[Diagnostic and prognostic power of biomarkers to improve the management of community acquired pneumonia in the emergency department]. / Poder diagnóstico y pronóstico de los biomarcadores para mejorar el manejo de la neumonía adquirida en la comunidad en los servicios de urgencias.

OBJECTIVES: 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.

Improved management of community-acquired pneumonia in the emergency department.

OBJECTIVES: To determine the impact of implementing clinical practice guidelines (CPGs) in the treatment of community-acquired pneumonia (CAP) in the emergency department (ED) by analyzing case management decisions (admission or discharge, appropriateness and timeliness of antibiotic therapy, complementary tests) and the consequent results (clinical stabilization time, length of hospital stay, re-admission to ED and mortality). METHODS: A prospective, observational, descriptive, comparative study carried out from 1st January 2008 to 1st August 2009 in two phases: before and after the implementation of the "Management of CAP in ED" SEMES-SEPAR (Spanish Society of Emergency Medicine - Spanish Society of Pneumology and Thoracic Surgery) clinical practice guidelines from 2008. Two hundred adult patients treated in the ED with a diagnosis of CAP were included in the study, both in the pre-intervention and post-intervention groups. RESULTS: The application of the guidelines increased the administration of early and appropriate antibiotic therapy (P<.001) and shortened both the total antibiotic therapy (P<.001) and the intravenous antibiotic therapy (P=.042) times. Time to clinical stabilization (P=.027), length of hospital stay (1.14 days, P=.01), intra-hospital mortality (P=.004) and total 30-day mortality (P=.044) were all reduced. Assessment with the Pneumonia Severity Index (PSI) and biomarkers aided in appropriate decision-making concerning admission/discharge (P<.001). CONCLUSIONS: The implementation of the SEMES-SEPAR 2008 guidelines, along with the use of PSI and biomarkers, significantly improved the entire treatment process of CAP. This benefitted both patients and the system by reducing mortality and improving the results of other patient management factors.