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

Management of Intra-Abdominal Infections: The Role of Procalcitonin

Patients with intra-abdominal sepsis suffer from significant mortality and morbidity. The main pillars of treatment for intra-abdominal infections are (1) source control and (2) early delivery of antibiotics. Antibiotic therapy should be started as soon as possible. However, the duration of antibiotics remains a matter of debate. Prolonged antibiotic delivery can lead to increased microbial resistance and the development of nosocomial infections. There has been much research on biomarkers and their ability to aid the decision on when to stop antibiotics. Some of these biomarkers include interleukins, C-reactive protein (CRP) and procalcitonin (PCT). PCT's value as a biomarker has been a focus area of research in recent years. Most studies use either a cut-off value of 0.50 ng/mL or an >80% reduction in PCT levels to determine when to stop antibiotics. This paper performs a literature review and provides a synthesized up-to-date global overview on the value of PCT in managing intra-abdominal infections.

The Advancement in Detecting Sepsis and Its Outcome: Usefulness of Procalcitonin in Diagnosing Sepsis and Predicting Fatal Outcomes in Patients Admitted to Intensive Care Unit

Sepsis still remains a big challenge in patients admitted to intensive care units (ICUs) despite stellar advances made in the field of medicine. We can achieve better clinical outcomes in patients by diagnosing sepsis earlier. Procalcitonin (PCT), an inflammatory biomarker, has shown promising results in this regard. Therefore, this systematic review was done to assess the use of PCT in diagnosing and predicting severe outcomes in patients admitted to ICU and to assess if introducing PCT as a routine biochemical tool in hospitals would be helpful to achieve better clinical course in ICU patients. To identify relevant articles, we searched PubMed, Google Scholar, and references of included articles. Eligible studies were identified by two investigators independently and data were extracted. Original articles that evaluated the diagnostic and prognostic value of serum PCT levels in predicting sepsis, the severity of sepsis, and mortality among adult patients admitted to ICU were included in this study. A total of 2,063 citations were identified by the search, among which 10 studies (five prospective cohort, three retrospective cohort, one cross-sectional, and one case-control study) met the inclusion criteria. Most studies showed moderate-to-low risk of bias which was evaluated using the Quality in Prognosis Studies tool. All studies showed a positive correlation between initial PCT levels and detecting mortality resulting from sepsis, six studies found PCT helpful in detecting sepsis, and four studies evaluated the role of PCT in detecting severity in patients with sepsis. One study found area under the curve of serum PCT level for predicting 28-day mortality to be 0.82 (95% confidence interval [CI]: 0.70-0.94; p < 0.001) in adults and 0.83 (95% CI: 0.73-0.92; p < 0.001) in the elderly having an optimal cut-off level of serum PCT of 0.2 ng/mL in both the adult and elderly groups, with a sensitivity of 81 and 75% and specificity of 81.7 and 80.4%, respectively. PCT has shown promising results in detecting sepsis and its clinical course. For early diagnosis and management of sepsis, severe sepsis, and mortality in patients admitted to the ICU for a more favorable clinical outcome, PCT can be used.

The prognostic value of serum procalcitonin measurements in critically injured patients: a systematic review

Background

Major trauma is associated with high incidence of septic complications and multiple organ dysfunction (MOD), which markedly influence the outcome of injured patients. Early identification of patients at risk of developing posttraumatic complications is crucial to provide early treatment and improve outcomes. We sought to evaluate the prognostic value of serum procalcitonin (PCT) levels after trauma as related to severity of injury, sepsis, organ dysfunction, and mortality.

Methods

We searched PubMed, MEDLINE, EMBASE, the Cochrane Database, and references of included articles. Two investigators independently identified eligible studies and extracted data. We included original studies that assessed the prognostic value of serum PCT levels in predicting severity of injury, sepsis, organ dysfunction, and mortality among critically injured adult patients.

Results

Among 2015 citations, 19 studies (17 prospective; 2 retrospective) met inclusion criteria. Methodological quality of included studies was moderate. All studies showed a strong correlation between initial PCT levels and Injury Severity Score (ISS). Twelve out of 16 studies demonstrated significant elevation of initial PCT levels in patients who later developed sepsis after trauma. PCT level appeared a strong predictor of MOD in seven out of nine studies. While two studies did not show association between PCT levels and mortality, four studies demonstrated significant elevation of PCT levels in non-survivors versus survivors. One study reported that the PCT level of ≥ 5 ng/mL was associated with significantly increased mortality (OR 3.65; 95% CI 1.03–12.9; p = 0.04).

Conclusion

PCT appears promising as a surrogate biomarker for trauma. Initial peak PCT level may be used as an early predictor of sepsis, MOD, and mortality in trauma population.

Procalcitonin and Presepsin as Prognostic Markers After Out-of-Hospital Cardiac Arrest

BACKGROUND

Patients resuscitated from cardiac arrest commonly develop an inflammatory response called post-cardiac arrest syndrome that clinically resembles septic shock.Procalcitonin and presepsin are associated with inflammation. We hypothesized that these biomarkers reflect the severity of post-cardiac arrest syndrome and predict short-term hemodynamical instability and long-term neurological outcome after cardiac arrest.

METHODS

As a subcohort analysis of a prospective, observational, multicenter study "FINNRESUSCI," we obtained plasma from 277 intensive care unit (ICU) patients treated following out-of-hospital cardiac arrest (OHCA). Procalcitonin and presepsin levels were measured 0 to 6 h from ICU admission and 24, 48, and 96 h thereafter. We defined poor outcome as a 12-month Cerebral Performance Category of 3 to 5. We tested statistical associations between biomarkers and hemodynamical parameters and outcome with regression models.

RESULTS

Plasma procalcitonin had best predictive value for 12-month poor outcome at 96 h (AUC 0.76; 95% CI 0.68-0.83) and presepsin at ICU admission (AUC 0.72; 95% CI 0.65-0.78). Elevated procalcitonin concentration at ICU admission predicted unstable hemodynamics in the following 48 h in a linear regression model. In a multivariate logistic regression model with clinical variables, only procalcitonin at 96 h had independent prognostic value for poor 12-month neurological outcome.

CONCLUSIONS

Elevated procalcitonin is associated with hemodynamical instability and worsened long-term outcome in OHCA patients. The association is not strong enough for it to be used as a single predictor. Presepsin did not provide clinically relevant information for risk stratification after OHCA.

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

INTRODUCTION AND OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Protective Effect of Melatonin Against Polymicrobial Sepsis Is Mediated by the Anti-bacterial Effect of Neutrophils

Sepsis is an infection- or toxin-mediated systemic inflammatory syndrome. Previous studies have shown that melatonin, the primary hormone produced by the pineal gland, attenuates the effect of polymicrobial infection-mediated septic shock in animals. However, the mechanism of the anti-septic effect of melatonin during polymicrobial infection has not been well-studied. In this study, we investigated how melatonin protects mice from polymicrobial sepsis. Melatonin treatment inhibited peripheral tissue inflammation and tissue damage in a cecal ligation puncture (CLP)-induced polymicrobial sepsis model, consequently reducing the mortality of the mice. We found that macrophages and neutrophils expressed melatonin receptors. Upon depletion of neutrophils, melatonin-induced protection against polymicrobial infection failed in the mice, but melatonin treatment in macrophage-depleted mice attenuated the mice mortality resulting from polymicrobial sepsis. Moreover, melatonin treatment promoted the development of the neutrophil extracellular trap (NET), which contributed to anti-bacterial activity during polymicrobial infection, whereas the phagocytic activities of neutrophils were inhibited by melatonin. The data from this study support previously unexplained antiseptic effects of melatonin during a polymicrobial infection and could be potentially useful for human patients with sepsis.

Use of biomarkers in the prediction of culture-proven infection in the surgical intensive care unit

PURPOSE

The purpose of this study was to prospectively analyze the predictive role of classic predictors for suspected infection (temperature, WBC and derivatives) with two biomarkers, procalcitonin and lactate, on the incidence of culture-proven infection in the surgical intensive care unit (SICU).

MATERIALS AND METHODS

One hundred forty-six consecutive patients admitted for suspected infection had admission and 12-h procalcitonin values, admission and every 6-h lactate values for 24 h, and admission temperature, leukocyte count, lymphocyte count and percentage measured and analyzed in this study.

RESULTS

Peak (highest measured value ≤24-h of admission) procalcitonin values were not predictive for culture-proven infection. However, a culture-negative subset was identified when peak procalcitonin values were  < 2.9 ng/mL and when peak lactate values were  < 1.3 mmol/L with a probability of 98.3% (P < .001). No other admission predictor was statistically associated with culture-proven infection. Following boosted-tree partitioning, a C-index of 0.85 was calculated with a misclassification rate of 23.3%.

CONCLUSIONS

The ability to utilize procalcitonin values in the diagnosis of culture-proven infection was not realized in this study. However, the association of admission peak procalcitonin values with admission peak lactate values identified a group of patients who were culture-negative for suspected infection. No other admission predictor was associated with culture-proven infection.

Is Procalcitonin Useful in Pediatric Critical Care Patients?

This review examines the use of procalcitonin in different clinical situations in the pediatric patient, with special emphasis on those requiring intensive care. We review the latest articles on its potency as a biomarker in both infectious processes at diagnosis and on the response to treatment.

A Collaborative Approach to Improve Consistent Use of Procalcitonin in Lower Respiratory Tract Infections

BACKGROUND

Procalcitonin (PCT) is a biomarker that can help differentiate bacterial from viral infections and has been extensively studied in patients with sepsis and pneumonia to guide antibiotic therapy. However, there is poor adherence to prescribed algorithms when used to discontinue antibiotics in the real world. A quality improvement project was implemented to increase consistent use of PCT.

OBJECTIVE

To evaluate use of PCT and impact on antibiotic length of therapy (LOT) preimplementation and postimplementation of a quality improvement initiative.

METHODS

This was a single-center retrospective cohort study in patients with lower respiratory tract infections (LRTIs).

RESULTS

In all, 330 patients were included in this study. Following implementation of the quality improvement initiative, ordering PCT in the first 24 hours increased from 59.6% to 75.5% ( P = 0.011). Documentation to discontinue antibiotics in patients with low initial PCT values increased from 13.2% to 28.6% ( P = 0.100). Increased PCT use correlated with an overall mean reduction of 1.05 antibiotic days between cohorts (6.82 ± 3.88 vs 5.77 ± 3.43, P = 0.028). There was no difference in incidence of antibiotic-associated adverse effects or 30-day hospital readmission rates attributed to pneumonia.

CONCLUSIONS

Consistent use of PCT was achieved through a collaborative effort with the clinical pharmacy and hospitalist staff. Increased use of PCT was associated with a significant reduction in antibiotic LOT among patients with LRTIs. When controlling for other factors, low initial PCT values had the strongest influence on discontinuing antibiotics within 72 hours in the intervention group.

Management of intra-abdominal infections: recommendations by the WSES 2016 consensus conference

This paper reports on the consensus conference on the management of intra-abdominal infections (IAIs) which was held on July 23, 2016, in Dublin, Ireland, as a part of the annual World Society of Emergency Surgery (WSES) meeting. This document covers all aspects of the management of IAIs. The Grading of Recommendations Assessment, Development and Evaluation recommendation is used, and this document represents the executive summary of the consensus conference findings.

A Broad-Spectrum Infection Diagnostic that Detects Pathogen-Associated Molecular Patterns (PAMPs) in Whole Blood

Background

Blood cultures, and molecular diagnostic tests that directly detect pathogen DNA in blood, fail to detect bloodstream infections in most infected patients. Thus, there is a need for a rapid test that can diagnose the presence of infection to triage patients, guide therapy, and decrease the incidence of sepsis.

Methods

An Enzyme-Linked Lectin-Sorbent Assay (ELLecSA) that uses magnetic microbeads coated with an engineered version of the human opsonin, Mannose Binding Lectin, containing the Fc immunoglobulin domain linked to its carbohydrate recognition domain (FcMBL) was developed to quantify pathogen-associated molecular patterns (PAMPs) in whole blood. This assay was tested in rats and pigs to explore whether it can detect infections and monitor disease progression, and in prospectively enrolled, emergency room patients with suspected sepsis. These results were also compared with data obtained from non-infected patients with or without traumatic injuries.

Results

The FcMBL ELLecSA was able to detect PAMPS present on, or released by, 85% of clinical isolates representing 47 of 55 different pathogen species, including the most common causes of sepsis. The PAMP assay rapidly (< 1 h) detected the presence of active infection in animals, even when blood cultures were negative and bacteriocidal antibiotics were administered. In patients with suspected sepsis, the FcMBL ELLecSA detected infection in 55 of 67 patients with high sensitivity (> 81%), specificity (> 89%), and diagnostic accuracy of 0·87. It also distinguished infection from trauma-related inflammation in the same patient cohorts with a higher specificity than the clinical sepsis biomarker, C-reactive Protein.

Conclusion

The FcMBL ELLecSA-based PAMP assay offers a rapid, simple, sensitive and specific method for diagnosing infections, even when blood cultures are negative and antibiotic therapy has been initiated. It may help to triage patients with suspected systemic infections, and serve as a companion diagnostic to guide administration of emerging dialysis-like sepsis therapies.

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The FcMBL ELLecSA-based PAMP assay offers a rapid, simple, sensitive and specific method for diagnosing infections.

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The FcMBL ELLecSA distinguished infection from trauma-related inflammation.

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It can detect infection even when blood cultures are negative and antibiotic therapy has been initiated.

Current diagnostics of sepsis using blood cultures and molecular diagnostic tests fail to detect bloodstream infections in most infected patients, whereas the inflammatory biomarkers of infection that have a higher sensitivity of detection, lack specificity in distinguishing infection from trauma-related inflammation. Therefore we have leveraged a broad-spectrum pathogen binding opsonin and developed a rapid test to directly diagnose the presence of infection in the blood to triage patients and guide antibiotic therapy.