Diagnosis of nosocomial pneumonia in medical ward: repeatability of the protected specimen brush

The Diagnostic Yield of Noninvasive Microbiologic Sputum Sampling in a Cohort of Patients with Clinically Diagnosed Hospital-Acquired Pneumonia

The clinical predictors of positive sputum culture have not been previously reported in hospital-acquired pneumonia (HAP), and data on yield of sputum culture in this setting are scant. Current Infectious Disease Society of America guidelines for HAP recommend noninvasive sputum sampling, though the data for this practice are limited. We assessed the yield of sputum culture in HAP cases at an academic medical center from January 2007 to July 2013. HAP cases were identifi ed by International Classifi cation of Diseases, Ninth Revision-Clinical Modifi cation codes for bacterial pneumonia and all cases were validated by chart review. Our cohort had 1172 hospitalizations with a HAP diagnosis. At least 1 sputum specimen was collected noninvasively and sent for bacterial culture after hospital day 2 and within 7 days of HAP diagnosis in 344 of these hospitalizations (29.4%), with a total of 478 sputum specimens, yielding 63 (13.2%) positive, 109 (22.8%) negative, and 306 (64.0%) contaminated cultures (>10 epithelial cells per high power fi eld). Signifi cant predictors of a positive sputum culture were chronic lung disease (relative risk [RR] = 2.0; 95% confi dence interval [CI], 1.2-3.4) and steroid use (RR = 1.8; 95% CI, 1.1-3.2). The most commonly identifi ed organisms were Gram-negative rods not further speciated (25.9%), Staphylococcus aureus (21.0%), and Pseudomonas aeruginosa (14.8%). Because of the ease of obtaining a sputum sample combined with the prevalence of commonly drug-resistant organisms, we suggest that sputum culture in HAP is a potentially useful noninvasive diagnostic technique.

Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.These guidelines are intended for use by healthcare professionals who care for patients at risk for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), including specialists in infectious diseases, pulmonary diseases, critical care, and surgeons, anesthesiologists, hospitalists, and any clinicians and healthcare providers caring for hospitalized patients with nosocomial pneumonia. The panel's recommendations for the diagnosis and treatment of HAP and VAP are based upon evidence derived from topic-specific systematic literature reviews.

Prediction of the pathogens that are the cause of pneumonia by the battlefield hypothesis

Commensal organisms are frequent causes of pneumonia. However, the detection of these organisms in the airway does not mean that they are the causative pathogens; they may exist merely as colonizers. In up to 50% cases of pneumonia, the causative pathogens remain unidentified, thereby hampering targeting therapies. In speculating on the role of a commensal organism in pneumonia, we devised the battlefield hypothesis. In the "pneumonia battlefield," the organism-to-human cell number ratio may be an index for the pathogenic role of the organism. Using real-time PCR reactions for sputum samples, we tested whether the hypothesis predicts the results of bacteriological clinical tests for 4 representative commensal organisms: Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas spp., and Moraxella catarrhalis. The cutoff value for the organism-to-human cell number ratio, above which the pathogenic role of the organism was suspected, was set up for each organism using 224 sputum samples. The validity of the cutoff value was then tested in a prospective study that included 153 samples; the samples were classified into 3 groups, and each group contained 93%, 7%, and 0% of the samples from pneumonia, in which the pathogenic role of Streptococcus pneumoniae was suggested by the clinical tests. The results for Haemophilus influenzae, Pseudomonas spp., and Moraxella catarrhalis were 100%, 0%, and 0%, respectively. The battlefield hypothesis enabled legitimate interpretation of the PCR results and predicted pneumonia in which the pathogenic role of the organism was suggested by the clinical test. The PCR reactions based on the battlefield hypothesis may help to promote targeted therapies for pneumonia. The prospective observatory study described in the current report had been registered to the University Hospital Medical Information Network (UMIN) registry before its initiation, where the UMIN is a registry approved by the International Committee of Medical Journal Editors (ICMJE). The UMIN registry number was UMIN000001118: A prospective study for the investigation of the validity of cutoff values established for the HIRA-TAN system (April 9, 2008).

Management of nosocomial pneumonia on a medical ward: a comparative study of outcomes and costs of invasive procedures

The goal of this study was to compare outcomes and costs of two management strategies for non-ventilator-associated nosocomial pneumonia (NP) in a medical ward. In this single-centre study, NP patients (n = 68) were randomized to receive non-invasive management (NIM) with immediate empirical antibiotic treatment (n = 34), or invasive management (IM) based on protected brush sampling of specimens (n = 34). The economic analysis adopted the hospital's perspective and took into account only direct costs. Baseline characteristics did not differ significantly between the two patient groups. The most frequently isolated organisms were Staphylococcus (25.4%), Streptococcus (23.7%) and Pseudomonas (18.6%) species. The 28-day clinical cure rate did not differ notably between the two groups (NIM, 79.4%; IM, 73.5%). Mortality at 28 days tended to be lower in the NIM group (10.0% vs. 21.8%). Mean antibiotic costs were lower in the IM group (euro194 +/- 355 vs. euro300 +/- 335, p <0.001) but overall management costs were similar (respectively, euro367 +/- 355 and euro346 +/- 363 in the IM and NIM groups, p = 0.08). With respect to both outcome and cost, this study does not support routine management of NP in medical wards using invasive procedures.

Neumonía nosocomial en el enfermo no intubado

Hospital-acquired pneumonia is one of the main causes of nosocomial infection. Although its incidence is higher in intubated patients, around half of all cases occur outside the intensive care unit (ICU). However, few studies have been performed in this setting and consequently most data come from hospitalized series that include patients undergoing mechanical ventilation. The epidemiological differences between intubated patients and non-ICU patients suggest that the etiology and therapeutic approach differ between these two groups. The present article reviews the epidemiology, diagnosis, treatment and prevention of nosocomial pneumonia in general wards.

Aportación del laboratorio de microbiología al diagnóstico de la neumonía asociada a la ventilación mecánica

The etiologic diagnosis of ventilator-associated pneumonia (VAP) should be considered as a microbiological emergency due to its impact on morbidity and mortality. Sampling of the lower respiratory tract (LRT) must be performed before starting or modifying antimicrobial therapy. Surveillance cultures in patients without criteria of VAP are not recommended. There is no evidence of any superiority of bronchoscopic over non-bronchoscopic sampling procedures, but quantitative bacterial cultures are essential to allow colonization to be differentiated from true infection of the LRT. Under these conditions, negative cultures practically rule out bacterial infection or, at least, identify patients who will not benefit from antibiotic therapy or who will require a very short course of treatment. Given that identification and antimicrobial susceptibility testing of microorganisms usually takes up to 3 or 4 days, rapid procedures that provide the clinician with useful information are essential. Rapid information, even if partial or less than perfect, is clearly better for the patient than a perfect but delayed report. Gram stain of LRT secretions is an immediate procedure that can guide management and it has a reasonable correlation with culture results. At present, new antibiogram procedures, performed on direct clinical samples, allow presumptive identification and information on susceptibility to commonly used antibiotics in less than 24 hours after sampling. The impact of using this procedure in clinical practice is currently under research.