title: [Diagnostic and prognostic power of biomarkers to improve the management of community acquired pneumonia in the emergency department].
abstract: OBJECTIVE
  To analyse the usefulness and performance of several biomarkers [C-reactive protein (CRP), mid-regional pro-adrenomedullin (MR-proADM), procalcitonin (PCT)] and lactate in predicting short- and medium-term mortality compared with the prognostic severity scales (PSS) usually employed for community-acquired pneumonia (CAP) and in assessing the aetiological suspicion of infection by Streptococcus pneumoniae and bacteraemia.
  
  
  METHODS
  Observational, prospective and analytical study was conducted on patients who were diagnosed with CAP in our emergency department (ED). The data collected included socio-demographic and comorbidity variables, Charlson index, priority level according to the Spanish Triage System (STS), stage in the Pneumonia Severity Index (PSI) and in the CURB-65 (confusion, urea, respiratory rate, blood pressure and age ≥65years), criteria of severe CAP, microbiological studies, and biomarkers determinations. The patients were followed-up for 180days to calculate the prognostic power and the diagnostic performance for bacteraemia and aetiology.
  
  
  RESULTS
  A total of 127patients were finally enrolled in the study. The 30-day mortality was 10.3% (13), and 22.6% (28) at 180 days. Blood cultures were positive in 29 patients (23%) and S.pneumoniae was identified as the responsible pathogen in 28 cases (22.2%). The area under the ROC curve (AUC-ROC) for lactate and MR-proADM to predict 30-day mortality was 0.898 (95%CI: 0.824-0.973; P<.0001) and 0.892 (95%CI: 0.811-0.974; P<.0001), respectively, and for MR-proADM at 180 days it was 0.921 (95%CI: 0.874-0.968; P<.0001). The AUC-ROC for PCT to predict bacteraemia was 0.952 (95%CI: 0.898-1.000; P<.0001) and, considering a cut-off value ≥0.95ng/ml, the negative predictive value (NPV) and the likelihood ratio (LR+) were 97.8% and 9.03, respectively. Using a PCT cut-off value >0.85ng/ml, the NPV and the LR+ were 96.6% and 5.89%, respectively, to predict a S.pneumoniae infection.
  
  
  CONCLUSIONS
  MR-proADM and lactate showed a similar or even better performance for 30-day intra-hospital mortality than PSI, CURB-65, STS and CAP severity criteria in patients diagnosed with CAP (P>.05). Furthermore, the MR-proADM capacity to predict 180-day mortality was higher than PSS and the rest of biomarkers (P>.05), and its AUC-ROC increased if it was used in combination with PSI, CURB65 and STS. The determination of PCT has a remarkable diagnostic performance to rule out bacteraemia and to orientate the aetiology towards a S.pneumoniae infection.
authors.affiliation: Servicio de Urgencias, Complejo Hospitalario de Toledo, Toledo, España. Electronic address: agustinj@sescam.jccm.es.
authors.forename: Agustín
authors.initials: A
authors.lastname: Julián-Jiménez
authors.affiliation: Servicio de Análisis Clínicos y Bioquímica, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Jesús
authors.initials: J
authors.lastname: Timón Zapata
authors.affiliation: Servicio de Análisis Clínicos y Bioquímica, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Emilio José
authors.initials: EJ
authors.lastname: Laserna Mendieta
authors.affiliation: Servicio de Análisis Clínicos y Bioquímica, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Isabel
authors.initials: I
authors.lastname: Sicilia-Bravo
authors.affiliation: Servicio de Urgencias, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: María José
authors.initials: MJ
authors.lastname: Palomo-de Los Reyes
authors.affiliation: Servicio de Análisis Clínicos y Bioquímica, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Angeles
authors.initials: A
authors.lastname: Cabezas-Martínez
authors.affiliation: Servicio de Urgencias, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Natividad
authors.initials: N
authors.lastname: Laín-Terés
authors.affiliation: Servicio de Urgencias, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Josefa
authors.initials: J
authors.lastname: Estebaran-Martín
authors.affiliation: Servicio de Urgencias, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Agustín
authors.initials: A
authors.lastname: Lozano-Ancín
authors.affiliation: Farmacología Clínica, Complejo Hospitalario de Toledo, Toledo, España.
authors.forename: Rafael
authors.initials: R
authors.lastname: Cuena-Boy
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D017714:Community-Acquired Infections / Q000097:blood / Q000175:diagnosis; D004636:Emergency Service, Hospital; D004638:Emergency Treatment; D005260:Female; D006801:Humans; D008297:Male; D018410:Pneumonia, Bacterial / Q000097:blood / Q000175:diagnosis* / Q000628:therapy*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D058996:Quality Improvement
chemical_list: D015415:Biomarkers
keywords: Bacteraemia; Bacteriemia; Biomarcadores; Biomarkers; C-reactive protein; Community-acquired pneumonia; Emergency Department; Lactate; Lactato; Mortalidad; Mortality; Neumonía adquirida en la comunidad; Pneumonia Severity Index; Pro-adrenomedullin; Proadrenomedulina; Procalcitonin; Procalcitonina; Proteína C reactiva; Urgencias