Ability of procalcitonin to predict bacterial meningitis in the emergency department

Diagnostic accuracy of procalcitonin for bacterial infection in the Emergency Department: a systematic review

INTRODUCTION AND OBJECTIVE

The care of patients with a suspected infectious process in hospital emergency departments (ED) accounts for 15%-35% of all daily care in these healthcare areas in Spain and Latin America. The early and adequate administration of antibiotic treatment (AB) and the immediate making of other diagnostic-therapeutic decisions have a direct impact on the survival of patients with severe bacterial infection. The main objective of this systematic review is to investigate the diagnostic accuracy of PCT to predict bacterial infection in adult patients treated with clinical suspicion of infection in the ED, as well as to analyze whether the different studies manage to identify a specific value of PCT as the most relevant from the diagnostic point of view of clinical decision that can be recommended for decision making in ED.

METHOD

A systematic review is carried out following the PRISMA regulations in the database of PubMed, Web of Science, EMBASE, Lilacs, Cochrane, Epistemonikos, Tripdatabase and ClinicalTrials.gov from January 2005 to May 31, 2023 without language restriction and using a combination of MESH terms: "Procalcitonin", "Infection/Bacterial Infection/Sepsis", "Emergencies/Emergency/Emergency Department", "Adults" and "Diagnostic". Observational cohort studies (diagnostic performance analyses) were included. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the method used and the risk of bias of the included articles. Observational cohort studies were included. No meta-analysis techniques were performed, but results were compared narratively.

RESULTS

A total of 1,323 articles were identified, of which 21 that met the inclusion criteria were finally analyzed. The studies include 10,333 patients with 4,856 bacterial infections (47%). Eight studies were rated as high, 9 as moderate, and 4 as low. The AUC-ROC of all studies ranges from 0.68 (95% CI: 0.61-0.72) to 0.99 (95% CI: 0.98-1). The value of PCT 0.2-0.3 ng/ml is the most used and proposed in up to twelve of the works included in this review whose average estimated performance is an AUC-ROC of 0.79. If only the results of the 5 high-quality studies using a cut-off point of 0.2-0.3 ng/ml PCT are taken into account, the estimated mean AUC-COR result is 0.78 with Se:69 % and Es:76%.

CONCLUSIONS

PCT has considerable diagnostic accuracy for bacterial infection in patients treated in ED for different infectious processes. The cut-off point of 0.25 (0.2-0.3) ng/ml has been positioned as the most appropriate to predict the existence of bacterial infection and can be used to help reasonably rule it out.

Extra-pulmonary applications of procalcitonin: an updated literature review

INTRODUCTION

: Procalcitonin (PCT) is a biomarker with established performance in the differentiation between bacterial and viral infections, predominantly in pulmonary infections, as well as the diagnosis and prognosis of bacterial sepsis. However, the role of PCT in extra-pulmonary infections is not well described.

AREAS COVERED

: We reviewed the role of PCT in commonly experienced extra-pulmonary infections including meningitis, diabetic foot infection, prosthetic joint infection, osteomyelitis, and skin and soft tissue infection. PubMed and Medline online libraries were searched, from 2013 till 2022, for relevant articles.

EXPERT OPINION

: For meningitis, PCT could distinguish bacterial from viral meningitis. PCT distinguished septic arthritis from different types of arthritis but had variable performance in discriminating septic arthritis from crystal arthropathy. For periprosthetic joint infections, results were inconclusive. PCT had a potential role in diagnosis of more complex infections such as osteomyelitis and diabetic foot infections, but further studies are needed for a definitive cutoff. In skin and soft tissue infections, PCT performance was more variable requiring further investigation to define cutoff for the discrimination of cellulitis from necrotizing fasciitis. We find that PCT performed best for meningitis and helps in the reduction of unnecessary antibiotic treatment, but has variable outcomes with other extra-pulmonary infections.

A 2020 review on the role of procalcitonin in different clinical settings: an update conducted with the tools of the Evidence Based Laboratory Medicine

Biomarkers to guide antibiotic treatment decisions have been proposed as an effective way to enhancing a more appropriate use of antibiotics. As a biomarker, procalcitonin (PCT) has been found to have good specificity to distinguish bacterial from non-bacterial inflammations. Decisions regarding antibiotic use in an individual patient are complex and should be based on the pre-test probability for bacterial infection, the severity of presentation and the results of PCT serum concentration. In the context of a high pre-test probability for bacterial infections and/or a high-risk patient with sepsis, monitoring of PCT over time helps to track the resolution of infection and decisions regarding early stop of antibiotic treatment. As outlined by the Evidence Based Laboratory Medicine (EBLM), not only the pre-test probability but also the positive likelihood ratio influence the performance of a test do be really diagnostic. This aspect should be taken into account in the interpretation of the results of clinical trials evaluating the performance of PCT in guiding antibiotic therapy.

Community-acquired acute bacterial meningitis in adults: a clinical update

BACKGROUND

Acute bacterial meningitis (ABM) in adults is associated with a mortality that may exceed 30%. Immunization programs have reduced the global burden; in the UK, declining incidence but persistently high mortality and morbidity mean that clinicians must remain vigilant.

SOURCES OF DATA

A systematic electronic literature search of PubMed was performed to identify all ABM literature published within the past 5 years.

AREAS OF AGREEMENT AND CONTROVERSY

Clinical features cannot reliably distinguish between ABM and other important infectious and non-infectious aetiologies. Prompt investigation and empirical treatment are imperative. Lumbar puncture (LP) and cerebrospinal fluid microscopy, biochemistry and culture remain the mainstay of diagnosis, but molecular techniques are increasingly useful. The 2016 UK joint specialist societies' guideline provides expert recommendations for the management of ABM, yet published data suggest clinical care delivered in the UK is frequently not adherent. Anxiety regarding risk of cerebral herniation following LP, unnecessary neuroimaging, underutilization of molecular diagnostics and suboptimal uptake of adjunctive corticosteroids compromise management.

GROWING POINTS

There is increasing recognition that current antibiotic regimens and adjunctive therapies alone are insufficient to reduce the mortality and morbidity associated with ABM.

AREAS TIMELY FOR DEVELOPING RESEARCH

Research should be focused on optimization of vaccines (e.g. pneumococcal conjugate vaccines with extended serotype coverage), targeting groups at risk for disease and reservoirs for transmission; improving adherence to management guidelines; development of new faster, more accurate diagnostic platforms (e.g. novel point-of-care molecular diagnostics); and development of new adjunctive therapies (aimed at the host-inflammatory response and bacterial virulence factors).

Diagnostic Value of Procalcitonin for Bacterial Meningitis in Children: A Comparison Analysis Between Serum and Cerebrospinal Fluid Procalcitonin Levels

The aim of this study was to analyze and compare procalcitonin (PCT) levels in serum and cerebrospinal fluid (CSF) as tools for detecting bacterial meningitis (BM) in children. Serum and CSF PCT levels as well as albumin index (AI = CSF albumin/serum albumin × 1000) were measured from 29 BM, 25 viral meningitis (VM), and 47 non-meningitis patients. Differences between groups only for CSF PCT were significant. A stronger positive correlation between CSF PCT level and AI was observed in the BM patients ( R = 0.68, P < .001). As a predictor of BM, the area under the receiver operating characteristics curve for CSF PCT was greater than that of serum PCT (0.76 vs 0.67, P < .05) and a cutoff of ⩾0.085 ng/mL achieved 55.17% sensitivity and 95.83% specificity. High levels of CSF PCT may indicate loss of integrity of the blood-brain barrier; only CSF PCT has a diagnostic value for BM in children suspected meningitis.

The Role of Procalcitonin in the Diagnosis of Meningitis: A Literature Review

OBJECTIVE

To review the current published literature on the use of procalcitonin as a diagnostic and prognostic marker in adult patients with meningitis.

METHODS

We conducted a PubMed search to identify all relevant publications regarding the diagnostic and prognostic value of serum procalcitonin in patients with a known or suspected central nervous system infection. We also reviewed the bibliographies of all identified manuscripts in an attempt to identify additional relevant references.

RESULTS

A significant body of evidence suggests that serum procalcitonin has a promising role and can be a useful biomarker in the assessment of patients with meningitis.

CONCLUSIONS

Our literature review suggests that data on the role of Cerebrospinal Fluid (CSF) procalcitonin are limited, whereas serum procalcitonin (S⁻PCT) is probably a useful tool in the evaluation of patients with a known or suspected central nervous system infection and can help distinguish between bacterial and viral meningitis.

Management of acute meningitis

Acute meningitis remains a devastating disease. Clinicians need a low threshold for suspecting meningitis, to undertake appropriate investigations and provide treatment in a timely manner, to minimise the risk of poor outcome in bacterial disease, while limiting unnecessary treatment in viral meningitis.

Usefulness of blood and cerebrospinal fluid laboratory testing to predict bacterial meningitis in the emergency department

INTRODUCTION

The classic clinical presentation of bacterial meningitis (BM) is observed in less than half of the cases in adults, and symptoms are less specific in children, the elderly or immunocompromised, and other chronic patients. The usual signs and symptoms do not provide optimal sensitivity and specificity for distinguishing possible BM from viral meningitis (VM), which may lead to a delay in the appropriate antimicrobial therapy. Society therefore stands to benefit from the development of effective, objective, and rapid tools able to predict and identify patients with BM. These tools include laboratory tests for blood and cerebrospinal fluid (CSF). The aim of this review is to summarise recently published scientific evidence in order to clarify existing controversies and compare the usefulness and diagnostic ability of the different parameters used to predict BM.

DEVELOPMENT

Systematic search of the main bibliographic databases and platforms to identify articles published between January 2000 and January 2016. We selected 59 articles that meet the objectives of this review.

CONCLUSIONS

CSF lactate, proportion of polymorphonuclear leukocytes, and CSF glucose, as well as serum procalcitonin (PCT), are the independent factors most predictive of bacterial aetiology. The model that combines serum PCT and CSF lactate achieves the highest predictive power for BM, with a sensitivity and specificity exceeding 99%. We should consider BM when CSF lactate >33 md/dL and/or PCT>0.25ng/mL.

Clinical decision rules for acute bacterial meningitis: current insights

Acute community-acquired bacterial meningitis (BM) requires rapid diagnosis so that suitable treatment can be instituted within 60 minutes of admitting the patient. The cornerstone of diagnostic examination is lumbar puncture, which enables microbiological analysis and determination of the cerebrospinal fluid (CSF) cytochemical characteristics. However, microbiological testing is not sufficiently sensitive to rule out this diagnosis. With regard to the analysis of standard CSF cytochemical characteristics (polymorphonuclear count, CSF glucose and protein concentration, and CSF:serum glucose), this is often misleading. Indeed, the relatively imprecise nature of the cutoff values for these BM diagnosis markers can make their interpretation difficult. However, there are two markers that appear to be more efficient than the standard ones: CSF lactate and serum procalcitonin levels. Scores and predictive models are also available; however, they only define a clinical probability, and in addition, their use calls for prior validation on the population in which they are used. In this article, we review current methods of BM diagnosis.

The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults

Bacterial meningitis and meningococcal sepsis are rare conditions with high case fatality rates. Early recognition and prompt treatment saves lives. In 1999 the British Infection Society produced a consensus statement for the management of immunocompetent adults with meningitis and meningococcal sepsis. Since 1999 there have been many changes. We therefore set out to produce revised guidelines which provide a standardised evidence-based approach to the management of acute community acquired meningitis and meningococcal sepsis in adults. A working party consisting of infectious diseases physicians, neurologists, acute physicians, intensivists, microbiologists, public health experts and patient group representatives was formed. Key questions were identified and the literature reviewed. All recommendations were graded and agreed upon by the working party. The guidelines, which for the first time include viral meningitis, are written in accordance with the AGREE 2 tool and recommendations graded according to the GRADE system. Main changes from the original statement include the indications for pre-hospital antibiotics, timing of the lumbar puncture and the indications for neuroimaging. The list of investigations has been updated and more emphasis is placed on molecular diagnosis. Approaches to both antibiotic and steroid therapy have been revised. Several recommendations have been given regarding the follow-up of patients.

Acute Phase Reactants in Infections: Evidence-Based Review and a Guide for Clinicians

There is increasing evidence to support the role of various acute phase reactants as an adjunct to clinical judgement in the management of various infections. Procalcitonin is more specific in diagnosing bacterial infections and has a wider role in the management of complex infections. Procalcitonin based antibiotic guidance is helpful in antibiotic management in patients with pneumonia and sepsis

Acute-phase reactants such as erythrocyte sedimentation rate and C-reactive protein have traditionally been used as markers for inflammation and as a measure of “sickness index” in infectious and noninfectious conditions. In the last decade, more data have become available on the wider and more specific role for these markers in the management of complex infections. This includes the potential role in early diagnosis, in differentiating infectious from noninfectious causes, as a prognostic marker, and in antibiotic guidance strategies. A better defined role for biological markers as a supplement to clinical assessment may lead to more judicious antibiotic prescriptions, and it has the potential for a long-term favorable impact on antimicrobial stewardship and antibiotic resistance. Procalcitonin as a biological marker has been of particular interest in this regard. This review examines the current published evidence and summarizes the role of various acute-phase markers in infections. A MEDLINE search of English-language articles on acute-phase reactants and infections published between 1986 and March 2015 was conducted. Additional articles were also identified through a search of references from the retrieved articles, published guidelines, systematic reviews, and meta-analyses.