title: Role of biomarkers in the management of antibiotic therapy: an expert panel review II: clinical use of biomarkers for initiation or discontinuation of antibiotic therapy.
abstract: Biomarker-guided initiation of antibiotic therapy has been studied in four conditions: acute pancreatitis, lower respiratory tract infection (LRTI), meningitis, and sepsis in the ICU. In pancreatitis with suspected infected necrosis, initiating antibiotics best relies on fine-needle aspiration and demonstration of infected material. We suggest that PCT be measured to help predict infection; however, available data are insufficient to decide on initiating antibiotics based on PCT levels. In adult patients suspected of community-acquired LRTI, we suggest withholding antibiotic therapy when the serum PCT level is low (<0.25 ng/mL); in patients having nosocomial LRTI, data are insufficient to recommend initiating therapy based on a single PCT level or even repeated measurements. For children with suspected bacterial meningitis, we recommend using a decision rule as an aid to therapeutic decisions, such as the Bacterial Meningitis Score or the Meningitest®; a single PCT level ≥0.5 ng/mL also may be used, but false-negatives may occur. In adults with suspected bacterial meningitis, we suggest integrating serum PCT measurements in a clinical decision rule to help distinguish between viral and bacterial meningitis, using a 0.5 ng/mL threshold. For ICU patients suspected of community-acquired infection, we do not recommend using a threshold serum PCT value to help the decision to initiate antibiotic therapy; data are insufficient to recommend using PCT serum kinetics for the decision to initiate antibiotic therapy in patients suspected of ICU-acquired infection. In children, CRP can probably be used to help discontinue therapy, although the evidence is limited. In adults, antibiotic discontinuation can be based on an algorithm using repeated PCT measurements. In non-immunocompromised out- or in- patients treated for RTI, antibiotics can be discontinued if the PCT level at day 3 is < 0.25 ng/mL or has decreased by >80-90%, whether or not microbiological documentation has been obtained. For ICU patients who have nonbacteremic sepsis from a known site of infection, antibiotics can be stopped if the PCT level at day 3 is < 0.5 ng/mL or has decreased by >80% relative to the highest level recorded, irrespective of the severity of the infectious episode; in bacteremic patients, a minimal duration of therapy of 5 days is recommended.
authors.affiliation: Service de Réanimation médicale, Hôpitaux Universitaires Henri Mondor, AP-HP & Université Paris-Est, 51, av de Lattre de Tassigny, 94000 Créteil, France. Christian.brun-buisson@hmn.aphp.fr.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Quenot
authors.forename: Charles-Edouard
authors.initials: CE
authors.lastname: Luyt
authors.forename: Nicolas
authors.initials: N
authors.lastname: Roche
authors.forename: Martin
authors.initials: M
authors.lastname: Chalumeau
authors.forename: Pierre-Emmanuel
authors.initials: PE
authors.lastname: Charles
authors.forename: Yann-Eric
authors.initials: YE
authors.lastname: Claessens
authors.forename: Sigismond
authors.initials: S
authors.lastname: Lasocki
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bedos
authors.forename: Yves
authors.initials: Y
authors.lastname: Péan
authors.forename: François
authors.initials: F
authors.lastname: Philippart
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Ruiz
authors.forename: Christele
authors.initials: C
authors.lastname: Gras-Leguen
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Dupuy
authors.forename: Jérôme
authors.initials: J
authors.lastname: Pugin
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Stahl
authors.forename: Benoit
authors.initials: B
authors.lastname: Misset
authors.forename: Rémy
authors.initials: R
authors.lastname: Gauzit
authors.forename: Christian
authors.initials: C
authors.lastname: Brun-Buisson