Using Procalcitonin to Guide Antibiotic Therapy

Fever and infections in surgical intensive care: an American Association for the Surgery of Trauma Critical Care Committee clinical consensus document

The evaluation and workup of fever and the use of antibiotics to treat infections is part of daily practice in the surgical intensive care unit (ICU). Fever can be infectious or non-infectious; it is important to distinguish between the two entities wherever possible. The evidence is growing for shortening the duration of antibiotic treatment of common infections. The purpose of this clinical consensus document, created by the American Association for the Surgery of Trauma Critical Care Committee, is to synthesize the available evidence, and to provide practical recommendations. We discuss the evaluation of fever, the indications to obtain cultures including urine, blood, and respiratory specimens for diagnosis of infections, the use of procalcitonin, and the decision to initiate empiric antibiotics. We then describe the treatment of common infections, specifically ventilator-associated pneumonia, catheter-associated urinary infection, catheter-related bloodstream infection, bacteremia, surgical site infection, intra-abdominal infection, ventriculitis, and necrotizing soft tissue infection.

Progress in Procalcitonin Detection Based on Immunoassay

Procalcitonin (PCT) serves as a crucial biomarker utilized in diverse clinical contexts, including sepsis diagnosis and emergency departments. Its applications extend to identifying pathogens, assessing infection severity, guiding drug administration, and implementing theranostic strategies. However, current clinical deployed methods cannot meet the needs for accurate or real-time quantitative monitoring of PCT. This review aims to introduce these emerging PCT immunoassay technologies, focusing on analyzing their advantages in improving detection performances, such as easy operation and high precision. The fundamental principles and characteristics of state-of-the-art methods are first introduced, including chemiluminescence, immunofluorescence, latex-enhanced turbidity, enzyme-linked immunosorbent, colloidal gold immunochromatography, and radioimmunoassay. Then, improved methods using new materials and new technologies are briefly described, for instance, the combination with responsive nanomaterials, Raman spectroscopy, and digital microfluidics. Finally, the detection performance parameters of these methods and the clinical importance of PCT detection are also discussed.

Antibiotic Stewardship in Surgical Departments

Antimicrobial resistance (AMR) has emerged as one of the leading public health threats of the 21st century. New evidence underscores its significance in patients' morbidity and mortality, length of stay, as well as healthcare costs. Globally, the factors that contribute to antimicrobial resistance include social and economic determinants, healthcare governance, and environmental interactions with impact on humans, plants, and animals. Antimicrobial stewardship (AS) programs have historically overlooked surgical teams as they considered them more difficult to engage. This review aims to summarize the evolution and significance of AS in surgical wards, including the surgical intensive care unit (SICU) and the role of diagnostic stewardship (DS). The contribution of AS team members is presented. The new diagnostic modalities and the new technologies including artificial intelligence (AI) are also reviewed.

Exploring the Impact of Model-Informed Precision Dosing on Procalcitonin Concentrations in Critically Ill Patients: A Secondary Analysis of the DOLPHIN Trial

Model-informed precision dosing (MIPD) might be used to optimize antibiotic treatment. Procalcitonin (PCT) is a biomarker for severity of infection and response to antibiotic treatment. The aim of this study was to assess the impact of MIPD on the course of PCT and to investigate the association of PCT with pharmacodynamic target (PDT) attainment in critically ill patients. This is a secondary analysis of the DOLPHIN trial, a multicentre, open-label, randomised controlled trial. Patients with a PCT value available at day 1 (T1), day 3 (T3), or day 5 (T5) after randomisation were included. The primary outcome was the absolute difference in PCT concentration at T1, T3, and T5 between the MIPD and the standard dosing group. In total, 662 PCT concentrations from 351 critically ill patients were analysed. There was no statistically significant difference in PCT concentration between the trial arms at T1, T3, or T5. The median PCT concentration was highest in patients who exceeded 10× PDT at T1 [13.15 ng/mL (IQR 5.43-22.75)]. In 28-day non-survivors and in patients that exceeded PDT at T1, PCT decreased significantly between T1 and T3, but plateaued between T3 and T5. PCT concentrations were not significantly different between patients receiving antibiotic treatment with or without MIPD guidance. The potential of PCT to guide antibiotic dosing merits further investigation.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Procalcitonin-Based Antibiotic Use for Neonatal Early-Onset Bacterial Infections: Pre- and Post-Intervention Clinical Study

We previously reported the 95th percentile cutoff value of the serum procalcitonin (PCT) reference curve for diagnosing early-onset bacterial infection. We aimed to verify the effectivity of these novel diagnostic criteria by comparing antibiotic use and incidence of early-onset bacterial infection between pre- and post-introduction periods. We included newborns admitted to our neonatal intensive care unit who underwent blood tests within 72 h after birth between 2018 and 2022. The neonates were divided into the pre-intervention (admitted before the introduction, n = 737) or post-intervention (admitted after the introduction, n = 686) group. The days of antibiotics therapy (DOT) per 1000 patient days up to 6 days after birth, percentage of antibiotic use, and incidence of early-onset bacterial infection were compared between the groups. The post-intervention group had significantly lower DOT per 1000 patient days (82.0 days vs. 211.3 days, p < 0.01) and percentage of newborns receiving antibiotics compared with the pre-intervention group (79 (12%) vs. 280 (38%), respectively, p < 0.01). The incidence of early-onset bacterial infections did not differ between the groups (2% each, p = 0.99). In conclusion, our diagnostic criteria using the 95th percentile cutoff value of the serum PCT reference curve for early-onset bacterial infection were proven safe and effective, promoting appropriate use of antibiotics.

Safety of Procalcitonin Guided Early Discontinuation of Antibiotic Therapy among Children Receiving Cancer Chemotherapy and Having Low-Risk Febrile Neutropenia: A Randomized Feasibility Trial (ProFenC Study)

In low-risk febrile neutropenia (LR-FN), the safety of early discontinuation of empiric antibiotics without marrow recovery is not well established. This study aimed to evaluate the safety of procalcitonin (PCT) guided early discontinuation of antibiotics in LR-FN. In this trial, children with LR-FN with an afebrile period of at least 24 h, sterile blood culture, and negative/normalized PCT were randomized at 72 h of starting antibiotics into two groups: intervention arm and standard arm. The antibiotics were stopped in the intervention arm regardless of absolute neutrophil count (ANC), while in the standard arm, antibiotics were continued for at least 7 days or until recovery of ANC (>500/mm3). The primary objective was to determine the treatment failure rates, and the secondary objective was to compare the duration of antibiotics and all-cause mortality between the two arms. A total of 46 children with LR-FN were randomized to either the intervention arm (n = 23) or the standard arm (n = 23). Treatment failure was observed in 2/23 (8.7%) of patients in the intervention arm compared to 1/23 (4.3%) in the standard arm [RR: 2 (95% CI: 0.19-20.6); p = 0.55]. The median duration of antibiotics in the intervention arm and standard arm were 3 days vs 7 days (P= <0.001). There was no mortality in this study. PCT-guided early discontinuation of empirical antibiotics in LR-FN is feasible. There was no significant difference observed in treatment failure between the early discontinuation of antibiotics vs standard therapy. The total duration of antibiotic exposure was significantly lesser in the discontinuation arm. Further, larger multicenter studies are needed to confirm the finding of this study.

Clinical Uncertainty Influences Antibiotic Prescribing for Upper Respiratory Tract Infections: A Qualitative Study of Township Hospital Physicians and Village Doctors in Rural Shandong Province, China

OBJECTIVE

This study aimed to explore how clinical uncertainty influences antibiotic prescribing practices among township hospital physicians and village doctors in rural Shandong Province, China.

METHODS

Qualitative semi-structured interviews were conducted with 30 township hospital physicians and 6 village doctors from rural Shandong Province, China. A multi-stage random sampling method was used to identify respondents. Conceptual content analysis together with Colaizzi's method were used to generate qualitative codes and identify themes.

RESULTS

Three final thematic categories emerged during the data analysis: (1) Incidence and treatment of Upper Respiratory Tract Infections (URTIs) in township hospitals and village clinics; (2) Antibiotic prescribing practices based on the clinical experience of clinicians; (3) Influence of clinical uncertainty on antibiotic prescribing. Respondents from both township hospitals and village clinics reported that URTIs were the most common reason for antibiotic prescriptions at their facilities and that clinical uncertainty appears to be an important driver for the overuse of antibiotics for URTIs. Clinical uncertainty was primarily due to: (1) Diagnostic uncertainty (establishing a relevant diagnosis is hindered by limited diagnostic resources and capacities, as well as limited willingness of patients to pay for investigations), and (2) Insufficient prognostic evidence. As a consequence of the clinical uncertainty caused by both diagnostic and prognostic uncertainty, respondents stated that antibiotics are frequently prescribed for URTIs to prevent both prolonged courses or recurrence of the disease, as well as clinical worsening, hospital admission, or complications.

CONCLUSION

Our study suggests that clinical uncertainty is a key driver for the overuse and misuse of prescribing antibiotics for URTIs in both rural township hospitals and village clinics in Shandong province, China, and that interventions to reduce clinical uncertainty may help minimize the unnecessary use of antibiotics in these settings. Interventions that use clinical rules to identify patients at low risk of complications or hospitalization may be more feasible in the near-future than laboratory-based interventions aimed at reducing diagnostic uncertainty.

Controversies in the management of acute pancreatitis: An update

This review summarized the current controversies in the management of acute pancreatitis (AP). The controversies in management range from issues involving fluid resuscitation, nutrition, the role of antibiotics and antifungals, which analgesic to use, role of anticoagulation and intervention for complications in AP. The interventions vary from percutaneous drainage, endoscopy or surgery. Active research and emerging data are helping to formulate better guidelines. The available evidence favors crystalloids, although the choice and type of fluid resuscitation is an area of dynamic research. The nutrition aspect does not have controversy as of now as early enteral feeding is preferred most often than not. The empirical use of antibiotics and antifungals are gray zones, and more data is needed for conclusive guidelines. The choice of analgesic is being studied, and the recommendations are still evolving. The position of using anticoagulation is still awaiting consensus. The role of intervention is well established, although the modality is constantly changing and favoring endoscopy or percutaneous drainage rather than surgery. It is evident that more multicenter randomized controlled trials are required for establishing the standard of care in these crucial management issues of AP to improve the morbidity and mortality worldwide.

The Role of Procalcitonin as an Antimicrobial Stewardship Tool in Patients Hospitalized with Seasonal Influenza

Background: Up to 60% of the antibiotics prescribed to patients hospitalized with seasonal influenza are unnecessary. Procalcitonin (PCT) has the potential as an antimicrobial stewardship program (ASP) tool because it can differentiate between viral and bacterial etiology. We aimed to explore the role of PCT as an ASP tool in hospitalized seasonal influenza patients. Methods: We prospectively included 116 adults with seasonal influenza from two influenza seasons, 2018–2020. All data was obtained from a single clinical setting and analyzed by descriptive statistics and regression models. Results: In regression analyses, we found a positive association of PCT with 30 days mortality and the amount of antibiotics used. Influenza diagnosis was associated with less antibiotic use if the PCT value was low. Patients with a low initial PCT (<0.25 µg/L) had fewer hospital and intensive care unit (ICU) days and fewer positive chest X-rays. PCT had a negative predictive value of 94% for ICU care stay, 98% for 30 days mortality, and 88% for bacterial coinfection. Conclusion: PCT can be a safe rule-out test for bacterial coinfection. Routine PCT use in seasonal influenza patients with an uncertain clinical picture, and rapid influenza PCR testing, may be efficient as ASP tools.

Predictive value of serum interleukin-6 to determine surgical drainage of deep neck space infection in adults

PURPOSE

The aim of this study was to determine whether interleukin-6 (IL-6) could be used as a predictor for surgical drainage in deep neck space infection (DNSI).

METHODS

A retrospective study was conducted to analyze 69 adult patients newly diagnosed as DNSI from January 2017 to December 2021 at a single center. The patients were treated with either surgical drainage or not. The following clinical data including age, gender, maximum diameter of abscess (MDA), laboratory data, therapeutic modalities, comorbidities, duration of hospitalization and complications were collected and evaluated.

RESULTS

Patients in drained group had significantly elevated MDA, IL-6, procalcitonin, C-reactive protein and neutrophil to lymphocyte ratio compared to patients in non-drained group (all P < 0.01). Significant predictors for surgical drainage were IL-6 and MDA as independent factors, with the optimum cutoff values of 52.5 pg/mL and 14.4 mm, respectively. Moreover, the IL-6 had a wider area under the curve than MDA for prediction of surgical drainage in DNSI.

CONCLUSIONS

IL-6 as a promising predictor of the need for surgical drainage can be effectively used for routine assessment in the early stage of DNSI to determine the optimal treatments.

Biomarkers as Prognostic Predictors and Therapeutic Guide in Critically Ill Patients: Clinical Evidence

A biomarker is a molecule that can be measured in a biological sample in an objective, systematic, and precise way, whose levels indicate whether a process is normal or pathological. Knowing the most important biomarkers and their characteristics is the key to precision medicine in intensive and perioperative care. Biomarkers can be used to diagnose, in assessment of disease severity, to stratify risk, to predict and guide clinical decisions, and to guide treatments and response to them. In this review, we will analyze what characteristics a biomarker should have and how to ensure its usefulness, and we will review the biomarkers that in our opinion can make their knowledge more useful to the reader in their clinical practice, with a future perspective. These biomarkers, in our opinion, are lactate, C-Reactive Protein, Troponins T and I, Brain Natriuretic Peptides, Procalcitonin, MR-ProAdrenomedullin and BioAdrenomedullin, Neutrophil/lymphocyte ratio and lymphopenia, Proenkephalin, NefroCheck, Neutrophil gelatinase-associated lipocalin (NGAL), Interleukin 6, Urokinase-type soluble plasminogen activator receptor (suPAR), Presepsin, Pancreatic Stone Protein (PSP), and Dipeptidyl peptidase 3 (DPP3). Finally, we propose an approach to the perioperative evaluation of high-risk patients and critically ill patients in the Intensive Care Unit (ICU) based on biomarkers.

Prognostic value of procalcitonin in cancer patients with coronavirus disease 2019

OBJECTIVES

Many biomarkers have been studied to assist in the risk stratification and prognostication of patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Procalcitonin (PCT), a circulating precursor of the hormone calcitonin, has been studied with mixed results as a predictor of severe coronavirus disease 2019 (COVID-19) in the general population; however, to date, no studies have focused on the utility of PCT in predicting disease severity and death from COVID-19 in the cancer population.

METHODS

We conducted a retrospective study of cancer patients hospitalized with COVID-19 at a comprehensive cancer center over a 10-month period who had PCT recorded on admission. We assessed associations between variables of clinical interest and the primary outcomes of progression of COVID-19 and death during or within 30 days of hospitalization using univariable and multivariable logistic regression.

RESULTS

The study included 209 unique patients. In the univariate analysis, elevated PCT on admission was associated with higher odds of progression of COVID-19 or death (Odds ratio [OR] 1.40, 95% CI 1.08-1.93) and mortality alone (OR 1.53, 95% CI 1.17-2.11). In multivariate regression, PCT remained significantly associated with progression or death after holding chronic kidney disease (CKD) status constant (OR 1.40, 95% CI: 1.08, 1.93, p=0.003). Similarly, the association of PCT and death remained significant after adjusting for age (OR 1.54, 95% CI: 1.17-2.15).

CONCLUSIONS

In hospitalized COVID-19 patients with underlying cancer, initial PCT levels on admission may be associated with prognosis, involving higher odds of progression of COVID-19 and/or mortality.

THE IMPACT OF TOCILIZUMAB ON THE BIOCHEMICAL MARKER PROCALCITONIN DURING COVID-19 INFECTION

OBJECTIVE

The aim: The primary objective of our study was to track the TCZ's impact on PCT levels in a cohort of COVID-19 patients who received dexamethasone daily from admission to the day of discharge.

PATIENTS AND METHODS

Materials and methods: There were two groups: a treatment group of 40 patients who received tocilizumab and a 40-patient control group that did not receive the medication. Both groups' daily blood culture results and serum procalcitonin biochemical indicators were observed for 20 days, or until discharge or death. After 10 days, non-parametric univariate and linear mixed model analyses were used to compare the two groups' differences.

RESULTS

Results: Tocilizumab is administered on Day 5 and greatly reduces procalcitonin. The two groups did not differ in the percentage of positive blood cultures.

CONCLUSION

Conclusions: Procalcitonin levels in COVID-19 individuals who have received tocilizumab maybe not a dependable predictor of superinfection with bacteria.

Optimal Predictors of Postoperative Complications After Gastrectomy: Results from the Procalcitonin and C-reactive Protein for the Early Diagnosis of Anastomotic Leakage in Esophagogastric Surgery (PEDALES) Study

BACKGROUND

The aim of this study was to define whether procalcitonin (PCT) is an earlier and more accurate predictor than C-reactive protein (CRP) for anastomotic leakage (AL) and major infective complications (MICs).

METHODS

This was a prospective multicentric observational study conducted in three Italian centers, including all patients undergoing gastrectomy from May 2016 to April 2021. The endpoint was the assessment of the discrimination and accuracy achieved by the PCT and CRP values measured from POD1 to POD7 for predicting the occurrence of AL and MICs. Accuracy was assessed by calculating the area under the receiver operating curve (AUROC) values and Youden's statistics. Two charts were created for risk stratification during the postoperative course.

RESULTS

The rate of AL was 4.6%, with a median day of occurrence on POD5 (range 3-26). The overall rate of major infective complications was 19.9%, with a median day of occurrence on POD6 (range 2-30). PCT showed a significant association with AL on POD6 and POD7 and a significant association with MICs on POD2, while CRP values showed a significant association with AL on POD4 and a significant association with MICs on POD1. No difference in the prediction of AL was observed between PCT and CRP, while CRP was found to be a superior predictor of major infective complications on POD5 (p = 0.024) and POD7 (p = 0.035).

CONCLUSIONS

PCT was not superior to CRP as an early predictor of AL and major infective complications after gastrectomy. CRP should be used as the reference screening postoperative marker.

Machine learning and synthetic outcome estimation for individualised antimicrobial cessation

The decision on when it is appropriate to stop antimicrobial treatment in an individual patient is complex and under-researched. Ceasing too early can drive treatment failure, while excessive treatment risks adverse events. Under- and over-treatment can promote the development of antimicrobial resistance (AMR). We extracted routinely collected electronic health record data from the MIMIC-IV database for 18,988 patients (22,845 unique stays) who received intravenous antibiotic treatment during an intensive care unit (ICU) admission. A model was developed that utilises a recurrent neural network autoencoder and a synthetic control-based approach to estimate patients' ICU length of stay (LOS) and mortality outcomes for any given day, under the alternative scenarios of if they were to stop vs. continue antibiotic treatment. Control days where our model should reproduce labels demonstrated minimal difference for both stopping and continuing scenarios indicating estimations are reliable (LOS results of 0.24 and 0.42 days mean delta, 1.93 and 3.76 root mean squared error, respectively). Meanwhile, impact days where we assess the potential effect of the unobserved scenario showed that stopping antibiotic therapy earlier had a statistically significant shorter LOS (mean reduction 2.71 days, p -value <0.01). No impact on mortality was observed. In summary, we have developed a model to reliably estimate patient outcomes under the contrasting scenarios of stopping or continuing antibiotic treatment. Retrospective results are in line with previous clinical studies that demonstrate shorter antibiotic treatment durations are often non-inferior. With additional development into a clinical decision support system, this could be used to support individualised antimicrobial cessation decision-making, reduce the excessive use of antibiotics, and address the problem of AMR.

Risk factors for difficult ventilatory weaning in intensive care patients with cervical cellulitis

PURPOSE

Cervical cellulitis is an infrequent but serious infection. The management of the upper airways is difficult, at the actual time of intubation but also regarding the necessity of maintaining mechanical ventilation. The objective of this study is to identify risk factors on admission to the intensive care unit for difficult ventilatory weaning in patients with cervical cellulitis.

METHODS

Between January 2013 and December 2018, this retrospective observational study was performed in an intensive care unit with 10 beds in a university hospital recognized as a reference center for the management of cellulitis. All intensive care patients receiving mechanical ventilation after surgery for cervical cellulitis were eligible. Difficult ventilatory weaning was defined as mechanical ventilation lasting more than 7 days or failure of extubation as established by the WIND 2017 study.

RESULTS

We included 120 patients with severe cervical cellulitis. The median age was 43 years. Eighteen patients (16%) presented mediastinal extension. The risk factor for difficult ventilatory weaning (n = 49) in multivariate analysis was a high level of procalcitonin on admission (OR at 1.14[1.005-1.29]; p&lt;0.042) and the protective factor was surgery in an expert center (OR at 0.11[0.026-0.47]; p&lt;0.003). Eight patients required a tracheotomy in our study: 3 patients during surgery and at a later time for the other 5 of our 8 patients.

CONCLUSION

No intensive care studies have investigated ventilatory weaning risk factors in patients with cervical cellulitis. Yet simple criteria seem to predict this risk. It is now necessary to confirm them by a multicenter prospective study.

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

BACKGROUND

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

An evaluation into the use of procalcitonin levels as a biomarker of bacterial sepsis to aid the management of intrapartum pyrexia and chorioamnionitis

BACKGROUND

Procalcitonin is an established biomarker for bacterial sepsis in the nonpregnant population with better diagnostic and prognostic value for bacterial infections.

OBJECTIVE

This study aimed to evaluate whether procalcitonin levels could be used in the diagnosis and management of intrapartum sepsis in women and their neonates suspected of intrapartum bacterial sepsis.

STUDY DESIGN

A prospective observational cohort study was conducted at the University Hospitals of Bristol and Weston NHS Foundation Trust. Overall, 117 women and their neonates managed for suspected intrapartum sepsis from June 2020 to October 2020 were included. Procalcitonin levels were measured in addition to routine biomarkers white cell count and C-reactive protein in women and their neonates during the initial septic screen and follow-up blood samples. The placentas underwent detailed histopathology. Maternal and neonatal parameters were used to categorize cases into “high-suspicion bacterial sepsis,” “equivocal bacterial sepsis,” and “low-suspicion bacterial sepsis.” The Kruskal-Wallis test was used to compare categories with biomarker values and placental histology scores.

RESULTS

Procalcitonin level was increased in 6 women in the initial septic screen sample, compared with 100 women with an increased C-reactive protein level. There was a significant difference in maternal postnatal procalcitonin results between “high-suspicion bacterial sepsis” and “low-suspicion bacterial sepsis” categories (P=.004). Moreover, 71.2% of placentas showed varying degrees of chorioamnionitis.

CONCLUSION

In our cohort of women, 94.6% had normal procalcitonin levels while in labor at the time of the septic screen, consistent with the low number of confirmed bacteremia. The result provided a basis that procalcitonin may complement clinical judgment and interpretation of already used prognostic and diagnostic tests, improving patient care in the management of intrapartum sepsis.

Antimicrobial Stewardship in the ICU

Increasing rates of infection and multidrug-resistant pathogens, along with a high use of antimicrobial therapy, make the intensive care unit (ICU) an ideal setting for implementing and supporting antimicrobial stewardship efforts. Overuse of antimicrobial agents is common in the ICU, as practitioners are challenged daily with achieving early, appropriate empiric antimicrobial therapy to improve patient outcomes. While early antimicrobial stewardship programs focused on the financial implications of antimicrobial overuse, current goals of stewardship programs align closely with those of critical care providers-to optimize patient outcomes, reduce development of resistance, and minimize adverse outcomes associated with antibiotic overuse and misuse such as acute kidney injury and Clostridioides difficile-associated disease. Significant opportunities exist in the ICU for critical care clinicians to support stewardship practices at the bedside, including thoughtful and restrained initiation of antimicrobial therapy, use of biomarkers in addition to rapid diagnostics, Staphylococcus aureus screening, and traditional microbiologic culture and susceptibilities to guide antibiotic de-escalation, and use of the shortest duration of therapy that is clinically appropriate. Integration of critical care practitioners into the initiatives of antimicrobial stewardship programs is key to their success. This review summarizes key components of antimicrobial stewardship programs and mechanisms for critical care practitioners to share the responsibility for antimicrobial stewardship.

Prediction of Prognosis in Adult Patients With Carbapenem-Resistant Klebsiella pneumoniae Infection

OBJECTIVE

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are associated with poor patient outcomes. We aimed to analyze the clinical information of adult patients with CRKP infection in order to establish a nomogram for mortality risk as well as to determine the treatment effectiveness of different antimicrobial regimens.

METHODS

Adult patients diagnosed with CRKP infection in a tertiary hospital in Shanghai between September 2019 and March 2021 were included. The clinical characteristics and clinical outcomes of these patients were analyzed.

RESULTS

A total of 199 cases of CRKP infection were examined. Five factors, namely age ≥65 years, respiratory failure, Sequential Organ Failure Assessment score, serum procalcitonin ≥5 ng/mL, and appropriate treatments in 3 days, were found to be associated with 30-day mortality. Upon incorporating these factors, the nomogram achieved good concordance indexes of 0.85 (95% confidence interval [CI]: 0.80-0.90) and well-fitted calibration curves. Receiver-operating characteristic curves for 7-, 15-, and 30-day survival had areas under the curve of 0.90, 0.87, and 0.88, respectively. Three-drug combination therapy was observed to be associated with lower mortality in the high-risk group (adjusted hazard ratio = 0.24, 95% CI: 0.06-0.99) but not in the low-risk group. Ceftazidime-avibactam, fosfomycin, and amikacin were effective against infections caused by CRKP. Tigecycline improved the treatment efficiency in 7 days, but a trend toward increased mortality was seen (HR, 1.69; 95% CI: 0.98-2.94; P = 0.061).

CONCLUSION

The antimicrobial regimen efficacy data and the predictive nomogram established in this study can help clinicians in identifying high-risk adult patients with CRKP infection, improving the therapeutic effect, and reducing mortality.

Impact of a Procalcitonin-Based Protocol on Antibiotic Exposure and Costs in Critically Ill Patients

Supplemental Digital Content is available in the text.

To examine the impact before and after adoption of a procalcitonin-based protocol to guide sepsis management has on antibiotic use, care costs, and outcomes of critically ill patients.

Antibiotic stewardship: Early discontinuation of antibiotics based on procalcitonin level in COVID-19 pneumonia

WHAT IS KNOWN AND OBJECTIVE

Procalcitonin (PCT) levels rise in systemic inflammation, especially if bacterial in origin. COVID-19, caused by the novel coronavirus SARS-CoV-2, presents with acute respiratory distress syndrome. Elevated procalcitonin in COVID-19 is considered as a marker for severity of disease. There is no study available that indicates whether elevated PCT in COVID-19 is associated with inflammation or superimposed bacterial infection. The objective of this study is to evaluate the association between PCT levels and superadded bacterial infection, and the effect of discontinuation of antibiotic in the low PCT (<0.25 ng/ml) group on patients' outcomes.

METHODS

A retrospective chart review of patients admitted with COVID-19 pneumonia at a single tertiary care centre. We collected information on demographics, co-morbidities, PCT level, antibiotic use, culture results for bacterial infection, hospital length of stay (LOS) and mortality.

STATISTICAL ANALYSIS

Continuous variables were summarized with the sample median, interquartile range, mean and range. Categorical variables were summarized with number and percentage of patients.

RESULTS AND DISCUSSION

We studied a total of 147 patients with COVID-19 pneumonia. 101 (69%) patients had a low PCT level (< 0.25 ng/ml). Bacterial culture results were negative for all patients, except 1 who had a markedly elevated PCT level (141.ng/ml). In patients with low PCT, 42% received no antibiotics, 59% received antibiotics initially, 32 (57%) patients antibiotic discontinued early (within 24 hours) and their culture remained negative for bacterial infections during hospitalizations. LOS was shorter (6 days in low PCT group compared to 9 days) in high PCT group. LOS was 1 day shorter (5 days vs 6 days) in no antibiotic group compared to antibiotic group. Our study examines the association between PCT level and superadded bacterial infection in COVID-19 pneumonia. Our results demonstrate that most patients admitted with COVID-19 have a low PCT (<0.25 ng/ml), which suggests no superadded bacterial infection and supports the previously published literature regarding low PCT in viral pneumonia.

WHAT IS NEW AND CONCLUSION

Procalcitonin level remains low in the absence of bacterial infection. Early de-escalation/discontinuation of antibiotics is safe without adverse outcomes in COVID-19 pneumonia. Early de-escalation/discontinuation of antibiotics is associated with lower LOS.

A retrospective analysis of the impact of a hospital pharmacist-led procalcitonin protocol

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PURPOSE

Procalcitonin is a precursor hormone to calcitonin that increases in response to systemic inflammation, especially of bacterial origin, and is otherwise undetectable in healthy states. Studies have shown that following effective antimicrobial treatment, procalcitonin levels steadily decline. To be utilized however, procalcitonin determinations must be ordered at specific times during a patient's antimicrobial treatment. A retrospective medication-use evaluation of patients was performed at Medical Center Hospital and showed that in 70% of patients, initial procalcitonin levels were ordered inappropriately and procalcitonin levels were trended inconsistently during antibiotic treatment.

METHODS

A pharmacist-led procalcitonin protocol was developed and presented to medical staff committees for approval. Data was collected from patients presenting with suspected or confirmed sepsis or lower respiratory tract infections for whom procalcitonin levels were utilized. Patient outcomes before and after protocol implementation were compared.

RESULTS

A total of 400 patients were included in the study. The primary outcome of appropriate ordering of initial procalcitonin levels was improved in the postprotocol group relative to the preprotocol group (28% of patients [n = 56] vs 72% of patients [n = 144]; P < 0.001). Patients in the postprotocol group had a procalcitonin level checked at discontinuation more frequently (8% [n = 16] vs 37% [n = 74], P < 0.001) and had a higher rate of appropriate discontinuation of antibiotics (12% [n = 21] vs 46% [n = 77]; P < 0.001). The postprotocol group also had fewer mean days of antibiotic therapy (9.17 vs 6.01; P < 0.001).

CONCLUSION

Studies have shown the usefulness of procalcitonin levels for antimicrobial stewardship, but for procalcitonin testing to be properly utilized it must be ordered at the correct times during the patient's therapy. The implementation of a hospital-wide pharmacist-led protocol resulted in an increase in appropriate ordering of baseline procalcitonin levels.

Evaluation of a Pharmacist-Driven Procalcitonin Protocol for Lower Respiratory Tract Infections Using a Clinical Decision Support System

Purpose: Procalcitonin (PCT) may be an effective biomarker in the management of lower respiratory tract infections (LRTI) when combined with antimicrobial stewardship support. We assessed the impact of a PCT protocol with clinical pharmacy support for LRTI using a clinical decision support system (CDSS) for monitoring. Methods: This was a single-center retrospective cohort study conducted at a large, nonteaching hospital in Nashville, TN. All patients who met eligibility requirements and were initiated on the PCT protocol for a suspected LRTI between February and March 2018 were included and matched to historical control patients from 2016 to 2017 on a 1:1 basis based on antibiotics, indication, and time of year. Results: During this 2-month period, a total of 126 patients met eligibility requirements for inclusion in the PCT group and were matched to historical control patients. Patients in the PCT group received decreased median antibiotic days of therapy (DOT) compared to controls (11 vs 14, P = .004). There was no change in median length of stay (LOS) between groups. The acceptance rate for patient-specific antibiotic de-escalation recommendations from the clinical pharmacist was 62.5%. Conclusion: PCT protocols that utilize clinical pharmacist interpretation and a CDSS may be an effective intervention of the antimicrobial stewardship program (ASP) for decreasing antibiotic DOT for LRTI.

Clinical utility of procalcitonin and its association with pathogenic microorganisms

In this review, we summarize the relationship of PCT with pathogens, evaluate the clinical utility of PCT in the diagnosis of clinical diseases, condition monitoring and evaluation, and guiding medical decision-making, and explore current knowledge on the mechanisms by which pathogens cause changes in PCT levels. The lipopolysaccharides of the microorganisms stimulate cytokine production in host cells, which in turn stimulates production of serum PCT. Pathogens have different virulence mechanisms that lead to variable host inflammatory responses, and differences in the specific signal transduction pathways result in variable serum PCT concentrations. The mechanisms of signal transduction have not been fully elucidated. Further studies are necessary to ascertain the PCT fluctuation range of each pathogen. PCT levels are helpful in distinguishing between certain pathogens, in deciding if antibiotics are indicated, and in monitoring response to antibiotics.

Analytical and clinical performance of the Advansure i3 procalcitonin assay

Procalcitonin (PCT) is a clinically useful biomarker for early diagnosis and subsequent management of sepsis. We evaluated the analytical performance of a new automated chemiluminescent immunoanalyzer-based procalcitonin assay, AdvanSure i3 PCT assay (LG Life Sciences, Korea) on an AdvanSure i3 (LG Life Sciences) and compared it to the Elecsys BRAHMS PCT assay (Roche, Switzerland) on a Cobas e801 (Roche). Analytical performance was performed for the precision, linearity, and method comparison with the Elecsys BRAHMS PCT assay by Clinical and Laboratory Standards Institute guidelines. Clinical evaluations were conducted using 87 residual samples from admitted patients with suspected infection. The patients were classified based on Sepsis-3 classification. The AdvanSure i3 PCT assay exhibited a CV <5.5% for between-run precision and <6.5% for within-laboratory precision. The assay was linear up to 80.32 µg/L (r = 0.990). Statistical analysis showed that the two assays yielded a good correlation (r = 0.996), with a weighted kappa value of 0.94. Median plasma PCT level was significantly different between the non-sepsis and sepsis groups (p < .001) and the non-sepsis and septic shock groups (p < .0018). The AdvanSure i3 PCT assay showed good analytical performance and correlation with the Elecsys BRAHMS PCT assay for the sepsis patients. This new assay can be used as a diagnostic early marker of sepsis in clinical laboratories.

Capacity and use of diagnostics and treatment for patients with severe acute respiratory infections in the pre-COVID-19 era in district and provincial hospitals in Viet Nam

Objective

To describe the burden of severe acute respiratory infection (SARI) and the infrastructure and current practices of SARI management in hospitals in Viet Nam.

Methods

We conducted a short observational study at critical care units (CCUs) in 32 district hospitals and 16 provincial hospitals in five provinces in Viet Nam from March to July 2019. We collected data on hospital equipment and medicines used in SARI management. At the patient level, data were collected for 14 consecutive days on all patients presenting to CCUs, including information on demographics, intervention and treatment within 24 hours of CCU admission and 7-day outcome.

Results

There were significant differences between district and provincial hospitals in the availability of microbial culture, rapid influenza diagnostic tests, inflammatory markers and mechanical ventilation. Among 1722 eligible patients admitted to CCUs, there were 395 (22.9%) patients with SARI. The median age of SARI patients was 74 (interquartile range: 58–84) years; 49.1% were male. Although systemic antibiotics were available in all hospitals and were empirically given to 93.4% of patients, oseltamivir was available in 25% of hospitals, and only 0.5% of patients received empiric oseltamivir within 24 hours of admission. The 7-day mortality was 6.6% (26/395). Independent factors associated with 7-day mortality were septic shock and requiring respiratory support within 24 hours of admission.

Discussion

SARI is a major burden on CCUs in Viet Nam. Barriers to delivering quality care include the limited availability of diagnostics and medication and non-protocolized management of SARI in CCUs.

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

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

Clinical outcomes and costs associated with procalcitonin utilization in hospitalized patients with pneumonia, heart failure, viral respiratory infection, or chronic obstructive pulmonary disease

Lower respiratory tract infections (LRTIs) due to bacterial pneumonia are common among hospitalized patients and are frequently treated with antibiotics. Viral illnesses and exacerbations of heart failure or COPD may present with symptoms mimicking a LRTI, resulting in unnecessary antibiotic utilization. Procalcitonin testing may be useful in these clinical scenarios. We attempted to assess the utility of procalcitonin testing versus not testing, and positive versus negative results among hospitalized patients with suspected LRTI. We performed a retrospective cohort study using multivariable analysis comparing clinical outcomes of patients with and without procalcitonin testing. Patients were 18 years or older, hospitalized for pneumonia, heart failure, COPD, or a viral respiratory illness between October 2014 and October 2015 (n = 2353). All patients received at least one dose of antibiotics. Major outcomes were duration of antibiotic therapy, length of hospital stay, C. difficile testing and infections, and normalized total direct costs. Procalcitonin testing occurred in 14.0% of patients and pneumonia (70.6%) was the most common diagnosis. After covariate adjustments, mean length of stay (5.61 vs. 6.67 days, p < 0.001) and duration of antibiotics (3.95 vs. 4.47 days, p < 0.001) were shorter among tested patients. Fewer 30-day readmissions (OR 0.62, 95% CI 0.40-0.95) were observed, and total direct healthcare costs were 34% lower (0.66, 95% CI 0.58-0.74) among tested patients. Negative procalcitonin results were associated with further reductions in some outcomes. In conclusion, procalcitonin testing among hospitalized patients with suspected LRTI is associated with reductions in antibiotic duration, length of stay, 30-day readmission, and healthcare costs.

The role of procalcitonin in reducing antibiotics across the surgical pathway

Procalcitonin (PCT) is widely considered as a highly sensitive biomarker of bacterial infection, offering general and emergency surgeons a key tool in the management of surgical infections. A multidisciplinary task force of experts met in Bologna, Italy, on April 4, 2019, to clarify the key issues in the use of PCT across the surgical pathway. The panelists presented the statements developed for each of the main questions regarding the use of PCT across the surgical pathway. An agreement on the statements was reached by the Delphi method, and this document reports the executive summary of the final recommendations approved by the expert panel.

Procalcitonin Correlates With but Is Not Superior to Other Diagnostic Markers of Bacterial Pneumonia

OBJECTIVES

Despite extensive research on procalcitonin (PCT)-guided therapy in lower respiratory tract infections, the association between PCT and bacterial pneumonia remains unclear.

METHODS

We evaluated retrospectively the performance of PCT in patients presenting with lower respiratory tract infection symptoms and grouped by seven diagnoses. All patients had microbial testing, chest imaging, and CBC counts within 1 day of PCT testing.

RESULTS

Median PCT level in patients diagnosed with bacterial pneumonia was significantly higher than in patients diagnosed with other sources of infections or those not diagnosed with infections. Median PCT levels were not different among patients grouped by type or quantity of pathogen detected. They were significantly higher in patients with higher pathogenicity scores for isolated bacteria, those with abnormal WBC count, and those with chest imaging consistent with bacterial pneumonia. A diagnostic workup that included imaging, WBC count, and Gram stain had an area under the receiver operating characteristic curve of 0.748, and the addition of PCT increased it to 0.778.

CONCLUSIONS

PCT was higher in patients diagnosed with bacterial pneumonia. Less clear is its diagnostic ability to detect bacterial pneumonia over and above imaging and laboratory data routinely available to clinicians.

Use of procalcitonin for antibiotic stewardship in patients with COVID-19: A quality improvement project in a district general hospital

Antibiotic stewardship during the COVID-19 pandemic is an important part of a comprehensive strategy to improve patient outcomes and reduce long-term adverse effects secondary to rising antibiotic resistance. This report describes a quality improvement project which incorporates the use of procalcitonin (PCT) testing to rationalise antibiotic prescribing in patients with suspected or confirmed COVID-19 at Chesterfield Royal Hospital. Data were collected from 118 patients with a total of 127 PCT levels checked over a period of 20 days. Each PCT level was correlated with the subsequent antibiotic outcome as well as the result of the COVID-19 PCR swab. Results indicate that antibiotics were either never started or were stopped within 48 hours in 72% of COVID-confirmed cases with a PCT less than 0.25 μg/L. Our findings suggest that procalcitonin testing, when used in combination with thorough clinical assessment, is a safe, simple and sustainable way of reducing antibiotic use in COVID-19.

Recommendations for antibacterial therapy in adults with COVID-19 - an evidence based guideline

SCOPE

The Dutch Working Party on Antibiotic Policy constituted a multidisciplinary expert committee to provide evidence-based recommendation for the use of antibacterial therapy in hospitalized adults with a respiratory infection and suspected or proven 2019 Coronavirus disease (COVID-19).

METHODS

We performed a literature search to answer four key questions. The committee graded the evidence and developed recommendations by using Grading of Recommendations Assessment, Development, and Evaluation methodology.

QUESTIONS ADDRESSED BY THE GUIDELINE AND RECOMMENDATIONS

We assessed evidence on the risk of bacterial infections in hospitalized COVID-19 patients, the associated bacterial pathogens, how to diagnose bacterial infections and how to treat bacterial infections. Bacterial co-infection upon admission was reported in 3.5% of COVID-19 patients, while bacterial secondary infections during hospitalization occurred up to 15%. No or very low quality evidence was found to answer the other key clinical questions. Although the evidence base on bacterial infections in COVID-19 is currently limited, available evidence supports restrictive antibiotic use from an antibiotic stewardship perspective, especially upon admission. To support restrictive antibiotic use, maximum efforts should be undertaken to obtain sputum and blood culture samples as well as pneumococcal urinary antigen testing. We suggest to stop antibiotics in patients who started antibiotic treatment upon admission when representative cultures as well as urinary antigen tests show no signs of involvement of bacterial pathogens after 48 hours. For patients with secondary bacterial respiratory infection we recommend to follow other guideline recommendations on antibacterial treatment for patients with hospital-acquired and ventilator-associated pneumonia. An antibiotic treatment duration of five days in patients with COVID-19 and suspected bacterial respiratory infection is recommended upon improvement of signs, symptoms and inflammatory markers. Larger, prospective studies about the epidemiology of bacterial infections in COVID-19 are urgently needed to confirm our conclusions and ultimately prevent unnecessary antibiotic use during the COVID-19 pandemic.

Pneumonia surveillance and its attendant clinical risk stratification for COVID-19 in low-risk patients

Objectives

The objective of the study is to determine the prevalence of COVID-19 in the context of a secondary pneumonia surveillance program targeted at low-risk patients and to identify clinical characteristics associated with COVID-19.

Study design

This study design is a retrospective cohort study.

Methods

This study is conducted in Tan Tock Seng Hospital, a University affiliated 1600-bed public hospital in Singapore. Patients with pneumonia admitted under our Enhanced Pneumonia Surveillance (EPS) program from 7 February 2020 to 20 March 2020 were included. Relevant clinical variables were collated.

Results

Of 1295 patients admitted under our EPS program, 47 (3.6%) patients tested positive for COVID-19. The prevalence of a radiologist-reported normal chest X-ray (CXR) in the COVID-19–positive group was 62.8% compared with 6.2% in the COVID-19–negative group. In patients with a normal CXR, a low normal white blood cell (WBC) count and minimal C-reactive protein (CRP) elevation were associated with COVID-19.

Conclusions

The pick-up rate of COVID-19 in low-risk patients with pneumonia is 3.6%. However, at least 7.9% of patients who were isolated had a normal CXR. For patients with pneumonia-like illness at presentation but a normal CXR, higher WBC and CRP values may guide early deisolation. Ultimately, this informs resource allocation for both COVID-19 and non–COVID-19 clinical services.

Procalcitonin as a predictor of early antibiotic treatment failure in patients with gram-negative bloodstream infections caused by urinary tract infections

We retrospectively evaluated whether initial procalcitonin (PCT) levels can predict early antibiotic treatment failure (ATF) in patients with gram-negative bloodstream infections (GN-BSI) caused by urinary tract infections from January 2018 to November 2019. Early ATF was defined as the following: (1) hemodynamically unstable or febrile at Day 3; (2) the need for mechanical ventilation or continuous renal replacement therapy at Day 3; (3) patients who died within 3 days (date of blood culture: Day 0). The study included 189 patients; 42 showed early ATF. Independent risk factors for early ATF were initial admission to the intensive care unit (odds ratio: 7.735, 95% confidence interval: 2.567-23.311; P < 0.001) and PCT levels ≥30 ng/mL (odds ratio: 5.413, 95% confidence interval: 2.188-13.388; P < 0.001). Antibiotic factors were not associated with early ATF. Initial PCT levels may be helpful to predict early ATF in these patients.

Diagnostic Accuracy of Biomarkers for Early-Onset Neonatal Bacterial Infections: Evaluation of Serum Procalcitonin Reference Curves

To date, no clinical studies have compared the accuracy of serum procalcitonin (PCT) reference curves. We aimed to validate the diagnostic accuracy of previously reported serum PCT reference curves and to determine which biomarkers among a cut-off value over the 95th percentile in the serum PCT reference curve, white blood cell (WBC) count, and C-reactive protein (CRP) and immunoglobulin M (IgM) levels, have the highest diagnostic accuracy for early-onset neonatal bacterial infections. This retrospective cohort study assessed 16 preterm and 23 term infants with suspected bacterial infections within 72 h after birth. Each infant group was divided into two subgroups: confirmed- and non-infection. The diagnostic accuracy was determined using the Youden index. The reference curves by Fukuzumi et al. in preterm and term infants had the highest Youden indexes: 1.000 and 0.324, respectively. Among preterm infants, the Youden index for PCT was 1.000. Among term infants, the Youden index for a combination of PCT, CRP, and WBC and/or IgM was 1.000. In conclusion, a serum PCT level over the 95th percentile on the reference curve for preterm infants and a combination of PCT and CRP levels with WBC count and/or IgM levels for term infants provided sufficient diagnostic accuracy.

Utility of procalcitonin in a medical intensive care unit in Croatia

AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Antimicrobial Treatment Duration in Sepsis and Serious Infections

Sepsis mortality has improved following advancements in early recognition and standardized management, including emphasis on early administration of appropriate antimicrobials. However, guidance regarding antimicrobial duration in sepsis is surprisingly limited. Decreased antibiotic exposure is associated with lower rates of de novo resistance development, Clostridioides difficile-associated disease, antibiotic-related toxicities, and health care costs. Consequently, data weighing safety versus adequacy of shorter treatment durations in sepsis would be beneficial. We provide a narrative review of evidence to guide antibiotic duration in sepsis. Evidence is significantly limited by noninferiority trial designs and exclusion of critically ill patients in many trials. Potential challenges to shorter antimicrobial duration in sepsis include inadequate source control, treatment of multidrug-resistant organisms, and pharmacokinetic alterations that predispose to inadequate antimicrobial levels. Additional studies specifically targeting patients with clinical indicators of sepsis are needed to guide measures to safely reduce antimicrobial exposure in this high-risk population while preserving clinical effectiveness.

Hospital physicians' experiences with procalcitonin - implications for antimicrobial stewardship; a qualitative study

Background

Procalcitonin is an inflammatory biomarker that is sensitive for bacterial infections and a promising clinical decision aid in antimicrobial stewardship programs. However, there are few studies of physicians’ experiences concerning the use of PCT. The objective of this study was to investigate whether hospital physicians’ experience with procalcitonin after 18 months of use can inform the PCT implementation in antimicrobial stewardship programs.

Materials/methods

We deployed a qualitative approach using semi-structured interviews with 14 hospital physicians who had experience with procalcitonin in clinical practice. Interviews were audio-taped, transcribed verbatim and analysed using thematic analysis.

Results

Physicians reported a knowledge gap, which made them uncertain about the appropriate procalcitonin use, interpretation, and trustworthiness. Simultaneously, the physicians experienced procalcitonin as a useful clinical decision aid but emphasised that their clinical evaluation of the patient was the most important factor when deciding on antibiotic treatment.

Conclusions

Procalcitonin was regarded a helpful clinical tool, but the physicians called for more knowledge about its appropriate uses. Active implementation of unambiguous procalcitonin algorithms and physician education may enhance the utility of the test as an antimicrobial stewardship adjunct.

Antibiotic modification versus withhold in febrile patients without evidence of bacterial infection, unresponsive to initial empiric regimen: a multicentre retrospective study conducted in Israel

Prescribing antibiotics for febrile patients without proof of bacterial infection contributes to antimicrobial resistance. Lack of clinical response in these patients often leads to antibiotic escalation, although data supporting this strategy are scarce. This study compared outcomes of modifying, withholding, or continuing the same antibiotic regimen for such patients. Febrile or hypothermic stable patients with suspected infection, unresponsive to empiric antibiotic treatment, admitted to one of 15 internal medicine departments in three hospitals during a 5-year study period, were included. Patients with a definitive clinical or microbiological bacterial infection, malignancy, immunodeficiency, altered mental status, or need for mechanical ventilation were excluded. Participants were divided into groups based on treatment strategy determined 72 h after antibiotic initiation: antibiotic modified, withheld or continued. Outcomes measured included in-hospital and 30-day post-discharge-mortality rates, length of hospital stay (LOS) and days of antimicrobial therapy (DOT). A total of 486 patients met the inclusion criteria: 124 in the Antibiotic modified group, 67 in the Antibiotic withheld group and 295 in the Initial antibiotic continued group. Patient characteristics were similar among groups with no differences in mortality rates in-hospital (23% vs. 25% vs. 20%, p = 0.58) and within 30 days after discharge (5% vs. 3% vs. 4%, p = 0.83). Changing antibiotics led to longer LOS (9.0 ± 6.8 vs. 6.2 ± 5.6 days, p = 0.003) and more DOT (8.6 ± 6.0 vs. 3.2 ± 1.0 days, p < 0.001) compared to withholding treatment. Withholding as compared to modifying antibiotics, in febrile patients with no clear evidence of bacterial infection, is a safe strategy associated with decreased LOS and DOT.

Dynamic Monitoring of sTREM-1 and Other Biomarkers in Acute Cholangitis

Background

Sepsis is a common complication of acute cholangitis (AC), which is associated with a high mortality rate. Our study is aimed at exploring the significance of white blood cell (WBC), C-reactive protein (CRP), procalcitonin (PCT), soluble triggering receptor expressed on myeloid cells 1 (sTREM-1), and temperature (T) alone or combined together in early identification and curative effect monitoring of AC with or without sepsis.

Methods

65 consecutive cases with AC and 76 control cases were enrolled. They were divided into three groups: Group A (AC with sepsis), Group B (AC without sepsis), and Group C (inpatients without AC or other infections). The levels of WBC, CRP, PCT, sTREM-1, and temperature were measured dynamically. The study was carried out and reported according to STARD 2015 reporting guidelines.

Results

CRP had the highest AUC to identify AC from individuals without AC or other infections (AUC 1.000, sensitivity 100.0%, specificity 100.0%, positive predictive value 100.0%, and negative predictive value 100.0%). Among various single indexes, PCT performed best (AUC 0.785, sensitivity 75.8%, specificity 72.2%, positive predictive value 68.7%, and negative predictive value 78.8%) to distinguish sepsis with AC, while different combinations of indexes did not perform better. From day 1 to day 5 of hospitalization, the levels of sTREM-1 in Group A were the highest, followed by Groups B and C (P < 0.05); on day 8, sTREM-1 levels in Groups A and B declined back to normal. However, other index levels among three groups still had a significant difference on day 10. Both in Groups A and B, sTREM-1 levels declined fast between day 1 and day 2 (P < 0.05).

Conclusions

CRP is the best biomarker to suggest infection here. PCT alone is sufficient enough to diagnose sepsis with AC. sTREM-1 is the best biomarker to monitor patients' response to antimicrobial therapy and biliary drainage.

Delta Neutrophil Index for the Prediction of Prognosis in Acute Gastrointestinal Diseases; Diagnostic Test Accuracy Meta-Analysis

Delta neutrophil index (DNI) is a novel diagnostic and prognostic biomarker of various infectious or inflammatory conditions. However, data on optimal measurement time are scarce, and no studies have evaluated the potential role of the DNI as a prognostic biomarker of gastrointestinal diseases with diagnostic test accuracy meta-analysis. Core databases were searched. The inclusion criteria were as follows: patients who have gastrointestinal diseases and DNI measurements presenting diagnostic indices for predicting the prognosis, including severity, surgical outcomes, and mortality from gastrointestinal diseases. We identified twelve studies for the systematic review and ten studies for the quantitative analysis. Pooled area under the curve, sensitivity, specificity, and diagnostic odds ratio of DNI at the initial admission date were 0.82 (95% confidence interval: 0.78–0.85), 0.75 (0.52–0.89), 0.76 (0.63–0.86), and 10 (3–35), respectively. Meta-regression showed no reasons for heterogeneity and publication bias was not detected. Fagan’s nomogram indicated that the posterior probability of ‘poor prognosis’ was 76% if the test was positive, and ‘no poor prognosis’ was 25% if the test was negative. The DNI can be considered as a reliable initial measurement biomarker for predicting prognosis in patients with gastrointestinal diseases,

ERS International Congress, Madrid, 2019: highlights from the Respiratory Infections Assembly

The European Respiratory Society (ERS) International Congress organised in Madrid, Spain, in 2019 welcomed >22 000 participants from 134 countries. For each ERS assembly, an impressive number of abstracts were submitted. The topics covered by Assembly 10 (Respiratory Infections and Tuberculosis) were included this year in the top five research areas with the most submitted abstracts, with a total of 424 abstracts accepted for presentation. As it would be difficult for any delegate to stay up to date with all the scientific advances in the field, we wanted to highlight three of the Congress sessions that included presentations on respiratory infections and tuberculosis that we deemed as important and we hope the readers will consider this material of great interest.

The effect of cefoperazone sulbactam and piperacillin tazobactam on mortality in Gram-negative nosocomial infections

Cefoperazone-sulbactam (CS) and piperacillin-tazobactam (TZP) are used in the treatment of Gram-negative nosocomial infections (NIs). We aimed to compare the effects of these two antibiotics on mortality and treatment success. Patients treated with CS or TZP empirically for at least three days with suspicion of NI were included in this retrospective study. In total, 308 (154 patients in both treatment arms) patients were analyzed. Treatment success rate in CS and TZP group respectively (50% vs 51.2%, p = 0.18), 28-day mortality rate (46.1% vs 42.8%, p = 0.56) and antibiotic-related side effects (50.6% vs 46.1%, p = 0.42) were similar except prolonged prothrombin time (19.4% vs 6.4%; p = 0.001). According to this study results, CS and TZP have equal effectivity and safety for the empirical treatment of Gram-negative NIs. CS may be an appropriate alternative to TZP for antibiotic cycling or mixing strategy to reduce antibiotic resistance.

Combining Procalcitonin and Rapid Multiplex Respiratory Virus Testing for Antibiotic Stewardship in Older Adult Patients With Severe Acute Respiratory Infection

OBJECTIVES

Virus infection is underevaluated in older adults with severe acute respiratory infections (SARIs). We aimed to evaluate the clinical impact of combining point-of-care molecular viral test and serum procalcitonin (PCT) level for antibiotic stewardship in the emergency department (ED).

DESIGN

A prospective twin-center cohort study was conducted between January 2017 and March 2018.

SETTING AND PARTICIPANTS

Older adult patients who presented to the ED with SARIs received a rapid molecular test for 17 respiratory viruses and a PCT test.

MEASURES

To evaluate the clinical impact, we compared the outcomes of SARI patients between the experimental cohort and a propensity score-matched historical cohort. The primary outcome was the proportion of antibiotics discontinuation or de-escalation in the ED. The secondary outcomes included duration of intravenous antibiotics, length of hospital stay, and mortality.

RESULTS

A total of 676 patients were included, of which 169 patients were in the experimental group and 507 patients were in the control group. More than one-fourth (27.9%) of the patients in the experimental group tested positive for virus. Compared with controls, the experimental group had a significantly higher proportion of antibiotics discontinuation or de-escalation in the ED (26.0% vs 16.1%, P = .007), neuraminidase inhibitor uses (8.9% vs 0.6%, P < .001), and shorter duration of intravenous antibiotics (10.0 vs 14.5 days, P < .001).

CONCLUSIONS AND IMPLICATIONS

Combining rapid viral surveillance and PCT test is a useful strategy for early detection of potential viral epidemics and antibiotic stewardship. Clustered viral respiratory infections in a nursing home is common. Patients transferred from nursing homes to ED may benefit from this approach.

Ventilator-Associated Pneumonia: Diagnostic Test Stewardship and Relevance of Culturing Practices

PURPOSE OF REVIEW

Ventilator-associated pneumonia (VAP) is one of the most common infections in the ICU. Prompt diagnosis is vital as mortality increases with delayed antibiotic therapy. However, accurate diagnosis is challenging due to non-specific clinical features in a complicated patient cohort. Microbiological culture data remains a crucial aspect in confirming diagnosis.

RECENT FINDINGS

Literature data comparing the benefit of invasive respiratory sampling to non-invasive is inconclusive. Differences in culturing practices translate in overidentification of organisms of unclear significance. Positive culture data in a low pre-test probability does not differentiate between true infection and colonization resulting in overtreatment. Furthermore, there are also opportunities for modifying the reporting of respiratory tract cultures that can better guide antimicrobial therapy. Under the umbrella of antimicrobial stewardship, diagnostic stewardship can be incorporated to create a systematic approach that would target culturing practices to match the right pre-test probability. Ideal outcome will be targeting cultures to the right patient population and minimizing unnecessary treatment.

Clinical Progress Note: Procalcitonin in the Diagnosis and Management of Community-Acquired Pneumonia in Hospitalized Adults

Community-acquired pneumonia (CAP) accounts for more than 1.5 million adult hospitalizations and 100,000 deaths each year in the United States.1 Antibiotic overuse in the hospital setting is an important contributor to the rise of antibiotic resistance, prompting increased efforts to limit inappropriate antibiotic use in hospitals.2 Procalcitonin, a precursor of the hormone calcitonin, is upregulated in bacterial infections and downregulated in viral infections. The US Food and Drug Administration has approved it as a serum biomarker to assist clinicians with decisions about using antibiotics.3 There is no consensus on how to best use procalcitonin in the management of CAP. We provide a practical update that includes a review of recent literature, added secondary analysis, and expert opinion surrounding the use of procalcitonin in the diagnosis and management of CAP in hospitalized adults.