Bacteremic pneumococcal pneumonia: clinical outcomes and preliminary results of inflammatory response

PURPOSE

Further examination of clinical outcomes and inflammatory response of bacteremic pneumococcal community-acquired pneumonia (CAP) is of great interest to enhance the care of patients with pneumococcal CAP.

METHODS

This is a secondary analysis of the Community Acquired Pneumonia Organization (CAPO) to compare the time to clinical stability (TCS), length of hospital stay (LOS), and in-hospital mortality of hospitalized pneumococcal CAP patients with and without bacteremia. To measure the effect of bacteremia in pneumococcal CAP patients on outcomes, we modeled all-cause in-hospital mortality using a Poisson regression model, and TCS and LOS using Cox proportional hazards models. Adjusted multivariate regression models were also used to predict the probability of occurrence of each of the study outcomes. To investigate the inflammatory response, we measured the plasma levels of pro- and anti-inflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1rα, IL-6, IL-8, IL-10], inflammatory biomarkers [C-reactive protein (CRP), pro-calcitonin (PCT), and B-type natriuretic peptide (BNP)], and peripheral blood neutrophil responses in 10 patients, 4 bacteremic and 6 non-bacteremic pneumococcal CAP, upon admission and every other day during the first 6 days of hospitalization. Functional data were presented as median and standard error of the median (SEM); due to small number of samples no statistical comparisons were performed between groups.

RESULTS

From 833 pneumococcal CAP patients, 394 patients (47 %) were bacteremic. Bacteremic pneumococcal CAP were less likely to reach TCS with an adjusted hazard ratio (AHR) of 0.82 (95 % CI 0.69-0.97; p = 0.02) and had higher in-hospital mortality with an AHR of 1.63 (95 % CI 1.06-2.50, p = 0.026). Bacteremic pneumococcal CAP patients had a longer LOS than non-bacteremic pneumococcal CAP (p < 0.003). Higher plasma levels of CRP, PCT, and BNP were found in bacteremic than in non-bacteremic patients. The bacteremic group had consistently higher plasma levels of both pro- and anti-inflammatory cytokines. The blood neutrophil functional responses were similar in both groups of patients.

CONCLUSIONS

Bacteremic pneumococcal CAP patients were significantly associated with higher in-hospital mortality, lower TCS, and longer LOS. HIV-infected patients showed a greater mortality which was not statistically significant. Bacteremic pneumococcal CAP patients had higher levels of biomarkers and systemic cytokines.

De-escalation therapy among bacteraemic patients with community-acquired pneumonia

There is no evidence supporting the use of de-escalation therapy (DET) among patients with community-acquired pneumonia (CAP). We assessed the outcomes associated with DET among bacteraemic CAP patients. We performed a secondary analysis of the Community-Acquired Pneumonia Organization database, which contains data on 660 bacteraemic patients hospitalized because of CAP in 35 countries (2001-2013). Exclusion criteria were death within 72 h from admission and an inappropriate empirical antibiotic regimen. DET was defined as changing an appropriate empirical broad-spectrum regimen to a narrower-spectrum regimen according to culture results within 7 days from hospital admission. Two study groups were identified: patients whose antibiotic therapy was de-escalated (the DET group), and patients whose antibiotic therapy was not de-escalated (the N-DET group). The primary study outcome was 30-day mortality. Two hundred and sixty-one bacteraemic CAP patients were included. Gram-positive bacteria were responsible for 88.1% of the cases (Streptococcus pneumoniae, 75.9%). Gram-negative bacteria were responsible for for 7.3% of the cases. DET was performed in 165 patients (63.2%). The N-DET group was characterized by a more severe presentation at admission. After adjustment for confounders, DET was not associated with an increased risk of 30-day mortality. DET seems to be safe among bacteraemic patients with CAP. Randomized clinical trials are warranted to further explore these findings.

Incidence of respiratory viruses in patients with community-acquired pneumonia admitted to the intensive care unit: results from the Severe Influenza Pneumonia Surveillance (SIPS) project

Few patients with community-acquired pneumonia (CAP) require admission to the intensive care unit (ICU-CAP). However, they represent the most severe form of the disease. An understanding of the etiologic agents of ICU-CAP may lead to better treatment decisions and patient outcomes. The objective of this study was to determine the incidence of respiratory viruses in patients with ICU-CAP. This was an observational study conducted in six Kentucky hospitals from December 2008 through October 2011. A case of ICU-CAP was defined as a patient admitted to an ICU with the diagnosis of CAP. The Luminex xTAG multiplex polymerase chain reaction (PCR) assay was used for viral identification. A total of 468 adult and pediatric patients with ICU-CAP were enrolled in the study. A total of 92 adult patients (23 %) and 14 pediatric patients (19 %) had a respiratory virus identified. Influenza was the most common virus identified in adults and the second most common in pediatric patients. This study suggests that respiratory viruses may be common etiologic agents of pneumonia in patients with ICU-CAP. The Centers for Disease Control and Prevention (CDC) recommend empiric anti-influenza therapy during the winter for hospitalized patients with CAP. This study supports this recommendation in patients with ICU-CAP.