databases. Expanding data sharing across more ICUs, with serial measurement and prompt reporting, could provide much-needed guidance for empiric treatment for patients as well as system-wide prevention methods to limit antimicrobial resistance.