Serial Procalcitonin Predicts Mortality in Severe Sepsis Patients: Results From the Multicenter Procalcitonin MOnitoring SEpsis (MOSES) Study

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.

Association between acute kidney injury and serum procalcitonin levels and their diagnostic usefulness in critically ill patients

Procalcitonin (PCT) is a useful marker for the diagnosis of systemic inflammatory response syndrome. In addition, PCT is affected by renal function. However, few studies have investigated the relationship between PCT and the development of acute kidney injury (AKI). Hence, we investigated whether serum PCT levels at the time of admission were associated with the development of AKI and clinical outcomes. A total of 790 patients in whom PCT was measured on admission to the intensive care unit (ICU) were analyzed retrospectively. We attempted to investigate whether serum PCT levels measured at the time of admission could be used as a risk factor for the development of AKI in septic and nonseptic patients or as a risk factor for all-cause mortality, and diagnostic usefulness of PCT was further assessed. Serum PCT levels were significantly higher in patients with AKI than in those without AKI (P < 0.001). After multivariable adjustment for clinical factors, laboratory findings, and comorbidities, PCT as a continuous variable showed a significant association with AKI (OR 1.006, 95% CI [1.000–1.011]; P = 0.035). However, PCT was not effective in predicting mortality. The cut-off value of PCT for the prediction of AKI incidence was calculated to be 0.315 ng/ml, with sensitivity and specificity of 60.9% and 56.9%, respectively. The odds ratios (ORs) from an equation adjusted for optimum thresholds of PCT levels for developing AKI with and without sepsis were 2.422 (1.222–4.802, P = 0.011) and 1.798 (1.101–2.937, P = 0.019), respectively. However, there were no absolute differences between the pre- and posttest probabilities after including the PCT value for AKI development. This study suggests that the PCT value was higher in AKI patients than in non-AKI patients, but PCT measurement at the time of admission did not improve the prediction model for AKI.

Study protocol for a multicentre prospective cohort study to identify predictors of adverse outcome in older medical emergency department patients (the Risk Stratification in the Emergency Department in Acutely Ill Older Patients (RISE UP) study)

BACKGROUND

Older patients (≥65 years old) experience high rates of adverse outcomes after an emergency department (ED) visit. Reliable tools to predict adverse outcomes in this population are lacking. This manuscript comprises a study protocol for the Risk Stratification in the Emergency Department in Acutely Ill Older Patients (RISE UP) study that aims to identify predictors of adverse outcome (including triage- and risk stratification scores) and intends to design a feasible prediction model for older patients that can be used in the ED.

METHODS

The RISE UP study is a prospective observational multicentre cohort study in older (≥65 years of age) ED patients treated by internists or gastroenterologists in Zuyderland Medical Centre and Maastricht University Medical Centre+ in the Netherlands. After obtaining informed consent, patients characteristics, vital signs, functional status and routine laboratory tests will be retrieved. In addition, disease perception questionnaires will be filled out by patients or their caregivers and clinical impression questionnaires by nurses and physicians. Moreover, both arterial and venous blood samples will be taken in order to determine additional biomarkers. The discriminatory value of triage- and risk stratification scores, clinical impression scores and laboratory tests will be evaluated. Univariable logistic regression will be used to identify predictors of adverse outcomes. With these data we intend to develop a clinical prediction model for 30-day mortality using multivariable logistic regression. This model will be validated in an external cohort. Our primary endpoint is 30-day all-cause mortality. The secondary (composite) endpoint consist of 30-day mortality, length of hospital stay, admission to intensive- or medium care units, readmission and loss of independent living. Patients will be followed up for at least 30 days and, if possible, for one year.

DISCUSSION

In this study, we will retrieve a broad range of data concerning adverse outcomes in older patients visiting the ED with medical problems. We intend to develop a clinical tool for identification of older patients at risk of adverse outcomes that is feasible for use in the ED, in order to improve clinical decision making and medical care.

TRIAL REGISTRATION

Retrospectively registered on clinicaltrials.gov ( NCT02946398 ; 9/20/2016).

Sustained Circulating Bacterial Deoxyribonucleic Acid Is Associated With Complicated Staphylococcus aureus Bacteremia

Background

Staphylococcus aureus (SA) bacteremia often requires a long treatment duration with antibiotics to prevent relapse due to the ability of SA to establish reservoirs of infection in sites such as heart and bone. These metastatic sites of infection cannot be serially sampled to monitor the clearance of SA infection. This study aimed to establish a link between persistence of circulating SA deoxyribonucleic acid (SA-DNA) and tissue reservoirs in patients with SA bacteremia.

Methods

A highly sensitive quantitative polymerase chain reaction was used to measure whole blood SA-DNA and plasma-derived SA cell-free DNA (SA-cfDNA) in a set of longitudinal samples from 73 patients with confirmed SA bacteremia and correlated with clinical features.

Results

Blood SA-DNA was detected for longer than the duration of positive blood cultures. Longer duration of circulating bacterial DNA was observed in complicated SA bacteremia infections, such as endocarditis and osteoarticular infections, compared with uncomplicated bloodstream infections. In contrast, traditional blood cultures demonstrated similar time to clearance regardless of foci of infection. Plasma-derived SA-cfDNA showed concordance with blood SA-DNA levels. Baseline levels of SA-DNA were higher in patients presenting with greater clinical severity and complicated bacteremia.

Conclusions

Prolonged levels of circulating SA-DNA in patients with complicated tissue reservoirs after clearance of blood cultures observed in this single-center study should be validated in additional cohorts to assess the potential utility for monitoring clearance of infection in patients with SA bacteremia.

Measurement of pancreatic stone protein in the identification and management of sepsis

Sepsis is a life-threatening syndrome characterized by a dysregulated host response to an infection resulting in multiple organ dysfunctions. Early diagnosis and management of sepsis is key to improve patient outcome but remains challenging. Despite extensive research, only few biomarkers have so far proven to be helpful in the diagnosis of sepsis. A novel protein biomarker, the pancreatic stone protein (PSP), is showing great promises. Several lines of evidences suggest that PSP has a higher diagnostic performance for the identification of sepsis than procalcitonin and C-reactive protein, and a strong prognostic value to predict unfavorable outcome at admission to intensive care unit. This review summarizes the current knowledge on the molecular mechanisms of PSP function and the clinical evidences available to highlight the relevance of this protein in the diagnosis and prognosis of sepsis.

Implementation of the Procalcitonin Assay in a Rural Hospital

Objective: Most positive studies in procalcitonin (PCT) utilization were done in large, tertiary medical centers. Furthermore, there is a paucity of data describing the implementation process. This article is the first to describe in detail the implementation process and initial outcomes after 6 months of PCT testing in a rural, 65-bed, primary hospital. Methods: Education before and during PCT implementation as well as facility rollout are described. Initial outcomes were assessed using a before and after quasi-experimental study design comparing 2 identical 6-month time periods: May to October 2016 and May to October 2017. Antibiotic consumption is described with days of therapy (DOT) per 1000 patient days (PD). Antimicrobial purchasing costs, admission rates, and length of stay (LOS) are also compared. Results: Antimicrobial consumption was variable with the greatest reduction at 6 months: 856 DOT/1000 PD before versus 576 DOT/1000 PD after (P < .0001). Admission rates and LOS were unaffected. There was no associated savings in antibiotic purchasing costs: $114 189.79 before and $139 829.26 after (difference +$25 639.47). Conclusion: Although implementation of PCT testing is feasible in a rural health care facility, after 6 months, it was associated with a marginal decrease in antibiotic consumption with no decrease in admission rates, LOS, or antibiotic cost savings.

Real-world use of procalcitonin and other biomarkers among sepsis hospitalizations in the United States: A retrospective, observational study

Background

Sepsis management guidelines endorse use of biomarkers to support clinical assessment and treatment decisions in septic patients. The impact of biomarkers on improving patient outcomes remains uncertain.

Methods

Retrospective observational study of adult sepsis discharges between January 1, 2012, and December 31, 2015, from Premier Healthcare Database hospitals. Sepsis was defined by an All Patients Refined Diagnosis-Related Group code of 720 (septicemia and disseminated infections). Use of four biomarker strategies was evaluated based on hospital records: (i) >1 procalcitonin (PCT), (ii) 1 PCT, (iii) no PCT but ≥1 C-reactive protein (CRP) and/or lactate and (iv) no sepsis biomarkers. Associations between biomarker use and clinical and cost outcomes were examined. The primary outcome was impact of biomarker strategy on hospital costs per day.

Results

Among 933,591 adult sepsis discharges during the study period, 731,392 (78%) had biomarker tests ordered. In multivariable analyses, discharges with >1 PCT had higher hospital costs per day ($1,904; 95% confidence interval [CI] $1,896–$1,911) compared with discharges with no sepsis biomarkers ($1,606; 95% CI $1,658–$1,664). Discharges with >1 PCT also had greater illness severity and antimicrobial exposure compared with other biomarker-use groups. The adjusted odds of dying during hospital stay compared with being discharged were significantly lower for sepsis discharges with >1 PCT (0.64; 95% CI 0.61–0.67) and 1 PCT (0.88; 95% CI 0.85–0.91) compared with no sepsis biomarker use. The proportion of discharges with ≥1 PCT increased almost six-fold during the study; use of other biomarkers remained constant.

Conclusions

Between 2012 and 2015, PCT use among sepsis discharges increased six-fold while lactate and CRP use remained unchanged. PCT use was associated with decreased odds of in-hospital mortality but increased hospital costs per day. Serial biomarker monitoring may be associated with improved patient outcomes in the most critically ill septic patients.

Highly visible sepsis publications from 2012 to 2017: Analysis and comparison of altmetrics and bibliometrics

PURPOSE

We sought to delineate highly visible publications related to sepsis. Within these subsets, elements of altmetrics performance, including mentions on Twitter, and the correlation between altmetrics and conventional citation counts were ascertained.

MATERIALS AND METHODS

Three subsets of sepsis publications from 2012 to 2017 were synthesized by the overall Altmetric.com attention score, number of mentions by unique Twitter users, and conventional citation counts. For these subsets, geolocated Twitter activity was plotted on a choropleth, the lag between publication date and altmetrics mentions was characterized, and correlations were examined between altmetrics performance and normalized conventional citation counts.

RESULTS

Of 57,152 PubMed query results, Altmetric.com data was available for 28,344 (49.6%). The top 50 publications by Altmetric.com attention score and Twitter attention represented a mix of original research and other types of work, garnering attention from Twitter users in 143 countries that was highly contemporaneous with publication. Altmetrics performance and conventional citation counts were poorly correlated.

CONCLUSIONS

While unreliable to gauge impact or future citation potential, altmetrics may be valuable for parties who wish to detect and drive public awareness of research findings and may enable researchers to dynamically explore the reach of their work in novel dimensions.

Procalcitonin kinetics after burn injury and burn surgery in septic and non-septic patients - a retrospective observational study

BACKGROUND

Early sepsis diagnosis is crucial for the correct management of burn patients, and it clearly influences outcomes. The systemic inflammatory response triggered by burns mimics sepsis presentation and complicates early sepsis diagnosis. Biomarkers were advocated to aid the diagnosis of early sepsis. Serum procalcitonin (PCT) exhibits fair accuracy and good correlation with sepsis severity, being used in diverse clinical settings. However, few studies have evaluated perioperative changes in PCT levels in burn patients. The present study evaluated PCT kinetics during the first days after burn injury and subsequent surgical interventions to assess PCT utility in distinguishing septic from non-septic inflammatory responses.

METHODS

This study was a retrospective observational study of all burn patients admitted to the Coimbra Burns Unit (Portugal) between January 2011 and December 2014 who presented with a total burn surface area ≥ 15% and who underwent subsequent surgery. PCT kinetics were investigated a) during the first five days after burn injury and b) preoperatively during the five days after surgery in three subsets of patients, including those with no preoperative and no postoperative sepsis (NN), no preoperative but postoperative sepsis (NS), and preoperative and postoperative sepsis (SS). A total of 145 patients met the selection criteria and were included in the analysis.

RESULTS

PCT levels in the first five days after burn injury were significantly higher in patients who developed at least one sepsis episode (n = 85) compared with patients who did not develop sepsis (n = 60). PCT values > 1.00 ng/mL were clearly associated with sepsis. Study participants (n = 145) underwent a total of 283 surgical interventions. Their distribution by preoperative/postoperative sepsis status was 142 (50.2%) in NN; 62 (21.9%) in NS; and 79 (27.9%) in SS. PCT values exhibited a parallel course in the three groups that peaked on the second postoperative day and returned to preoperative levels on the third day or later. The lowest PCT values were found in NN, and the highest values were observed in SS; the NS values were intermediate.

CONCLUSIONS

PCT kinetics coupled with a clinical examination may be helpful for sepsis diagnosis during the first days after burn injury and burn surgery.

The usage of procalcitonin in Finland

BACKGROUND

We have surveyed the use of procalcitonin (PCT) in Finland with a specific emphasis on intensive care unit (ICU) patients.

METHODS

The PCT use was surveyed from all 11 laboratories providing services for all 15 secondary and all five tertiary care hospitals in Finland. The laboratories reported the PCT use of each hospital in 2014 and 2015. Four hospitals were analysed for the first 100 adult ICU patients with PCT measurements in 2015. The indication for PCT measurement and whether PCT values affected antibiotic treatment were collected from patient records.

RESULTS

The overall national PCT use was similar between 2014 and 2015 with around 15 000 measurements annually. The PCT use varied greatly between hospitals and specialities; one tertiary care hospital used 5600 measurements annually, while another tertiary care hospital did not use PCT at all. Over half of the requests for PCT were in the ICU. There were significant differences in PCT use for ICU patients: in the most frequent user, PCT was mainly used for follow-up of antibiotic treatment, whereas in the other three hospitals, PCT was mainly used for differential diagnosis. The most frequent user also had the highest per patient rate of PCT measurements, with a mean of six PCT tests/patient compared to two PCT tests/patient in the three other hospitals. PCT had an effect on antibiotic treatment in every 5th case.

CONCLUSION

The use of PCT in Finland varies significantly between hospitals, even though the national guideline proposes its use for septic patients.

Effect of procalcitonin-guided antibiotic treatment on clinical outcomes in intensive care unit patients with infection and sepsis patients: a patient-level meta-analysis of randomized trials

BACKGROUND

The clinical utility of serum procalcitonin levels in guiding antibiotic treatment decisions in patients with sepsis remains unclear. This patient-level meta-analysis based on 11 randomized trials investigates the impact of procalcitonin-guided antibiotic therapy on mortality in intensive care unit (ICU) patients with infection, both overall and stratified according to sepsis definition, severity, and type of infection.

METHODS

For this meta-analysis focusing on procalcitonin-guided antibiotic management in critically ill patients with sepsis of any type, in February 2018 we updated the database of a previous individual patient data meta-analysis which was limited to patients with respiratory infections only. We used individual patient data from 11 trials that randomly assigned patients to receive antibiotics based on procalcitonin levels (the "procalcitonin-guided" group) or the current standard of care (the "controls"). The primary endpoint was mortality within 30 days. Secondary endpoints were duration of antibiotic treatment and length of stay.

RESULTS

Mortality in the 2252 procalcitonin-guided patients was significantly lower compared with the 2230 control group patients (21.1% vs 23.7%; adjusted odds ratio 0.89, 95% confidence interval (CI) 0.8 to 0.99; p = 0.03). These effects on mortality persisted in a subgroup of patients meeting the sepsis 3 definition and based on the severity of sepsis (assessed on the basis of the Sequential Organ Failure Assessment (SOFA) score, occurrence of septic shock or renal failure, and need for vasopressor or ventilatory support) and on the type of infection (respiratory, urinary tract, abdominal, skin, or central nervous system), with interaction for each analysis being > 0.05. Procalcitonin guidance also facilitated earlier discontinuation of antibiotics, with a reduction in treatment duration (9.3 vs 10.4 days; adjusted coefficient -1.19 days, 95% CI -1.73 to -0.66; p <  0.001).

CONCLUSION

Procalcitonin-guided antibiotic treatment in ICU patients with infection and sepsis patients results in improved survival and lower antibiotic treatment duration.

[Bacterial sepsis : Diagnostics and calculated antibiotic therapy]

The mortality of patients with sepsis and septic shock is still unacceptably high. An effective antibiotic treatment within 1 h of recognition of sepsis is an important target of sepsis treatment. Delays lead to an increase in mortality; therefore, structured treatment concepts form a rational foundation, taking relevant diagnostic and treatment steps into consideration. In addition to the assumed focus and individual risks of each patient, local resistance patterns and specific problem pathogens must be taken into account for selection of anti-infection treatment. Many pathophysiological alterations influence the pharmacokinetics of antibiotics during sepsis. The principle of standard dosing should be abandoned and replaced by an individual treatment approach with stronger weighting of the pharmacokinetics/pharmacodynamics (PK/PD) index of the substance groups. Although this is not yet the clinical standard, prolonged (or continuous) infusion of beta-lactam antibiotics and therapeutic drug monitoring (TDM) can help to achieve defined PK targets. Prolonged infusion is sufficient without TDM but for continuous infusion TDM is basically necessary. A further argument for individual PK/PD-oriented antibiotic approaches is the increasing number of infections due to multidrug resistant pathogens (MDR) in the intensive care unit. For effective treatment antibiotic stewardship teams (ABS team) are becoming more established. Interdisciplinary cooperation of the ABS team with infectiologists, microbiologists and clinical pharmacists leads not only to a rational administration of antibiotics but also has a positive influence on the outcome. The gold standards for pathogen detection are still culture-based detection and microbiological resistance testing for the various antibiotic groups. Despite the rapid investigation time, novel polymerase chain reaction (PCR)-based procedures for pathogen identification and resistance determination, are currently only an adjunct to routine sepsis diagnostics due to the limited number of studies, high costs and limited availability. In complicated septic courses with multiple anti-infective treatment or recurrent sepsis, PCR-based procedures can be used in addition to therapy monitoring and diagnostics. Novel antibiotics represent potent alternatives in the treatment of MDR infections. Due to the often defined spectrum of pathogens and the practically absent resistance, they are suitable for targeted treatment of severe MDR infections (therapy escalation).

Procalcitonin-guided antibiotic therapy: an expert consensus

Background:

Procalcitonin (PCT) is a useful biomarker of bacterial infection and its use is associated to reduced duration of antibiotic therapy in the setting of intensive care medicine. To address the need of practical guidance for the use of PCT in various clinical settings, a group of experts was invited to participate at a consensus process with the aims of defining the rationale for appropriate use of PCT and for improving the management of critically ill patients with sepsis.

Methods:

A group of 14 experts from anesthesiology and critical care, infectious diseases, internal medicine, pulmonology, clinical microbiology, laboratory medicine, clinical pharmacology and methodology provided expert opinion through a modified Delphi process, after a comprehensive literature review.

Results:

The appropriateness of use of PCT in terms of diagnosis, prognosis and antimicrobial stewardship was assessed for different scenarios or settings such us management of infection in the emergency department, regular wards, surgical wards or in the intensive care unit. Similarly, appropriateness and timing of PCT measurement were evaluated. All the process consisted in three Delphi rounds.

Conclusions:

PCT use is appropriate in algorithms for antibiotic de-escalation and discontinuation. In this case, reproducible, high sensitive assays should be used. However, initiation or escalation of antibiotic therapy in specific scenarios, including acute respiratory infections, should not be based solely on PCT serum levels. Clinical and radiological findings, evaluation of severity of illness and of patient’s characteristics should be taken into proper account in order to correctly interpret PCT results.

Combined Biomarkers Predict Acute Mortality Among Critically Ill Patients With Suspected Sepsis

OBJECTIVES

Sepsis is associated with high early and total in-hospital mortality. Despite recent revisions in the diagnostic criteria for sepsis that sought to improve predictive validity for mortality, it remains difficult to identify patients at greatest risk of death. We compared the utility of nine biomarkers to predict mortality in subjects with clinically suspected bacterial sepsis.

DESIGN

Cohort study.

SETTING

The medical and surgical ICUs at an academic medical center.

SUBJECTS

We enrolled 139 subjects who met two or more systemic inflammatory response syndrome (systemic inflammatory response syndrome) criteria and received new broad-spectrum antibacterial therapy.

INTERVENTIONS

We assayed nine biomarkers (α-2 macroglobulin, C-reactive protein, ferritin, fibrinogen, haptoglobin, procalcitonin, serum amyloid A, serum amyloid P, and tissue plasminogen activator) at onset of suspected sepsis and 24, 48, and 72 hours thereafter. We compared biomarkers between groups based on both 14-day and total in-hospital mortality and evaluated the predictive validity of single and paired biomarkers via area under the receiver operating characteristic curve.

MEASUREMENTS AND MAIN RESULTS

Fourteen-day mortality was 12.9%, and total in-hospital mortality was 29.5%. Serum amyloid P was significantly lower (4/4 timepoints) and tissue plasminogen activator significantly higher (3/4 timepoints) in the 14-day mortality group, and the same pattern held for total in-hospital mortality (Wilcoxon p ≤ 0.046 for all timepoints). Serum amyloid P and tissue plasminogen activator demonstrated the best individual predictive performance for mortality, and combinations of biomarkers including serum amyloid P and tissue plasminogen activator achieved greater predictive performance (area under the receiver operating characteristic curve > 0.76 for 14-d and 0.74 for total mortality).

CONCLUSIONS

Combined biomarkers predict risk for 14-day and total mortality among subjects with suspected sepsis. Serum amyloid P and tissue plasminogen activator demonstrated the best discriminatory ability in this cohort.

Sepsis in pregnancy and the puerperium

Sepsis remains a leading cause of maternal morbidity and mortality. Recognition and treatment of maternal sepsis are often delayed due to the physiological adaptations of pregnancy and vague or absent signs and symptoms during its initial presentation. Over the past decade, our understanding of sepsis has evolved and maternal early warning systems have been developed in an effort to help providers promptly identify and stratify parturients who are at risk. In addition, new consensus definitions and care bundles have recently been published by the World Health Organization and the Surviving Sepsis Campaign to facilitate earlier recognition and timely management of sepsis. In this narrative review, we summarize the available evidence about sepsis and provide an overview of the research efforts focused on maternal sepsis to date. Controversies and challenges surrounding the anesthetic management of parturients with sepsis or at risk of developing sepsis during pregnancy or the puerperium will be highlighted.

Adherence to a procalcitonin-guided antibiotic treatment protocol in patients with severe sepsis and septic shock

Background

In randomised controlled trials, procalcitonin (PCT)-guided antibiotic treatment has been proven to significantly reduce length of antibiotic therapy in intensive care unit (ICU) patients. However, concern was raised on low protocol adherence and high rates of overruling, and thus the value of PCT-guided treatment in real clinical life outside study conditions remains unclear. In this study, adherence to a PCT protocol to guide antibiotic treatment in patients with severe sepsis and septic shock was analysed.

Methods

From 2012 to 2014, surgical ICU patients with severe sepsis or septic shock were retrospectively screened for PCT measurement series appropriate to make treatment decisions on antibiotic therapy. We compared (1) patients with appropriate PCT measurement series to patients without appropriate series; (2) patients who reached the antibiotic stopping advice threshold (PCT < 0.5 ng/mL and/or decrease to 10% of peak level) to patients who did not reach a stopping advice threshold; and (3) patients who were treated adherently to the PCT protocol to non-adherently treated patients. The groups were compared in terms of antibiotic treatment duration, PCT kinetics, and other clinical outcomes.

Results

Of 81 patients with severe sepsis or septic shock, 14 were excluded due to treatment restriction or short course in the ICU. The final analysis was performed on 67 patients. Forty-two patients (62.7%) had appropriate PCT measurement series. In patients with appropriate PCT series, median initial PCT (p = 0.001) and peak PCT levels (p < 0.001) were significantly higher compared to those with non-appropriate series. In 26 patients with appropriate series, PCT levels reached an antibiotic stopping advice. In 8 of 26 patients with stopping advice, antibiotics were discontinued adherently to the PCT protocol (30.8%). Patients with adherently discontinued antibiotics had a shorter antibiotic treatment (7d [IQR 6–9] vs. 12d [IQR 9–16]; p = 0.002). No differences were seen in terms of other clinical outcomes.

Conclusion

In patients with severe sepsis and septic shock, procalcitonin testing was irregular and adherence to a local PCT protocol was low in real clinical life. However, adherently treated patients had a shorter duration of antibiotic treatment without negative clinical outcomes. Procalcitonin peak values and kinetics had a clear impact on the regularity of PCT testing.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0415-5) contains supplementary material, which is available to authorized users.

Cell-Free DNA, High-Mobility Group Box-1, and Procalcitonin Concentrations in Dogs With Gastric Dilatation-Volvulus Syndrome

Canine gastric dilatation–volvulus (GDV) is a life-threatening disease characterized by extensive tissue ischemia, tissue hypoperfusion, and systemic inflammation. Biomarkers that better reflect the severity of gastric necrosis and systemic inflammation would aid clinicians in the management of these patients. This study aimed to investigate the prognostic significance of cell-free DNA (cfDNA), high-mobility group box-1 (HMGB1), and procalcitonin (PCT) in dogs with GDV. Concentrations of cfDNA, HMGB1, and PCT were measured in citrated plasma samples collected from 29 dogs with GDV at hospital admission. Additional data collected included baseline lactate concentrations, APPLE_fast score, evidence of gastric necrosis, occurrence of postoperative complications, and outcome. Twenty-four healthy dogs were sampled as controls. Continuous variables between groups were compared with the Mann–Whitney U and correlations between continuous variables were assessed by calculation of Spearman’s correlation coefficient. Alpha was set at 0.05. Dogs with GDV had significantly greater concentrations of cfDNA, HMGB1, and PCT compared to controls (P = 0.0009, P = 0.004, and P = 0.009, respectively). PCT concentrations were significantly higher in non-survivors compared to survivors (P = 0.008). Dogs with gastric necrosis had significantly greater lactate concentrations compared to dogs without gastric necrosis (P = 0.0005). The APPLE_fast score was not prognostic. Lactate and PCT concentrations were moderately, positively correlated (r_s 0.51, P = 0.0005). Concentrations of the inflammatory biomarkers cfDNA, HMGB1, and PCT are increased in canine GDV. Only lactate and PCT concentrations were prognostic in this population of GDV dogs and were predictive of the presence of gastric necrosis and of non-survival to hospital discharge, respectively.

Plasma procalcitonin concentrations predict organ dysfunction and outcome in dogs with sepsis

Background

Procalcitonin (PCT) is a valuable prognostic biomarker in human sepsis that is predictive of organ dysfunction, septic shock and mortality. Data on PCT in dogs is limited. This study aimed to investigate the prognostic value of baseline and serial PCT measurements in dogs with sepsis and to determine the association between PCT and sepsis severity and the presence of organ dysfunction. PCT concentrations were measured in citrated plasma samples collected from 53 dogs with sepsis at the time of admission (T0, n = 53) and at 24 h (T1, n = 35) and 48 h (T2, n = 30) post-admission using a commercial ELISA. Dogs were classified by sepsis severity (sepsis without organ dysfunction; severe sepsis; septic shock) and outcome (survivors; non-survivors). Organ dysfunctions were recorded at T0 and during hospitalization, and the APPLE_fast score calculated at T0. Healthy dogs (n = 12) were used as controls.

Results

There were 18 septic dogs without organ dysfunction, 24 dogs with severe sepsis and 11 with septic shock. Baseline PCT concentrations were significantly greater in dogs with sepsis compared to healthy controls (P < 0.0001), and in dogs with septic shock compared to dogs without cardiovascular compromise (P = 0.01). Baseline PCT was significantly correlated with organ dysfunction (P = 0.003). Declining PCT concentrations were documented in survivors at T1 and T2 compared to PCT at T0 (P = 0.0006), and PCT clearance at 24 h was significantly higher in survivors (n = 38) compared to non-survivors (n = 15) (P = 0.037). Canine APPLE_fast score was not predictive of sepsis severity, the development of MODS or outcome.

Conclusion

In dogs with sepsis, PCT concentrations at hospital admissions are predictive of organ dysfunction and septic shock. Serial procalcitonin monitoring may offer valuable prognostic information in canine sepsis, wherein early decreases in PCT concentrations are associated with survival.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1427-y) contains supplementary material, which is available to authorized users.

Pre-eclampsia affects procalcitonin production in placental tissue

PROBLEM

Procalcitonin (PCT) is the prohormone of calcitonin which is usually released from neuroendocrine cells of the thyroid gland (parafollicular) and the lungs (K cells). PCT is synthesized by almost all cell types and tissues, including monocytes and parenchymal tissue, upon LPS stimulation. To date, there is no evidence for PCT expression in the placenta both in physiological and pathological conditions.

METHOD

Circulating and placental PCT levels were analysed in pre-eclamptic (PE) and control patients. Placental cells and macrophages (PBDM), stimulated with PE sera, were analysed for PCT expression. The effect of anti-TNF-α antibody was analysed.

RESULTS

Higher PCT levels were detected in PE sera and in PE placentae compared to healthy women. PE trophoblasts showed increased PCT expression compared to those isolated from healthy placentae. PE sera induced an upregulation of PCT production in macrophages and placental cells. The treatment of PBDM with PE sera in the presence of anti-TNF-α completely abrogated the effect induced by pathologic sera.

CONCLUSION

Trophoblast cells are the main producer of PCT in PE placentae. TNF-α, in association with other circulating factors present in PE sera, upregulates PCT production in macrophages and normal placental cells, thus contributing to the observed increased in circulating PCT in PE sera.

Low-picomolar, label-free procalcitonin analytical detection with an electrolyte-gated organic field-effect transistor based electronic immunosensor

Herein a label-free immunosensor based on electrolyte-gated organic field-effect transistor (EGOFET) was developed for the detection of procalcitonin (PCT), a sepsis marker. Antibodies specific to PCT were immobilized on the poly-3-hexylthiophene (P3HT) organic semiconductor surface through direct physical adsorption followed by a post-treatment with bovine serum albumin (BSA) which served as the blocking agent to prevent non-specific adsorption. Antibodies together with BSA (forming the whole biorecognition layer) served to selectively capture the procalcitonin target analyte. The entire immunosensor fabrication process was fast, requiring overall 45min to be completed before analyte sensing. The EGOFET immunosensor showed excellent electrical properties, comparable to those of bare P3HT based EGOFET confirming reliable biosensing with bio-functional EGOFET immunosensor. The detection limit of the immunosensor was as low as 2.2pM and within a range of clinical relevance. The relative standard deviation of the individual calibration data points, measured on immunosensors fabricated on different chips (reproducibility error) was below 7%. The developed immunosensor showed high selectivity to the PCT analyte which was evident through control experiments. This report of PCT detection is first of its kind among the electronic sensors based on EGOFETs. The developed sensor is versatile and compatible with low-cost fabrication techniques.

Pentraxin-3, procalcitonin and lactate as prognostic markers in patients with sepsis and septic shock

The purpose of this study was to confirm the prognostic value of pentraxin-3 (PTX3), procalcitonin (PCT) and lactate in patients with severe infections requiring ICU management and to develop and validate a model to enhance mortality prediction by combining severity scores with biomarkers. We included 141 patients with the diagnosis of sepsis/septic shock. The levels of PTX3, PCT and lactate were measured on day 0, 3, 7 of hospitalization and Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were also evaluated. The influence of these variables on 28-day mortality was evaluated. The 28-day mortality rate in this study was 28.8%. The baseline levels of PTX3, PCT and lactate in the non-survival group were higher than in the survival group (P < 0.05 for all). Pearson's correlation found that PTX3, PCT and lactate were all positively correlated with SOFA and APACHE II scores (P <0.01 for all). Univariate and multivariate Cox regression revealed that PTX3, PCT and lactate were independently associated with 28-day mortality. The models combining above three biomarkers performed better predictive property than each individual one as determined by receiver operating characteristic (ROC) analysis. In summary, our results suggest that PTX3, PCT and lactate could serve as clinically informative biomarkers of disease severity and patient outcome in sepsis/septic shock. A model combining PTX3, PCT and lactate improves mortality prediction in these patients.

Management of Respiratory Infections with Use of Procalcitonin: Moving toward More Personalized Antibiotic Treatment Decisions

Due to overlap of clinical findings and low sensitivity of bacterial diagnostic tests, differentiation between bacterial and viral respiratory tract infections remains challenging, ultimately leading to antibiotic overuse in this population of patients. Addition of procalcitonin, a blood biomarker expressed by epithelial cells in response to bacterial infections, to the clinical assessment leads to a reduction in inappropriate antibiotic initiation. Procalcitonin also provides prognostic information about the resolution of illness, and significant decreases over time are a strong signal for the discontinuation of antibiotics. Current evidence from randomized trials indicates that procalcitonin-guided antibiotic stewardship results in a reduction in antibiotic use and antibiotic side effects, which importantly translates into improved survival of patients with respiratory infections. Inclusion of procalcitonin into antibiotic stewardship algorithms thus improves the diagnostic and therapeutic management of patients presenting with respiratory illnesses and holds great promise to mitigate the global bacterial resistance crisis.

Effects of procalcitonin testing on antibiotic use and clinical outcomes in patients with upper respiratory tract infections. An individual patient data meta-analysis

BACKGROUND

Several trials found procalcitonin (PCT) helpful for guiding antibiotic treatment in patients with lower respiratory tract infections and sepsis. We aimed to perform an individual patient data meta-analysis on the effects of PCT guided antibiotic therapy in upper respiratory tract infections (URTI).

METHODS

A comprehensive search of the literature was conducted using PubMed (MEDLINE) and Cochrane Library to identify relevant studies published until September 2016. We reanalysed individual data of adult URTI patients with a clinical diagnosis of URTI. Data of two trials were used based on PRISMA-IPD guidelines. Safety outcomes were (1) treatment failure defined as death, hospitalization, ARI-specific complications, recurrent or worsening infection at 28 days follow-up; and (2) restricted activity within a 14-day follow-up. Secondary endpoints were initiation of antibiotic therapy, and total days of antibiotic exposure.

RESULTS

In total, 644 patients with a follow up of 28 days had a final diagnosis of URTI and were thus included in this analysis. There was no difference in treatment failure (33.1% vs. 34.0%, OR 1.0, 95% CI 0.7-1.4; p=0.896) and days with restricted activity between groups (8.0 vs. 8.0 days, regression coefficient 0.2 (95% CI -0.4 to 0.9), p=0.465). However, PCT guided antibiotic therapy resulted in lower antibiotic prescription (17.8% vs. 51.0%, OR 0.2, 95% CI 0.1-0.3; p<0.001) and in a 2.4 day (95% CI -2.9 to -1.9; p<0.001) shorter antibiotic exposure compared to control patients.

CONCLUSIONS

PCT guided antibiotic therapy in the primary care setting was associated with reduced antibiotic exposure in URTI patients without compromising outcomes.

Effect of procalcitonin-guided antibiotic treatment on mortality in acute respiratory infections: a patient level meta-analysis

BACKGROUND

In February, 2017, the US Food and Drug Administration approved the blood infection marker procalcitonin for guiding antibiotic therapy in patients with acute respiratory infections. This meta-analysis of patient data from 26 randomised controlled trials was designed to assess safety of procalcitonin-guided treatment in patients with acute respiratory infections from different clinical settings.

METHODS

Based on a prespecified Cochrane protocol, we did a systematic literature search on the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase, and pooled individual patient data from trials in which patients with respiratory infections were randomly assigned to receive antibiotics based on procalcitonin concentrations (procalcitonin-guided group) or control. The coprimary endpoints were 30-day mortality and setting-specific treatment failure. Secondary endpoints were antibiotic use, length of stay, and antibiotic side-effects.

FINDINGS

We identified 990 records from the literature search, of which 71 articles were assessed for eligibility after exclusion of 919 records. We collected data on 6708 patients from 26 eligible trials in 12 countries. Mortality at 30 days was significantly lower in procalcitonin-guided patients than in control patients (286 [9%] deaths in 3336 procalcitonin-guided patients vs 336 [10%] in 3372 controls; adjusted odds ratio [OR] 0·83 [95% CI 0·70 to 0·99], p=0·037). This mortality benefit was similar across subgroups by setting and type of infection (p_interactions>0·05), although mortality was very low in primary care and in patients with acute bronchitis. Procalcitonin guidance was also associated with a 2·4-day reduction in antibiotic exposure (5·7 vs 8·1 days [95% CI -2·71 to -2·15], p<0·0001) and a reduction in antibiotic-related side-effects (16% vs 22%, adjusted OR 0·68 [95% CI 0·57 to 0·82], p<0·0001).

INTERPRETATION

Use of procalcitonin to guide antibiotic treatment in patients with acute respiratory infections reduces antibiotic exposure and side-effects, and improves survival. Widespread implementation of procalcitonin protocols in patients with acute respiratory infections thus has the potential to improve antibiotic management with positive effects on clinical outcomes and on the current threat of increasing antibiotic multiresistance.

FUNDING

National Institute for Health Research.

Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections

BACKGROUND

Acute respiratory infections (ARIs) comprise of a large and heterogeneous group of infections including bacterial, viral, and other aetiologies. In recent years, procalcitonin (PCT), a blood marker for bacterial infections, has emerged as a promising tool to improve decisions about antibiotic therapy (PCT-guided antibiotic therapy). Several randomised controlled trials (RCTs) have demonstrated the feasibility of using procalcitonin for starting and stopping antibiotics in different patient populations with ARIs and different settings ranging from primary care settings to emergency departments, hospital wards, and intensive care units. However, the effect of using procalcitonin on clinical outcomes is unclear. This is an update of a Cochrane review and individual participant data meta-analysis first published in 2012 designed to look at the safety of PCT-guided antibiotic stewardship.

OBJECTIVES

The aim of this systematic review based on individual participant data was to assess the safety and efficacy of using procalcitonin for starting or stopping antibiotics over a large range of patients with varying severity of ARIs and from different clinical settings.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE, and Embase, in February 2017, to identify suitable trials. We also searched ClinicalTrials.gov to identify ongoing trials in April 2017.

SELECTION CRITERIA

We included RCTs of adult participants with ARIs who received an antibiotic treatment either based on a procalcitonin algorithm (PCT-guided antibiotic stewardship algorithm) or usual care. We excluded trials if they focused exclusively on children or used procalcitonin for a purpose other than to guide initiation and duration of antibiotic treatment.

DATA COLLECTION AND ANALYSIS

Two teams of review authors independently evaluated the methodology and extracted data from primary studies. The primary endpoints were all-cause mortality and treatment failure at 30 days, for which definitions were harmonised among trials. Secondary endpoints were antibiotic use, antibiotic-related side effects, and length of hospital stay. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable hierarchical logistic regression adjusted for age, gender, and clinical diagnosis using a fixed-effect model. The different trials were added as random-effects into the model. We conducted sensitivity analyses stratified by clinical setting and type of ARI. We also performed an aggregate data meta-analysis.

MAIN RESULTS

From 32 eligible RCTs including 18 new trials for this 2017 update, we obtained individual participant data from 26 trials including 6708 participants, which we included in the main individual participant data meta-analysis. We did not obtain individual participant data for four trials, and two trials did not include people with confirmed ARIs. According to GRADE, the quality of the evidence was high for the outcomes mortality and antibiotic exposure, and quality was moderate for the outcomes treatment failure and antibiotic-related side effects.Primary endpoints: there were 286 deaths in 3336 procalcitonin-guided participants (8.6%) compared to 336 in 3372 controls (10.0%), resulting in a significantly lower mortality associated with procalcitonin-guided therapy (adjusted OR 0.83, 95% CI 0.70 to 0.99, P = 0.037). We could not estimate mortality in primary care trials because only one death was reported in a control group participant. Treatment failure was not significantly lower in procalcitonin-guided participants (23.0% versus 24.9% in the control group, adjusted OR 0.90, 95% CI 0.80 to 1.01, P = 0.068). Results were similar among subgroups by clinical setting and type of respiratory infection, with no evidence for effect modification (P for interaction > 0.05). Secondary endpoints: procalcitonin guidance was associated with a 2.4-day reduction in antibiotic exposure (5.7 versus 8.1 days, 95% CI -2.71 to -2.15, P < 0.001) and lower risk of antibiotic-related side effects (16.3% versus 22.1%, adjusted OR 0.68, 95% CI 0.57 to 0.82, P < 0.001). Length of hospital stay and intensive care unit stay were similar in both groups. A sensitivity aggregate-data analysis based on all 32 eligible trials showed similar results.

AUTHORS' CONCLUSIONS

This updated meta-analysis of individual participant data from 12 countries shows that the use of procalcitonin to guide initiation and duration of antibiotic treatment results in lower risks of mortality, lower antibiotic consumption, and lower risk for antibiotic-related side effects. Results were similar for different clinical settings and types of ARIs, thus supporting the use of procalcitonin in the context of antibiotic stewardship in people with ARIs. Future high-quality research is needed to confirm the results in immunosuppressed patients and patients with non-respiratory infections.

Biomarkers in Sepsis

A biomarker is a characteristic by which a (patho)physiologic process can be identified. Biomarkers can be of diagnostic value (to discriminate infection from noninfectious conditions or to determine the causative pathogen), of prognostic value (assigning risk profiles and predict outcome), and in the future may be of theranostic value (aid in selection and monitoring of therapy). Systems biology provides a promising tool for the discovery of novel biomarkers. Biomarkers can be the key to personalized targeted treatment in the future clinical management of sepsis.

Impact of Procalcitonin-Guided Antibiotic Management on Antibiotic Exposure and Outcomes: Real-world Evidence

Background

Delayed pathogen identification and nonspecific clinical findings make definitive decisions regarding antibiotics challenging. The stimuli of bacterial toxins and inflammation make procalcitonin (PCT) unique in its ability to differentiate bacterial infection from other causes of inflammation, and thus it is useful for antibiotic management. The objective of our study was to evaluate the impact of a PCT algorithm (PCT-A) on current practice.

Methods

A single-center, retrospective cohort study was conducted to evaluate the impact of adding PCT-A to stewardship practices. Data from 4 years prior to and after PCT-A implementation were compared in critical and acute care patients of all ages receiving parenteral antibiotics for a DRG coded for infection. A baseline PCT was obtained on admission in patients with suspected bacterial infection. Serial PCT measurements were repeated daily to evaluate effectiveness of therapy. Outcomes of interest were antibiotic exposure, hospital mortality, 30-day readmission, Clostridium difficile infection (CDI), and adverse drug events during hospitalization.

Results

A total of 985 patients (pre-PCT-A group) were compared with 1167 patients (post-PCT-A group). Antimicrobial stewardship alone (pre-PCT-A) resulted in a median days of therapy (DOT) of 17 (interquartile range [IQR], 8.5–22.5) vs 9.0 (IQR, 6.5–12) in the post-PCT-A group (P < .0001). Secondary outcomes were also significantly reduced in the post-PCT-A group.

Conclusion

The addition of PCT in a facility with an established stewardship program resulted in a significant reduction in antibiotic exposure and adverse outcomes. PCT may improve antibiotic management when diagnostic clarity and resolution of infection are lacking.

Update in sepsis guidelines: what is really new?

Sepsis remains a highly lethal entity resulting in more than 200 000 deaths in the USA each year. The in-hospital mortality approaches 30% despite advances in critical care during the last several decades. The direct health care costs in the USA exceed $24 billion dollars annually and continue to escalate each year especially as the population ages. The Surviving Sepsis Campaign published their initial clinical practice guidelines for the management of severe sepsis and septic shock in 2004. Updated versions were published in 2008, 2012 and most recently in 2016 following the convening of the Third International Consensus Definitions Task Force. This task force was convened by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine to address prior criticisms of the multiple definitions used clinically for sepsis-related illnesses. In the 2016 guidelines, sepsis is redefined by the taskforce as a life-threatening organ dysfunction caused by a dysregulated host response to infection. In addition to using the Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score to more rapidly identify patients with sepsis, the task force also proposed a novel scoring system to rapidly screen for patients outside the ICU who are at risk of developing sepsis: the ‘quickSOFA’ (qSOFA) score. To date, the largest reductions in mortality have been associated with early identification of sepsis, initiation of a 3-hour care bundle and rapid administration of broad-spectrum antibiotics. The lack of progress in mortality reduction in sepsis treatment despite extraordinary investment of research resources underscores the variability in patients with sepsis. No single solution is likely to be universally beneficial, and sepsis continues to be an entity that should receive high priority for the development of precision health approaches for treatment.

Laboratory Medicine is Faced with the Evolution of Medical Practice

Laboratory medicine and clinical medicine are co-dependent components of medicine. Laboratory medicine functions most effectively when focused through a clinical lens. Me dical practice as a whole undergoes change. New drugs, treatments and changes in management strategies are introduced. New techniques, new technologies and new tests are developed. These changes may be either clinically or laboratory initiated, and so their introduction requires dialogue and interaction between clinical and laboratory medicine specialists. Treatment monitoring is integral to laboratory medicine, varying from direct drug measurement to monitoring cholesterol levels in response to treatment. The current trend to »personalised medicine« is an extension of this process with the development of companion diagnostics. Technological innovation forms part of modern laboratory practice. Introduction of new technology both facilitates standard laboratory approaches and permits introduction of new tests and testing strategies previously confined to the research laboratory only. The revolution in cardiac biomarker testing has been largely a laboratory led change. Flexibility in service provision in response to changing clinical practice or evolving technology provides a significant laboratory management challenge in the light of increasing expectations, shifts in population demographics and constraint in resource availability. Laboratory medicine practitioners are adept at meeting these challenges. One thing remains constant, that there will be a constant need laboratory medicine to meet the challenges of novel clinical challenges from infectious diseases to medical conditions developing from lifestyle and longevity.