Meta-analysis of procalcitonin for sepsis detection

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014010822.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

De-escalation of antimicrobial treatment for adults with sepsis, severe sepsis or septic shock

BACKGROUND

Mortality rates among patients with sepsis, severe sepsis or septic shock are highly variable throughout different regions or services and can be upwards of 50%. Empirical broad-spectrum antimicrobial treatment is aimed at achieving adequate antimicrobial therapy, thus reducing mortality; however, there is a risk that empirical broad-spectrum antimicrobial treatment can expose patients to overuse of antimicrobials. De-escalation has been proposed as a strategy to replace empirical broad-spectrum antimicrobial treatment by using a narrower antimicrobial therapy. This is done by reviewing the patient's microbial culture results and then making changes to the pharmacological agent or discontinuing a pharmacological combination.

OBJECTIVES

To evaluate the effectiveness and safety of de-escalation antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic shock caused by any micro-organism.

SEARCH METHODS

In this updated version, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 10); MEDLINE via PubMed (from inception to October 2012); EMBASE (from inception to October 2012); LILACS (from inception to October 2012); Current Controlled Trials; bibliographic references of relevant studies; and specialists in the area. We applied no language restriction. We had previously searched the databases to August 2010.

SELECTION CRITERIA

We planned to include randomized controlled trials (RCTs) comparing de-escalation (based on culture results) versus standard therapy for adults with sepsis, severe sepsis or septic shock. The primary outcome was mortality (at 28 days, hospital discharge or at the end of the follow-up period). Studies including patients initially treated with an empirical but not adequate antimicrobial therapy were not considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors planned to independently select and extract data and to evaluate methodological quality of all studies. We planned to use relative risk (risk ratio) for dichotomous data and mean difference (MD) for continuous data, with 95% confidence intervals. We planned to use the random-effects statistical model when the estimate effects of two or more studies could be combined in a meta-analysis.

MAIN RESULTS

Our search strategy retrieved 493 studies. No published RCTs testing de-escalation of antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic were included in this review. We found one ongoing RCT.

AUTHORS' CONCLUSIONS

There is no adequate, direct evidence as to whether de-escalation of antimicrobial agents is effective and safe for adults with sepsis, severe sepsis or septic shock. This uncertainty warrants further research via RCTs and the authors are awaiting the results of an ongoing RCT testing the de-escalation of empirical antimicrobial therapy for severe sepsis.

Procalcitonin in pediatrics

Over the past two decades, the body of literature on the clinical usefulness of procalcitonin (PCT) in adults has grown rapidly. Although this approach has led to increased insight, it has also prompted debate regarding its potential use in diagnosis and management of severe infection. Clinicians, however, are less familiar with the use of PCT in pediatric populations. In this review, we examine PCT as a marker of severe clinical pediatric conditions including its role in systemic inflammation, infection, and sepsis.

[Procalcitonin-based algorithm. Management of antibiotic therapy in critically ill patients]

Sepsis is one of the most cost-intensive conditions of critically ill patients in intensive care medicine. Furthermore, sepsis is known to be the leading cause of morbidity and of mortality in intensive care patients. Early initiation of antibiotic therapy can significantly reduce mortality. The development of resistance of bacterial species against antibiotics is a compelling issue to reconsider indications and administration of antibiotic treatment. Adequate indications and duration of therapy are particularly important for the use of highly potent substances in the intensive care setting. Until recently no laboratory marker has been available to distinguish bacterial infections from viral or non-infectious inflammatory responses. However, procalcitonin (PCT) appears to be the first among a large array of inflammatory markers that offers this possibility. Regular procalcitonin measurements can significantly shorten the length of antibiotic therapy, show positive influence on antibiotic costs and have no adverse affects on patient outcome.

De-escalation of antimicrobial treatment for adults with sepsis, severe sepsis or septic shock

BACKGROUND

Mortality rates among patients with sepsis, severe sepsis or septic shock ranges from 27% to 54%. Empirical broad-spectrum antimicrobial treatment is aimed at achieving adequate antimicrobial therapy and thus reducing mortality. However, there is a risk that empirical broad-spectrum antimicrobial treatment can expose patients to overuse of antimicrobials. De-escalation has been proposed as a strategy to replace empirical broad-spectrum antimicrobial treatment with a narrower antimicrobial therapy. This is done by either changing the pharmacological agent or discontinuing a pharmacological combination according to the patient's microbial culture results.

OBJECTIVES

To evaluate the effectiveness and safety of de-escalation antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic shock caused by any micro-organism.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 8); MEDLINE via PubMed (from inception to August 2010); EMBASE (from inception to August 2010); LILACS (from inception to August 2010); Current Controlled Trials and bibliographic references of relevant studies. We also contacted the main authors in the area. We applied no language restriction.

SELECTION CRITERIA

We planned to include randomized controlled trials comparing de-escalation (based on culture results) versus standard therapy for adults with sepsis, severe sepsis or septic shock. The primary outcome was mortality (at 28 days, hospital discharge or the end of the follow-up period). Studies including patients initially treated with an empirical but not adequate antimicrobial therapy were not considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors planned to independently select and extract data and evaluate methodological quality of all studies. We planned to use relative risk (risk ratio) for dichotomous data and mean difference (MD) for continuous data, with 95% confidence intervals. We planned to use the random-effects statistical model when the estimate effects of two or more studies could be combined in a meta-analysis.

MAIN RESULTS

We retrieved 436 references via the search strategy. No randomized controlled trials testing de-escalation antimicrobial treatment for adult patients diagnosed with sepsis, severe sepsis or septic shock could be included in this review.

AUTHORS' CONCLUSIONS

There is no adequate, direct evidence as to whether de-escalation of antimicrobial agents is effective and safe for adults with sepsis, severe sepsis or septic shock. Therefore, it is not possible to either recommend or not recommend the de-escalation of antimicrobial agents in clinical practice for septic patients. This uncertainty warrants further research via randomized controlled trials or cohort studies.