Procalcitonin-guided antibiotic therapy in intensive care unit patients: a systematic review and meta-analysis

Unravelling the complexity of ventilator-associated pneumonia: a systematic methodological literature review of diagnostic criteria and definitions used in clinical research

BACKGROUND

Ventilator-associated pneumonia (VAP) is a prevalent and grave hospital-acquired infection that affects mechanically ventilated patients. Diverse diagnostic criteria can significantly affect VAP research by complicating the identification and management of the condition, which may also impact clinical management.

OBJECTIVES

We conducted this review to assess the diagnostic criteria and the definitions of the term "ventilator-associated" used in randomised controlled trials (RCTs) of VAP management.

SEARCH METHODS

Based on the protocol (PROSPERO 2019 CRD42019147411), we conducted a systematic search on MEDLINE/PubMed and Cochrane CENTRAL for RCTs, published or registered between 2010 and 2024.

SELECTION CRITERIA

We included completed and ongoing RCTs that assessed pharmacological or non-pharmacological interventions in adults with VAP.

DATA COLLECTION AND SYNTHESIS

Data were collected using a tested extraction sheet, as endorsed by the Cochrane Collaboration. After cross-checking, data were summarised in a narrative and tabular form.

RESULTS

In total, 7,173 records were identified through the literature search. Following the exclusion of records that did not meet the eligibility criteria, 119 studies were included. Diagnostic criteria were provided in 51.2% of studies, and the term "ventilator-associated" was defined in 52.1% of studies. The most frequently included diagnostic criteria were pulmonary infiltrates (96.7%), fever (86.9%), hypothermia (49.1%), sputum (70.5%), and hypoxia (32.8%). The different criteria were used in 38 combinations across studies. The term "ventilator-associated" was defined in nine different ways.

CONCLUSIONS

When provided, diagnostic criteria and definitions of VAP in RCTs display notable variability. Continuous efforts to harmonise VAP diagnostic criteria in future clinical trials are crucial to improve quality of care, enable accurate epidemiological assessments, and guide effective antimicrobial stewardship.

Benefits and Harms of Procalcitonin- or C-Reactive Protein-Guided Antimicrobial Discontinuation in Critically Ill Adults With Sepsis: A Systematic Review and Network Meta-Analysis

OBJECTIVES

In sepsis treatment, antibiotics are crucial, but overuse risks development of antibiotic resistance. Recent guidelines recommended the use of procalcitonin to guide antibiotic cessation, but solid evidence is insufficient. Recently, concerns were raised that this strategy would increase recurrence. Additionally, optimal protocol or difference from the commonly used C-reactive protein (CRP) are uncertain. We aimed to compare the effectiveness and safety of procalcitonin- or CRP-guided antibiotic cessation strategies with standard of care in sepsis.

DATA SOURCES

A systematic search of PubMed, Embase, CENTRAL, Igaku Chuo Zasshi, ClinicalTrials.gov, and World Health Organization International Clinical Trials Platform.

STUDY SELECTION

Randomized controlled trials involving adults with sepsis in intensive care.

DATA EXTRACTION

A systematic review with network meta-analyses was performed. The Grading of Recommendations, Assessments, Developments, and Evaluation method was used to assess certainty.

DATA SYNTHESIS

Eighteen studies involving 5023 participants were included. Procalcitonin-guided and CRP-guided strategies shortened antibiotic treatment (-1.89 days [95% CI, -2.30 to -1.47], -2.56 days [95% CI, -4.21 to -0.91]) with low- to moderate-certainty evidence. In procalcitonin-guided strategies, this benefit was consistent even in subsets with shorter baseline antimicrobial duration (7-10 d) or in Sepsis-3, and more pronounced in procalcitonin cutoff of "0.5 μg/L and 80% reduction." No benefit was observed when monitoring frequency was less than half of the initial 10 days. Procalcitonin-guided strategies lowered mortality (-27 per 1000 participants [95% CI, -45 to -7]) and this was pronounced in Sepsis-3, but CRP-guided strategies led to no difference in mortality. Recurrence did not increase significantly with either strategy (very low to low certainty).

CONCLUSIONS

In sepsis, procalcitonin- or CRP-guided antibiotic discontinuation strategies may be beneficial and safe. In particular, the usefulness of procalcitonin guidance for current Sepsis-3, where antimicrobials are used for more than 7 days, was supported. Well-designed studies are needed focusing on monitoring protocol and recurrence.

The Role of Biomarkers in the Diagnosis and Management of Pneumonia

Biomarkers are used in the diagnosis, severity determination, and prognosis for patients with community-acquired pneumonia (CAP). Selected biomarkers may indicate a bacterial infection and need for antibiotic therapy (C-reactive protein, procalcitonin, soluble triggering receptor expressed on myeloid cells). Biomarkers can differentiate CAP patients who require hospital admission and severe CAP requiring intensive care unit admission. Biomarker-guided antibiotic therapy may limit antibiotic exposure without compromising outcome and thus improve antibiotic stewardship. The authors discuss the role of biomarkers in diagnosing, determining severity, defining the prognosis, and limiting antibiotic exposure in CAP and ventilator-associated pneumonia patients.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement from the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Critical Care Management of Patients After Cardiac Arrest: A Scientific Statement From the American Heart Association and Neurocritical Care Society

The critical care management of patients after cardiac arrest is burdened by a lack of high-quality clinical studies and the resultant lack of high-certainty evidence. This results in limited practice guideline recommendations, which may lead to uncertainty and variability in management. Critical care management is crucial in patients after cardiac arrest and affects outcome. Although guidelines address some relevant topics (including temperature control and neurological prognostication of comatose survivors, 2 topics for which there are more robust clinical studies), many important subject areas have limited or nonexistent clinical studies, leading to the absence of guidelines or low-certainty evidence. The American Heart Association Emergency Cardiovascular Care Committee and the Neurocritical Care Society collaborated to address this gap by organizing an expert consensus panel and conference. Twenty-four experienced practitioners (including physicians, nurses, pharmacists, and a respiratory therapist) from multiple medical specialties, levels, institutions, and countries made up the panel. Topics were identified and prioritized by the panel and arranged by organ system to facilitate discussion, debate, and consensus building. Statements related to postarrest management were generated, and 80% agreement was required to approve a statement. Voting was anonymous and web based. Topics addressed include neurological, cardiac, pulmonary, hematological, infectious, gastrointestinal, endocrine, and general critical care management. Areas of uncertainty, areas for which no consensus was reached, and future research directions are also included. Until high-quality studies that inform practice guidelines in these areas are available, the expert panel consensus statements that are provided can advise clinicians on the critical care management of patients after cardiac arrest.

Clinical utility of procalcitonin in implementation of procalcitonin-guided antibiotic stewardship in the South-East Asia and India: evidence and consensus-based recommendations

INTRODUCTION

The South-East Asian (SEA) region and India are highly susceptible to antibiotic resistance, which is caused due to lack of antimicrobial stewardship (AMS) knowledge, uncontrolled use of antibiotics, and poor infection control. Nonadherence to national/local guidelines, developed to combat antimicrobial resistance, is a major concern. A virtual advisory board was conducted to understand the current AMS standards and challenges in its implementation in these regions.

AREAS COVERED

Procalcitonin (PCT)-guided antibiotic use was discussed in various clinical conditions across initiation, management, and discontinuation stages. Most experts strongly recommended using PCT-driven antibiotic therapy among patients with lower respiratory tract infections, sepsis, and COVID-19. However, additional research is required to understand the optimal use of PCT in patients with organ transplantation and cancer patients with febrile neutropenia. Implementation of the solutions discussed in this review can help improve PCT utilization in guiding AMS in these regions and reducing challenges.

EXPERT OPINION

Experts strongly support the inclusion of PCT in AMS. They believe that PCT in combination with other clinical data to guide antibiotic therapy may result in more personalized and precise targeted antibiotic treatment. The future of PCT in antibiotic treatment is promising and may result in effective utilization of this biomarker.

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.

BIOMARKERS: CAN THEY REALLY GUIDE OUR DAILY PRACTICE?

ABSTRACT

Optimal management of septic patients requires accurate assessment of both current severity status and prognosis. Since the 1990s, substantial advances have been made in the use of circulating biomarkers for such assessments. This summary of the session on "Biomarkers: can they really use guide our daily practice?" presented at the 2021 WEB-CONFERENCE OF THE EUROPEAN SHOCK SOCIETY, 6 November 2021. These biomarkers include ultrasensitive detection of bacteremia, circulating soluble urokina-type plasminogen activator receptor (suPAR), C-reactive protein (CRP) and ferritin and procalcitonin. In addition, the potential application of novel multiwavelength optical biosensor technology allows noninvasive monitoring of multiple metabolites that can be used to assess severity and prognosis in septic patients. The application these biomarkers and improved technologies provide the potential for improved personalized management of septic patients.

Integrating biology into clinical trial design

PURPOSE OF REVIEW

Critical care medicine revolves around syndromes, such as acute respiratory distress syndrome (ARDS), sepsis and acute kidney injury. Few interventions have shown to be effective in large clinical trials, likely because of between-patient heterogeneity. Translational evidence suggests that more homogeneous biological subgroups can be identified and that differential treatment effects exist. Integrating biological considerations into clinical trial design is therefore an important frontier of critical care research.

RECENT FINDINGS

The pathophysiology of critical care syndromes involves a multiplicity of processes, which emphasizes the difficulty of integrating biology into clinical trial design. Biological assessment can be integrated into clinical trials using predictive enrichment at trial inclusion, time-dependent variation to better understand treatment effects and biological markers as surrogate outcomes.

SUMMARY

Integrating our knowledge on biological heterogeneity into clinical trial design, which has revolutionized other medical fields, could serve as a solution to implement personalized treatment in critical care syndromes. Changing the trial design by using predictive enrichment, incorporation of the evaluation of time-dependent changes and biological markers as surrogate outcomes may improve the likelihood of detecting a beneficial effect from targeted therapeutic interventions and the opportunity to test multiple lines of treatment per patient.

Current Status of Antibiotic Stewardship and the Role of Biomarkers in Antibiotic Stewardship Programs

The importance of antibiotic stewardship is increasingly emphasized in accordance with the increasing incidences of multidrug-resistant organisms and accompanying increases in disease burden. This review describes the obstacles in operating an antibiotic stewardship program (ASP), and whether the use of biomarkers within currently available resources can help. Surveys conducted around the world have shown that major obstacles to ASPs are shortages of time and personnel, lack of appropriate compensation for ASP operation, and lack of guidelines or appropriate manuals. Sufficient investment, such as the provision of full-time equivalent ASP practitioners, and adoption of computerized clinical decision systems are useful measures to improve ASP within an institution. However, these methods are not easy in terms of both time commitments and cost. Some biomarkers, such as C-reactive protein, procalcitonin, and presepsin are promising tools in ASP due to their utility in diagnosis and forecasting the prognosis of sepsis. Recent studies have demonstrated the usefulness of algorithmic approaches based on procalcitonin level to determine the initiation or discontinuation of antibiotics, which would be helpful in decreasing antibiotics use, resulting in more appropriate antibiotics use.

Diagnostic des pneumonies aiguës communautaires aux urgences et distinction entre étiologie virale ou bactérienne

La pandémie actuelle liée à l’émergence du SARSCoV-2 en 2019 a considérablement modifié la perception des médecins de l’impact des virus respiratoires et de leur rôle dans les pneumonies aiguës communautaires (PAC). Alors que plus de 25 % des tableaux de PAC chez l’adulte étaient d’origine virale, les virus respiratoires étaient souvent perçus comme des agents pathogènes peu graves. Devant le défi que représente encore à nos jours la documentation microbiologique d’une PAC, l’instauration d’un traitement empirique par antibiotiques est souvent réalisée aux urgences. La pandémie de COVID-19 a surtout mis en exergue le rôle déterminant de la biologie moléculaire et du scanner thoracique dans l’algorithme diagnostique de la PAC. En effet, un diagnostic rapide et fiable est la clé pour améliorer les mesures de précaution et réduire la prescription inutile d’antibiotiques. Du fait de prises en charges très différentes, il est nécessaire de distinguer l’étiologie virale de la bactérienne d’une PAC.

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.

Antibiotic Decision-Making in the ICU

It is well established that Intensive Care Units (ICUs) are a focal point in antimicrobial consumption with a major influence on the ecological consequences of antibiotic use. With the high prevalence and mortality of infections in critically ill patients, and the clinical challenges of treating patients with septic shock, the impact of real life clinical decisions made by intensivists becomes more significant. Both under- and over-treatment with unnecessarily broad spectrum antibiotics can lead to detrimental outcomes. Even though substantial progress has been made in developing rapid diagnostic tests that can help guide antibiotic use, there is still a time window when clinicians must decide the empiric antibiotic treatment with insufficient clinical data. The continuous streams of data available in the ICU environment make antimicrobial optimization an ongoing challenge for clinicians but at the same time can serve as the input for sophisticated models. In this review, we summarize the evidence to help guide antibiotic decision-making in the ICU. We focus on 1) deciding IF: to start antibiotics, 2) choosing the spectrum of the empiric agents to use, and 3) de-escalating the chosen empiric antibiotics. We provide a perspective on the role of machine learning and artificial intelligence models for clinical decision support systems that can be incorporated seamlessly into clinical practice in order to improve the antibiotic selection process and, more importantly, current and future patients' outcomes.

Paving the way towards continuous biosensing by implementing affinity-based nanoswitches on state-dependent readout platforms

Combining affinity-based nanoswitches with state-dependent readout platforms allows for continuous biosensing and acquisition of real-time information about biochemical processes occurring in the environment of interest.

The role of lung ultrasound in procalcitonin-guided antibiotic discontinuation in ventilator-associated pneumonia

Background and Aims:

Starting antibiotic therapy at the proper time is the cornerstone of the management of ventilator-associated pneumonia (VAP). However, using antibiotics for a long duration of therapy in intensive care leads to increased bacterial resistance, financial burden and adverse drug reactions. We hypothesised that lung ultrasound may have a role in guiding antibiotic discontinuation in patients with VAP that will help to reduce the antibiotic duration and decrease the resistance.

Methods:

This was a prospective blinded cohort study from October 2020 to September 2021 in which 62 VAP patients were recruited. Antibiotics were started, procalcitonin (PCT) level and clinical pulmonary infection score were estimated and lung ultrasound (US) was performed on day 1 and repeated on day 7. On day 7, discontinuation of antibiotics was recommended if the PCT level was <0.25 μg/L. A lung reaeration score was recorded.

Results:

Based on the PCT levels, antibiotics were discontinued in 40 patients. The computed tomography findings of VAP had improved in all. The ultrasound reaeration score showed a highly significant negative correlation with the PCT on day 7 (-0.718, P < 0.001). A cut-off of 5 for the US score showed a sensitivity of 92.5%, specificity of 95.5%, positive predictive value of 97.4% and negative predictive value of 87.5% in detecting a low PCT score on day 7.

Conclusion:

Lung US is a non-invasive and safe method that can be used to guide antibiotic therapy in VAP.

A comparison of host response strategies to distinguish bacterial and viral infection

OBJECTIVES

Compare three host response strategies to distinguish bacterial and viral etiologies of acute respiratory illness (ARI).

METHODS

In this observational cohort study, procalcitonin, a 3-protein panel (CRP, IP-10, TRAIL), and a host gene expression mRNA panel were measured in 286 subjects with ARI from four emergency departments. Multinomial logistic regression and leave-one-out cross validation were used to evaluate the protein and mRNA tests.

RESULTS

The mRNA panel performed better than alternative strategies to identify bacterial infection: AUC 0.93 vs. 0.83 for the protein panel and 0.84 for procalcitonin (P<0.02 for each comparison). This corresponded to a sensitivity and specificity of 92% and 83% for the mRNA panel, 81% and 73% for the protein panel, and 68% and 87% for procalcitonin, respectively. A model utilizing all three strategies was the same as mRNA alone. For the diagnosis of viral infection, the AUC was 0.93 for mRNA and 0.84 for the protein panel (p<0.05). This corresponded to a sensitivity and specificity of 89% and 82% for the mRNA panel, and 85% and 62% for the protein panel, respectively.

CONCLUSIONS

A gene expression signature was the most accurate host response strategy for classifying subjects with bacterial, viral, or non-infectious ARI.

Microbiology and Outcomes of Institutionalized Patients With Stroke-Associated Pneumonia: An Observational Cohort Study

Background: The attributable mortality and microbial etiology of stroke-associated pneumonia (SAP) vary among different studies and were inconsistent. Purpose: To determine the microbiology and outcomes of SAP in the lower respiratory tract (LRT) for patients with invasive mechanical ventilation (MV). Methods: In this observational study, included patients were divided into SAP and non-SAP based on a comprehensive analysis of symptom, imaging, and laboratory results. Baseline characteristics, clinical characteristics, microbiology, and outcomes were recorded and evaluated. Results: Of 200 patients, 42.5% developed SAP after the onset of stroke, and they had a lower proportion of non-smokers (p = 0.002), lower GCS score (p < 0.001), higher serum CRP (p < 0.001) at ICU admission, and a higher proportion of males (p < 0.001) and hypertension (p = 0.039) than patients with non-SAP. Gram-negative aerobic bacilli were the predominant organisms isolated (78.8%), followed by Gram-positive aerobic cocci (29.4%). The main pathogens included K. pneumoniae, S. aureus, H. influenzae, A. baumannii, P. aeruginosa, E. aerogenes, Serratia marcescens, and Burkholderia cepacia. SAP prolonged length of MV (p < 0.001), duration of ICU stay (p < 0.001) and hospital stay (p = 0.027), shortened MV-free days by 28 (p < 0.001), and caused elevated vasopressor application (p = 0.001) and 60-day mortality (p = 0.001). Logistic regression analysis suggested that patients with coma (p < 0.001) have a higher risk of developing SAP. Conclusion: The microbiology of SAP is similar to early phase of HAP and VAP. SAP prolongs the duration of MV and length of ICU and hospital stays, but also markedly increases 60-day mortality.

Duration of antibiotic therapy for Enterobacterales and Pseudomonas aeruginosa: a review of recent evidence

PURPOSE OF REVIEW

Emergence of multidrug-resistant organisms, impact on intestinal microbiome, side effects and hospital costs are some of the factors that have encouraged multiple studies over the past two decades to evaluate different duration of antibiotic therapy with the goal of shorter but effective regimens. Here, we reviewed the most recent relevant data on the duration of therapy focused on two of the most common Gram-negative organisms in clinical practice, Pseudomonas aeruginosa and Enterobacterales.

RECENT FINDINGS

Recent studies including meta-analysis confirm that short antibiotic courses for both Enterobacterales and P. aeruginosa infections have comparable clinical outcomes to longer courses of therapy. Despite the advocacy for short-course therapy in contemporary guidelines, recent evidence in the USA has revealed a high prevalence of inappropriate antibiotic usage due to excessive duration of therapy.

SUMMARY

Although the decision process regarding the optimal duration of antibiotic therapy is multifactorial, the vast majority of infections other than endocardial or bone and joint, can be treated with short-course antibiotic therapy (i.e., ≤7 days). The combination of biomarkers, clinical response to therapy, and microbiologic clearance help determine the optimal duration in patients with infections caused by P. aeruginosa and Enterobacterales.

Procalcitonin for individualizing antibiotic treatment: an update with a focus on COVID-19

Procalcitonin (PCT) is useful for differentiating between viral and bacterial infections and for reducing the unnecessary use of antibiotics. As the rise of antimicrobial resistance reaches “alarming” levels according to the World Health Organization, the importance of using biomarkers, such as PCT to limit unnecessary antibiotic exposure has further increased. Randomized trials in patients with respiratory tract infections have shown that PCT has prognostic implications and its use, embedded in stewardship protocols, leads to reductions in the use of antibiotics in different clinical settings without compromising clinical outcomes. However, available data are heterogeneous and recent trials found no significant benefit. Still, from these trials, we have learned several key considerations for the optimal use of PCT, which depend on the clinical setting, severity of presentation, and pretest probability for bacterial infection. For patients with respiratory infections and sepsis, PCT can be used to determine whether to initiate antimicrobial therapy in low-risk settings and, together with clinical data, whether to discontinue antimicrobial therapy in certain high-risk settings. There is also increasing evidence regarding PCT-guided therapy in patients with coronavirus disease 2019 (COVID-19). This review provides an up-to-date overview of the use of PCT in different clinical settings and diseases, including a discussion about its potential to improve the care of patients with COVID-19.

Prediction of ventilator-associated pneumonia outcomes according to the early microbiological response: a retrospective observational study

Ventilator-associated pneumonia is a leading infectious cause of morbidity in critically ill patients; yet current guidelines offer no indications for follow-up cultures.We aimed to evaluate the role of follow-up cultures and microbiological response 3 days after diagnosing ventilator-associated pneumonia as predictors of short- and long-term outcomes.We performed a retrospective analysis of a cohort prospectively collected from 2004 to 2017. Ventilator-associated pneumonia was diagnosed based on clinical, radiographic, and microbiological criteria. For microbiological identification, a tracheobronchial aspirate was performed at diagnosis and repeated after 72 h. We defined three groups when comparing the two tracheobronchial aspirate results: persistence, superinfection, and eradication of causative pathogens.One-hundred-fifty-seven patients were enrolled in the study, among whom microbiological persistence, superinfection, and eradication was present in 67 (48%), 25 (16%), and 65 (41%), respectively, after 72hs. Those with superinfection had the highest mortalities in the intensive care unit (p=0.015) and at 90 days (p=0.036), while also having the fewest ventilation-free days (p=0.024). Multivariable analysis revealed shock at VAP diagnosis (odds ratios [OR] 3.43; 95% confidence interval [CI] 1.25 to 9.40), Staphylococcus aureus isolation at VAP diagnosis (OR 2.87; 95%CI 1.06 to 7.75), and hypothermia at VAP diagnosis (OR 0.67; 95%CI 0.48 to 0.95, per +1°C) to be associated with superinfection.Our retrospective analysis suggests that ventilator-associated pneumonia short-term and long-term outcomes may be associated with superinfection in follow-up cultures. Follow-up cultures may help guiding antibiotic therapy and its duration. Further prospective studies are necessary to verify our findings.

Evaluation of Plasmatic Procalcitonin in Healthy, and in Systemic Inflammatory Response Syndrome (SIRS) Negative or Positive Colic Horses

Simple Summary

Procalcitonin (PCT) increased in the case of systemic inflammatory response syndrome (SIRS), especially due to bacterial infection. The correlation between SIRS score and plasma PCT levels in horses have not been evaluated, and no studies investigated plasma PCT concentration over time. In the present study, PCT and SIRS score were evaluated in colic horses at admission to the hospital and at 24, 48, 72 and 96 h. Statistically differences were detected between healthy vs. all colic horses and between healthy vs. SIRS positive or SIRS negative horses. No correlation was observed between SIRS score and PCT. This suggests a role of plasmatic PCT as good biomarker for colic.

Abstract

Colic horses show systemic inflammatory response syndrome (SIRS) clinical signs. Procalcitonin (PCT) showed increased circulating levels in sick horses. This study compares plasma PCT concentrations in healthy vs. SIRS negative/positive colic horses over time, and evaluates PCT and SIRS score potential correlation, to verify the usefulness of PCT for the evaluation of SIRS severity. Ninety-one horses were included; 43/91 were healthy, on basis of physical examination, blood work and SIRS score (score = 0), while 48/91 were sick colic horses, classified as SIRS-negative (score < 2) and positive (score ≥ 2). Moreover, a 0–6 point-scale SIRS score was calculated (assessing mucous membrane color and blood lactate concentration). PCT was evaluated at admission, and at 24, 48, 72 and 96 h, using a commercial kit for equine species. We verified by the ANOVA test PCT differences between healthy vs. colic horses, healthy vs. SIRS-negative or SIRS-positive colic horses, at all sampling times, and the correlation between the SIRS score at admission with the SIRS score. Statistically significant differences were detected between healthy vs. all colic horses and between healthy vs. SIRS-positive or negative horses at all sampling times. No correlation was observed between the SIRS score at admission and PCT values. PCT was statistically higher in colic horses compared to the healthy ones, suggesting a role as a biomarker for colic.

Clinical impact of procalcitonin-based algorithms for duration of antibiotic treatment in critically ill adult patients with sepsis: a meta-analysis of randomized clinical trials

Background: Our objective was to assess the impact on mortality, antibacterial therapy duration, and length of stay of using PCT to guide antibiotic cessation in critically ill patients with sepsis or septic shock.Research design and Methods: A systematic literature search was performed in PubMed, Embase, ISI Web of Knowledge, BioMed Central, ScienceDirect and the Cochrane Central Register of Controlled Trials, of clinical trials published in English before December 31, 2019. Eligible studies should be carried out in adults at ICU with sepsis, comparing the PCT-guided antimicrobial therapy with standard of care. A random effects model was used.Results: Twelve studies were eligible with a total of 4292 patients included. The combined relative risk for 28-day mortality was 0.89 (95% CI: 0.79; 0.99), for the duration of antimicrobial therapy was -1.98 days (95% CI: -2.76, -1.21) and for ICU- length of stay was-1.21 days (95% CI: -4.16, 1.74).Conclusions: In critically ill adults with sepsis, a procalcitonin-guided strategy is associated with a significant shorter duration of antimicrobial therapy. This reduction was associated with a significant decrease in mortality although the length of ICU stay was not affected.

Effect of Antibiotic Discontinuation Strategies on Mortality and Infectious Complications in Critically Ill Septic Patients: A Meta-Analysis and Trial Sequential Analysis

OBJECTIVE

To investigate methods of antibiotic duration minimization and their effect on mortality and infectious complications in critically ill patients.

DATA SOURCES

A systematic search of PubMed, Embase (via Ovid), clinicaltrials.gov, and the Cochrane Central Register of Controlled Trials (via Wiley) (CENTRAL, Issue 2, 2015).

STUDY SELECTION

Randomized clinical trials comparing strategies to minimize antibiotic duration (days) for patients with infections or sepsis in intensive care.

DATA EXTRACTION

A systematic review with meta-analyses and trial sequential analyses of randomized clinical trials. Dichotomous data are presented as relative risk (95% CIs) and p value, and continuous data are presented as mean difference (CI) and p value.

DATA SYNTHESIS

We included 22 randomized clinical trials (6,046 patients). Strategies to minimize antibiotic use included procalcitonin (14 randomized clinical trials), clinical algorithms (two randomized clinical trials), and fixed-antibiotic duration (six randomized clinical trials). Procalcitonin (-1.23 [-1.61 to -0.85]; p < 0.001), but not clinical algorithm-guided antibiotic therapy (-7.41 [-18.18 to 3.37]; p = 0.18), was associated with shorter duration of antibiotic therapy. The intended reduction in antibiotic duration ranged from 3 to 7 days in fixed-duration antibiotic therapy randomized clinical trials. Neither procalcitonin-guided antibiotic treatment (0.91 [0.82-1.01]; p = 0.09), clinical algorithm-guided antibiotic treatment (0.67 [0.30-1.54]; p = 0.35), nor fixed-duration antibiotics (1.21 [0.90-1.63]; p = 0.20) were associated with reduction in mortality. Z-curve for trial sequential analyses of mortality associated with procalcitonin-guided therapy did not reach the trial sequential monitoring boundaries for benefit, harm, or futility (adjusted CI, 0.72-1.10). Trial sequential analyses for mortality associated with clinical algorithm and fixed-duration treatment accumulated less than 5% of the required information size. Despite shorter antibiotic duration, neither procalcitonin-guided therapy (0.93 [0.84-1.03]; p = 0.15) nor fixed-duration antibiotic therapy (1.06 [0.74-1.53]; p = 0.75) was associated with treatment failure.

CONCLUSIONS

Although the duration of antibiotic therapy is reduced with procalcitonin-guided therapy or prespecified limited duration, meta-analysis and trial sequential analyses are inconclusive for mortality benefit. Data on clinical algorithms to guide antibiotic cessation are limited.

Budget impact analysis of using procalcitonin to optimize antimicrobial treatment for patients with suspected sepsis in the intensive care unit and hospitalized lower respiratory tract infections in Argentina

BACKGROUND

Inappropriate antibiotic use represents a major global threat. Sepsis and bacterial lower respiratory tract infections (LRTIs) have been linked to antimicrobial resistance, carrying important consequences for patients and health systems. Procalcitonin-guided algorithms may represent helpful tools to reduce antibiotic overuse but the financial burden is unclear. The aim of this study was to estimate the healthcare and budget impact in Argentina of using procalcitonin-guided algorithms to guide antibiotic prescription.

METHODS

A decision tree was used to model health and cost outcomes for the Argentinean health system, over a one-year duration. Patients with suspected sepsis in the intensive care unit and hospitalized patients with LRTI were included. Model parameters were obtained from a focused, non-systematic, local and international bibliographic search, and validated by a panel of local experts. Deterministic and probabilistic sensitivity analyses were performed to analyze the uncertainty of parameters.

RESULTS

The model predicted that using procalcitonin-guided algorithms would result in 734.5 [95% confidence interval (CI): 1,105.2;438.8] thousand fewer antibiotic treatment days, 7.9 [95% CI: 18.5;8.5] thousand antibiotic-resistant cases avoided, and 5.1 [95% CI: 6.7;4.2] thousand fewer Clostridioides difficile cases. In total, this would save $422.4 US dollars (USD) [95% CI: $935;$267] per patient per year, meaning cost savings of $83.0 [95% CI: $183.6;$57.7] million USD for the entire health system and $0.4 [95% CI: $0.9;$0.3] million USD for a healthcare provider with 1,000 cases per year of sepsis and LRTI patients. The sensitivity analysis showed that the probability of cost-saving for the sepsis patient group was lower than for the LRTI patient group (85% vs. 100%).

CONCLUSIONS

Healthcare and financial benefits can be obtained by implementing procalcitonin-guided algorithms in Argentina. Although we found results to be robust on an aggregate level, some caution must be used when focusing only on sepsis patients in the intensive care unit.

Ability of procalcitonin to distinguish between bacterial and nonbacterial infection in severe acute exacerbation of chronic obstructive pulmonary syndrome in the ICU

Background

To assess the ability of procalcitonin (PCT) to distinguish between bacterial and nonbacterial causes of patients with severe acute exacerbation of COPD (AECOPD) admitted to the ICU, we conducted a retrospective analysis of two prospective studies including 375 patients with severe AECOPD with suspected lower respiratory tract infections. PCT levels were sequentially assessed at the time of inclusion, 6 h after and at day 1, using a sensitive immunoassay. The patients were classified according to the presence of a documented bacterial infection (including bacterial and viral coinfection) (BAC + group), or the absence of a documented bacterial infection (i.e., a documented viral infection alone or absence of a documented pathogen) (BAC- group). The accuracy of PCT levels in predicting bacterial infection (BAC + group) vs no bacterial infection (BAC- group) at different time points was evaluated by receiver operating characteristic (ROC) analysis.

Results

Regarding the entire cohort (n = 375), at any time, the PCT levels significantly differed between groups (Kruskal–Wallis test, p < 0.001). A pairwise comparison showed that PCT levels were significantly higher in patients with bacterial infection (n = 94) than in patients without documented pathogens (n = 218) (p < 0.001). No significant difference was observed between patients with bacterial and viral infection (n = 63). For example, the median PCT-H₀ levels were 0.64 ng/ml [0.22–0.87] in the bacterial group vs 0.24 ng/ml [0.15–0.37] in the viral group and 0.16 ng/mL [0.11–0.22] in the group without documented pathogens. With a c-index of 0.64 (95% CI; 0.58–0.71) at H₀, 0.64 [95% CI 0.57–0.70] at H₆ and 0.63 (95% CI; 0.56–0.69) at H₂₄, PCT had a low accuracy for predicting bacterial infection (BAC + group).

Conclusion

Despite higher PCT levels in severe AECOPD caused by bacterial infection, PCT had a poor accuracy to distinguish between bacterial and nonbacterial infection. Procalcitonin might not be sufficient as a standalone marker for initiating antibiotic treatment in this setting.

Procalcitonin (PCT) Level in the Emergency Department Identifies a High-Risk Cohort for All Patients Treated for Possible Sepsis

WHAT IS ALREADY KNOWN?

The benefits of measuring PCT in the Emergency Department (ED) are not yet fully characterised.PCT is widely used in the intensive care setting to guide antimicrobial prescribing.

WHAT THIS ADDS?

Measurement of PCT as a routine in the emergency department for all patients treated for possible sepsis identifies a high-risk cohort.

KEY IMPROVEMENT IN PATIENT CARE

A PCT measurement of >0.2ug/L in the Emergency Department identifies a patient at increased risk of deterioration and of in-hospital death.

BACKGROUND

Early recognition and management of sepsis in the Emergency Department (ED) is a clinical challenge. Our aim was to determine if measuring the biomarker PCT in patients with suspected sepsis enables the identification of patients at increased risk of deterioration or in-hospital death in the ED setting of a district general hospital in the United Kingdom.

METHODS

A prospective observational study was conducted on all patients aged 18 and over presenting to ED fulfilling NICE criteria for moderate to high risk of sepsis admitted to hospital. Patients had a PCT test alongside the sepsis six protocol. PCT was measured using Brahms's chemiluminescent micro particle assay (CMIA) for the quantitative determination of PCT in human serum and plasma on the Abbott Alinity I analytical platform. The cost per test was approximately 13 GBP.The analysis was performed on patients having a PCT in ED over a 7-month period, with in-depth scrutiny of an appropriate subgroup. A high level quality improvement (QI) approach was used in the study.

RESULTS

A total of 1242 patients were included in the study. Mean/median age was 67.9/72, (range 18-102). 88.7% of deaths occurred in patients over 65 years of age. 42.4% (n=532) had a PCT level in ED of >0.2 ug/L. This identified a high risk group with a 2.4 fold increase in mortality rate (7.7%:18.2% p value <0.001). The median length of stay (LOS) was 5 (IQR 9) and 8 days (IQR 11) in patients with a first PCT of ≤0.2 ug/L versus >0.2 ug/L respectively.

CONCLUSION

An immediate PCT on patients presenting to ED with signs of sepsis in a non-specialised acute trust identifies those patients at an increased risk of deterioration and in hospital death.

Best practice: antibiotic decision-making in ICUs

PURPOSE OF REVIEW

A major challenge in the ICU is optimization of antibiotic use. This review assesses current understanding of core best practices supporting and promoting astute antibiotic decision-making.

RECENT FINDINGS

Limiting exposure to the shortest effective duration is the cornerstone of antibiotic decision-making. The decision to initiate antibiotics should include assessment of risk for resistance. This requires synthesis of patient-level data and environmental factors to determine whether delayed initiation could be considered in some patients with suspected sepsis until sensitivity data is available. Until improved stratification scores and clinically meaningful cut-off values to identify MDR are available and externally validated, decisions as to which empiric antibiotic is used should rely on syndromic antibiograms and institutional guidance. Optimization of initial and maintenance doses is another enabler of enhanced outcome. Stewardship practices must be streamlined by re-assessment to minimize negative effects, such as a potential increase in duration of therapy and increased risk of collateral damage from exposure to multiple, sequential antibiotics that may ensue from de-escalation.

SUMMARY

Multiple challenges and research priorities for antibiotic optimization remain; however, the best stewardship practices should be identified and entrenched in daily practice. Reducing unnecessary exposure remains a vital strategy to limit resistance development.

Utility of procalcitonin in a medical intensive care unit in Croatia

AIMS

To investigate the clinical benefit of routine procalcitonin (PCT) measurement in the medical intensive care unit (ICU) of a tertiary referral hospital.

METHODS

Adult patients with suspected infections were included. White blood cells, C‑reactive protein (CRP), and PCT were measured.

RESULTS

In this study 129 patients of median age 64 years (interquartile range 39-89 years) were prospectively included. The Acute Physiology And Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were 21 ± 14 and 7 ± 6, respectively. Intensive care unit (ICU) mortality was 22.5%. Immunocompromised patients constituted 39.5%. A significant correlation was observed between PCT and APACHE II (Spearman's rho 0.461, p < 0.01), PCT and SOFA (Spearman's rho 0.494, p < 0.01) and PCT and CRP (Spearman's rho 0.403, p < 0.01). Most patients (n = 83, 64.3%) received antibiotics before admission. No difference in PCT (1.56 ± 8 µg/L vs. 1.44 ± 13 µg/L, p = 0.6) was observed with respect to previous antibiotic therapy. Levels of PCT and CRP were significantly increased in patients with positive blood cultures, the infection caused by Gram-negative microorganism regardless of disease severity and pneumonia with complications. PCT did not differ among patients with positive vs negative urine culture (4.6 ± 16 µg/L vs. 1.76 ± 11.9 µg/L) or positive vs. negative endotracheal aspirate (1.93 ± 11.4 µg/L vs. 1.76 ± 1.11 µg/L). PCT-guided stewardship was applied in 36 patients (28%).

CONCLUSION

Increased initial PCT levels might point to the development of more severe disease caused by Gram-negative bacteria, regardless of previous antibiotic treatment. The results pertain to immunocompetent and immunocompromised patients. Implementation of PCT-guided stewardship in those patients is possible and relies on experience as well as knowledge of reference change value for a marker within the specific setting.

Antimicrobial peptide polymers: no escape to ESKAPE pathogens-a review

Antimicrobial resistance (AMR) is one of the significant clinical challenges and also an emerging area of concern arising from nosocomial infections of ESKAPE pathogens, which has been on the rise in both the developed and developing countries alike. These pathogens/superbugs can undergo rapid mutagenesis, which helps them to generate resistance against antimicrobials in addition to the patient's non-adherence to the antibiotic regimen. Sticking to the idea of a 'one-size-fits-all' approach has led to the inappropriate administration of antibiotics resulting in augmentation of antimicrobial resistance. Antimicrobial peptides (AMPs) are the natural host defense peptides that have gained attention in the field of AMR, and recently, synthetic AMPs are well studied to overcome the drawbacks of natural counterparts. This review deals with the novel techniques utilizing the bacteriolytic activity of natural AMPs. The effective localization of these peptides onto the negatively charged bacterial surface by using nanocarriers and structurally nanoengineered antimicrobial peptide polymers (SNAPPs) owing to its smaller size and better antimicrobial activity is also described here.

Point-of-Care Biomarkers to Guide Antibiotic Prescription for Acute Febrile Illness in Sub-Saharan Africa: Promises and Caveats

Empiric malaria treatment in Sub-Saharan Africa has significantly decreased with the scaling-up of malaria rapid diagnostic tests; this coincided with a pronounced increase in empiric antibiotic prescriptions. In high-income countries, guidance for antibiotic prescriptions using biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT) has reduced antibiotic use while safe-guarding patient safety. Importantly, several low-cost point-of-care CRP/PCT tests are currently available. However, only a few studies on the role of CRP/PCT in differentiating bacterial vs viral infections in acute febrile illness have been conducted in Sub-Saharan Africa. Studies from Central and West Africa (most of which is malaria-endemic) are particularly scarce, and only 1 has included adults. The evidence base for point-of-care use of CRP/PCT biomarkers in acute fever in Sub-Saharan Africa should be urgently built. Before engaging in clinical trials to assess clinical impact, pilot studies should be conducted to address key knowledge gaps including recommended CRP/PCT cutoff values and the effect of malaria coinfection.

COVID-19: lessons for junior doctors redeployed to critical care

Approximately 4% of patients with coronavirus disease 2019 (COVID-19) will require admission to an intensive care unit (ICU). Governments have cancelled elective procedures, ordered new ventilators and built new hospitals to meet this unprecedented challenge. However, intensive care ultimately relies on human resources. To enhance surge capacity, many junior doctors have been redeployed to ICU despite a relative lack of training and experience. The COVID-19 pandemic poses additional challenges to new ICU recruits, from the practicalities of using personal protective equipment to higher risks of burnout and moral injury. In this article, we describe lessons for junior doctors responsible for managing patients who are critically ill with COVID-19 based on our experiences at an urban teaching hospital.

Role of procalcitonin use in the management of sepsis

Important aspects of sepsis management include early diagnosis as well as timely and specific treatment in the first few hours of triage. However, diagnosis and differentiation from non-infectious causes often cause uncertainties and potential time delays. Correct use of antibiotics still represents a major challenge, leading to increased risk for opportunistic infections, resistances to multiple antimicrobial agents and toxic side effects, which in turn increase mortality and healthcare costs. Optimized procedures for reliable diagnosis and management of antibiotic therapy has great potential to improve patient care. Herein, biomarkers have been shown to improve infection diagnosis, help in early risk stratification and provide prognostic information which helps optimizing therapeutic decisions ("antibiotic stewardship"). In this context, the use of the blood infection marker procalcitonin (PCT) has gained much attention. There is still no gold standard for the detection of sepsis and use of conventional diagnostic approaches are restricted by some limitations. Therefore, additional tests are necessary to enable early and reliable diagnosis. PCT has good discriminatory properties to differentiate between bacterial and viral inflammations with rapidly available results. Further, PCT adds to risk stratification and prognostication, which may influence appropriate use of health-care resources and therapeutic options. PCT kinetics over time also improves the monitoring of critically ill patients with sepsis and thus influences decisions regarding de-escalation of antibiotics. Most importantly, PCT helps in guiding antibiotic use in patients with respiratory infection and sepsis by limiting initiation and by shortening treatment duration. To date, PCT is the best studied biomarker regarding antibiotic stewardship. Still, further research is needed to understand optimal use of PCT, also in combination with other remerging diagnostic tests for most efficient sepsis care.

Sepsis 2019: What Surgeons Need to Know

The definition of sepsis continues to be as dynamic as the management strategies used to treat this. Sepsis-3 has replaced the earlier systemic inflammatory response syndrome (SIRS)-based diagnoses with the rapid Sequential Organ Failure Assessment (SOFA) score assisting in predicting overall prognosis with regards to mortality. Surgeons have an important role in ensuring adequate source control while recognizing the threat of carbapenem-resistance in gram-negative organisms. Rapid diagnostic tests are being used increasingly for the early identification of multi-drug-resistant organisms (MDROs), with a key emphasis on the multidisciplinary alert of results. Novel, higher generation antibiotic agents have been developed for resistance in ESKCAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) organisms while surgeons have an important role in the prevention of spread. The Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial has challenged the previous paradigm of length of antibiotic treatment whereas biomarkers such as procalcitonin are playing a prominent role in individualizing therapy. Several novel therapies for refractory septic shock, while still investigational, are gaining prominence rapidly (such as vitamin C) whereas others await further clinical trials. Management strategies presented as care bundles continue to be updated by the Surviving Sepsis Campaign, yet still remain controversial in its global adoption. We have broadened our temporal and epidemiologic perspective of sepsis by understanding it both as an acute, time-sensitive, life-threatening illness to a chronic condition that increases the risk of mortality up to five years post-discharge. Artificial intelligence, machine learning, and bedside scoring systems can assist the clinician in predicting post-operative sepsis. The public health role of the surgeon is key. This includes collaboration and multi-disciplinary antibiotic stewardship at a hospital level. It also requires controlling pharmaceutical sales and the unregulated dispensing of antibiotic agents globally through policy initiatives to control emerging resistance through prevention.

Rapid Rule Out of Culture-Negative Bloodstream Infections by Use of a Novel Approach to Universal Detection of Bacteria and Fungi

BACKGROUND

Currently it can take up to 5 days to rule out bloodstream infection. With the low yield of blood cultures (approximately 10%), a significant number of patients are potentially exposed to inappropriate therapy that can lead to adverse events. More rapid rule out can accelerate deescalation or cessation of antimicrobial therapy, improving patient outcomes.

METHODS

A method is described, termed enzymatic template generation and amplification (ETGA), that universally and sensitively detects DNA polymerase activity liberated from viable bacteria and fungi isolated from blood culture samples as a measure of bloodstream infection. ETGA was applied in a diagnostic test format to identify negative blood cultures after an overnight incubation. Performance data for a prototype (Cognitor) and automated (Magnitor) version of the test are presented.

RESULTS

The Cognitor manual assay displayed analytical reactivity for a panel of the 20 most prevalent causes of bloodstream infection, with a detection range of 28-9050 CFU/mL. Validation with 1457 clinical blood cultures showed a negative predictive value of 99.0% compared to blood culture incubation for 5 days. Magnitor showed an improved detection range of 1-67 CFU/mL, allowing for detection of bacteria-supplemented blood cultures after 2-8 h incubation, and Candida albicans-supplemented blood cultures at 16-22 h, 5-15 h faster than blood culture. Removing an aliquot from a blood culture bottle and replacing the bottle into the incubator was shown not to result in contaminating organisms being introduced.

CONCLUSIONS

The described method displays excellent breadth and detection for microbial cells and demonstrates the capability of confirming negative blood cultures after an overnight incubation in a blood culture instrument.

Optimal duration of antibiotic treatment in Gram-negative infections

PURPOSE OF REVIEW

Whilst many guidelines recommend limiting the use of antibiotics because of the increase in antimicrobial resistance (AMR), this strategy becomes challenging when dealing with severe infections in critically ill patients. Moreover, some Gram-negative bacilli (GNB) can exhibit mechanisms of resistance that make the patient more vulnerable to recurrence of infections. We reviewed recent data on the optimal duration of antibiotic therapy in these patients.

RECENT FINDINGS

Apart from having no additional clinical benefit at a certain point after initiation, antibiotics might have negative effects. Prolonged antibiotic exposure has been associated to development of AMR and represents a strong reason to avoid long courses of antibiotic therapy in GNB infections. Recent data suggest that also patients with severe infections, in whom source control is adequate, can be managed with short-course antibiotic therapy.

SUMMARY

The optimal duration of antibiotic therapy depends on many factors, but overall, many infections in the critically ill can be treated with short-course antibiotic therapy (7 days or less). The integration of signs of resolution, biomarkers, clinical judgment, and microbiologic eradication might help to define this optimal duration in patients with life-threatening infections caused by GNB.

Procalcitonin to stop antibiotics after cardiovascular surgery in a pediatric intensive care unit-The PROSACAB study

INTRODUCTION AND OBJECTIVE

Children admitted to the pediatric intensive care unit after cardiovascular surgery usually require treatment with antibiotics due to suspicion of infection. The aim of this study was to assess the effectiveness of procalcitonin in decreasing the duration of antibiotic treatment in children after cardiovascular surgery.

METHODS

Prospective, interventional study carried out in a pediatric intensive care unit. Included patients under 18 years old admitted after cardiopulmonary bypass. Two groups were compared, depending on the implementation of the PCT-guided protocol to stop or de-escalate the antibiotic treatment (Group 1, 2011-2013 and group 2, 2014-2018). This new protocol was based on the decrease of the PCT value by 20% or 50% with respect to the maximum value of PCT. Primary endpoints were mortality, stewardship indication, duration of antibiotic treatment, and antibiotic-free days.

RESULTS

886 patients were recruited. There were 226 suspicions of infection (25.5%), and they were confirmed in 38 cases (16.8%). The global rate of infections was 4.3%. 102 patients received broad-spectrum antibiotic (4.7±1.7 days in group 1, 3.9±1 days in group 2 with p = 0.160). The rate of de-escalation was higher in group 2 (30/62, 48.4%) than in group 1 (24/92, 26.1%) with p = 0.004. A reduction of 1.1 days of antibiotic treatment (group 1, 7.7±2.2 and group 2, 6.7±2.2, with p = 0.005) and 2 more antibiotic free-days free in PICU in group 2 were observed (p = 0.001), without adverse outcomes.

CONCLUSIONS

Procalcitonin-guided protocol for stewardship after cardiac surgery seems to be safe and useful to decrease the antibiotic exposure. This protocol could help to reduce the duration of broad-spectrum antibiotics and the duration of antibiotics in total, without developing complications or adverse effects.

Do we need biomarkers for the follow-up and shortening of antibiotic treatment duration?

PURPOSE OF REVIEW

Clinical and laboratory parameters are useful tools for the diagnosis, follow-up and evaluation of resolution, and to predict outcomes when measured at different time-points onset and serially during follow-up in patients with hospital-acquired pneumonia and/or ventilator-associated pneumonia (HAP/VAP).

RECENT FINDINGS

Both, the 2017 ERS/ESICM/ESCMID/Asociación Latino Americana de Tórax (EEEAG) and the 2016 IDSA/ATS guidelines (IAG) for the management of HAP/VAP recommend using clinical criteria alone, rather than biomarkers for diagnosis. Several studies were conducted to assess the value of serum biomarker concentration and kinetics for predicting the outcome in HAP/VAP, including C-reactive protein and procalcitonin (PCT). Although the EEEAG do not recommend routinely performing biomarker determinations in addition to bedside clinical assessment in patients receiving antibiotic treatment for VAP or HAP to predict adverse outcomes and clinical response, the IAG recommend that routine bedside clinical assessment should be accompanied by measurements of PCT to guide antimicrobial therapy. Additionally, the 2016 Surviving Sepsis Campaign also suggests that PCT levels can be used to support the shortening of antibiotic therapy.

SUMMARY

Current evidence indicate that there is no recommendation to use biomarkers systematically to guide every decision. However, in some circumstances they might add some relevant information to our everyday practice.

Host-Based Diagnostics for Acute Respiratory Infections

PURPOSE

The inappropriate use of antimicrobials, especially in acute respiratory infections (ARIs), is largely driven by difficulty distinguishing bacterial, viral, and noninfectious etiologies of illness. A new frontier in infectious disease diagnostics looks to the host response for disease classification. This article examines how host response-based diagnostics for ARIs are being used in clinical practice, as well as new developments in the research pipeline.

METHODS

A limited search was conducted of the relevant literature, with emphasis placed on literature published in the last 5 years (2014-2019).

FINDINGS

Advances are being made in all areas of host response-based diagnostics for ARIs. Specifically, there has been significant progress made in single protein biomarkers, as well as in various "omics" fields (including proteomics, metabolomics, and transcriptomics) and wearable technologies. There are many potential applications of a host response-based approach; a few key examples include the ability to discriminate bacterial and viral disease, presymptomatic diagnosis of infection, and pathogen-specific host response diagnostics, including modeling disease progression.

IMPLICATIONS

As biomarker measurement technologies continue to improve, host response-based diagnostics will increasingly be translated to clinically available platforms that can generate a holistic characterization of an individual's health. This knowledge, in the hands of both patient and provider, can improve care for the individual patient and help fight rising rates of antibiotic resistance.

Sepsis - What's new in 2019?

PURPOSE OF REVIEW

Sepsis-3 guidelines have implications in a deeper understanding of the biopathology of the disease. Further, the review focuses on timely topics and new literature on fluid resuscitation, the value of steroids in sepsis, and new therapeutic options such as angiotensin II, vitamin C, and thiamine as well as the emerging role of procalcitonin (PCT) in managing antibiotics.

RECENT FINDINGS

Traditional therapies such as type of crystalloid fluid administration and steroid therapy for sepsis are currently under re-evaluation. Angiotensin II is investigated for reversing vasodilatory shock. The role of capillary endothelium leak and cellular metabolism can be affected by vitamin C and thiamine levels. Biomarker level trends, specifically PCT, can aid clinical suspicion of infection.

SUMMARY

Sepsis-3 shifts the focus from a noninfectious inflammatory process and an emphasis on a dysregulated host response to infection. Hyperchloremic crystalloid resuscitation is associated with poor clinical outcomes. Steroid administration can reverse shock physiology; however, mortality benefits remain uncertain. Angiotensin II, vitamin C, and thiamine are novel treatment options that need further validation. PCT assays can help discern between infectious and noninfectious inflammation.

Can biomarkers improve the rational use of antibiotics?

PURPOSE OF REVIEW

We aim to review recent literature about the use of biomarkers to guide the initiation and duration of antibiotic treatments for suspected bacterial infections.

RECENT FINDINGS

Several good quality meta-analyses show that procalcitonin can be safely used to guide antibiotic-related decisions, especially for respiratory infections, thereby decreasing unnecessary antibiotic exposure. Furthermore, the use of CRP-based algorithms to guide antibiotic initiation in primary care patients with acute respiratory infections is associated with a reduction in antibiotic use without an increase in adverse events. Regarding neutrophil CD64 and serum amyloid A, more good-quality evidence is needed to assess their utility as biomarkers to tailor antibiotic use. Finally, transcriptomics, metabolomics and proteomics are promising tools for the development of tests to differentiate specific host responses to viral, bacterial and noninfectious stimuli, but such tests still need further validation.

SUMMARY

Evidence shows that the use of biomarkers, procalcitonin and CRP, can safely reduce unnecessary antibiotic prescriptions in certain infectious syndromes. The clinical utility of host-based strategies such as transcriptomics, metabolomics and proteomics for the diagnosis of infectious diseases has yet to be evaluated, as well as considerations such as costs, technical complexity and result turnaround time.

Procalcitonin-Guided Antibiotic Discontinuation and Mortality in Critically Ill Adults: A Systematic Review and Meta-analysis

BACKGROUND

Procalcitonin (PCT)-guided antibiotic discontinuation appears to decrease antibiotic use in critically ill patients, but its impact on survival remains less certain.

METHODS

We searched PubMed, Embase, Scopus, Web of Science, and CENTRAL for randomized controlled trials (RCTs) of PCT-guided antibiotic discontinuation in critically ill adults reporting survival or antibiotic duration. Searches were conducted without language restrictions from inception to July 23, 2018. Two reviewers independently conducted all review stages; another adjudicated differences. Data were pooled using random-effects meta-analysis. Study quality was assessed with the Cochrane risk of bias tool, and evidence was graded using GRADEpro.

RESULTS

Among critically ill adults (5,158 randomized; 5,000 analyzed), PCT-guided antibiotic discontinuation was associated with decreased mortality (16 RCTs; risk ratio [RR], 0.89; 95% CI, 0.83-0.97; I2 = 0%; low certainty). Death was the primary outcome in only one study and a survival benefit was not observed in the subset specified as sepsis (10 RCTs; RR, 0.94; 95% CI, 0.85-1.03; I2 = 0%), those without industry sponsorship (nine RCTs; RR, 0.98; 95% CI, 0.87-1.10; I2 = 0%), high PCT-guided algorithm adherence (five RCTs; RR, 0.93; 95% CI, 0.71-1.22; I2 = 0%), and PCT-guided algorithms without C-reactive protein (eight RCTs; RR, 0.96; 95% CI, 0.87-1.06; I2 = 0%). PCT-guided antibiotic discontinuation decreased antibiotic duration (mean difference, 1.31 days; 95% CI, -2.27 to -0.35; I2 = 93%) (low certainty).

CONCLUSIONS

Our findings of increased survival and decreased antibiotic utilization associated with PCT-guided antibiotic discontinuation represent low-certainty evidence with a high risk of bias. This relationship was primarily observed in studies without high protocol adherence and in studies with algorithms combining PCT and C-reactive protein. Properly designed studies with mortality as the primary outcome are needed to address this question.

TRIAL REGISTRY

International Prospective Register of Systematic Reviews (PROSPERO); No.: CRD42016049715; URL: http://www.crd.york.ac.uk/PROSPERO_REBRANDING/display_record.asp?ID=CRD42016049715.

Ability of serum procalcitonin to distinguish focus of infection and pathogen types in patients with bloodstream infection

Background

Serum procalcitonin (PCT) is a widely recognized inflammatory marker which can distinguish systemic bacterial infection from other types of infections. The ability of PCT levels to distinguish different pathogens from different focus of infection is contradictory.

Methods

This study included 551 patients with bloodstream infection (BSI) diagnosed with positive blood culture (BC) during Jan 2013 and May 2018. The patients were divided into two groups with or without definite focus of infection. In this study, we analyzed PCT levels induced by Gram-positive bacteria, Gram-negative bacteria and fungal infection. Relationship of time between PCT peak and BC collection, and the impact of antibiotics usage on PCT peak distribution were examined.

Results

For patients without definite focus of infection, the serum PCT values of Gram-negative bacteria were higher than that of Gram-positive bacteria (P<0.05). A cut-off value of 7.54 ng/mL for PCT showed a sensitivity of 88.3%. For patients with definite focus of infection, the serum PCT values of Gram-negative bacteria were significantly higher than Gram-positive bacteria in patients with lower respiratory tract (P=0.003), abdominal (P=0.039), urinary tract infection (P=0.025), but not in patients with upper respiratory tract infection (P=0.664). The PCT values between multidrug-resistant organism (MDRO) and sensitive bacteria were not statistically significant (P>0.05) among all patients. Moreover, among patients who use antibiotics before BC collection, the longer antibiotics used, the higher trend of the proportion for PCT peak distribution after BC collection. The higher proportion of antibiotics combined before BC collection, the lower proportion of PCT peak distribution appeared before BC collection, and the higher the proportion of PCT peak distribution appeared after BC collection.

Conclusions

PCT value is determined by many factors. PCT value is related to not only Gram-positive bacteria or Gram-negative bacteria, but also related to specific pathogens, and specific of infection sites etc. The use of Antibiotics is also an important factor of PCT value.

Impact of Pharmacist-Led Procalcitonin-Guided Antibiotic Therapy in Critically Ill Patients With Pneumonia

Purpose: Procalcitonin (PCT) is a peptide that is released in response to bacterial infections. The 2016 Infectious Diseases Society of America pneumonia guidelines recommend PCT monitoring to help guide antibiotic discontinuation. Utilization of PCT is well described in the literature; however, there is a paucity of literature regarding pharmacists' involvement for using PCT in antibiotic interventions. The objective of this study was to investigate the effect of pharmacist-led intervention with PCT-guided antibiotic therapy in critically ill patients with pneumonia. Methods: This was a pre-post study conducted at a 1368-bed community teaching hospital in the United States. A prospective cohort with pharmacist intervention utilizing PCT-algorithm guidance was compared with a retrospective historical cohort with standard therapy. Adult patients admitted to the intensive care unit (ICU) with pneumonia were included. The primary endpoint was duration of antibiotic therapy. Secondary endpoints included 28-day mortality, ICU and hospital length of stay, reinitiation of antibiotic therapy, and the incidence of Clostridium difficile infection. Results: From August 2016 to July 2017, 113 patients were screened in the PCT group and 123 patients in the standard therapy group. Of these, 37 patients were included in the PCT group and 37 patients in the standard therapy group. Baseline characteristics were similar between the 2 groups. The antibiotic duration of therapy was 6.3 days in the PCT group versus 9.7 days in the standard therapy group (P < .001). There were no differences in secondary endpoints between the 2 groups. Conclusion: Clinical pharmacists' intervention with PCT-guided antibiotic therapy led to a reduction in the duration of antibiotic therapy in critically ill patients with pneumonia without increasing complications.