Stop Antibiotics on guidance of Procalcitonin Study (SAPS): a randomised prospective multicenter investigator-initiated trial to analyse whether daily measurements of procalcitonin versus a standard-of-care approach can safely shorten antibiotic duration in intensive care unit patients--calculated sample size: 1816 patients

Application of MIDD to accelerate the development of anti-infectives: Current status and future perspectives

This review examines the role of model-informed drug development (MIDD) in advancing antibacterial and antiviral drug development, with an emphasis on the inclusion of host system dynamics into modeling efforts. Amidst the growing challenges of multidrug resistance and diminishing market returns, innovative methodologies are crucial for continuous drug discovery and development. The MIDD approach, with its robust capacity to integrate diverse data types, offers a promising solution. In particular, the utilization of appropriate modeling and simulation techniques for better characterization and early assessment of drug resistance are discussed. The evolution of MIDD practices across different infectious disease fields is also summarized, and compared to advancements achieved in oncology. Moving forward, the application of MIDD should expand into host system dynamics as these considerations are critical for the development of "live drugs" (e.g. chimeric antigen receptor T cells or bacteriophages) to address issues like antibiotic resistance or latent viral infections.

The Impact of Antimicrobial Stewardship in Treating Patients with Escherichia coli Bacteremia in a Small Single Center Community Hospital

Purpose: There are many challenges that pharmacist led antimicrobial stewardship programs can encounter including lack of resources, costs, and inaccurate antimicrobial susceptibility testing (AST) results. The COVID-19 pandemic has led to increased resistance especially with gram negative infections. At a small single center community hospital, gram negative infections, particularly Escherichia coli infections, predominately occur. Therefore, this study aims to address gram negative bacteremia burden and its impact on antimicrobial stewardship efforts for combatting Escherichia coli and ESBL organisms with such barriers during the pandemic. Methods: In a retrospective cohort study, patients ≥ 18 years of age from a small community hospital were reviewed. Patients were excluded if their blood cultures were not positive for Escherichia coli and if antibiotics were not initiated during hospital stay. The primary endpoint was to determine the length of hospital stay. Critical secondary endpoints include antibiotic de-escalations, duration of antibiotics, time to definitive antibiotic therapy, serum procalcitonin levels, blood culture availabilities, MIC breakpoints, co-infection of COVID-19, and Clostridioides difficile occurrences. Results: Out of 74 patients with gram negative bacteremia, 41 patients specifically had Escherichia coli bacteremia. The primary endpoint results showed that patients with Escherichia coli bacteremia that stayed in the ICU had a length of stay of 13.6 days. Patients with Escherichia coli bacteremia in the Non-ICU setting has a length of stay of 7.3 days, and patients with ESBL bacteremia in the Non-ICU setting had a length of stay of 6.8 days. Conclusions: Despite the various challenges that antimicrobial stewardship programs (ASP) face in a single center small community hospital, the ASP at this small community hospital utilizes various policies and tools to increase appropriate antibiotic use and decrease hospital length of stay in patients with Escherichia coli bacteremia.

Procalcitonin Use for Predicting Mortality and Morbidity of Patients Diagnosed With Sepsis Within the Intensive Care Unit

Objective Infections leading to severe sepsis and septic shock are among the top five causes requiring admission to the intensive care unit (ICU). Up to 40% of ICU admissions contain a sepsis diagnosis. Without a clear marker to diagnose and manage sepsis, procalcitonin has been extensively studied for its usefulness in the management of bacterial infections. These studies, however, have been focused toward how it can be used to help guide when antibiotics should be initiated and de-escalated. There, however, has not been a study on how this biomarker could be used to predict mortality, and morbidity and help guide a need for antibiotic escalation. Design A retrospective chart review was conducted on patients admitted to the ICU at Northeast Georgia Medical Center between January 1, 2019, to June 30, 2021. Inclusion criteria were all patients above the age of 18 admitted to the ICU with a diagnosis of sepsis and having at least two procalcitonin drawn within 10 days of each other. Exclusion criteria were any patient with a diagnosis of COVID-19. Data Analysis was conducted to identify how delta procalcitonin could identify mortality and morbidity and if there was any change in antibiotics based on the delta procalcitonin.  Conclusion There was a statistically significant association between a delta positive procalcitonin and increased ICU length of stay. There was no statistical significance in expiration based on the antibiotic change in relationship to delta positive change in procalcitonin.

Procalcitonin as a biomarker to guide treatments for patients with lower respiratory tract infections

INTRODUCTION

Lower respiratory tract infections are amongst the main causes for hospital/intensive care unit admissions and antimicrobial prescriptions. In order to reduce antimicrobial pressure, antibiotic administration could be optimized through procalcitonin-based algorithms.

AREAS COVERED

In this review, we discuss the performances of procalcitonin for the diagnosis and the management of community-acquired and ventilator-associated pneumonia. We provide up-to-date evidence and deliver clear messages regarding the purpose of procalcitonin to reduce unnecessary antimicrobial exposure.

EXPERT OPINION

Antimicrobial pressure and resulting antimicrobial resistances are a major public health issue as well as a daily struggle in the management of patients with severe infectious diseases, especially in intensive care units where antibiotic exposure is high. Procalcitonin-guided antibiotic administration has proven its efficacy in reducing unnecessary antibiotic use in lower respiratory tract infections without excess in mortality, hospital length of stay or disease relapse. Procalcitonin-guided algorithms should be implemented in wards taking care of patients with severe infections. However, procalcitonin performances are different regarding the setting of the infection (community versus hospital-acquired infections) the antibiotic management (start or termination of antibiotic) as well as patient's condition (immunosuppressed or in shock) and we encourage the physicians to be aware of these limitations.

Biomarker-guided duration of antibiotic treatment in children hospitalised with confirmed or suspected bacterial infection: statistical analysis plan for the BATCH trial and PRECISE sub-study

INTRODUCTION

The BATCH trial is a multi-centre randomised controlled trial to compare procalcitonin-guided management of severe bacterial infection in children with current management. PRECISE is a mechanistic sub-study embedded into the BATCH trial. This paper describes the statistical analysis plan for the BATCH trial and PRECISE sub-study.

METHODS

The BATCH trial will assess the effectiveness of an additional procalcitonin test in children (aged 72 h to 18 years) hospitalised with suspected or confirmed bacterial infection to guide antimicrobial prescribing decisions. Participants will be enrolled in the trial from randomisation until day 28 follow-up. The co-primary outcomes are duration of intravenous antibiotic use and a composite safety outcome. Target sample size is 1942 patients, based on detecting a 1-day reduction in intravenous antibiotic use (90% power, two-sided) and on a non-inferiority margin of 5% risk difference in the composite safety outcome (90% power, one-sided), while allowing for up to 10% loss to follow-up.

RESULTS

Baseline characteristics will be summarised overall, by trial arm, and by whether patients were recruited before or after the pause in recruitment due to the COVID-19 pandemic. In the primary analysis, duration of intravenous antibiotic use will be tested for superiority using Cox regression, and the composite safety outcome will be tested for non-inferiority using logistic regression. The intervention will be judged successful if it reduces the duration of intravenous antibiotic use without compromising safety. Secondary analyses will include sensitivity analyses, pre-specified subgroup analyses, and analysis of secondary outcomes. Two sub-studies, including PRECISE, involve additional pre-specified subgroup analyses. All analyses will be adjusted for the balancing factors used in the randomisation, namely centre and patient age.

CONCLUSION

We describe the statistical analysis plan for the BATCH trial and PRECISE sub-study, including definitions of clinical outcomes, reporting guidelines, statistical principles, and analysis methods. The trial uses a design with co-primary superiority and non-inferiority endpoints. The analysis plan has been written prior to the completion of follow-up.

TRIAL REGISTRATION

BATCH: ISRCTN11369832, registered 20 September 2017, doi.org/10.1186/ISRCTN11369832.

PRECISE

ISRCTN14945050, registered 17 December 2020, doi.org/10.1186/ISRCTN14945050.

PROCALCITONIN GUIDED ANTIBIOTIC STEWARDSHIP: A BALKAN EXPERT CONSENSUS STATEMENT

Sepsis as a consequence of infection is a frequent cause of death among critically ill patients. The most common sites of infection are lover respiratory tract, abdominal, urinary tract and catheter-associated blood stream infections. Early empiric, broad-spectrum therapy in those with severe sepsis and/or shock with the aim of reducing mortality may lead to antibiotic overuse, resistance and increased costs. Among numerous serum biomarkers, procalcitonin (PCT) has proved to be one of the most reliable ones in the diagnosis of sepsis. An important means of limiting antibiotic resistance is the antibiotic stewardship program, especially in intensive care units with critically ill patients and prevalence of multiple drug-resistant pathogens. The PCT-guided antibiotic stewardship was first started in Western Europe and Asia-Pacific countries, as well as in the United States. Considering that this method has proven to be effective in reducing antibiotic consumption while improving clinical outcome, a group of experts from the Balkan region decided to make their own recommendations and PCT protocol. When creating this protocol for initiation and duration of antibiotic treatment, they especially reviewed the literature for lower respiratory tract infection and sepsis. In the protocol, they have included the severity of illness, clinical assessment, and PCT levels. Developing a consensus on the clinical algorithm by eminent experts/specialists in various fields of medicine should enable clinicians to use PCT for initiation of antibiotic therapy and monitoring PCT to stop antibiotics earlier. It is crucial that the PCT-guided algorithm becomes an integral part of institutional stewardship program.

Impact of reduced antibiotic treatment duration on antimicrobial resistance in critically ill patients in the randomized controlled SAPS-trial

Background

In the previously reported SAPS trial (https://clinicaltrials.gov/ct2/show/NCT01139489), procalcitonin-guidance safely reduced the duration of antibiotic treatment in critically ill patients. We assessed the impact of shorter antibiotic treatment on antimicrobial resistance development in SAPS patients.

Materials and methods

Cultures were assessed for the presence of multi-drug resistant (MDR) or highly resistant organisms (HRMO) and compared between PCT-guided and control patients. Baseline isolates from 30 days before to 5 days after randomization were compared with those from 5 to 30 days post-randomization. The primary endpoint was the incidence of new MDR/HRMO positive patients.

Results

In total, 8,113 cultures with 96,515 antibiotic test results were evaluated for 439 and 482 patients randomized to the PCT and control groups, respectively. Disease severity at admission was similar for both groups. Median (IQR) durations of the first course of antibiotics were 6 days (4-10) and 7 days (5-11), respectively (p = 0.0001). Antibiotic-free days were 7 days (IQR 0-14) and 6 days (0-13; p = 0.05). Of all isolates assessed, 13% were MDR/HRMO positive and at baseline 186 (20%) patients were MDR/HMRO-positive. The incidence of new MDR/HRMO was 39 (8.9%) and 45 (9.3%) in PCT and control patients, respectively (p = 0.82). The time courses for MDR/HRMO development were also similar for both groups (p = 0.33).

Conclusions

In the 921 randomized patients studied, the small but statistically significant reduction in antibiotic treatment in the PCT-group did not translate into a detectable change in antimicrobial resistance. Studies with larger differences in antibiotic treatment duration, larger study populations or populations with higher MDR/HRMO incidences might detect such differences.

Using Procalcitonin to Guide Antibiotic Escalation in Patients With Suspected Bacterial Infection: A New Application of Procalcitonin in the Intensive Care Unit

Background

Procalcitonin (PCT) is efficient in reducing antibiotic usage without increasing complications for its sensitivity and specificity in detecting bacterial infection. However, its role in guiding antibiotic-spectrum escalation has not been studied. This study was performed to validate the role of PCT in indicating antibiotic spectrum escalation when pathogen results are unknown for ICU patients of suspected bacterial infections.

Methods

This was a single-center retrospective study including patients who were admitted to Peking Union Medical College Hospital from January 2014 to June 2018 for suspected bacterial infections. Patients were divided into “escalation” or “non-escalation” groups according to the change of employed antibiotic spectrum before and after the occurrence of “PCT alert”. The main study endpoint was the length of ICU stay (LIS), and LIS longer than 7 days was defined as “prolonged-ICU-stay (PIS)” while LIS equal to or shorter than 7 days was defined as “non-prolonged-ICU-stay(nPIS)”. Demographics, clinical characteristics, and infection characteristics were compared between patients in the “nPIS” and “PIS” groups. Multivariable logistic regression was used to evaluate independent risk factors for PIS.

Results

Totally, 1109 patients were included, and 654 in the PIS group, other 455 in the nPIS group. Respiratory infection was the main cause in both groups. Patients were older in PIS group than in nPIS group(PIS vs. nPIS: 58.99 ± 16.30 vs. 56.12 ± 15.93 years, P=0.002). The baseline Sequential Organ Failure Assessment (SOFA) score was 11.16 ± 7.33 and 9.73 ± 3.70 in PIS and nPIS groups. Fewer patients received antibiotic escalation in face of “PCT alert” in PIS group (PIS vs. nPIS: 27.68 vs.35.38%, P=0.014). In the multivariable logistic regression model, older age, higher heart rate, not undergoing surgery, higher baseline SOFA score, and not escalating antibiotics in face of “PCT alert” were associated with a prolonged ICU stay. The odds ratio of antibiotic escalation for PIS was 0.582 (95% CI: 0.365, 0.926, P=0.022).

Conclusions

Using PCT to guide antibiotic escalation when pathogen evidence is unavailable could be associated with a shorter length of ICU stay for ICU patients of suspected bacterial infection.

Infection Biomarkers Based on Metabolomics

Current infection biomarkers are highly limited since they have low capability to predict infection in the presence of confounding processes such as in non-infectious inflammatory processes, low capability to predict disease outcomes and have limited applications to guide and evaluate therapeutic regimes. Therefore, it is critical to discover and develop new and effective clinical infection biomarkers, especially applicable in patients at risk of developing severe illness and critically ill patients. Ideal biomarkers would effectively help physicians with better patient management, leading to a decrease of severe outcomes, personalize therapies, minimize antibiotics overuse and hospitalization time, and significantly improve patient survival. Metabolomics, by providing a direct insight into the functional metabolic outcome of an organism, presents a highly appealing strategy to discover these biomarkers. The present work reviews the desired main characteristics of infection biomarkers, the main metabolomics strategies to discover these biomarkers and the next steps for developing the area towards effective clinical biomarkers.

Procalcitonin-guided initiation of antibiotics in AECOPD inpatients: study protocol for a multicenter randomised controlled trial

INTRODUCTION

Current antibiotic prescription for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is generally based on the Anthonisen criteria in The Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) guideline that have a potential risk of antibiotics overuse. The dilemma is to identify patients who are most likely to benefit from antibiotics while avoiding unnecessary antibiotic use. Procalcitonin (PCT), a more sensitive and specific biomarker of bacterial infection than other conventional laboratory tests, has the potential to determine those patients in whom antibiotics would be beneficial. It is unclear whether PCT-guided antibiotic therapy is safe and effective for patients hospitalised with AECOPD. The study hypothesis is that PCT-guided antibiotic therapy could reduce the antibiotic prescription rate for AECOPD, compared with the GOLD guideline recommendations, without negatively impacting the treatment success rate.

METHODS AND ANALYSIS

In this multicenter, open-label, randomised controlled trial, we aim to enrol 500 hospitalised patients with AECOPD that will be randomly assigned to either a PCT-guided group or a GOLD guideline-guided group. The coprimary endpoints are antibiotic prescription rate for AECOPD within 30 days post randomisation and treatment success rate at day 30 post randomisation. The secondary outcomes include: antibiotic prescription rate at day 1 post randomisation; hospital antibiotic exposure; length of hospital stay; rate of subsequent exacerbation and hospital readmission; overall mortality within 30 days post randomisation; changes in lung function and the score of COPD assessment test and modified Medical Research Council; and rate of intensive care unit admission.

ETHICS AND DISSEMINATION

This trial has been approved by the ethic committee of China-Japan Friendship Hospital. The findings of the study will be disseminated in peer-reviewed journals. If the results of the study are positive, PCT-guided antibiotic therapy is likely to change the guidelines for antibiotic recommendations for patients with AECOPD.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT04682899.

Biomarker-Guided Individualization of Antibiotic Therapy

Treatment failure of antibiotic therapy due to insufficient efficacy or occurrence of toxicity is a major clinical challenge, and is expected to become even more urgent with the global rise of antibiotic resistance. Strategies to optimize treatment in individual patients are therefore of crucial importance. Currently, therapeutic drug monitoring plays an important role in optimizing antibiotic exposure to reduce treatment failure and toxicity. Biomarker-based strategies may be a powerful tool to further quantify and monitor antibiotic treatment response, and reduce variation in treatment response between patients. Host response biomarkers, such as CRP, procalcitonin, IL-6, and presepsin, could potentially carry significant information to be utilized for treatment individualization. To achieve this, the complex interactions among immune system, pathogen, drug, and biomarker need to be better understood and characterized. The purpose of this tutorial is to discuss the use and evidence of currently available biomarker-based approaches to inform antibiotic treatment. To this end, we also included a discussion on how treatment response biomarker data from preclinical, healthy volunteer, and patient-based studies can be further characterized using pharmacometric and system pharmacology based modeling approaches. As an illustrative example of how such modeling strategies can be used, we describe a case study in which we quantitatively characterize procalcitonin dynamics in relation to antibiotic treatments in patients with sepsis.

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.

Procalcitonin Measurement in Pleural Fluid to Predict Infectious Complications of the Chest Post Lung Resection

AIM

Procalcitonin (PCT) is variably used in clinical practice to identify infectious processes. This study investigated whether PCT level in pleural fluids could predict the infectious complications in the chests of patients undergoing lobectomy.

PATIENTS AND METHODS

Thirty-four patients undergoing lobectomy for lung cancer were enrolled. PCT levels were measured in serum (S-PCT) and pleural effusion (PF-PCT) on consecutive postoperative days (PODs). The patients were grouped according to the development of chest infectious complications (atelectasis/pneumonia, postoperative infected pleural effusion/empyema/infected space, prolonged air leak >5 days with evidence of infection, lung torsion, and lung infarction). Multivariate analysis was performed to identify if S-PCT or PF-PCT and on which PODs were predictive of chest infectious complications. Receiver operating characteristic (ROC) analysis was further performed to identify cutoff values.

RESULTS

Eleven patients experienced infectious complications within a median of 4 days (range 3-5 days) postoperatively. S-PCT and PF-PCT in non-complicated patients did not significantly increase postoperatively and followed a decreasing course. Only PF-PCT was significantly increased in complicated patients from POD1; the level peaked on POD4, as did that of S-PCT. PF-PCT on POD2 and 3 and S-PCT on POD3 independently predicted chest infectious complications. ROC analysis showed that PF-PCT > 0.88 ng/dL on POD2 was the most sensitive predictor of such complications (area under the ROC curve [AUC]: 0.979, sensitivity 85%/specificity 91%, p < .001) compared to S-PCT POD3 and PF-PCT POD3.

CONCLUSION

Compared to PCT concentrations in serum, those in pleural fluids were more sensitive and predicted chest infectious complications earlier in patients undergoing lobectomy.

The use of procalcitonin for the management of sepsis in Internal Medicine wards: current evidence

Procalcitonin (PCT) is a circulating polypeptide produced in response to bacterial infections. Studies conducted in the Intensive Care Unit (ICU) setting have demonstrated its utility as a biomarker of bacterial infection and sepsis. Thus, PCT is widely used to distinguish between sepsis and SIRS, and to guide antibiotic therapy. At present sepsis represents a frequent diagnosis among patients admitted to internal medicine (IM) departments. Basing on the knowledge derived from ICU studies, the use of PCT has become routine in non-intensive wards, contributing to improve the management of sepsis. However, some differences between the two populations of patients - the IM being older, affected by multiple chronic comorbidities and lacking of invasive monitoring - could limit the generalizability of ICU results. Most of the studies on PCT conducted in the IM setting have focused on chronic obstructive pulmonary disease, pneumonia and sepsis. Although PCT represents one of the best biomarker available in routine clinical practice, there are uncertainties on the optimal cut-offs to be used for starting or discontinuing antibiotic treatment in patients with suspected bacterial infection or sepsis, for predicting outcome and on the role of PCT variations during antibiotic treatment. Moreover, several diseases can produce an elevation of PCT levels, thus producing false positive results. This represents a narrative review summarizing current evidences on PCT for the management of sepsis in an Internal Medicine wards, highlighting differences with ICU, with a special focus on the role of PCT variations as predictor of outcomes in non-ICU wards.

Procalcitonin and MR-Proadrenomedullin Combination with SOFA and qSOFA Scores for Sepsis Diagnosis and Prognosis: A Diagnostic Algorithm

PURPOSE

The third Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) defined sepsis as an organ dysfunction consequent to infection. A Sequential Organ Failure Assessment (SOFA) score at least 2 identifies sepsis. In this study, procalcitonin (PCT) and midregional pro-adrenomedullin (MR-proADM) were evaluated along with SOFA and quick SOFA (qSOFA) scores in patients with sepsis or septic shock.

METHODS

A total of 109 septic patients and 50 patients with noninfectious disease admitted at the Department of Internal Medicine and General Surgery of the University Hospital Campus Bio-Medico of Rome were enrolled. PCT and MR-proADM were measured with immunoluminometric assays (Brahms, Hennigsdorf, Germany). Data were analyzed with receiver-operating characteristic (ROC) curve analysis, likelihood ratios, and Mann-Whitney U test using MedCalc 11.6.1.0 package.

RESULTS

At ROC curve analysis, PCT showed the highest area under the curve and positive likelihood ratio values of 27.42 in sepsis and 43.62 in septic shock. MR-proADM and SOFA score showed a comparable performance. In septic shock, lactate showed the most accurate diagnostic ability. In sepsis, the best combination was PCT with MR-proADM with a posttest probability of 0.988. Based upon these results, an algorithm for sepsis and septic shock diagnosis has been developed. MR-proADM, SOFA, and qSOFA scores significantly discriminated survivors from nonsurvivors.

CONCLUSIONS

PCT and MR-proADM test combination represent a good tool in sepsis diagnosis and prognosis suggesting their inclusion in the diagnostic algorithm besides SOFA and qSOFA scores. Furthermore, MR-proADM as marker of organ dysfunction, with a turn around time of about 30 min, has the advantage to be more objective and rapid than SOFA score.

Method Verification Shows a Negative Bias between 2 Procalcitonin Methods at Medical Decision Concentrations

BACKGROUND

Procalcitonin (PCT) concentration increases as a result of systemic inflammation owing to bacterial infection. Many PCT algorithms and medical decision concentrations (MDCs) have been clinically validated using the B·R·A·H·M·S PCT™ sensitive Kryptor™ assay. Alternative PCT assays have recently been approved by the Food and Drug Administration for clinical use in the US and require method verification before clinical implementation.

METHODS

Precision, sensitivity, linearity, reportable range, and reference intervals were verified for the Architect B·R·A·H·M·S PCT assay. Accuracy of the Architect B·R·A·H·M·S PCT assay was evaluated by comparison with the B·R·A·H·M·S PCT sensitive Kryptor assay.

RESULTS

The Architect B·R·A·H·M·S PCT assay was found to be precise (CV, ≤4.6%), sensitive (limit of blank, 0.001 ng/mL; limit of quantitation, ≤0.01 ng/mL), and linear according to the manufacturer's claims. The analytical measurement range (0.20-100.00 ng/mL) and the reference interval (≤0.07 ng/mL) were also verified. Patient result comparisons indicated high agreement at 0.10 ng/mL and 0.25 ng/mL and reduced positive agreement at 0.50 ng/mL and 2.00 ng/mL MDCs owing to negative bias compared with the B·R·A·H·M·S PCT sensitive Kryptor assay.

CONCLUSIONS

The Architect B·R·A·H·M·S PCT assay meets most performance specifications claimed by the manufacturer; however, negative bias at 0.50 ng/mL and 2.00 ng/mL PCT concentrations is evident.

Cost-effectiveness of procalcitonin testing to guide antibiotic treatment duration in critically ill patients: results from a randomised controlled multicentre trial in the Netherlands

BACKGROUND

Procalcitonin (PCT) testing can help in safely reducing antibiotic treatment duration in intensive care patients with sepsis. However, the cost-effectiveness of such PCT guidance is not yet known.

METHODS

A trial-based analysis was performed to estimate the cost-effectiveness of PCT guidance compared with standard of care (without PCT guidance). Patient-level data were used from the SAPS trial in which 1546 patients were randomised. This trial was performed in the Netherlands, which is a country with, on average, low antibiotic use and a short duration of hospital stay. As quality of life among sepsis survivors was not measured during the SAPS, this was derived from a Dutch follow-up study. Outcome measures were (1) incremental direct hospital cost and (2) incremental cost per quality-adjusted life year (QALY) gained from a healthcare perspective over a one-year time horizon. Uncertainty in outcomes was assessed with bootstrapping.

RESULTS

Mean in-hospital costs were €46,081/patient in the PCT group compared with €46,146/patient with standard of care (i.e. - €65 (95% CI - €6314 to €6107); - 0.1%). The duration of the first course of antibiotic treatment was lower in the PCT group with 6.9 vs. 8.2 days (i.e. - 1.2 days (95% CI - 1.9 to - 0.4), - 14.8%). This was accompanied by lower in-hospital mortality of 21.8% vs. 29.8% (absolute decrease 7.9% (95% CI - 13.9% to - 1.8%), relative decrease 26.6%), resulting in an increase in mean QALYs/patient from 0.47 to 0.52 (i.e. + 0.05 (95% CI 0.00 to 0.10); + 10.1%). However, owing to high costs among sepsis survivors, healthcare costs over a one-year time horizon were €73,665/patient in the PCT group compared with €70,961/patient with standard of care (i.e. + €2704 (95% CI - €4495 to €10,005), + 3.8%), resulting in an incremental cost-effectiveness ratio of €57,402/QALY gained. Within this time frame, the probability of PCT guidance being cost-effective was 64% at a willingness-to-pay threshold of €80,000/QALY.

CONCLUSIONS

Although the impact of PCT guidance on total healthcare-related costs during the initial hospitalisation episode is likely negligible, the lower in-hospital mortality may lead to a non-significant increase in costs over a one-year time horizon. However, since uncertainty remains, it is recommended to investigate the long-term cost-effectiveness of PCT guidance, from a societal perspective, in different countries and settings.

Using Procalcitonin in Septic Shock to Guide Antibacterial Therapy

Over the last decade, the biomarkers procalcitonin and C-reactive protein have gained interest in sepsis research. Procalcitonin is a unique biomarker that is specific to bacterial infection and has demonstrated utility in the risk stratification of patients with potential life-threatening bacterial infections. In addition, procalcitonin has been documented as having a role in reducing the rate of unnecessary antibiotics while positively impacting antibiotic resistance rates and cost savings. The purposes of this review article are to discuss the clinical relevance of C-reactive protein and procalcitonin as diagnostic and prognostic markers for sepsis with a focus on the use of serial procalcitonin levels as a component of antibiotic stewardship programs. The federal government has recently become invested in combating the progression of antibiotic resistance; a 5-year national plan has been developed to address these concerns. Establishing a reliable antibiotic stewardship program is one of the goals of this national plan.

The role of procalcitonin in the diagnosis of bacterial infection after major abdominal surgery: Advantage from daily measurement

Postsurgical infections represent an important cause of morbidity after abdominal surgery. The microbiological diagnosis is not achieved in at least 30% of culture with consequent worsening of patient outcome. In this study, procalcitonin measurement, during the first 3 days after abdominal surgery, has been evaluated for the early diagnosis of postsurgical infection.Ninety consecutive patients subjected to major abdominal surgery at the University Campus Bio-Medico of Rome, have been included. PCT concentrations were measured by time-resolved amplified cryptate emission (TRACE) assay at admission and at the first, second, and third day after surgery. PCT levels were compared using the Mann-Whitney test and by ANOVA test for variance analysis. Receiver operating characteristic (ROC) analysis was performed to define the diagnostic ability of PCT in case of postsurgical infections.PCT values resulted significantly different between patients developing or not developing postsurgical infections. PCT >1.0 ng/mL at first or second day after surgery and >0.5 ng/mL at third day resulted diagnostic for infectious complication, whereas a value <0.5 ng/mL at the fifth day after surgery was useful for early and safety discharge of patients.In conclusion, PCT daily measurement could represent a useful diagnostic tool improving health care in the postsurgical period following major abdominal surgery and should be recommended.

Effectiveness and safety of procalcitonin evaluation for reducing mortality in adults with sepsis, severe sepsis or septic shock

BACKGROUND

Serum procalcitonin (PCT) evaluation has been proposed for early diagnosis and accurate staging and to guide decisions regarding patients with sepsis, severe sepsis and septic shock, with possible reduction in mortality.

OBJECTIVES

To assess the effectiveness and safety of serum PCT evaluation for reducing mortality and duration of antimicrobial therapy in adults with sepsis, severe sepsis or septic shock.

SEARCH METHODS

We searched the Central Register of Controlled Trials (CENTRAL; 2015, Issue 7); MEDLINE (1950 to July 2015); Embase (Ovid SP, 1980 to July 2015); Latin American Caribbean Health Sciences Literature (LILACS via BIREME, 1982 to July 2015); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; EBSCO host, 1982 to July 2015), and trial registers (ISRCTN registry, ClinicalTrials.gov and CenterWatch, to July 2015). We reran the search in October 2016. We added three studies of interest to a list of 'Studies awaiting classification' and will incorporate these into formal review findings during the review update.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) testing PCT-guided decisions in at least one of the comparison arms for adults (≥ 18 years old) with sepsis, severe sepsis or septic shock, according to international definitions and irrespective of the setting.

DATA COLLECTION AND ANALYSIS

Two review authors extracted study data and assessed the methodological quality of included studies. We conducted meta-analysis with random-effects models for the following primary outcomes: mortality and time spent receiving antimicrobial therapy in hospital and in the intensive care unit (ICU), as well as time spent on mechanical ventilation and change in antimicrobial regimen from a broad to a narrower spectrum.

MAIN RESULTS

We included 10 trials with 1215 participants. Low-quality evidence showed no significant differences in mortality at longest follow-up (risk ratio (RR) 0.81, 95% confidence interval (CI) 0.65 to 1.01; I2 = 10%; 10 trials; N = 1156), at 28 days (RR 0.89, 95% CI 0.61 to 1.31; I2 = 0%; four trials; N = 316), at ICU discharge (RR 1.03, 95% CI 0.50 to 2.11; I2 = 49%; three trials; N = 506) and at hospital discharge (RR 0.98, 95% CI 0.75 to 1.27; I2 = 0%; seven trials; N = 805; moderate-quality evidence). However, mean time receiving antimicrobial therapy in the intervention groups was -1.28 days (95% CI to -1.95 to -0.61; I2 = 86%; four trials; N = 313; very low-quality evidence). No primary study has analysed the change in antimicrobial regimen from a broad to a narrower spectrum.

AUTHORS' CONCLUSIONS

Up-to-date evidence of very low to moderate quality, with insufficient sample power per outcome, does not clearly support the use of procalcitonin-guided antimicrobial therapy to minimize mortality, mechanical ventilation, clinical severity, reinfection or duration of antimicrobial therapy of patients with septic conditions.

Tools for outcome prediction in patients with community acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is one of the most common causes of mortality world-wide. The mortality rate of patients with CAP is influenced by the severity of the disease, treatment failure and the requirement for hospitalization and/or intensive care unit (ICU) management, all of which may be predicted by biomarkers and clinical scoring systems. Areas covered: We review the recent literature examining the efficacy of established and newly-developed clinical scores, biological and inflammatory markers such as C-Reactive protein (CRP), procalcitonin (PCT) and Interleukin-6 (IL-6), whether used alone or in conjunction with clinical severity scores to assess the severity of CAP, predict treatment failure, guide acute in-hospital or ICU admission and predict mortality. Expert commentary: The early prediction of treatment failure using clinical scores and biomarkers plays a developing role in improving survival of patients with CAP by identifying high-risk patients requiring hospitalization or ICU admission; and may enable more efficient allocation of resources. However, it is likely that combinations of scoring systems and biomarkers will be of greater use than individual markers. Further larger studies are needed to corroborate the additive value of these markers to clinical prediction scores to provide a safer and more effective assessment tool for clinicians.

Procalcitonin testing to guide antibiotic therapy for the treatment of sepsis in intensive care settings and for suspected bacterial infection in emergency department settings: a systematic review and cost-effectiveness analysis

BACKGROUND

Determination of the presence or absence of bacterial infection is important to guide appropriate therapy and reduce antibiotic exposure. Procalcitonin (PCT) is an inflammatory marker that has been suggested as a marker for bacterial infection.

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of adding PCT testing to the information used to guide antibiotic therapy in adults and children (1) with confirmed or highly suspected sepsis in intensive care and (2) presenting to the emergency department (ED) with suspected bacterial infection.

METHODS

Twelve databases were searched to June 2014. Randomised controlled trials were assessed for quality using the Cochrane Risk of Bias tool. Summary relative risks (RRs) and weighted mean differences (WMDs) were estimated using random-effects models. Heterogeneity was assessed visually using forest plots and statistically using the I (2) and Q statistics and investigated through subgroup analysis. The cost-effectiveness of PCT testing in addition to current clinical practice was compared with current clinical practice using a decision tree with a 6 months' time horizon.

RESULTS

Eighteen studies (36 reports) were included in the systematic review. PCT algorithms were associated with reduced antibiotic duration [WMD -3.19 days, 95% confidence interval (CI) -5.44 to -0.95 days, I (2) = 95.2%; four studies], hospital stay (WMD -3.85 days, 95% CI -6.78 to -0.92 days, I (2) = 75.2%; four studies) and a trend towards reduced intensive care unit (ICU) stay (WMD -2.03 days, 95% CI -4.19 to 0.13 days, I (2) = 81.0%; four studies). There were no differences for adverse clinical outcomes. PCT algorithms were associated with a reduction in the proportion of adults (RR 0.77, 95% CI 0.68 to 0.87; seven studies) and children (RR 0.86, 95% CI 0.80 to 0.93) receiving antibiotics, reduced antibiotic duration (two studies). There were no differences for adverse clinical outcomes. All but one of the studies in the ED were conducted in people presenting with respiratory symptoms. Cost-effectiveness: the base-case analyses indicated that PCT testing was cost-saving for (1) adults with confirmed or highly suspected sepsis in an ICU setting; (2) adults with suspected bacterial infection presenting to the ED; and (3) children with suspected bacterial infection presenting to the ED. Cost-savings ranged from £368 to £3268. Moreover, PCT-guided treatment resulted in a small quality-adjusted life-year (QALY) gain (ranging between < 0.001 and 0.005). Cost-effectiveness acceptability curves showed that PCT-guided treatment has a probability of ≥ 84% of being cost-effective for all settings and populations considered (at willingness-to-pay thresholds of £20,000 and £30,000 per QALY).

CONCLUSIONS

The limited available data suggest that PCT testing may be effective and cost-effective when used to guide discontinuation of antibiotics in adults being treated for suspected or confirmed sepsis in ICU settings and initiation of antibiotics in adults presenting to the ED with respiratory symptoms and suspected bacterial infection. However, it is not clear that observed costs and effects are directly attributable to PCT testing, are generalisable outside people presenting with respiratory symptoms (for the ED setting) and would be reproducible in the UK NHS. Further studies are needed to assess the effectiveness of adding PCT algorithms to the information used to guide antibiotic treatment in children with suspected or confirmed sepsis in ICU settings. Additional research is needed to examine whether the outcomes presented in this report are fully generalisable to the UK.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014010822.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

A new sensitive automated assay for procalcitonin detection: LIAISON® BRAHMS PCT® II GEN

Objectives

To assess the performance of LIAISON^® BRAHMS PCT^® II GEN (DiaSorin, Saluggia, Italy) in procalcitonin (PCT) determination by comparing it to the assay reference method B·R·A·H·M·S PCT KRYPTOR (Thermo Fisher Scientific Clinical Diagnostics, Hennigsdorf, Germany) and assessing its ability to discriminate between healthy subjects and patients with suspected infection.

Methods

Diagnostic performance was evaluated on: a) 193 selected samples covering the assay range, whose procalcitonin levels were already evaluated with the B·R·A·H·M·S PCT^® KRYPTOR; b) prospective samples: 150 apparently healthy specimens obtained from a blood bank, 161 hospitalized patients (not with specific pathologies), 243 apparently healthy children.

Results

The comparison of LIAISON^® BRAHMS PCT^® II GEN to the reference method B·R·A·H·M·S PCT KRYPTOR yielded high correlation coefficients: slope of Deming fit equal to 1.04 (95% CI: 0.99–1.09) with an intercept equal to 0.05 (95% CI: −0.09 to 0.19) and a high concordance (98.4% (95% CI: 95.5–99.7%)) at the 0.5 ng/mL cut-off. Moreover, the results obtained using prospective samples showed: (i) no samples with PCT concentration >0.5 ng/mL (cut-off) for the apparently healthy adults (highest value=0.033 ng/mL, 95th percentile and 97.5th percentile <0.02 ng/mL); (ii) 2 samples >0.5 ng/mL for hospitalized patients (highest value=0.715 ng/mL, 95th percentile: 0.054 ng/mL; 97.5th percentile: 0.088 ng/mL); (iii) 3 samples >0.5 ng/mL for the healthy children population (highest value=0.713 ng/mL, 95th percentile: 0.155 ng/mL; 97.5th percentile: 0.275 ng/mL).

Conclusion

The fully automated LIAISON^® BRAHMS PCT^® II GEN agrees well with the reference method and is suitable for early diagnosis of sepsis, severe bacterial infection and guiding antibiotic therapy.

Efficacy and safety of procalcitonin guidance in reducing the duration of antibiotic treatment in critically ill patients: a randomised, controlled, open-label trial

BACKGROUND

In critically ill patients, antibiotic therapy is of great importance but long duration of treatment is associated with the development of antimicrobial resistance. Procalcitonin is a marker used to guide antibacterial therapy and reduce its duration, but data about safety of this reduction are scarce. We assessed the efficacy and safety of procalcitonin-guided antibiotic treatment in patients in intensive care units (ICUs) in a health-care system with a comparatively low use of antibiotics.

METHODS

We did a prospective, multicentre, randomised, controlled, open-label intervention trial in 15 hospitals in the Netherlands. Critically ill patients aged at least 18 years, admitted to the ICU, and who received their first dose of antibiotics no longer than 24 h before inclusion in the study for an assumed or proven infection were eligible to participate. Patients who received antibiotics for presumed infection were randomly assigned (1:1), using a computer-generated list, and stratified (according to treatment centre, whether infection was acquired before or during ICU stay, and dependent on severity of infection [ie, sepsis, severe sepsis, or septic shock]) to receive either procalcitonin-guided or standard-of-care antibiotic discontinuation. Both patients and investigators were aware of group assignment. In the procalcitonin-guided group, a non-binding advice to discontinue antibiotics was provided if procalcitonin concentration had decreased by 80% or more of its peak value or to 0·5 μg/L or lower. In the standard-of-care group, patients were treated according to local antibiotic protocols. Primary endpoints were antibiotic daily defined doses and duration of antibiotic treatment. All analyses were done by intention to treat. Mortality analyses were completed for all patients (intention to treat) and for patients in whom antibiotics were stopped while being on the ICU (per-protocol analysis). Safety endpoints were reinstitution of antibiotics and recurrent inflammation measured by C-reactive protein concentrations and they were measured in the population adhering to the stopping rules (per-protocol analysis). The study is registered with ClinicalTrials.gov, number NCT01139489, and was completed in August, 2014.

FINDINGS

Between Sept 18, 2009, and July 1, 2013, 1575 of the 4507 patients assessed for eligibility were randomly assigned to the procalcitonin-guided group (761) or to standard-of-care (785). In 538 patients (71%) in the procalcitonin-guided group antibiotics were discontinued in the ICU. Median consumption of antibiotics was 7·5 daily defined doses (IQR 4·0-12·7) in the procalcitonin-guided group versus 9·3 daily defined doses (5·0-16·6) in the standard-of-care group (between-group absolute difference 2·69, 95% CI 1·26-4·12, p<0·0001). Median duration of treatment was 5 days (3-9) in the procalcitonin-guided group and 7 days (4-11) in the standard-of-care group (between-group absolute difference 1·22, 0·65-1·78, p<0·0001). Mortality at 28 days was 149 (20%) of 761 patients in the procalcitonin-guided group and 196 (25%) of 785 patients in the standard-of-care group (between-group absolute difference 5·4%, 95% CI 1·2-9·5, p=0·0122) according to the intention-to-treat analysis, and 107 (20%) of 538 patients in the procalcitonin-guided group versus 121 (27%) of 457 patients in the standard-of-care group (between-group absolute difference 6·6%, 1·3-11·9, p=0·0154) in the per-protocol analysis. 1-year mortality in the per-protocol analysis was 191 (36%) of 538 patients in the procalcitonin-guided and 196 (43%) of 457 patients in the standard-of-care groups (between-group absolute difference 7·4, 1·3-13·8, p=0·0188).

INTERPRETATION

Procalcitonin guidance stimulates reduction of duration of treatment and daily defined doses in critically ill patients with a presumed bacterial infection. This reduction was associated with a significant decrease in mortality. Procalcitonin concentrations might help physicians in deciding whether or not the presumed infection is truly bacterial, leading to more adequate diagnosis and treatment, the cornerstones of antibiotic stewardship.

FUNDING

Thermo Fisher Scientific.

Procalcitonin-based algorithms to initiate or stop antibiotic therapy in critically ill patients: Is it time to rethink our strategy?

Procalcitonin (PCT)-based antibiotic management algorithms for critically ill patients have been described in the literature. An evaluation of the available evidence demonstrates that studies have utilised PCT in various clinical scenarios: for the initiation of antimicrobials; for cessation or de-escalation of antimicrobials; or for the combination of both strategies. Current PCT reviews and meta-analyses have combined studies from all different clinical scenarios. However, there may be significant variations in algorithm compliance and clinical outcomes associated with the use of PCT in these different strategies. As such, the current review focused on separating out the studies utilising PCT in the critically ill population for different treatment strategies. Based on this review, we would recommend that PCT should not be used as the sole deciding factor for the initiation of antimicrobials. As such, PCT should not be obtained in patients who do not exhibit evidence of infection. In patients who do have signs of infection and antimicrobials have been initiated, a strategy that utilises PCT for the discontinuation or de-escalation of antimicrobials is likely to decrease the duration of treatment without adversely affecting outcome.

Markers of bacterial translocation in end-stage liver disease

Bacterial translocation (BT) refers to the passage of viable bacteria or bacterial products from the intestinal lumen, through the intestinal epithelium, into the systemic circulation and extraintestinal locations. The three principal mechanisms that are thought to be involved in BT include bacterial overgrowth, disruption of the gut mucosal barrier and an impaired host defence. BT is commonly observed in liver cirrhosis and has been shown to play an important role in the pathogenesis of the complications of end stage liver disease, including infections as well as hepatic encephalopathy and hepatorenal syndrome. Due to the importance of BT in the natural history of cirrhosis, there is intense interest for the discovery of biomarkers of BT. To date, several such candidates have been proposed, which include bacterial DNA, soluble CD14, lipopolysaccharides endotoxin, lipopolysaccharide-binding protein, calprotectin and procalcitonin. Studies on the association of these markers with BT have demonstrated not only promising data but, oftentimes, contradictory results. As a consequence, currently, there is no optimal marker that may be used in clinical practice as a surrogate for the presence of BT.

Procalcitonin-guided antibiotic therapy for septic patients in the surgical intensive care unit

In critically ill patients, elucidating those patients with the systemic inflammatory response syndrome (SIRS) from an infectious source (sepsis), versus those who have SIRS without infection, can be challenging since the clinical features are the same.

Even with strict monitoring and testing, 39–98 % of patients with SIRS will never have bacteriological confirmation of an infection, and 6–17 % of patients with a documented infection will not show signs of SIRS. Due to this overlap, an extensive amount of research has been performed to investigate ways of determining and separating SIRS from infection, compared to SIRS due to trauma, surgical stress, or other non-infectious causes. This review article will discuss the recommended and peer-approved use of procalcitonin in septic patients in the intensive care unit and its use as a guide to antibiotic initiation and termination. The article will focus on the prospective randomized trials (Level 1 evidence) that have been conducted, and lesser levels of evidence will be referenced as needed to substantiate a conclusion.

The literature documents multiple benefits of using procalcitonin as a guide to cost savings and appropriate termination of antibiotics by its use as a new objective marker of bacteremia that was previously not available. This article will show that antibiotics should be terminated when the procalcitonin level falls below 0.5 ng/mL.

Agreement on the prescription of antimicrobial drugs

BACKGROUND

There is universal awareness of the difficulties faced by doctors when prescribing antimicrobials.

METHODS

Over a six-month period patients hospitalized in the ICU and under treatment with antibiotics and/or antifungals were eligible to participate in the study. The data were assessed by two infectious diseases specialists. Once completed, all case forms were sent independently to both evaluators (TZSC and ARM) by e-mail. Based on the data received, the evaluator completed a form automatically generated on the e-mail and returned it to the original mailbox for further analysis. We assessed the level of agreement between infectious disease specialists and the physicians directly responsible for the decision to begin antimicrobial therapy, as well as to assess the appropriateness of the regimen prescribed.

RESULTS

Among the antimicrobial regimens prescribed to the 177 patients, 36% were considered inappropriate by specialist #1 and 38% were considered inappropriate by specialist #2. We found 78% agreement by at least one of the infectious disease specialists with the prescribed antimicrobial regimen, and in 49% of cases both specialists agreed with the prescribed regimen. Both disagreed with the prescribed regimen in 22% of the cases and they disagreed between themselves in 29% of the cases.

CONCLUSION

This study highlights the difficulties in prescribing effective empirical antimicrobial therapy--they are of such magnitude that even two specialists in infectious diseases, well acquainted with our hospital's resistance patterns and our patients' profiles have considerable disagreement.

Measurement of serum procalcitonin levels for the early diagnosis of spontaneous bacterial peritonitis in patients with decompensated liver cirrhosis

Background

It is difficult to diagnose spontaneous bacterial peritonitis (SBP) early in decompensated liver cirrhotic ascites patients (DCPs). The aim of the study was to measure serum procalcitonin (PCT) levels and peripheral blood leukocyte/platelet (WBC/PLT) ratios to obtain an early diagnostic indication of SBP in DCPs.

Methods

Our cohort of 129 patients included 112 DCPs (94 of whom had infections) and 17 cases with compensated cirrhosis as controls. Bacterial cultures, ascitic fluid (AF) leukocyte and peripheral WBC/PLT counts, and serum PCT measurements at admission were carried out prior to the use of antibiotics. Receiver operating characteristic (ROC) curves were generated to test the accuracies and cut-off values for different inflammatory markers.

Results

Among the 94 infected patients, 66 tested positive by bacterial culture, for which the positivity of blood, ascites and other secretions were 25.8%, 30.3% and 43.9%, respectively. Lung infection, SBP and unknown sites of infection accounted for 8.5%, 64.9% and 26.6% of the cases, respectively. Serum PCT levels (3.02 ± 3.30 ng/mL) in DCPs with infections were significantly higher than those in control patients (0.15 ± 0.08 ng/mL); p < 0.05. We used PCT ≥0.5 ng/mL as a cut-off value to diagnose infections, for which the sensitivity and specificity was 92.5% and 77.1%. The area under the curve (AUC) was 0.89 (95% confidence interval: 0.84–0.91). The sensitivity and specificity were 62.8% and 94.2% for the diagnosis of infections, and were 68.8% and 94.2% for the diagnosis of SBP in DCPs when PCT ≥2 ng/mL was used as a cut-off value. For the combined PCT and WBC/PLT measurements, the sensitivity was 76.8% and 83.6% for the diagnosis of infections or SBP in DCPs, respectively.

Conclusion

Serum PCT levels alone or in combination with WBC/PLT measurements seem to provide a satisfactory early diagnostic biomarker in DCPs with infections, especially for patients with SBP.

Sepsis biomarkers

Sepsis is the most frequent cause of death in non-coronary intensive care units (ICUs). In the past 10 years, progress has been made in the early identification of septic patients and in their treatment and these improvements in support and therapy mean that the mortality is gradually decreasing but it still remains unacceptably high. Leaving clinical diagnosis aside, the laboratory diagnostics represent a complex range of investigations that can place significant demands on the system given the speed of response required. There are hundreds of biomarkers which could be potentially used for diagnosis and prognosis in septic patients. The main attributes of successful markers would be high sensitivity, specificity, possibility of bed-side monitoring, and financial accessibility. Only a fraction is used in routine clinical practice because many lack sufficient sensitivity or specificity. The following review gives a short overview of the current epidemiology of sepsis, its pathogenesis and state-of-the-art knowledge on the use of specific biochemical, hematological and immunological parameters in its diagnostics. Prospective approaches towards discovery of new diagnostic biomarkers have been shortly mentioned.

Year in review 2013: Critical Care--respiratory infections

Infectious complications, particularly in the respiratory tract of critically ill patients, are related to increased mortality. Severe infection is part of a multiple system illness and female patients with severe sepsis have a worse prognosis compared to males. Kallistatin is a protective hormokine released during monocyte activation and low levels in the setting of septic shock can predict adverse outcomes. Presepsin is another biomarker that was recently evaluated and is elevated in patients with severe sepsis patients at risk of dying. The Centers for Disease Control and Prevention has introduced new definitions for identifying patients at risk of ventilator-associated complications (VACs), but several other conditions, such as pulmonary edema and acute respiratory distress syndrome, may cause VACs, and not all patients with VACs may have ventilator-associated pneumonia. New studies have suggested strategies to identify patients at risk for resistant pathogen infection and therapies that optimize efficacy, without the overuse of broad-spectrum therapy in patients with healthcare-associated pneumonia. Innovative strategies using optimized dosing of antimicrobials, maximizing the pharmacokinetic and pharmacodynamic properties of drugs in critically ill patients, and newer routes of drug delivery are being explored to combat drug-resistant pathogens. We summarize the major clinical studies on respiratory infections in critically ill patients published in 2013.

Update on procalcitonin measurements

Procalcitonin (PCT) is used as a biomarker for the diagnosis of sepsis, severe sepsis and septic shock. At the same time, PCT has also been used to guide antibiotic therapy. This review outlines the main indications for PCT measurement and points out possible pitfalls. The classic indications for PCT measurement are: (i) confirmation or exclusion of diagnosis of sepsis, severe sepsis, or septic shock, (ii) severity assessment and follow up of systemic inflammation mainly induced by microbial infection, and (iii) individual, patient adapted guide of antibiotic therapy and focus treatment. Using serially monitored PCT levels, the duration and need of antibiotic therapy can be better adapted to the individual requirements of the patient. This individualized approach has been evaluated in various studies, and it is recommended to be a part of an antibiotic stewardship program.

Procalcitonin for antibiotic treatment in intensive care unit patients

Procalcitonin (PCT), a 116-aminoacids prohormone, has been substantially studied over the last 2 decades in the field of sepsis. Disappointingly low sensitivity values led to the abandonment of the concept of it as a diagnostic tool and then to its being considered more as a prognostic marker with a good correlation with severe infection. Later on, growing concerns about multidrug-resistant bacteria in the ICU environment and about the cost and side effects of antibiotics suggested that PCT might prove to be a valuable asset in stewardship programs. Numerous but hardly comparable randomized controlled trials assessing either initiation or deescalation in ICU patients have been published. Stewardship encompassing PCT should focus on the latter, because of the high negative predictive value of this biomarker. However, there still would be safety concerns if a systematic implementation of PCT were to be considered in daily stewardship programs in the ICU, especially in extra-thoracic sepsis.

An updated review of sepsis for the anesthesiologist

Severe sepsis and septic shock continue to be among of the leading causes of death in intensive care unit patients, carrying an estimated mortality rate between 30% and 50%. This article provides an evidence-based focused review of sepsis, including an update on management strategies based on the most recent guidelines published by the Surviving Sepsis Campaign.