Aspiration pneumonia: A renewed perspective and practical approach.

Aspiration pneumonia (AP) is a sub-type of community-acquired pneumonia (CAP) still poorly recognized especially in the absence of an aspiration event. A further difficulty is the differentiation between AP and aspiration pneumonitis. From a clinical perspective, AP is becoming increasingly relevant as a potential cause of severe and life-threatening respiratory infection among frail and very old patients, particularly among those with CAP requiring inpatient care. Moreover, AP is frequently underdiagnosed and a clear-cut definition of this pathological entity is lacking. There are different factors that increase the risk for aspiration, but other common factors influencing oral colonization such as malnutrition, smoking, poor oral hygiene or dry mouth, are also important in the pathogenesis of AP and should be considered. While there is no doubt in the diagnosis of AP in cases of a recent witnessed aspiration of oropharyngeal or gastric content, we here proposed a definition of AP that also includes silent unobserved aspirations. For this reason, the presence of one or more risk factors of oropharyngeal aspiration is required together with one or more risk factors for oral bacterial colonization. This proposed definition based on expert opinion not only unifies the diagnostic criteria of AP, but also provides the possibility to devise easily applicable strategies to prevent oral colonization.

Validation of a Prediction Score for Drug-Resistant Microorganisms in Community-acquired Pneumonia.

Rationale: Recommended initial empiric antimicrobial treatment covers the most common bacterial pathogens; however, community-acquired pneumonia (CAP) may be caused by microorganisms not targeted by this treatment. Developed in 2015, the PES (Pseudomonas aeruginosa, extended-spectrum ß-lactamase-producing Enterobacteriaceae, and methicillin-resistant Staphylococcus aureus) score was developed in 2015 to predict the microbiological etiology of CAP caused by PES microorganisms.Objective: To validate the usefulness of the PES score for predicting PES microorganisms in two cohorts of patients with CAP from Valencia and Mataró.Methods: We analyzed two prospective observational cohorts of patients with CAP from Valencia and Mataró. Patients in the Mataró cohort were all admitted to an intensive care unit (ICU).Results: Of the 1,024 patients in the Valencia cohort, 505 (51%) had a microbiological etiology and 31 (6%) had a PES microorganism isolated. The area under the receiver operating characteristic curve was 0.81 (95% confidence interval [95% CI], 0.74-0.88). For a PES score ≥5, sensitivity, specificity, the negative and positive predictive values as well as the negative and positive likelihood ratios were 72%, 74%, 98%, 14%, 0.38, and 2.75, respectively. Of the 299 patients in the Mataró cohort, 213 (71%) had a microbiological etiology and 11 (5%) had a PES microorganism isolated. The area under the receiver operating characteristic curve was 0.73 (95% CI 0.61-0.86). For a PES score ≥ 5, sensitivity, specificity, the negative and positive predictive values, and the negative and positive likelihood ratios were 36%, 83%, 96%, 11%, 0.77, and 2.09, respectively. The best cutoff for patients admitted to the ICU was 4 points, which improved sensitivity to 86%. The hypothetical application of the PES score showed high rates of overtreatment in both cohorts (26% and 35%, respectively) and similar rates of undertreatment.Conclusions: The PES score showed good accuracy in predicting the risk for microorganisms that required different empirical therapy; however, its use as a single strategy for detecting noncore pathogens could lead to high rates of overtreatment. Given its high negative predictive value, the PES score may be used as a first step of a wider strategy that includes subsequent advanced diagnostic tests.

Impact of Lymphocyte and Neutrophil Counts on Mortality Risk in Severe Community-Acquired Pneumonia with or without Septic Shock.

BACKGROUND: Community-acquired pneumonia (CAP) is a frequent cause of death worldwide. As recently described, CAP shows different biological endotypes. Improving characterization of these endotypes is needed to optimize individualized treatment of this disease. The potential value of the leukogram to assist prognosis in severe CAP has not been previously addressed. METHODS: A cohort of 710 patients with CAP admitted to the intensive care units (ICUs) at Hospital of Mataró and Parc Taulí Hospital of Sabadell was retrospectively analyzed. Patients were split in those with septic shock (n = 304) and those with no septic shock (n = 406). A single blood sample was drawn from all the patients at the time of admission to the emergency room. ICU mortality was the main outcome. RESULTS: Multivariate analysis demonstrated that lymphopenia <675 cells/mm3 or <501 cells/mm3 translated into 2.32- and 3.76-fold risk of mortality in patients with or without septic shock, respectively. In turn, neutrophil counts were associated with prognosis just in the group of patients with septic shock, where neutrophils <8850 cells/mm3 translated into 3.6-fold risk of mortality. CONCLUSION: lymphopenia is a preserved risk factor for mortality across the different clinical presentations of severe CAP (sCAP), while failing to expand circulating neutrophils counts beyond the upper limit of normality represents an incremental immunological failure observed just in those patients with the most severe form of CAP, septic shock.

IgG2 as an independent risk factor for mortality in patients with community-acquired pneumonia.

BACKGROUND: Mortality in patients with community-acquired pneumonia (CAP) remains high despite improvements in treatment. OBJECTIVE: To determine immunoglobulin levels in patients with CAP and impact on disease severity and mortality. METHODOLOGY: Observational study. Hospitalized patients with CAP were followed up for 30 days. Levels of immunoglobulin G (IgG) and subclasses, immunoglobulin A (IgA) and immunoglobulin M (IgM) were measured in serum within 24 hours of CAP diagnosis. RESULTS: Three hundred sixty-two patients with CAP were enrolled -172 ward-treated and 190 intensive care unit-treated. Intensive care unit-treated patients had significantly lower values of IgG1, IgG2, IgG3 subclasses, and IgA than ward-treated patients. Thirty-eight patients died before 30 days. Levels of IgG2 were significantly lower in non-survivors than survivors (P=.004) and IgG2 <301 mg/dL was associated with poorer survival according to both the bivariate (hazard ratio 4.47; P<.001) and multivariate (HR 3.48; P=.003) analyses. CONCLUSIONS: Patients with CAP with IgG2 levels <301 mg/dL had a poorer prognosis and a higher risk of death. Our study suggests the usefulness of IgG2 to predict CAP evolution and to provide support measures or additional treatment.

[Epidemiology of community-acquired severe sepsis. A population-based study]. / Epidemiología de la sepsis grave adquirida en la comunidad. Estudio de base poblacional.

BACKGROUND AND OBJECTIVE: Most studies aimed at getting to know the incidence of severe sepsis have methodological limitations which condition results that are difficult to compare and are inapplicable when it comes to estimating the necessary resources. Our objective is to evaluate the incidence and epidemiological aspects of community-acquired severe sepsis which require intensive care unit admission. PATIENTS AND METHOD: Prospective observational population-based study in a population of 180,000 adults over 15 years old and a general hospital with 350 beds and 14 ICU beds. All episodes of community-acquired infection requiring admission to ICU due to severe sepsis were registered over a period of 9 years. The variables analyzed were: age, sex, SAPS II score, length of stay in ICU, type of infection, isolated microorganism, and deaths during their ICU admission. A statistical bivariate analysis and a multiple logistic regression were performed. RESULTS: Nine hundred and seventeen episodes with an average age of 65.2 years. The most frequent infectious focus was pulmonary (55.2%). The average SAPS II severity score index was 37.87 and mortality 19.7%. The annual incidence was 51.54 episodes per 100,000 adult inhabitants, meaning 1.97 ICU beds per day. In the multivariate analysis, the SAPS II score and a known aetiology were demonstrated as mortality risk factors. CONCLUSIONS: This study brings us some epidemiological data from a population-based perspective which help us to care for patients better in our geographical area. The average annual incidence is 51.5 cases per 100,000 adult inhabitants which means that 2 ICU beds per day to attend this population.

Serum levels of immunoglobulins and severity of community-acquired pneumonia.

INSTRUCTION: There is evidence of a relationship between severity of infection and inflammatory response of the immune system. The objective is to assess serum levels of immunoglobulins and to establish its relationship with severity of community-acquired pneumonia (CAP) and clinical outcome. METHODS: This was an observational and cross-sectional study in which 3 groups of patients diagnosed with CAP were compared: patients treated in the outpatient setting (n=54), patients requiring in-patient care (hospital ward) (n=173), and patients requiring admission to the intensive care unit (ICU) (n=191). RESULTS: Serum total IgG (and IgG subclasses IgG1, IgG2, IgG3, IgG4), IgA and IgM were measured at the first clinical visit. Normal cutpoints were defined as the lowest value obtained in controls (≤680, ≤323, ≤154, ≤10, ≤5, ≤30 and ≤50 mg/dL for total IgG, IgG1, IgG2, IgG3, IgG4, IgM and IgA, respectively). Serum immunoglobulin levels decreased in relation to severity of CAP. Low serum levels of total IgG, IgG1 and IgG2 showed a relationship with ICU admission. Low serum level of total IgG was independently associated with ICU admission (OR=2.45, 95% CI 1.4 to 4.2, p=0.002), adjusted by the CURB-65 severity score and comorbidities (chronic respiratory and heart diseases). Low levels of total IgG, IgG1 and IgG2 were significantly associated with 30-day mortality. CONCLUSIONS: Patients with severe CAP admitted to the ICU showed lower levels of immunoglobulins than non-ICU patients and this increased mortality.

Serum immunoglobulins in the infected and convalescent phases in community-acquired pneumonia.

BACKGROUND: A population-based case-control study was designed to assess changes of serum levels of immunoglobulins and IgG subclasses between infected and convalescent phase in community-acquired pneumonia (CAP). METHODS: Over a 2-year period, all subjects who were >14 years of age living in the Maresme region (Barcelona, Spain) diagnosed of CAP were registered. Controls were healthy subjects selected from the municipal census. Prognostic factors were assessed and serum levels of total IgG, IgA, IgM, and IgG subclasses were measured at diagnosis and 1 month later (cases). RESULTS: We studied 171 patients with CAP and 90 controls. All immunoglobulins were significantly lower in cases than in controls. At diagnosis, 42.7% of cases showed low levels of some immunologic parameter, mainly total IgG and IgG2. Low immunoglobulin levels at diagnosis were more frequent in patients requiring in-patient care and in those with pneumonia of other etiology than Streptococcus pneumoniae. In the convalescent phase, 26 (23.6%) patients normalized immunological levels. In 27 (24.5%) cases, some parameter with low levels persisted especially in patients with etiology of CAP other than S. pneumoniae. CONCLUSIONS: Low serum levels of immunoglobulins particularly total IgG and IgG2 were a common finding in patients with CAP compared to healthy controls. Low immunoglobulin levels may be related to CAP prognosis and persisted in the convalescent phase in one-fourth of cases.