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Can Procalcitonin accurately diagnose serious bacterial infection in the Emergency Department Setting?

Three Part Question

'[Is procalcitonin more sensitive or specific] than other currently available biomarkers for [identifying serious bacterial infection] [in the undifferentiated patient presenting to the emergency department with SIRS criteria]?

Clinical Scenario

A 55 year old female presents to the ED with the complaint of fever, chills, weakness. Upon presentation she appears pale Vitals are Temp 39, HR 105, RR 22 and WBC count 13,000. Given this patient meets SIRS criteria, will a procalcitonin level accurately diagnose serious bacterial infection?

Search Strategy

Pub med 2002-2012
details of search [procalcitonin and sepsis and sirs][limited to english and human]

Search Outcome

returned 354 articles, 9 of which were reviewed, 4 of which were found to be relevant

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Joo Suk Oh MD
Received 4 June 2008; revised
Republic of Korea
80 patients (36 women, 44 men) mean age 65 who were admitted to the emergency department for suspected infectionProspective Cohort StudyPCT levelsFor PCT = 2 ng/ml, Sensitivity 93.94%, Specificity 87.23%, PPV 87.38%, NPV 95.35%, PLR 7.36, NLR 0.069, AUC 0.916 for detecting sepsis/septic shockSmall sample size, used initial variables for Apache II/SOFA scoring, unable to differentiate viral from bacterial causes
Benjamin M P Tang et al.
18 studies included, 2097 patients, of which 1452 were ICU, 440 Emergency Dept, and 205 from hospital wardsSystematic review and meta-analysisSensitivity and specificity of PCT for diagnosing sepsis: Sensitivity and Specificity 71% (95% CI 67-76), AUC 0.78 (95% CI 0.73-0.83).Excluded studies that did not provide enough info to fit into 2x2 table, excluded studies that specifically focused on pediatrics, cardiac, burns, abdominal sepsis, meningitis, did not include risk stratification or prognosis studies
E.J. Giamarellos-Bourboulis et al.
1156 Hospitalized patients, 234 ICU patients and 922 ward patients, PCT was sampled within 24 hr of onset of sepsisProspective multicenter observational investigationMortalityAmong patients outside the ICU, mortality was 8% in those with PCT ≤0.12 ng/mL but 19.9% in those with PCT >0.12 ng/mL [P < 0.0001, odds ratio (OR) for death: 2.606; 95% confidence interval (CI): 1.553-4.371]. Among patients whose sepsis presented in ICU, mortality was 25.6% in those with PCT ≤0.85 ng/mL but 45.3% in those with PCT >0.85 ng/mL (P 0.002; OR for death: 2.404; 95% CI: 1.385-4.171).Predominance of gram negative sepsis questions whether results would apply to other types of sepsis, patients diagnosed with sepsis on the floor were not transferred to the ICU
Reinhart K,
75 articles included in review, 1186 patients including adults and childrensystematic review and meta-analysisAcute Meningitis Viral Vs Bacterial in Children , PCT cutoff 0.5 microg/dlSensitivity 94% Specificity 100%Large review article, no major weaknesses
Autoimmune Disorders: infectious vs non infectious, PCT cutoff 0.5 g/dlSensitivity 100% Specificity 84%
Renal Transplantation acute rejection vs infection, PCT cutoff 0.5 microgram/dlSensitivity 87% Specificity 70%
Pneumonia Bacterial Vs Viral, PCT cutoff 2 ng/dlSensitivity 63%, Specificity 96%
Invasive Vs local infection in children, PCT cutoff 0.9 ng/dlSensitivity 93%, Specificity 78%
Pancreatitis sterile vs infected necrosis, PCT cutoff 1.8 microg/LSensitivity 94%, Specificity 91%
ICU patients, infection Vs no infection, PCT cutoff 0.6 microg/LSensitivity 67% Specificity 61%


Procalcitonin is a promising bio-marker in detecting serious bacterial infection and sepsis, although not the gold standard. In the above studies there are wide ranges for sensitivity and specificity which lowers it’s usefulness as a single diagnostic marker. Although, Procalcitonin does outperform CRP repeatedly at detecting SBI. Procalcitonin has proven to be a excellent tool when used in conjunction with clinical judgment. Serum levels do seem to correlate with severity of disease, help differentiate bacterial vs viral infections, systemic vs local infections, and could help with the disposition of patient to the critical care setting when the clinical presentation is confusing or when the diagnosis is in doubt

Editor Comment


Clinical Bottom Line

Procalcitonin alone cannot reliably predict serious bacterial infection in the Emergency Department setting. But when used along with clinical judgement and other diagnostic tools Procalcitonin can help detect serious bacterial infection in patients presenting with SIRS.


  1. Joo Suk Oh MD, Seong Uk Kim MD, Young Min Oh MD, Se Min Choe MD, Gyeong Ho Choe MD, Seung Pil Choe MD, Young Min Kim MD, Tae Yong Hong MD, Kyu Nam Park MD The usefulness of the semiquantitative procalcitonin test kit as a guideline for starting antibiotic administration
  2. Benjamin M P Tang, Guy D Eslick, Jonathan C Craig, Anthony S McLean Accuracy of procalcitonin for sepsis diagnosis in critically ill patients: systematic review and meta-analysis
  3. E.J. Giamarellos-Bourboulis a,*, I. Tsangaris b, Th. Kanni a, M. Mouktaroudi a, I. Pantelidou a, G. Adamis c, S. Atmatzidis d, M. Chrisofos e, V. Evangelopoulou f, F. Frantzeskaki b, P. Giannopoulos g Procalcitonin as an early indicator of outcome in sepsis: a prospective observational study
  4. Konrad Reinhart, Dr Meda, Michael Meisner, Dr Med Habilb, Biomarkers in the Critically Ill Patient: Procalcitonin