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.

Cytokines and neutrophils responses in influenza pneumonia.

This case report shows a striking correlation of remarkable brief high levels of pro- and anti-inflammatory cytokines coupled with increased neutrophil activation, followed by a sharp decrease in cytokine levels and increased neutrophil apoptosis associated with the favorable clinical outcomes of a patient with severe influenza infection. The host response examined in our case is not complete, given it did not assess the full spectrum of host response. The brief neutrophil and cytokine response seen in our case in the absence of antiviral therapy and in the presence of methotrexate immunosuppressive therapy rise the question as to whether the latter optimally modulated the macrophage function, resulting in a favorable outcome of severe influenza viral infection.

Empiric therapy directed against MRSA in patients admitted to the intensive care unit does not improve outcomes in community-acquired pneumonia.

PURPOSE: The Infectious Diseases Society of America has recommended empiric therapy active against methicillin-resistant Staphylococcus aureus (MRSA) for all community-acquired pneumonia (CAP) patients admitted to the intensive care unit (ICU). However, there is sparse data to support this recommendation. The objective of our study was to ascertain if such a practice improves outcomes. METHODS: This study was a secondary, retrospective analysis of the Community-Acquired Pneumonia Organization (CAPO) international database on CAP. Outcomes in patients admitted to the ICU were compared according to empiric initiation of anti-MRSA therapy (vancomycin or linezolid) with standard ICU CAP therapy (MRSA therapy group) or standard therapy alone for ICU CAP (standard therapy group). RESULTS: A total of 621 patients were identified with ICU pneumonia, of whom 57 patients had been initiated empirically on vancomycin or linezolid (MRSA therapy group). Patients of the MRSA therapy group had more comorbidities and were more severely ill than those of the standard therapy group. However, there were no statistical differences between the MRSA therapy group and standard therapy group for the primary outcomes of in-hospital and 28-day mortality, length of stay and time to clinical stability. CONCLUSIONS: These findings suggest that empiric MRSA therapy in all ICU CAP patients may not improve outcomes and argue for clinician review of local epidemiologic trends on MRSA prevalence to ascertain the need for empiric MRSA coverage.

Computed tomography measurements of parapneumonic effusion indicative of thoracentesis.

Patients with parapneumonic effusions (PPE) measuring <1 cm by lateral decubitus radiograph (LDR) or <5 cm by lateral erect radiograph (LER) do not require thoracentesis. No such data exist for chest computed tomography (CCT). The objective of this study was to identify a PPE measurement by CCT that indicates the need for thoracentesis. A secondary data analysis of two pneumonia databases was conducted to identify patients with PPE. Measurements of PPE using LDR, LER and CCT were correlated by linear regression analysis. The clinical outcome of community-acquired pneumonia patients managed with the newly defined CCT measurement was evaluated. PPE was identified in 419 out of 1,460 patients with possible pneumonia. PPE measurements of 1 cm and 5 cm by LDR and LER, respectively, correlated with a measurement of 2.5 cm by CCT. Out of 95 patients with CCT measurements <2.5 cm, 31 poor clinical outcomes were reported: outcome was PPE related (n = 1); outcome was PPE unrelated (n = 26); and outcome was not evaluable (n = 4). The single case of poor outcome also measured <1 cm by LDR. This study indicates that patients with community-acquired pneumonia and a PPE measuring <2.5 cm by CCT can be managed without the need for thoracentesis.