Utilidad de la proteína C reactiva sérica en el diagnóstico y tratamiento del adulto inmunocompetente hospitalizado por neumonía adquirida en la comunidad / Immunocompetent adults hospitalized for a community-acquired pneumonia: Serum C-reactive protein as a prognostic marker

Background: C-reactive protein (CRP) is used to monitor patients' response during treatment of infectious diseases. Morbidity and mortality associated with community-acquired pneumonia (CAP) is high, particularly in hospitalized patients. Better risk prediction during hospitalization could improve management and ultimately reduce mortality rates. Aim: To evaluate CRP measured at admission and the third day of hospitalization as a predictor for adverse events in CAP. Material and Methods: A prospective cohort study of adult patients hospitalized with CAP at an academic hospital. Major adverse outcomes were admission to ICU, mechanical ventilation, prolonged hospital length of stay, hospital complications and 30-day mortality. Predictive associations between CRP (as absolute levels and relative decline at third day) and adverse events were analyzed. Results: Eight hundred and twenty-three patients were assessed, 19% were admitted to ICU and 10.6% required mechanical ventilation. The average hospital stay was 8.8 ± 8.2 days, 42% had nosocomial complications and 8.1% died within 30 days. Ninety eight percent of patients had elevated serum CRP on admission to the hospital (18.1 ± 14.1 mg/dL). C-reactive protein measured at admission was associated with the risk of bacterial pneumonia, bacteremic pneumonia, septic shock and use of mechanical ventilation. Lack of CRP decline within three days of hospitalization was associated with high risk of complications, septic shock, mechanical ventilation and prolonged hospital stay. Conclusions: CRP responses at third day of hospital admission was a valuable predictor of adverse events in hospitalized CAP adult patients.

Do N-terminal pro-brain natriuretic peptide levels determine the prognosis of community acquired pneumonia? / Os níveis de pró-peptídeo natriurético cerebral N-terminal determinam o prognóstico de pneumonia adquirida na comunidade?

ABSTRACT Objective: Pneumonia is a leading cause of mortality worldwide, especially in the elderly. The use of clinical risk scores to determine prognosis is complex and therefore leads to errors in clinical practice. Pneumonia can cause increases in the levels of cardiac biomarkers such as N-terminal pro-brain natriuretic peptide (NT-proBNP). The prognostic role of the NT-proBNP level in community acquired pneumonia (CAP) remains unclear. The aim of this study was to evaluate the prognostic role of the NT-proBNP level in patients with CAP, as well as its correlation with clinical risk scores. Methods: Consecutive inpatients with CAP were enrolled in the study. At hospital admission, venous blood samples were collected for the evaluation of NT-proBNP levels. The Pneumonia Severity Index (PSI) and the Confusion, Urea, Respiratory rate, Blood pressure, and age ≥ 65 years (CURB-65) score were calculated. The primary outcome of interest was all-cause mortality within the first 30 days after hospital admission, and a secondary outcome was ICU admission. Results: The NT-proBNP level was one of the best predictors of 30-day mortality, with an area under the curve (AUC) of 0.735 (95% CI: 0.642-0.828; p < 0.001), as was the PSI, which had an AUC of 0.739 (95% CI: 0.634-0.843; p < 0.001), whereas the CURB-65 had an AUC of only 0.659 (95% CI: 0.556-0.763; p = 0.006). The NT-proBNP cut-off level found to be the best predictor of ICU admission and 30-day mortality was 1,434.5 pg/mL. Conclusions: The NT-proBNP level appears to be a good predictor of ICU admission and 30-day mortality among inpatients with CAP, with a predictive value for mortality comparable to that of the PSI and better than that of the CURB-65 score.

RESUMO Objetivo: A pneumonia é uma das principais causas de mortalidade no mundo, especialmente em idosos. O uso de escores de risco clínico para determinar o prognóstico é complexo e, portanto, leva a erros na prática clínica. A pneumonia pode causar aumento nos níveis de biomarcadores cardíacos, como o N-terminal pro-brain natriuretic peptide (NT-proBNP, pró-peptídeo natriurético cerebral N-terminal). O papel prognóstico do nível de NT-proBNP na pneumonia adquirida na comunidade (PAC) continua incerto. O objetivo deste estudo foi avaliar o papel prognóstico do nível de NT-proBNP em pacientes com PAC, bem como sua correlação com escores de risco clínico. Métodos: Pacientes consecutivos internados com PAC foram incluídos no estudo. Na internação hospitalar, foram coletadas amostras de sangue venoso para avaliação dos níveis de NT-proBNP. Foram calculados o Pneumonia Severity Index (PSI, Índice de Gravidade de Pneumonia) e o escore Confusão mental, Ureia, frequência Respiratória, Blood pressure (pressão arterial) e idade ≥ 65 anos (CURB-65). O desfecho primário de interesse foi mortalidade por todas as causas nos primeiros 30 dias após a admissão hospitalar, e um desfecho secundário foi admissão na UTI. Resultados: O nível de NT-proBNP foi um dos melhores preditores de mortalidade em 30 dias, com uma área sob a curva (ASC) de 0,735 (IC95%: 0,642-0,828; p < 0,001), assim como o PSI, que teve uma ASC de 0,739 (IC95%: 0,634-0,843; p < 0,001), enquanto CURB-65 teve uma ASC de apenas 0,659 (IC95%: 0,556-0,763; p = 0,006). O nível de corte do NT-proBNP que mostrou ser o melhor preditor de admissão na UTI e de mortalidade em 30 dias foi de 1.434,5 pg/ml. Conclusões: O nível de NT-proBNP parece ser um bom preditor de admissão na UTI e de mortalidade em 30 dias entre pacientes internados com PAC, com um valor preditivo para mortalidade comparável ao do PSI e superior ao do CURB-65.

Evaluación de predictores clínicos de bacteriemia en adultos hospitalizados por neumonía adquirida en la comunidad / Evaluation of clinical predictors of bacteremia in adults hospitalized for community-acquired pneumonia

OBJETIVO: Identificar elementos clínicos sencillos que hagan posible determinar adecuadamente los casos con mayor probabilidad de presentar aislamientos bacterianos en los hemocultivos. MÉTODOS: Estudio de casos y controles con pacientes internados por neumonía adquirida en la comunidad entre 1998 y 2009, definiéndose como casos a los pacientes que presentaron hemocultivos positivos y como controles a aquellos con hemocultivos negativos. Se registraron variables demográficas y clínicas y se las sometió a un análisis bivariado. Las que presentaron diferencias estadísticamente significativas entre los grupos fueron introducidas en un modelo de regresión logística para definir predictores independientes y generar un modelo de predicción clínica. RESULTADOS: De los 322 pacientes estudiados, 15,2 por ciento tuvo hemocultivos positivos. Diez variables mostraron diferencias significativas, pero solo tres (temperatura <38°C, sodio <135 mEq/L y puntaje CURB-65) fueron seleccionadas para el análisis multivariado. El modelo desarrollado mostró escasa capacidad para predecir el resultado de los hemocultivos (R² = 0,176; Hosmer-Lemeshow: P = 0,338). CONCLUSIONES: Los datos obtenidos en esta serie no evidenciaron elementos clínicos con capacidad suficiente para predecir el resultado de los hemocultivos.

OBJECTIVE: Identify simple clinical elements that can be used to adequately determine the cases with the highest probability of presenting bacterial isolates in blood cultures. METHODS: Case-control study with patients hospitalized for community-acquired pneumonia from 1998-2009. Patients with positive blood cultures were defined as cases, and patients with negative blood cultures were defined as controls. The demographic and clinical variables were recorded and a bivariate analysis was conducted. The variables with statistically significant differences between the groups were introduced in a logistic regression model in order to define the independent predictors and generate a clinical prediction model. RESULTS: A total of 15.2 percent of the 322 patients studied had positive blood cultures. Ten variables showed significant differences, but only three variables (temperature <38°C, sodium <135 mEq/L and CURB-65 score) were selected for the multivariate analysis. The model developed showed limited capacity to predict the result of the blood cultures (R² = 0.176; Hosmer-Lemeshow: P = 0.338). CONCLUSIONS: The data obtained in this series did not demonstrate clinical elements with sufficient capacity to predict the result of the blood cultures.