Serum Procalcitonin Measurement and Viral Testing to Guide Antibiotic Use for Respiratory Infections in Hospitalized Adults: A Randomized Controlled Trial

European society of clinical microbiology and infectious diseases guidelines for antimicrobial stewardship in emergency departments (endorsed by European association of hospital pharmacists)

SCOPE

This European Society of Clinical Microbiology and Infectious Diseases guideline provides evidence-based recommendations to support a selection of appropriate antibiotic use practices for patients seen in the emergency department (ED) and guidance for their implementation. The topics addressed in this guideline are (a) Do biomarkers or rapid pathogen tests improve antibiotic prescribing and/or clinical outcomes? (b) Does taking blood cultures in common infectious syndromes improve antibiotic prescribing and/or clinical outcomes? (c) Does watchful waiting without antibacterial therapy or with delayed antibiotic prescribing reduce antibiotic prescribing without worsening clinical outcomes in patients with specific infectious syndromes? (d) Do structured culture follow-up programs in patients discharged from the ED with cultures pending improve antibiotic prescribing?

METHODS

An expert panel was convened by European Society of Clinical Microbiology and Infectious Diseases and the guideline chair. The panel selected in consensus the four most relevant antimicrobial stewardship topics according to pre-defined relevance criteria. For each main question for the four topics, a systematic review was performed, including randomized controlled trials and observational studies. Both clinical outcomes and stewardship process outcomes related to antibiotic use were deemed relevant. The literature searches were conducted between May 2021 and March 2022. In April 2022, the panel members were formally asked to suggest additional studies that were not identified in the initial searches. Data were summarized in a meta-analysis if possible or otherwise summarized narratively. The certainty of the evidence was classified according to the Grading of Recommendations Assessment, Development and Evaluation criteria. The guideline panel reviewed the evidence per topic critically appraising the evidence and formulated recommendations through a consensus-based process. The strength of the recommendations was classified as strong or weak. To substantiate the implementation process, implementation trials or observational studies describing facilitators/barriers for implementation were identified from the same searches and were summarized narratively.

RECOMMENDATIONS

The recommendations on the use of biomarkers and rapid pathogen diagnostic tests focus on the initiation of antibiotics in patients admitted through the ED. Their effect on the discontinuation or de-escalation of antibiotics during hospital stay was not reported, neither was their effect on hospital infection prevention and control practices. The recommendations on watchful waiting (i.e. withholding antibiotics with some form of follow-up) focus on specific infectious syndromes for which the primary care literature was also included. The recommendations on blood cultures focus on the indication in three common infectious syndromes in the ED explicitly excluding patients with sepsis or septic shock. Most recommendations are based on very low and low certainty of evidence, leading to weak recommendations or, when no evidence was available, to best practice statements. Implementation of these recommendations needs to be adapted to the specific settings and circumstances of the ED. The scarcity of high-quality studies in the area of antimicrobial stewardship in the ED highlights the need for future research in this field.

Acute kidney injury in critical care: complications of hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is an immune dysfunction characterized by an exaggerated and pathological inflammatory response, potentially leading to systemic inflammatory reactions and multiple-organ failure, including renal involvement. HLH can be classified as primary or secondary, with primary HLH associated with genetic mutations affecting cell degranulation capacity, and secondary HLH often linked to infections, tumors, and autoimmune diseases. The pathogenesis of HLH is not fully understood, but primary HLH is typically driven by genetic defects, whereas secondary HLH involves the activation of CD8+ T cells and macrophages, leading to the release of inflammatory cytokines and systemic inflammatory response syndrome (SIRS). The clinical presentation of HLH includes non-specific manifestations, making it challenging to differentiate from severe sepsis, particularly secondary HLH due to infections. Shared features include prolonged fever, hepatosplenomegaly, hematopenia, hepatic dysfunction, hypertriglyceridemia, and hypofibrinogenemia, along with histiocytosis and hemophagocytosis. However, distinctive markers like dual hemocytopenia, hypertriglyceridemia, hypofibrinogenemia, and elevated sCD25 levels may aid in differentiating HLH from sepsis. Indeed, no singular biomarker effectively distinguishes between hemophagocytic lymphohistiocytosis and infection. However, research on combined biomarkers provides insights into the differential diagnosis. Renal impairment is frequently encountered in both HLH and sepsis. It can result from a systemic inflammatory response triggered by an influx of inflammatory mediators, from direct damage caused by these factors, or as a consequence of the primary disease process. For instance, macrophage infiltration of the kidney can lead to structural damage affecting various renal components, precipitating disease. Presently, tubular necrosis remains the predominant form of renal involvement in HLH-associated acute kidney injury (HLH-AKI). However, histopathological changes may also encompass interstitial inflammation, glomerular abnormalities, microscopic lesions, and thrombotic microangiopathy. Treatment approaches for HLH and sepsis diverge significantly. HLH is primarily managed with repeated chemotherapy to eliminate immune-activating stimuli and suppress hypercellularity. The treatment approach for sepsis primarily focuses on anti-infective therapy and intensive symptomatic supportive care. Renal function significantly influences clinical decision-making, particularly regarding the selection of chemotherapy and antibiotic dosages, which can profoundly impact patient prognosis. Conversely, renal function recovery is a complex process influenced by factors such as disease severity, timely diagnosis, and the intensity of treatment. A crucial aspect in managing HLH-AKI is the timely diagnosis, which plays a pivotal role in reversing renal impairment and creating a therapeutic window for intervention, may have opportunity to improve patient prognosis. Understanding the clinical characteristics, underlying causes, biomarkers, immunopathogenesis, and treatment options for hemophagocytic lymphohistiocytosis associated with acute kidney injury (HLH-AKI) is crucial for improving patient prognosis.

Influenza and Viral Pneumonia

Influenza and other respiratory viruses are commonly identified in patients with community-acquired pneumonia, hospital-acquired pneumonia, and in immunocompromised patients with pneumonia. Clinically, it is difficult to differentiate viral from bacterial pneumonia. Similarly, the radiological findings of viral infection are in general nonspecific. The advent of polymerase chain reaction testing has enormously facilitated the identification of respiratory viruses, which has important implications for infection control measures and treatment. Currently, treatment options for patients with viral infection are limited but there is ongoing research on the development and clinical testing of new treatment regimens and strategies.

Diagnostic Stewardship for Multiplex Respiratory Testing: What We Know and What Needs to Be Done

Syndromic respiratory panels are now widely available in clinical microbiology laboratories and health care institutions. These panels can rapidly diagnose infections and detect antimicrobial resistance genes allowing for more rapid therapeutic optimization compared to standard microbiology approaches. However, given reimbursement concerns and limitations of multiplex molecular testing and results interpretation, maximum clinical utility and positive clinical outcomes depend on active diagnostic stewardship. Here, the authors review clinical outcomes of both upper and lower respiratory panels and present diagnostic stewardship strategies for optimal use of respiratory panels.

Diagnostic yield of viral multiplex PCR during acute exacerbation of COPD admitted to the intensive care unit: a pilot study

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is one of the leading causes of admission to the intensive care unit, often triggered by a respiratory tract infection of bacterial or viral aetiology. Managing antibiotic therapy in this context remains a challenge. Respiratory panel molecular tests allow identifying viral aetiologies of AECOPD. We hypothesized that the systematic use of a respiratory multiplex PCR (mPCR) would help antibiotics saving in severe AECOPD. Our objectives were to describe the spectrum of infectious aetiologies of severe AECOPD, using a diagnostic approach combining conventional diagnostic tests and mPCR, and to measure antibiotics exposure. The study was bicentric, prospective, observational, and included 105 critically ill patients with a severe AECOPD of presumed infectious aetiology, in whom a respiratory mPCR with a viral panel was performed in addition to conventional microbiological tests. Altogether, the microbiological documentation rate was 50%, including bacteria alone (19%), respiratory viruses alone (16%), and mixed viruses and bacterial species (16%). The duration of antibiotic therapy was shorter in patients without documented bacterial infection (5.6 vs. 9 days; P = 0.0006). This pilot study suggests that molecular tests may help for the proper use of anti-infective treatments in critically ill patients with severe AECOPD.

Point-of-care multiplex molecular diagnosis coupled with procalcitonin-guided algorithm for antibiotic stewardship in lower respiratory tract infection: a randomized controlled trial

OBJECTIVE

We aimed to show that coupling molecular syndromic respiratory panel (RP) testing with procalcitonin (PCT) measurement in the emergency department improves antibiotic (ATB) stewardship in lower respiratory tract infection.

METHODS

Open-label, prospective, randomized interventional trial, conducted from 2019 to 2022 in an adult emergency department. Patients with a suspicion of lower respiratory tract infection were randomized into an intervention arm (PCT measurement and point-of-care BIOFIRE RP2.1 plus testing, accompanied by a recommended ATB algorithm) or a standard of care (SOC) arm (PCT allowed as current practice). The primary endpoint was the duration of antibiotic exposure.

RESULTS

Four hundred fifty-one patients were randomized, median age 65 years (Q1-Q3: 49-77), the hospitalization rate was 59.9% (270/451), the median length of stay 5 days (Q1-Q3: 3 - 12), and the 28-day mortality rate 5.3% (23/451). The median duration of ATB exposure was 6 days (Q1-Q3: 0-9) and 5 days (Q1-Q3: 0-9) in the SOC and interventional arm respectively (p = 0.71). ATB was started in 29.6 % (67/226) and 33.8% (76/225) respectively (p = 0.54). The BIOFIRE RP2.1 plus identified at least one viral species in 112/225 patients (49.8%) of intervention arm. Two hundred twelve out of two hundred twenty-six (93.8%) SOC patients had PCT measurement. The adherence rate to algorithm in the intervention arm was 93.3 % (210/225).

CONCLUSION

Displaying PCT and real-time RP results to emergency physicians failed to significantly reduce ATB exposure in lower respiratory tract infection suspicions. However, the median ATB duration and rate of initiation were already low in the SOC arm using PCT measurement routinely.

Procalcitonin-guided antibiotic therapy may shorten length of treatment and may improve survival-a systematic review and meta-analysis

BACKGROUND

Appropriate antibiotic (AB) therapy remains a challenge in the intensive care unit (ICU). Procalcitonin (PCT)-guided AB stewardship could help optimize AB treatment and decrease AB-related adverse effects, but firm evidence is still lacking. Our aim was to compare the effects of PCT-guided AB therapy with standard of care (SOC) in critically ill patients.

METHODS

We searched databases CENTRAL, Embase and Medline. We included randomized controlled trials (RCTs) comparing PCT-guided AB therapy (PCT group) with SOC reporting on length of AB therapy, mortality, recurrent and secondary infection, ICU length of stay (LOS), hospital LOS or healthcare costs. Due to recent changes in sepsis definitions, subgroup analyses were performed in studies applying the Sepsis-3 definition. In the statistical analysis, a random-effects model was used to pool effect sizes.

RESULTS

We included 26 RCTs (n = 9048 patients) in the quantitative analysis. In comparison with SOC, length of AB therapy was significantly shorter in the PCT group (MD - 1.79 days, 95% CI: -2.65, - 0.92) and was associated with a significantly lower 28-day mortality (OR 0.84, 95% CI: 0.74, 0.95). In Sepsis-3 patients, mortality benefit was more pronounced (OR 0.46 95% CI: 0.27, 0.79). Odds of recurrent infection were significantly higher in the PCT group (OR 1.36, 95% CI: 1.10, 1.68), but there was no significant difference in the odds of secondary infection (OR 0.81, 95% CI: 0.54, 1.21), ICU and hospital length of stay (MD - 0.67 days 95% CI: - 1.76, 0.41 and MD - 1.23 days, 95% CI: - 3.13, 0.67, respectively).

CONCLUSIONS

PCT-guided AB therapy may be associated with reduced AB use, lower 28-day mortality but higher infection recurrence, with similar ICU and hospital length of stay. Our results render the need for better designed studies investigating the role of PCT-guided AB stewardship in critically ill patients.

AACC Guidance Document on the Clinical Use of Procalcitonin

BACKGROUND

Procalcitonin (PCT), a peptide precursor of the hormone calcitonin, is a biomarker whose serum concentrations are elevated in response to systemic inflammation caused by bacterial infection and sepsis. Clinical adoption of PCT in the United States has only recently gained traction with an increasing number of Food and Drug Administration-approved assays and expanded indications for use. There is interest in the use of PCT as an outcomes predictor as well as an antibiotic stewardship tool. However, PCT has limitations in specificity, and conclusions surrounding its utility have been mixed. Further, there is a lack of consensus regarding appropriate timing of measurements and interpretation of results. There is also a lack of method harmonization for PCT assays, and questions remain regarding whether the same clinical decision points may be used across different methods.

CONTENT

This guidance document aims to address key questions related to the use of PCT to manage adult, pediatric, and neonatal patients with suspected sepsis and/or bacterial infections, particularly respiratory infections. The document explores the evidence for PCT utility for antimicrobial therapy decisions and outcomes prediction. Additionally, the document discusses analytical and preanalytical considerations for PCT analysis and confounding factors that may affect the interpretation of PCT results.

SUMMARY

While PCT has been studied widely in various clinical settings, there is considerable variability in study designs and study populations. Evidence to support the use of PCT to guide antibiotic cessation is compelling in the critically ill and in some lower respiratory tract infections but is lacking in other clinical scenarios, and evidence is also limited in the pediatric and neonatal populations. Interpretation of PCT results requires guidance from multidisciplinary care teams of clinicians, pharmacists, and clinical laboratorians.

Rapid Multiplex PCR for Respiratory Viruses Reduces Time to Result and Improves Clinical Care: Results of a Systematic Review and Meta-Analysis

OBJECTIVES

The clinical impact of rapid sample-to-answer 'syndromic' multiplex polymerase chain reaction (PCR) testing for respiratory viruses is not clearly established. We performed a systematic literature review and meta-analysis to evaluate this impact for patients with possible acute respiratory tract infection in the hospital setting.

METHODS

We searched EMBASE, MEDLINE, and Cochrane databases from 2012 to present and conference proceedings from 2021 for studies comparing clinical impact outcomes between multiplex PCR testing and standard testing.

RESULTS

Twenty-seven studies with 17,321 patient encounters were included in this review. Rapid multiplex PCR testing was associated with a reduction of -24.22hours (95% CI -28.70 to -19.74hours) in the time to results. Hospital length of stay was decreased by -0.82 days (95% CI -1.52 to -0.11 days). Among influenza positive patients, antivirals were more likely to be given (RR 1.25, 95% CI 1.06 to 1.48) and appropriate infection control facility use was more common with rapid multiplex PCR testing (RR 1.55, 95% CI 1.16 to 2.07).

CONCLUSIONS

Our systematic review and meta-analysis demonstrates a reduction in time to results and length of stay for patients overall along with improvements in appropriate antiviral and infection control management among influenza positive patients. This evidence supports the routine use of rapid sample-to-answer multiplex PCR testing for respiratory viruses in the hospital setting.

Leveraging diagnostic stewardship within antimicrobial stewardship programmes

Novel diagnostic stewardship in infectious disease consists of interventions that modify ordering, processing, and reporting of diagnostic tests to provide the right test for the right patient, prompting the right action. The interventions work upstream and synergistically with traditional antimicrobial stewardship efforts. As diagnostic stewardship continues to gain public attention, it is critical that antimicrobial stewardship programmes not only learn how to effectively leverage diagnostic testing to improve antimicrobial use but also ensure that they are stakeholders and leaders in developing new diagnostic stewardship interventions within their institutions. This review will discuss the need for diagnostic and antimicrobial stewardship, the interplay of diagnostic and antimicrobial stewardship, evidence of benefit to antimicrobial stewardship programmes, and considerations for successfully engaging in diagnostic stewardship interventions. This article is part of the Antibiotic stewardship Special Issue: https://www.drugsincontext.com/special_issues/antimicrobial-stewardship-a-focus-on-the-need-for-moderation.

Trends in the Use of Procalcitonin at US Children's Hospital Emergency Departments

OBJECTIVES

Procalcitonin (PCT) was approved by the Food and Drug Administration in 2016. We assessed changes in PCT utilization over time in emergency departments (EDs) at US Children's Hospitals and identified the most common conditions associated with PCT testing.

METHODS

We performed a cross-sectional study of children <18 years of age presenting to 1 of 33 EDs contributing data to the Pediatric Health Information System between 2016 and 2020. We examined trends in PCT utilization during an ED encounter between institutions and over the study period. Using All Patients Refined Diagnosis Related Groups, we identified the most common conditions for which PCT was obtained (overall, and relative to the performance of a complete blood count).

RESULTS

The overall rate of PCT testing increased from 0.2% of all ED visits in 2016 to 1.8% in 2020. Across hospitals, the proportion of ED encounters with PCT obtained ranged from 0.0005% to 4.3% with marked variability in overall use. Among children who had PCT testing performed, the most common diagnoses were fever (10.7%), infections of the upper respiratory tract (9.2%), and pneumonia (5.9%). Relative to the performance of a complete blood count, rates of PCT testing were highest among children with sepsis (28.7%), fever (21.4%), pulmonary edema/respiratory failure (17.3%), and bronchiolitis/respiratory syncytial virus pneumonia (15.6%).

CONCLUSIONS

PCT utilization in the ED has increased over the past 5 years with variation between hospitals. PCT is most frequently obtained for children with respiratory infections and febrile illnesses.

A retrospective cohort study of the effect of rapid versus delayed-result procalcitonin testing on antibiotic use at a community hospital

BACKGROUND

Procalcitonin is a serum biomarker used to distinguish bacterial infection from viral or noninfectious syndromes. Primary literature shows mixed data on use of procalcitonin for de-escalation of antimicrobials. Delays in test results of send-out procalcitonin assays may result in prolonged antimicrobial durations. It is unknown whether availability of rapid-result assays may shorten time to antibiotic de-escalation.

AIM

This retrospective, cohort study compared antibiotic durations of treatment between groups with rapid-result versus delayed send-out, procalcitonin test modality. This study was exempt from Ethics Committee Approval, as determined by the Institutional Review Board at the study site.

METHOD

Adult hospitalized patients were included if they had at least one procalcitonin test performed during the study period. The primary outcome compared mean duration of antimicrobial therapy between groups receiving a rapid-result procalcitonin test and a send-out test. Secondary outcomes included incidence of Clostridiodes difficile infection, mention of procalcitonin testing in the electronic medical record in reference to antimicrobial therapy decision making, and presence of comorbidities which affect procalcitonin levels independent of infection.

RESULTS

A total of 350 lab results were analyzed. The duration of antimicrobial treatment between groups was not statistically different with the median duration of treatment in the send-out group being 2.95 days compared to 3.35 in the rapid result group, p = 0.856. Patient comorbidities with potential to lead to a noninfectious elevation or falsely high level of procalcitonin were common.

CONCLUSION

Use of a rapid-result procalcitonin assay does not reduce hospital antimicrobial therapy duration as compared with send-out testing.

Antimicrobial Stewardship Using Biomarkers: Accumulating Evidence for the Critically Ill

This review aims to summarize current progress in the management of critically ill, using biomarkers as guidance for antimicrobial treatment with a focus on antimicrobial stewardship. Accumulated evidence from randomized clinical trials (RCTs) and observational studies in adults for the biomarker-guided antimicrobial treatment of critically ill (mainly sepsis and COVID-19 patients) has been extensively searched and is provided. Procalcitonin (PCT) is the best studied biomarker; in the majority of randomized clinical trials an algorithm of discontinuation of antibiotics with decreasing PCT over serial measurements has been proven safe and effective to reduce length of antimicrobial treatment, antibiotic-associated adverse events and long-term infectious complications like infections by multidrug-resistant organisms and Clostridioides difficile. Other biomarkers, such as C-reactive protein and presepsin, are already being tested as guidance for shorter antimicrobial treatment, but more research is needed. Current evidence suggests that biomarkers, mainly procalcitonin, should be implemented in antimicrobial stewardship programs even in the COVID-19 era, when, although bacterial coinfection rate is low, antimicrobial overconsumption remains high.

Molecular Diagnosis of Pneumonia (Including Multiplex Panels)

Background

Pneumonia is a common illness, accounting for a staggering amount of worldwide morbidity and mortality. The diagnosis of pneumonia is challenging given the variety of responsible pathogens. Diagnostic testing for bacterial pneumonia has traditionally relied on time-consuming culture-based methods, though recently multiplexed molecular approaches have been described. Multiplexed molecular assays for pneumonia have the potential to provide broad diagnostic information in a rapid timeframe. Much has yet to be learned about these assays regarding analytical performance, potential impact, and optimal implementation strategy.

Content

Herein we provide a summary of what is known and what has yet to be learned about multiplexed molecular pneumonia assays. We provide a comparison of the different commercially available assays and summarize the most current performance data for each. We further describe outcome data and lessons learned from those who have implemented these assays worldwide. Finally, based on the current state of performance and outcome data, we provide informed strategies and considerations for laboratories contemplating implementation.

Summary

Multiplexed molecular assays for the diagnosis of pneumonia boast high accuracy though the diagnostic information gained from these assays is inherently different from culture and must be interpreted in cultural context. Despite this, these assays can be powerful and effective diagnostic tools with a potential to positively impact patient care. The extent to which this is realized varies from setting to setting, though is dependent on thoughtful implementation and a focus on delivering clear, rapid, and actionable results that can be interpreted in the appropriate context.

Impact of multiplexed respiratory viral panels on infection control measures and antimicrobial stewardship: a review of the literature

Multiplexed respiratory viral panels (MRVP) have recently been added to the diagnostic work-up of respiratory infections. This review provides a summary of the main literature of MRVP for patients with regard to 3 different topics. Can the results of MRVP reduce the inappropriate use of antibiotics, can they guide the use of appropriate antiviral therapy and do they have an added value with respect to infection control measures? Literature was searched for based on a defined search string using both the PubMed and Embase database. Twenty-five articles report on the impact of MRVP on antibiotic therapy. In all the articles where active antimicrobial stewardship was performed (e.g., education/advice on interpreting results of MRVP) (N = 9), a reduction in antibiotic therapy was shown (with exception of 2 studies). Three studies evaluating the effect of MRVP on antimicrobial use in a population that is not suspected of having bacterial pneumonia (e.g., absence of radiology suggestive for bacterial infection or low PCT) found a positive impact on antibiotic therapy. Eight studies with a short TAT (< 7 h) had a positive impact on use of antibiotic therapy. Eleven studies focused on the impact of MRVP on antiviral use. In contrast to antibiotic reduction, all studies systematically objectified improved antiviral use as a consequence of MRVP results. With regard to the impact of MRVP on infection control, eleven articles were withheld. All these studies led to a more accurate use of infection control measures by detecting unidentified pathogens or stopping isolation precautions in case of a negative MRVP result. MRVP don’t reduce antibiotic therapy in all populations. Reduction seems more likely if the following factors are present: active antimicrobial stewardship, low likelihood of a bacterial infection, and a short turnaround time to result. With respect to antiviral therapy, all studies have an impact but the targeted use of antivirals is so far not that evidence based for all viral respiratory pathogens. Regarding infection control measures, the potential impact of MRVP is high because of the need of additional isolation precautions for many respiratory viruses, although logistical problems can occur.

Respiratory viral infections in pragmatically selected adults in intensive care units

Respiratory viruses can be detected in 18.3 to 48.9% of critically ill adults with severe respiratory tract infections (RTIs). The present study aims to assess the clinical significance of respiratory viruses in pragmatically selected adults in medical intensive care unit patients and to identify factors associated with viral respiratory viral tract infections (VRTIs). We conducted a prospective study on critically ill adults with suspected RTIs without recognized respiratory pathogens. Viral cultures with monoclonal antibody identification, in-house real-time polymerase chain reaction (PCR) for influenza virus, and FilmArray respiratory panel were used to detect viral pathogens. Multivariable logistic regression was applied to identify factors associated with VRTIs. Sixty-four (40.5%) of the included 158 critically ill adults had respiratory viruses detected in their respiratory specimens. The commonly detected viruses included influenza virus (20), followed by human rhinovirus/enterovirus (11), respiratory syncitial virus (9), human metapneumovirus (9), human parainfluenza viruses (8), human adenovirus (7), and human coronaviruses (2). The FilmArray respiratory panel detected respiratory viruses in 54 (34.6%) patients, but showed negative results for seven of 13 patients with influenza A/H3 infection. In the multivariable logistic regression model, patient characters associated with VRTIs included those aged < 65 years, household contact with individuals with upper RTI, the presence of fever, cough with sputum production, and sore throat. Respiratory viruses were not uncommonly detected in the pragmatically selected adults with critical illness. The application of multiplex PCR testing for respiratory viruses in selected patient population is a practical strategy, and the viral detection rate could be further improved by the patient characters recognized in this study.

Molecular diagnostic methods for pneumonia: how can they be applied in practice?

PURPOSE OF REVIEW

Pneumonia represents a major burden in clinical practice. A rapid etiological diagnosis is critical for optimizing the antibiotic use. Owing to the variety of possible pathogens and the time needed for bacterial cultures or usual polymerase chain reaction (PCR) assays, timely and precise diagnosis is a huge challenge. Several new rapid multiplex assays have been developed in the last decade to resolve these issues. This review aims to provide an overview of recent evidence on improvements and limitations of new rapid molecular assays for pneumonia.

RECENT FINDINGS

Several rapid multiplex-PCR assays are commercially available for upper or lower respiratory tract samples, allowing detection of a wide range of respiratory viruses, bacteria, and, in some cases, of several antibiotic resistance genes. Clinical evaluations demonstrated their good correlation with gold-standard assays but their lack of exhaustiveness, especially for hospital-acquired pneumonia. Studies that evaluated their potential benefits on antibiotic use suffered from important weaknesses with conflicting and limited results.

SUMMARY

New molecular assays may enable improvements in patient management and antibiotic use. Available studies highlight several benefits and the strong interrelations needed between microbiologists and physicians for their implementation and interpretation according to the clinical and epidemiological context.

Combined use of a broad-panel respiratory multiplex PCR and procalcitonin to reduce duration of antibiotics exposure in patients with severe community-acquired pneumonia (MULTI-CAP): a multicentre, parallel-group, open-label, individual randomised trial conducted in French intensive care units

INTRODUCTION

At the time of the worrying emergence and spread of bacterial resistance, reducing the selection pressure by reducing the exposure to antibiotics in patients with community-acquired pneumonia (CAP) is a public health issue. In this context, the combined use of molecular tests and biomarkers for guiding antibiotics discontinuation is attractive. Therefore, we have designed a trial comparing an integrated approach of diagnosis and treatment of severe CAP to usual care.

METHODS AND ANALYSIS

The multiplex PCR and procalcitonin to reduce duration of antibiotics exposure in patients with severe-CAP (MULTI-CAP) trial is a multicentre (n=20), parallel-group, superiority, open-label, randomised trial. Patients are included if adult admitted to intensive care unit for a CAP. Diagnosis of pneumonia is based on clinical criteria and a newly appeared parenchymal infiltrate. Immunocompromised patients are excluded. Subjects are randomised (1:1 ratio) to either the intervention arm (experimental strategy) or the control arm (usual strategy). In the intervention arm, the microbiological diagnosis combines a respiratory multiplex PCR (mPCR) and conventional microbiological investigations. An algorithm of early antibiotic de-escalation or discontinuation is recommended, based on mPCR results and the procalcitonin value. In the control arm, only conventional microbiological investigations are performed and antibiotics de-escalation remains at the clinician's discretion. The primary endpoint is the number of days alive without any antibiotic from the randomisation to day 28. Based on our hypothesis of 2 days gain in the intervention arm, we aim to enrol a total of 450 patients over a 30-month period.

ETHICS AND DISSEMINATION

The MULTI-CAP trial is conducted according to the principles of the Declaration of Helsinki, is registered in Clinical Trials and has been approved by the Committee for Protection of Persons and the National French Drug Safety Agency. Written informed consents are obtained from all the patients (or representatives). The results will be disseminated through educational institutions, submitted to peer-reviewed journals for publication and presented at medical congresses.

TRIAL REGISTRATION NUMBER

NCT03452826; Pre-results.

Nucleic Acid-based Testing for Noninfluenza Viral Pathogens in Adults with Suspected Community-acquired Pneumonia. An Official American Thoracic Society Clinical Practice Guideline

Background: This document provides evidence-based clinical practice guidelines on the diagnostic utility of nucleic acid–based testing of respiratory samples for viral pathogens other than influenza in adults with suspected community-acquired pneumonia (CAP).

Methods: A multidisciplinary panel developed a Population–Intervention–Comparison–Outcome question, conducted a pragmatic systematic review, and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology for clinical recommendations.

Results: The panel evaluated the literature to develop recommendations regarding whether routine diagnostics should include nucleic acid–based testing of respiratory samples for viral pathogens other than influenza in suspected CAP. The evidence addressing this topic was generally adjudicated to be of very low quality because of risk of bias and imprecision. Furthermore, there was little direct evidence supporting a role for routine nucleic acid–based testing of respiratory samples in improving critical outcomes such as overall survival or antibiotic use patterns. However, on the basis of direct and indirect evidence, recommendations were made for both outpatient and hospitalized patients with suspected CAP. Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was not addressed in the literature at the time of the evidence review.

Conclusions: The panel formulated and provided their rationale for recommendations on nucleic acid–based diagnostics for viral pathogens other than influenza for patients with suspected CAP.

Alterations in biochemical markers in adenovirus infection

BACKGROUND

Analyze possible relationships between HAdV and markers for inflammation, specifically the C-reactive protein (CRP) and procalcitonin (PCT) tests, along with other haematological markers.

METHODS

Retrospective study of 487 children presenting with fever and/or acute respiratory symptoms in the Paediatric Emergency Department. Analyses included viral presence/absence (both HAdV and other respiratory viruses) in respiratory exudates, CRP and PCT alterations in plasma, and haematological markers in whole blood.

RESULTS

Viral load was >500 copies/10³ cells of HAdV in 127 cases (26.1%), of which 66 (52%, P<0.0001) had alterations in PCT, and 112 (88.1%, P<0.0001) in CRP. Haematological markers were similar either HAdV was present or not, although many HAdV positive patients demonstrated leukocytosis (66%). Bacterial cultures from 141 samples showed altered PCT in 27 (60%) with HAdV infection, in 3 (18.7%) with bacterial infection, and 13 (26.5%) without either viral or bacterial infection (P<0.05). CRP was altered in 88.9% of HAdV infected children and in 87% infected with bacteria, although the percentage was greater than in cases where other respiratory viruses were present (61.3% P<0.05).

CONCLUSIONS

Results demonstrate a clear relationship between HAdV infection and alterations in PCT and CRP which should be taken into account in paediatric patient management.

Use of Procalcitonin and a Respiratory Polymerase Chain Reaction Panel to Reduce Antibiotic Use via an Electronic Medical Record Alert

Background

Respiratory tract infections are often viral and but are frequently treated with antibiotics, providing a significant opportunity for antibiotic de-escalation in patients. We sought to determine whether an automated electronic medical record best practice alert (BPA) based on procalcitonin and respiratory polymerase chain reaction (PCR) results could help reduce inappropriate antibiotic use in patients with likely viral respiratory illness.

Methods

This multisite, pre–post, quasi-experimental study included patients 18 years and older with a procalcitonin level <0.25 ng/mL and a virus identified on respiratory PCR within 48 hours of each other, and 1 or more systemic antibiotics ordered. In the study group, a BPA alerted providers of the diagnostic results suggesting viral infection and prompted them to reassess the need for antibiotics. The primary outcome measured was total antibiotic-days of therapy.

Results

The BPA reduced inpatient antibiotic-days of therapy by a mean of 2.2 days compared with patients who met criteria but did not have the alert fire (8.0 vs 5.8 days, respectively, P < .001). The BPA also reduced the percentage of patients prescribed antibiotics on discharge (20% vs 47.8%, P < .001), whereas there was no difference in need for antibiotic escalation after initial discontinuation (7.6% vs 4.3%, P = .198).

Conclusions

The automated antimicrobial stewardship BPA effectively reduced antibiotic use and discharge prescribing rates when diagnostics suggested viral respiratory tract infection, without a higher rate for reinitiation of antibiotics after discontinuation.

Clinical impact of a routine, molecular, point-of-care, test-and-treat strategy for influenza in adults admitted to hospital (FluPOC): a multicentre, open-label, randomised controlled trial

BACKGROUND

Diagnosis of influenza in patients admitted to hospital is delayed due to long turnaround times with laboratory testing, leading to inappropriate and late antiviral treatment and isolation facility use. Molecular point-of-care tests (mPOCTs) are highly accurate, easy to use, and generate results in less than 1 h, but high-quality evidence for their effect on management and clinical outcomes is needed. The aim of this study was to assess the clinical impact of an mPOCT on influenza detection, antiviral use, infection control measures, and clinical outcomes in adults admitted to hospital with acute respiratory illness.

METHODS

In this multicentre, pragmatic, open-label, randomised controlled trial (FluPOC), we recruited adults admitted to hospital with acute respiratory illness during influenza seasons from two hospitals in Hampshire, UK. Eligible patients were aged 18 years and older, with acute respiratory illness of 10 days or fewer duration before admission to hospital, who were recruited within 16 h of admission to hospital. Participants were randomly assigned (1:1), using random permuted blocks of varying sizes (4, 6 and 8), to receive mPOCT for influenza or routine clinical care (control group). The primary outcome was the proportion of patients infected with influenza who were treated appropriately with antivirals (neuraminidase inhibitors) within 5 days of admission. Safety was assessed in all patients. Secondary outcomes included time to antivirals, isolation facility use, and clinical outcomes. This study is registered with the ISRCTN registry, ISRCTN17197293, and is now complete.

FINDINGS

Between Dec 12, 2017, and May 3, 2019, over two influenza seasons, 613 patients were enrolled, of whom 307 were assigned to the mPOCT group and 306 to the control group, and all were analysed. Median age was 62 years (IQR 45-75) and 332 (54%) of 612 participants with data were female. 100 (33%) of 307 patients in the mPOCT group and 102 (33%) of 306 in the control group had influenza. 100 (100%) of 100 patients with influenza were diagnosed in the mPOCT group and 60 (59%) of 102 were diagnosed though routine clinical care in the control group (relative risk 1·7, 95% CI 1·7-1·7; p<0·0001). 99 (99%) of 100 patients with influenza in the mPOCT group were given antiviral treatment within 5 days of admission versus 63 (62%) 102 in the control group (relative risk 1·6, 95% CI 1·4-1·9; p<0·0001). Median time to antivirals was 1·0 h (IQR 0·0 to 2·0) in the mPOCT group versus 6·0 h (0·0 to 12·0) in the control group (difference of 5·0 h [95% CI 0·0-6·0; p=0·0039]). 70 (70%) of 100 patients with influenza in the mPOCT group were isolated to single-room accommodation versus 39 (38%) of 102 in the control group (relative risk 1·8 [95% CI 1·4-2·4; p<0·0001]). 19 adverse events occurred among patients with influenza in the mPOCT group compared with 34 events in the control group. No patients with influenza died in the mPOCT group and two (2%) died in the control group (p=0·16).

INTERPRETATION

Routine mPOCT for influenza was associated with improved influenza detection and improvements in appropriate and timely antiviral and isolation facility use. Routine mPOCT should replace laboratory-based diagnostics for acute admissions to hospital during the influenza season.

FUNDING

National Institute for Health Research.

Syndromic Multiplex Polymerase Chain Reaction (mPCR) Testing and Antimicrobial Stewardship: Current Practice and Future Directions

PURPOSE OF REVIEW

Syndromic multiplex polymerase chain reaction (mPCR) panels offer the antimicrobial steward a rapid tool for optimizing and de-escalating antimicrobials. In this review, we analyze the role of syndromic mPCR in respiratory, gastrointestinal, and central nervous system infections within the context of antimicrobial stewardship efforts.

RECENT FINDINGS

For all mPCR syndromic panels, multiple studies analyzed the pre-and-post implementation impact of mPCR on antimicrobial utilization. Prospective studies and trials of respiratory mPCR stewardship interventions, including diagnostic algorithms, educational efforts, co-testing with procalcitonin, and targeted provider feedback currently exist. For gastrointestinal and cerebrospinal fluid mPCR, fewer peer-reviewed reports exist for the use of mPCR in antimicrobial stewardship. These studies demonstrated an inconsistent trend towards decreasing antibiotic use with mPCR. This is further limited by a lack of statistical significance, the absence of controlled, prospective trials, and issues with data generalizability.

SUMMARY

Antibiotic overuse may improve when mPCR is coupled with electronic medical record algorithm-based approaches and direct provider feedback by an antimicrobial stewardship professional. mPCR may prove a useful tool for antimicrobial stewardship but future studies are needed to define the best practice for its utilization.

Molecular Testing for Acute Respiratory Tract Infections: Clinical and Diagnostic Recommendations From the IDSA's Diagnostics Committee

The clinical signs and symptoms of acute respiratory tract infections (RTIs) are not pathogen specific. Highly sensitive and specific nucleic acid amplification tests have become the diagnostic reference standard for viruses, and translation of bacterial assays from basic research to routine clinical practice represents an exciting advance in respiratory medicine. Most recently, molecular diagnostics have played an essential role in the global health response to the novel coronavirus pandemic. How best to use newer molecular tests for RTI in combination with clinical judgment and traditional methods can be bewildering given the plethora of available assays and rapidly evolving technologies. Here, we summarize the current state of the art with respect to the diagnosis of viral and bacterial RTIs, provide a practical framework for diagnostic decision making using selected patient-centered vignettes, and make recommendations for future studies to advance the field.

Respiratory viral testing and antibacterial treatment in patients hospitalized with community-acquired pneumonia

OBJECTIVE

Viruses are more common than bacteria in patients hospitalized with community-acquired pneumonia. Little is known, however, about the frequency of respiratory viral testing and its associations with antimicrobial utilization.

DESIGN

Retrospective cohort study.

SETTING

The study included 179 US hospitals.

PATIENTS

Adults admitted with pneumonia between July 2010 and June 2015.

METHODS

We assessed the frequency of respiratory virus testing and compared antimicrobial utilization, mortality, length of stay, and costs between tested versus untested patients, and between virus-positive versus virus-negative patients.

RESULTS

Among 166,273 patients with pneumonia on admission, 40,787 patients (24.5%) were tested for respiratory viruses, 94.8% were tested for influenza, and 20.7% were tested for other viruses. Viral assays were positive in 5,133 of 40,787 tested patients (12.6%), typically for influenza and rhinovirus. Tested patients were younger and had fewer comorbidities than untested patients, but patients with positive viral assays were older and had more comorbidities than those with negative assays. Blood cultures were positive for bacterial pathogens in 2.7% of patients with positive viral assays versus 5.3% of patients with negative viral tests (P < .001). Antibacterial courses were shorter for virus-positive versus -negative patients overall (mean 5.5 vs 6.4 days; P < .001) but varied by bacterial testing: 8.1 versus 8.0 days (P = .60) if bacterial tests were positive; 5.3 versus 6.1 days (P < .001) if bacterial tests were negative; and 3.3 versus 5.2 days (P < .001) if bacterial tests were not obtained (interaction P < .001).

CONCLUSIONS

A minority of patients hospitalized with pneumonia were tested for respiratory viruses; only a fraction of potential viral pathogens were assayed; and patients with positive viral tests often received long antibacterial courses.

A qualitative process evaluation of the introduction of procalcitonin testing as an antimicrobial stewardship intervention

Background Successful antimicrobial stewardship interventions are imperative in today's environment of antimicrobial resistance. New antimicrobial stewardship interventions should include qualitative analysis such as a process evaluation to determine which elements within an intervention are effective and provide insight into the context in which the intervention is introduced. Objective To assess the implementation process and explore the contextual factors which influenced implementation. Setting An academic teaching hospital in Cork, Ireland. Methods A process evaluation was conducted on completion of a feasibility study of the introduction of a procalcitonin antimicrobial stewardship intervention. The process evaluation consisted of semi-structured face-to-face interviews of key stakeholders including participating (senior) doctors (5), medical laboratory scientists (3) and a hospital administrator. The Consolidated Framework for Implementation Research was used to guide data collection, analysis, and interpretation. Main outcome measures Qualitative assessment of the intervention implementation process, the contextual factors which influenced implementation and identification of improvements to the intervention and its implementation and determine if proceeding to a randomised controlled trial would be appropriate. Results Analysis of the interviews identified three main themes. (1) The procalcitonin intervention and implementation process was viewed positively to support prescribing decisions. Participants identified modifications to procalcitonin processing and availability to improve implementation and allow procalcitonin to be "more of a clinical influence". (2) In the antimicrobial stewardship context the concept of fear of missing an infection and risks of potentially serious outcomes for patients emerged. (3) The hospital context consisted of barriers such as available resources and facilitators including the hospital culture of quality improvement. Conclusion This process evaluation provides a detailed analysis of the implementation of procalcitonin testing as an antimicrobial stewardship intervention. The positive findings of this process evaluation and feasibility study should be built upon and a full randomised controlled trial and economic evaluation should be conducted in a variety of hospital settings to confirm the effectiveness of procalcitonin as an antimicrobial stewardship intervention.

Biochemical indicators of coronavirus disease 2019 exacerbation and the clinical implications

Coronavirus Disease 2019 (COVID-19) has sparked a global pandemic, affecting more than 4 million people worldwide. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause acute lung injury (ALI) and even acute respiratory distress syndrome (ARDS); with a fatality of 7.0 %. Accumulating evidence suggested that the progression of COVID-19 is associated with lymphopenia and excessive inflammation, and a subset of severe cases might exhibit cytokine storm triggered by secondary hemophagocytic lymphohistiocytosis (sHLH). Furthermore, secondary bacterial infection may contribute to the exacerbation of COVID-19. We recommend using both IL-10 and IL-6 as the indicators of cytokine storm, and monitoring the elevation of procalcitonin (PCT) as an alert for initiating antibacterial agents. Understanding the dynamic progression of SARS-CoV-2 infection is crucial to determine an effective treatment strategy to reduce the rising mortality of this global pandemic.

Diagnostic accuracy of procalcitonin for bacterial pneumonia in children - a systematic review and meta-analysis

Objective: The predictive role of procalcitonin for childhood bacterial pneumonia, a leading cause of death, is unclear. We aimed to evaluate the diagnostic accuracy of procalcitonin for childhood bacterial pneumonia.Methods: Major bibliographic databases were searched from inception through September 2019 using pre-defined index terms, including 'procalcitonin,' 'pneumonia' and 'children'. The study is reported according to Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies. Meta-analyses of the diagnostic accuracy and odds ratio of procalcitonin for bacterial pneumonia were conducted along with subgroup analyses for different cut-offs of procalcitonin. The Quality Assessment of Diagnostic Accuracy Studies 2 instrument was used to assess the methodologic quality of eligible studies.Results: Twenty-five studies (with 2,864 patients) showed that procalcitonin for bacterial pneumonia had an overall sensitivity of 0.64 (95% confidence interval: 0.53-0.74), specificity of 0.72 (95% confidence interval: 0.64-0.79), positive likelihood ratio of 2.3 (95% confidence interval: 1.8-3.0) and negative likelihood ratio of 0.50 (95% confidence interval: 0.38-0.66), and Area Under the Receiver Operating Characteristics of 0.74 (95% confidence interval: 0.70-0.78). Using a cut-off of 0.5 ng/ml, Procalcitonin had a sensitivity of 0.68 (95% confidence interval: 0.50-0.82), specificity of 0.60 (95% confidence interval: 0.47-0.72), and Area Under the Receiver Operating Characteristics of 0.68 (95% confidence interval: 0.64-0.72). Using a cut-off of 2 ng/ml, procalcitonin had a sensitivity of 0.59 (95% confidence interval: 0.40-0.76), specificity of 0.71 (95% confidence interval: 0.58-0.81), and AUROC curve of 0.71 (95% confidence interval: 0.67-0.75). Elevated procalcitonin was not associated with increased odds of bacterial pneumonia (odds ratio: 1.36, 95% confidence interval: 0.81-1.92, p = .18). Quality assessment found minimal concerns for bias or applicability.Conclusions: Given the moderate diagnostic accuracy of procalcitonin for bacterial pneumonia, we recommend that procalcitonin be used in conjunction with other findings for management and disposition of children with pneumonia.

Acute respiratory failure among lung transplant adults requiring intensive care: Changing spectrum of causative organisms and impact of procalcitonin test in the diagnostic workup

BACKGROUND

The aim was to identify the causing organisms and assess the association of procalcitonin (PCT) with bacterial pneumonia within 24 hours of intensive care unit admission (ICU-A) among lung transplant (LT) adult recipients.

METHODS

Secondary analysis from a prospective cohort study. All LT adults admitted to ICU for acute respiratory failure (ARF) over 5 years were included. Patients were followed until hospital discharge or death.

RESULTS

Fifty-eight consecutive LT patients were enrolled. The most important cause of ICU-A due to ARF was pneumonia 29 (50%) followed by acute rejection 3 (5.2%) and bronchiolitis obliterans syndrome exacerbation 3 (5.2%). Microorganisms were isolated from 22/29 cases with pneumonia (75.9%): 17 (77.2%) bacterial, 4 (18.2%) viral, 1 (4.5%) Aspergillus fumigates, with Pseudomonas aeruginosa being the most common cause (45.5%) of pneumonia, with 10 patients presenting chronic colonization by P aeruginosa. Median [Interquartile range (IQR)] PCT levels within 24 hours after admission were higher in pneumonia (1.5 µg/L; IQR:0.3-22.0), than in non-pneumonia cases (0.2 µg/L; IQR:0.1-0.7) (P = .019) and PCT levels within 24 hours helped to discriminate bacterial pneumonia (8.2 µg/L; IQR:0.2-43.0) from viral pneumonia and non-pneumonia cases (0.2 µg/L; IQR:0.1-0.7). The overall negative predictive value for bacterial pneumonia was 85.1%, increasing to 91.6% among episodes after 6 months of LT.

CONCLUSIONS

Causes of severe pneumonia in LT are changing, with predominant role of P aeruginosa and respiratory viruses. PCT ≤ 0.5 μg/L within 24 hours helps to exclude bacterial pneumonia diagnosis in LT adults requiring ICU-A. A negative PCT test allows antimicrobial de-escalation and requires an alternative diagnostic to bacterial pneumonia.

The clinical impact of PCR-based point-of-care diagnostic in respiratory tract infections in children

Background

Children are commonly affected by respiratory tract infections. Based on clinical symptoms, laboratory evaluation, and imaging, the causative pathogen often cannot be delineated. Point‐of‐care‐testing systems that provide an opportunity for fast detection of common viruses and some bacteria can therefore influence treatment's options. We aimed to examine whether the Biofire® FilmArray® has an effect on antibiotic treatment, duration of antibiotic therapy, and length of hospital stay within a pediatric cohort.

Methods

We included children who were admitted to inpatient treatment with an acute respiratory tract infection from 02/2017 to 04/2018 using the FA respiratory panel for pathogen detection. The study group data were compared to the retrospective data of children admitted from 02/2016 to 02/2017, using a proprietary multiplex RT‐PCR.

Results

A total of 322 children of the study group and 464 children of the control group were analyzed for clinical symptoms, laboratory findings, antibiotic treatment, and length of hospital stay. There was no significant reduction (P < .05) of antibiotic treatment and length of hospital stay. CRP, prehospital antibiotic treatment, antibiotic treatment, past medical history, age, and further pathogen detection showed a significant impact on antibiotic therapy, duration of antibiotic treatment, and length of hospital stay.

Conclusion

The use of the FA did not result in a significant reduction of antibiotic treatment or in length of hospital stay. Other parameters had a more significant impact. Therefore, we suggest that standard operation procedures with therapy guidelines are necessary to provide an effective application of POCT systems.

Improving care for critically ill patients with community-acquired pneumonia

PURPOSE

The purpose of this study was to improve antimicrobial management and outcomes of critically ill patients with community-acquired pneumonia (CAP) through implementation of a pharmacist-driven bundle for ordering evidence-based diagnostic tests in a medical intensive care unit (MICU).

METHODS

An inpatient collaborative practice agreement (CPA) was established for MICU pharmacists to order criteria-driven diagnostic testing for CAP from November 2017-March 2018. Adults admitted to the MICU and started on empiric antibiotics for CAP were included. The intervention arm was compared with a standard of care (SOC) group from November 2016-March 2017.

RESULTS

Ninety-one patients were included in each group. There was no difference in the median antibiotic duration between SOC and CPA, at 7 days (interquartile range [IQR], 6-10) versus 7 days (IQR, 6-8), respectively. The overall use of evidence-based diagnostic tests increased in the CPA group. Patients in the CPA group had more frequent pathogen identification (SOC and CPA, respectively: 31 [34%] versus 46 [51%], p = 0.035) and antimicrobial deescalation (24 [26%] versus 53 [58%], p < 0.001). There was no significant difference in length of intensive care unit stay, at 4 days for SOC (IQR, 2-10) versus 6 days for CPA (IQR, 3-10), and no significant difference in inpatient all-cause mortality (13 [14%] versus 7 [8%]), retreatment 14 [15%] versus 11 [12%]), or 30-day readmission 16 ([18%] versus 13 [14%]) for SOC and CPA, respectively. The CPA was the only variable that was independently associated with antimicrobial deescalation (odds ratio, 4.030; 95% confidence interval, 2.101-7.731) in a multiple logistic regression.

CONCLUSION

Implementation of a pharmacy-driven pneumonia diagnostic stewardship bundle improved the use of evidence-based diagnostics and increased the frequency of pathogen identification. This intervention was associated with increased antimicrobial deescalation without a negative impact on patient safety outcomes.

Severe flu management: a point of view

Annual flu seasons are typically characterized by changes in types and subtypes of influenza, with variations in terms of severity. Despite remarkable improvements in the prevention and management of patients with suspected or laboratory-confirmed diagnosis of influenza, annual seasonal influenza continues to be associated with a high morbidity and mortality. Admission to the intensive care unit is required for patients with severe forms of seasonal influenza infection, with primary pneumonia being present in most of the cases. This review summarizes the most recent knowledge on the diagnosis and treatment strategies in critically ill patients with influenza, focused on diagnostic testing methods, antiviral therapy, use of corticosteroids, antibacterial and antifungal therapy, and supportive measures. The review focuses on diagnostic testing methods, antiviral therapy, use of corticosteroids, antibacterial and antifungal therapy, supportive measures and relevant existing evidence, in order to provide the non-expert clinician a useful overview. An enhanced understanding of current diagnostic and treatment aspects of influenza infection can contribute to improve outcomes and reduce mortality among ICU patients with influenza.

Pragmatic multicentre randomised controlled trial evaluating the impact of a routine molecular point-of-care 'test-and-treat' strategy for influenza in adults hospitalised with acute respiratory illness (FluPOC): trial protocol

BACKGROUND

Influenza infections often remain undiagnosed in patients admitted to hospital due to lack of routine testing. When tested for, the diagnosis and treatment of influenza are often delayed due to the slow turnaround times of centralised laboratory PCR testing. Newer molecular systems, have comparable accuracy to laboratory PCR testing, and can generate a result in under 1 hour, making them potentially deployable as point-of-care tests (POCTs). High-quality evidence for the impact of routine POCT for influenza on clinical outcomes is, however, currently lacking. This large pragmatic multicentre randomised controlled trial aims to address this evidence gap.

METHODS AND ANALYSIS

The FluPOC trial is a pragmatic, multicentre, randomised controlled trial evaluating adults admitted to a large teaching hospital and a district general hospital with an acute respiratory illness, during influenza season and defined by Public Health England. Up to 840 patients will be recruited over up to three influenza seasons, and randomised (1:1) to receive either POCT using the FilmArray respiratory panel, or routine clinical care. Clinical and infection control teams will be informed of the results in real time and where influenza is detected clinical teams will be encouraged to offer neuraminidase inhibitor (NAI) treatment in accordance with national guidelines. Those allocated to standard clinical care will have a swab taken for later analysis to allow assessment of missed diagnoses. The outcomes assessment will be by retrospective case note analysis. The outcome measures include the proportion of influenza-positive patients detected and appropriately treated with NAIs, isolation facility use, antibiotic use, length of hospital stay, complications and mortality.

ETHICS AND DISSEMINATION

Prior to commencing the study, approval was obtained from the South Central Hampshire A Ethics Committee (reference 17/SC/0368, granted 7 September 2017). Results generated from this protocol will be published in peer-reviewed scientific journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN17197293.

Impact of multiplex respiratory virus testing on antimicrobial consumption in adults in acute care: a randomized clinical trial

Objectives

Inappropriate use of antibiotics is associated with development of antimicrobial resistance. In respiratory infections it is often difficult to differentiate between viral and bacterial infections, and empirical treatment is common. Enhanced viral testing is expected to clarify clinical decision-making and reduce the prescription of antibacterial agents, but the impact of such information on patient care is unclear.

Methods

We conducted a (1:1) randomized controlled clinical trial involving 998 adults with respiratory symptoms, fever, chest pain or poor general condition in the emergency unit of a tertiary hospital. Multiplex PCR results for 496 patients were available in 24 hours (intervention group) and those for the remaining 502 patients were available in 7 days (control group). Our primary outcome measures were the duration of hospitalization and the consumption of antibiotics within 30 days of enrolment.

Results

In all, 841 of 998 (84%) patients had respiratory symptoms at study entry. A respiratory virus was detected in 175 (17.5%). The mean duration of hospitalization was 4.2 days (SD 5.4) in the intervention group and 4.1 days (SD 4.9) in the control group (difference 0.1, 95% CI –0.5 to 0.6, p 0.810). The mean days on antibiotics were 11.3 days (SD 12.6) in the intervention group and 10.4 days (SD 11.4) in the control group (difference 0.9, 95% CI –0.6 to 2.4, p 0.235).

Conclusions

Multiplex PCR testing for respiratory viruses with results available within 24 hours did not reduce the consumption of bacterial antibiotics or the length of hospital stay in adults presenting with respiratory symptoms, fever, chest pain or reduced general condition in acute care.

Opportunities Revealed for Antimicrobial Stewardship and Clinical Practice with Implementation of a Rapid Respiratory Multiplex Assay

Few studies assess the utility of rapid multiplex molecular respiratory panels in adult patients. Previous multiplex PCR assays took hours to days from order time to result. We analyze the clinical impact of switching to a molecular assay with a 3-h test-turnaround-time (TAT). We performed a retrospective review of adult patients who presented to our emergency departments with respiratory symptoms and had a respiratory viral panel (xTAG RVP; RVP) or respiratory pathogen panel (ePlex RP; RPP) within 48 h of presentation. The average TATs for the RVP and RPP were 27.9 and 3.0 h, respectively (P < 0.0001). In RVP-positive and RPP-positive patients, 68.9 and 44.5% of those with normal chest imaging received antibiotics (P = 0.013), while 95.4 and 89.6% of those with abnormal imaging received antibiotics, respectively (P = 0.187). There was no difference in antibiotic duration in RVP-positive and RPP-positive patients with abnormal chest imaging (6.2 and 6.0 days, respectively; P = 0.923) and normal chest imaging (4.5 and 4.3 days, respectively; P = 0.922). Fewer patients were admitted in the RPP-positive compared to the RVP-positive group (76.9 and 88.6%, respectively; P = 0.013), while the proportion of admissions were similar among RPP-negative and RVP-negative patients (85.3 and 87.1%, P = 0.726). Switching to a multiplex respiratory panel with a clinically actionable TAT is associated with reduced hospital admissions and, in admitted adults without focal radiographic findings, reduced antibiotic initiation. Opportunities to further mitigate inappropriate antibiotic use may be realized by combining rapid multiplex PCR with provider education, clinical decision-care algorithms, and active antibiotic stewardship.

Rapid Molecular Tests for Influenza, Respiratory Syncytial Virus, and Other Respiratory Viruses: A Systematic Review of Diagnostic Accuracy and Clinical Impact Studies

We systematically reviewed available evidence from Embase, Medline, and the Cochrane Library on diagnostic accuracy and clinical impact of commercially available rapid (results <3 hours) molecular diagnostics for respiratory viruses as compared to conventional molecular tests. Quality of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies criteria for diagnostic test accuracy (DTA) studies, and the Cochrane Risk of Bias Assessment and Risk of Bias in Nonrandomized Studies of Interventions criteria for randomized and observational impact studies, respectively. Sixty-three DTA reports (56 studies) were meta-analyzed with a pooled sensitivity of 90.9% (95% confidence interval [CI], 88.7%-93.1%) and specificity of 96.1% (95% CI, 94.2%-97.9%) for the detection of either influenza virus (n = 29), respiratory syncytial virus (RSV) (n = 1), influenza virus and RSV (n = 19), or a viral panel including influenza virus and RSV (n = 14). The 15 included impact studies (5 randomized) were very heterogeneous and results were therefore inconclusive. However, we suggest that implementation of rapid diagnostics in hospital care settings should be considered.

Human metapneumovirus as cause of severe community-acquired pneumonia in adults: insights from a ten-year molecular and epidemiological analysis

Background

Information on the clinical, epidemiological and molecular characterization of human metapneumovirus in critically ill adult patients with severe community-acquired pneumonia (CAP) and the role of biomarkers identifying bacterial coinfection is scarce.

Methods

This is a retrospective epidemiological study of adult patients with hMPV severe CAP admitted to ICU during a ten-year period with admission PSI score ≥ 3.

Results

The 92.8% of the 28 patients with severe CAP due to human metapneumovirus were detected during the first half of the year. Median age was 62 years and 60.7% were male. The genotyping of isolated human metapneumovirus showed group B predominance (60.7%). All patients had acute respiratory failure. Median APACHE II and SOFA score were 13 and 6.55, respectively. The 25% were coinfected with Streptococcus pneumoniae. 60.7% of the patients had shock at admission and 50% underwent mechanical ventilation. Seven patients developed ARDS, three of them younger than 60 years and without comorbidities. Mortality in ICU was 14.3%. Among survivors, ICU and hospital stay were 6.5 and 14 days, respectively. Plasma levels of procalcitonin were higher in patients with bacterial coinfection (18.2 vs 0.54; p < 0.05). The levels of C-reactive protein, however, were similar.

Conclusion

Human metapneumovirus was associated with severe CAP requiring ICU admission among elderly patients or patients with comorbidities, but also in healthy young subjects. These patients often underwent mechanical ventilation with elevated health resource consumption. While one out of four patients showed pneumococcal coinfection, plasma procalcitonin helped to implement antimicrobial stewardship.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0559-y) contains supplementary material, which is available to authorized users.

Evaluation of a molecular point-of-care testing for viral and atypical pathogens on intravenous antibiotic duration in hospitalized adults with lower respiratory tract infection: a randomized clinical trial

Objectives

The primary objective was to evaluate whether a molecular point-of-care test (POCT) for viral and atypical pathogens added to routine real-time PCR could reduce duration of intravenous antibiotics in hospitalized patients with lower respiratory tract infection (LRTI) compared with routine real-time PCR.

Methods

In this single-centre, open-label, randomized controlled study, we enrolled hospitalized adults diagnosed with LRTI. Patients were randomized to an intervention group (POCT FilmArray Panel for 20 viruses, atypical pathogens and bacteria plus routine real-time PCR) or a control group (routine real-time PCR for ten pathogens). The primary outcome was duration of intravenous antibiotics during hospitalization. The secondary outcomes included length of stay, cost of hospitalization and de-escalation within 72 hours and between 72 hours and 7 days. Intention-to-treat analysis was used.

Results

Between October 2017 and July 2018, we enrolled 800 eligible patients (398 in the intervention group and 402 in the control group). Duration of intravenous antibiotics in the intervention group was shorter than in the control (7.0 days (interquartile range (IQR) 5.0–9.0) versus 8.0 days (IQR 6.0–11.0); p <0.001). Length of hospital stay in the intervention group was significantly shorter (8.0 days (IQR 7.0–11.0) versus 9.0 days (IQR 7.0–12.0; p <0.001) and the cost of hospitalization in the intervention group was significantly lower ($1804.7 (IQR 1298.4–2633.8) versus $2042.5 (IQR 1427.4–2926.2); p 0.002) than control group. More patients in the intervention group achieved de-escalation within 72 hours (7.9%, 29/367 versus 3.2%, 12/377; p 0.005) and between 72 hours and 7 days (29.7%, 109/367 versus 22.0%, 83/377; p 0.024).

Conclusions

Use of molecular POCT testing for respiratory viruses and atypical pathogens might help to reduce intravenous antibiotic use in hospitalized LRTI patients.

Clinical Trial Registration

clinicaltrials.gov Identifier: NCT03391076.

The Clinical Utility of Respiratory Viral Testing in Hospitalized Children: A Meta-analysis

CONTEXT

Respiratory virus (RV) detection tests are commonly used in hospitalized children to diagnose viral acute respiratory infection (ARI), but their clinical utility is uncertain.

OBJECTIVES

To systematically review and meta-analyze the impact of RV test results on antibiotic consumption, ancillary testing, hospital length of stay, and antiviral use in children hospitalized with severe ARI.

DATA SOURCES

Seven medical literature databases from 1985 through January 2018 were analyzed.

STUDY SELECTION

Studies in children <18 years old hospitalized for severe ARI in which the clinical impact of a positive versus negative RV test result or RV testing versus no testing are compared.

DATA EXTRACTION

Two reviewers independently screened titles, abstracts, and full texts; extracted data; and assessed study quality.

RESULTS

We included 23 studies. High heterogeneity did not permit an overall meta-analysis. Subgroup analyses by age, RV test type, and viral target showed no difference in the proportion of patients receiving antibiotics between those with positive versus negative test results. Stratification by study design revealed that RV testing decreased antibiotic use in prospective cohort studies (odds ratio = 0.58; 95% confidence interval: 0.45-0.75). Pooled results revealed no conclusive impact on chest radiograph use (odds ratio = 0.71; 95% confidence interval: 0.48-1.04). Results of most studies found that positive RV test results did not impact median hospital length of stay, but they may decrease antibiotic duration. Nineteen (83%) studies were at serious risk of bias.

LIMITATIONS

Low-quality studies and high clinical and statistical heterogeneity were among the limitations.

CONCLUSIONS

Higher-quality prospective studies are needed to determine the impact of RV testing on antibiotic use in children hospitalized with severe ARI.

Procalcitonin guidance in patients with lower respiratory tract infections: a systematic review and meta-analysis

Although effective for bacterial lower respiratory tract infections (LRTIs), antibiotic treatment is often incorrectly prescribed for non-bacterial LRTIs. Procalcitonin has emerged as a promising biomarker to diagnose bacterial infections and guide antibiotic treatment decisions. As part of a regulatory submission to the U.S. Food and Drug Administration, this systematic review and meta-analysis summarizes the effects of procalcitonin-guided antibiotic stewardship on antibiotic use and clinical outcomes in adult LRTI patients. PubMed and the Cochrane Database of Systematic Reviews were searched for English-language randomized controlled trials published between January 2004 and May 2016. Random and fixed effects meta-analyses were performed to study efficacy (initiation of antibiotics, antibiotic use) and safety (mortality, length of hospital stay). Eleven trials were retained, comprising 4090 patients. Procalcitonin-guided patients had lower odds of antibiotic initiation (odds ratio: 0.26; 95% confidence interval [CI]: 0.13-0.52) and shorter mean antibiotic use (weighted mean difference: -2.15 days; 95% CI: -3.30 to -0.99) compared to patients treated with standard care. Procalcitonin use had no adverse impact on mortality (relative risk: 0.94; 95% CI: 0.69-1.28) and length of hospital stay (weighted mean difference: -0.15 days; 95% CI: -0.60 to 0.30). Procalcitonin guidance reduces antibiotic initiation and use among adults with LRTIs with no apparent adverse impact on length of hospital stay or mortality.

Effectiveness of clinical pathway for upper respiratory tract infections in emergency department

OBJECTIVE

We aimed to demonstrate the benefits of implementing a clinical pathway to decrease the inappropriate use of antibiotics in upper respiratory tract infections (URTI) in an emergency department (ED).

METHODS

The study was performed in a hospital with 300 beds. All patients who applied with URTI from 1st to 30th of April 2017 were included and the appropriateness of the antibiotics were compared with the patients in the same period in 2016. A checklist for the clinical pathway of URTI was completed by the ED physicians.

RESULTS

351 patients were included, 176 these patients were in pre-ASP period and 175 patients were in post-ASP period. The rate of prescriptions including antibiotics was 49% in pre-ASP period and has decreased to 29% in post-ASP period (p < 0.001). Adherence to clinical pathway has increased from 50% to 80% (p < 0.001). In the post-ASP period, clinical pathway was used in 133 out of 175 patients (76%) and the consequently rate of appropriate antibiotic use was 82%.

CONCLUSION

The implementation of clinical pathway for URTI has decreased inappropriate antibiotic use in ED. As the secondary effect, using clinical pathway in ED also has increased the awareness of ED physicians who did not adhere to clinical pathway.

The cost impact of PCT-guided antibiotic stewardship versus usual care for hospitalised patients with suspected sepsis or lower respiratory tract infections in the US: A health economic model analysis

Background

Procalcitonin is a biomarker that supports clinical decision-making on when to initiate and discontinue antibiotic therapy. Several cost (-effectiveness) analyses have been conducted on Procalcitonin-guided antibiotic stewardship, but none mainly based on US originated data.

Objective

To compare effectiveness and costs of a Procalcitonin-algorithm versus standard care to guide antibiotic prescription for patients hospitalized with a diagnosis of suspected sepsis or lower respiratory tract infection in the US.

Methods

A previously published health economic decision model was used to compare the costs and effects of Procalcitonin-guided care. The analysis considered the societal and hospital perspective with a time horizon covering the length of hospital stay. The main outcomes were total costs per patient, including treatment costs and productivity losses, the number of patients with antibiotic resistance or C.difficile infections, and costs per antibiotic day avoided.

Results

Procalcitonin -guided care for hospitalized patients with suspected sepsis and lower respiratory tract infection is associated with a reduction in antibiotic days, a shorter length of stay on the regular ward and the intensive care unit, shorter duration of mechanical ventilation, and fewer patients at risk for antibiotic resistant or C.difficile infection. Total costs in the Procalcitonin-group compared to standard care were reduced by 26.0% in sepsis and 17.7% in lower respiratory tract infection (total incremental costs of −$11,311 per patient and −$2,867 per patient respectively).

Conclusions

Using a Procalcitonin-algorithm to guide antibiotic use in sepsis and hospitalised lower respiratory tract infection patients is expected to generate cost-savings to the hospital and lower rates of antibiotic resistance and C.difficile infections.

Procalcitonin-Guided Antibiotic Discontinuation Might Shorten the Duration of Antibiotic Treatment Without Increasing Pneumonia Recurrence

BACKGROUND

The optimal duration of antibiotic treatment has not been established for pneumonia patients. Some investigators reported procalcitonin (PCT)-guided antimicrobial stewardship reduces the duration of antibiotic use without increasing mortality in pneumonia patients.

MATERIAL AND METHODS

We prospectively enrolled hospitalized community-acquired pneumonia or healthcare-associated pneumonia patients with PCT levels >0.20 ng/mL on admission, who were admitted between 2014 and 2017. PCT levels were measured on days 5, 8 and 11 and every 3 days thereafter if needed. Physicians were encouraged and strongly encouraged to discontinue antibiotics when PCT levels decreased below 0.20 ng/mL and 0.10 ng/mL, respectively. Those admitted between 2010 and 2014 were included in the study as historical controls. Primary endpoints were duration of antibiotic treatment and recurrence of pneumonia within 30 days after antibiotic discontinuation.

RESULTS

The PCT-guided and control groups consisted of 116 patients each. Background factors including pneumonia severity and PCT levels did not differ between the 2 groups. Median duration of antibiotic treatment was 8.0 and 11 days in the PCT-guided and control groups, respectively (P < 0.001). Multivariable regression analysis revealed that PCT-guided antibiotic discontinuation (partial regression coefficient [PRC] -1.9319, P < 0.001), PCT (PRC 0.1501, P = 0.0059) and albumin (PRC -1.4398, P = 0.0096) were significantly related to duration of antibiotic treatment. Pneumonia recurrence within 30 days after antibiotic discontinuation was not statistically different between the 2 groups (4.3% vs. 6.0%, P = 0.5541).

CONCLUSIONS

PCT-guided antibiotic discontinuation might be useful for shortening the duration of antibiotic treatment without increasing pneumonia recurrence.

More targeted use of oseltamivir and in-hospital isolation facilities after implementation of a multifaceted strategy including a rapid molecular diagnostic panel for respiratory viruses in immunocompromised adult patients

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Rapid molecular testing for respiratory viruses in immunocompromised adults in a hospital emergency care setting is useful.

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Implementation results in more targeted use of oseltamivir and a reduction in the use of in-hospital isolation facilities.

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No effect was seen on antibiotic use, antibiotic duration, hospital admissions and length of hospital stay.

Background

Immunocompromised adults are more vulnerable to a complicated course of viral respiratory tract infections (RTI).

Objectives

Provide evidence on the effect of implementation of rapid molecular diagnostics for viruses on use of in-hospital isolation facilities, oseltamivir and antibiotic usage, and other clinical outcomes in immunocompromised patients.

Study design

A before-after study during two consecutive respiratory viral seasons, including immunocompromised adult patients presenting at a tertiary care emergency department with clinical suspicion of RTI. During the first season (2016/2017), respiratory viruses were detected using inhouse real-time PCR. The second season (2017/2018), we implemented a diagnostic flowchart including a rapid molecular test for 15 respiratory viruses (FilmArray®). We assessed the effect of this implementation on need for isolation, antivirals and empirical antibiotics.

Results

We included 192 immunocompromised adult patients during the first and 378 during the second season. Respiratory viral testing was performed in 135 patients (70%) during the first and 284 (75%) during the second season (p = 0.218) of which 213 (75%) using the rapid test. After implementation, use of in-hospital isolation facilities was reduced (adjusted odds ratio 0.35, 95%CI 0.19-0.64). Furthermore, adequate use of oseltamivir improved, with fewer prescriptions in influenza negative patients (0.15, 95%CI 0.08-0.28) and more in influenza positive patients (11.13, 95%CI 1.75–70.86). No effect was observed on empirical antibiotic use, hospital admissions, length of hospital stay or safety outcomes.

Conclusions

Implementation of rapid molecular testing for respiratory viruses in adult immunocompromised patients results in more adequate use of oseltamivir and in-hospital isolation facilities without compromising safety.

Neutrophil Count Percentage and Neutrophil-Lymphocyte Ratio as Prognostic Markers in Patients Hospitalized for Community-Acquired Pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is a common serious infection. This study aimed to evaluate the prognostic utility of neutrophil count percentage (NCP) and neutrophil-lymphocyte ratio (NLR) in patients with CAP.

METHODS

Retrospective study of hospitalized patients with CAP. Patients had a blood test at admission and 3-5 days after hospitalization (early-stage test). The main outcome variables were 30-day and 90-day mortality.

RESULTS

Two hundred and 9patients were included. Patients who survived had significant reductions in both NCP and NLR between admission and the day 3-5 blood tests (from 85.8% to 65.4% for NCP and from 10.1 to 3.2 for NLR). Twenty-five patients died in the first 90 days. Patients who died had lower, non-significant reductions in NCP (from 84.8% to 74%) and NLR (from 9.9 to 6.9) and significantly higher early-stage NCP and NLR than those who survived. NCP values higher than 85% and NLR values higher than 10 in the early-stage blood test were associated with a higher risk of mortality, even after multivariate adjustment (HR for NCP: 12; HR for NLR: 6.5).

CONCLUSION

NCP and NLR are simple, low-cost parameters with prognostic utility, especially when measured 3-5 days after CAP diagnosis. High NLR and/or NCP levels are associated with a greater risk of mortality at 90 days.