The contribution of blood cultures to the clinical management of adult patients admitted to the hospital with community-acquired pneumonia: a prospective observational study

Increasing blood culture use at US hospital emergency department visits, 2001 to 2004

STUDY OBJECTIVE

We describe emergency department (ED) visits in which patients had blood cultured and examine changes in blood culture use.

METHODS

Data from the 2001 to 2004 National Hospital Ambulatory Medical Care Survey, an annual sample survey of visits to US hospital EDs, were analyzed. About 400 EDs reported data for approximately 37,000 visits each year. Trends in blood culture use were examined among persons 3 months of age and older. Visits by admitted/transferred patients were compared to those released.

RESULTS

About 3.1 million blood cultures were ordered annually in US EDs; blood cultures were ordered at 2.8% of all visits. From 2001 through 2004, the proportion of visits where a blood culture was ordered increased by 33%, particularly in adults. The proportion of visits with a pneumonia diagnosis where a blood culture was ordered rose by 23% during the study period; these visits accounted for 22% of the increase in blood culture use among admitted patients. Almost half of blood cultures were ordered at visits in which the patient was released from the ED. For visits by released patients 3 years of age and older who had blood cultured, 43% had neither fever nor antibiotic prescriptions.

CONCLUSION

There is an increasing national trend in the use of blood cultures at adult patient ED visits; a large proportion of these cultures were for released patients without apparent indicators for bacteremia, such as fever or antibiotic prescriptions. Factors and impact associated with this dynamically changing practice need further evaluation.

Tailored interventions to improve antibiotic use for lower respiratory tract infections in hospitals: a cluster-randomized, controlled trial

BACKGROUND

Limited data exist on the most effective approach to increase the quality of antibiotic use for lower respiratory tract infections at hospitals.

METHODS

One thousand nine hundred six patients with community-acquired pneumonia or an exacerbation of chronic obstructive pulmonary disease (acute exacerbation of chronic bronchitis) were included in a cluster-randomized, controlled trial at 6 medium-to-large Dutch hospitals. A multifaceted guideline-implementation strategy that was tailored to baseline performance and considered the barriers in the target group was used. Principal outcome measures were (1) guideline-adherent antibiotic prescription, (2) adaptation of dose and dose interval of antibiotics according to renal function, (3) switches in therapy, (4) streamlining of therapy, and (5) Gram staining and culture of sputum samples. Secondary process outcomes were applicable to community-acquired pneumonia (e.g., timely administration of antibiotics) or acute exacerbation of chronic bronchitis (e.g., not prescribing macrolides).

RESULTS

The rate of guideline-adherent antibiotic prescription increased from 50.3% to 64.3% in the intervention hospitals (odds ratio [OR], 2.63; 95% confidence interval [CI], 1.57-4.42; P=.0008). The rate of adaptation of antibiotic dose according to renal function increased from 79.4% to 95.1% in the intervention hospitals (OR, 7.32; 95% CI, 2.09-25.7; P=.02). The switch from intravenous to oral therapy improved more in the control hospitals (from 53.3% to 71.9%) than in the intervention hospitals (from 74% to 83.6%). The change from broad-spectrum empirical therapy to pathogen-directed therapy improved by 5.7% in the intervention hospitals (P = not significant). Fewer sputum samples were obtained from both the intervention group (rate of sputum samples obtained decreased from 55.8% to 53.1%) and the control group (rate of sputum samples obtained decreased from 49.6% to 42.7%). Timely administration of antibiotics for community-acquired pneumonia increased significantly in the intervention group (from 55.2% to 62.9%; OR, 2.49; 95% CI, 1.11-5.57; P=.026).

CONCLUSIONS

With regard to some important aspects, tailoring interventions to change antibiotic use improved the quality of treatment for patients hospitalized with lower respiratory tract infection.

The bacteriology of pneumonia diagnosed in Western Australian emergency departments

We used Western Australian emergency department data linked to hospital morbidity, death and microbiology data to describe the bacteriology of pneumonia according to age. The 'atypical' organisms and viruses were not assessed. A total of 6908 patients over a 3-year period were given an emergency department diagnosis of pneumonia, 76.9% were admitted and 6.3% died in hospital. Blood was cultured from 52.9% of patients with 6.4% growing potential pathogens. Streptococcus pneumoniae was the most common organism isolated and accounted for 92% of pathogens in those aged <15 years. Isolation of Enterobacteriaceae species tended to increase with age and accounted for around 25% of isolates from the elderly. Sputum was cultured from 25.3% of patients and bacteria were isolated from 30.3% of samples, commonly Haemophilus influenzae and S. pneumoniae. Isolates from sputum showed no distinct trend across age groups. These patterns question the value of routine blood and sputum cultures and have implications for empiric therapy for the elderly.

Évaluation des soins et pneumopathies aiguës communautaires

INTRODUCTION

Evaluations of care strategies for patients with community acquired pneumonia (CAP) tend to focus more on their necessity (variation in practice...) than on efficacy (adherence, impact of markers of disease severity or medico-economic factors...).

STATE OF THE ART

A number of studies are reported in the literature based on a simple evaluation of practice at a given moment on time or else on the impact of guidelines. These evaluations relate either to outcome criteria (mortality, and duration of stay especially) or the economic impact of CAP (rate of hospitalization, duration of stay, costs of the treatments or hospitalizations...), or on process of care (evaluation of initial severity, delay in administration of antibiotics, appropriateness of antibiotic therapy, evaluation of oxygenation and taking of specimens prior to treatment).

PERSPECTIVES AND CONCLUSIONS

Taken together these studies demonstrate the need to improve and standardise care. Where studies have not found a benefit from guidelines this can often be attributed to problems with assessment or study design and there are many studies showing the benefit of guideline based management and the introduction of standardised care pathways.

[Contribution of microbiological investigations to the diagnosis of lower respiratory tract infections]

The diagnosis of community-acquired pneumonia is usually based on clinical and radiological criteria. The identification of a causative organism is not required for the diagnosis. Although numerous microbiological techniques are available, their sensitivity and specificity are not high enough to guide first-line antimicrobial therapy. Consequently, this treatment remains most often empiric. If the causative organism is identified, the antimicrobial treatment is adapted. Sputum analysis may be proposed as a diagnostic tool for patients with an acute exacerbation of chronic obstructive pulmonary disease, in specific cases (prior antibiotherapy, hospitalization, failure of the empiric antimicrobial treatment).

[Managing lower respiratory tract infections in immunocompetent patients. Definitions, epidemiology, and diagnostic features]

Les infections respiratoires basses sont une des principales cause de mortalité dans le monde et les pneumopathies représentent en France la première cause de décès d'origine infectieuse. Trois entités nosologiques distinctes sont habituellement isolées en fonction de la localisation infectieuse : la bronchite aiguë, la pneumopathie et la bronchopneumopathie (atteignant les bronches et le parenchyme pulmonaire). En cas d'infections de l'arbre bronchique dans le cadre d'une bronchopathie chronique on parle de décompensation infectieuse de la maladie bronchique. Les deux principales difficultés diagnostiques de ces infections sont de déterminer la présence d'une participation alvéolaire au processus infectieux et de définir l'agent (ou les agents) pathogènes. Ces deux éléments vont conditionner la prise en charge thérapeutique. En dehors de l'examen physique, indispensable dans ce contexte, seule la radiographie thoracique pourra, en cas de persistance d'un doute, permettre de confirmer la présence d'une participation alvéolaire. Le diagnostic microbiologique pose la question de sa nécessité systématique et celui de sa valeur. Il n'est pas indispensable de réaliser un diagnostic microbiologique de certitude dans tous les cas. La décision de documentation doit répondre à deux impératifs : faisabilité et valeur diagnostique. La valeur d'un prélèvement dépend de son aptitude à mettre en évidence l'agent pathogène et dans certains cas de la possibilité d'en déterminer le profil de sensibilité (qui reste une indication majeure à la réalisation de ces prélèvements).

Do Educational Interventions Improve Management of Patients with Community-Acquired Pneumonia?

Community-acquired pneumonia (CAP) is the Leading cause of death from infection. In order to evaluate physicians' adherence to hospital guidelines for CAP, an observational prospective study during two consecutive winter periods at an Irish teaching hospital was performed. A series of educational sessions on management of CAP was provided for medical staff at the end of the first year. Comparison of results showed significant improvement in the rate of blood culture sampling (p < .01), sputum sampling (p < .05), and combined blood culture and sputum sampling (p < .01). Length of antibiotic treatment was more appropriate in the second study year. Results indicate that antibiotic audit and educational interventions improve physicians' adherence to hospital guidelines.

Community-acquired pneumonia: defining quality care

BACKGROUND

Community-acquired pneumonia (CAP) is one of 3 initial conditions for which the Joint Commission for Accreditation of Healthcare Organizations and the Centers for Medicare & Medicaid Services have defined quality measures. Eight "core measures" of pneumonia care have been targeted for reporting by U.S. hospitals to facilitate performance monitoring.

METHODS

A review of the literature supporting the core measures was performed.

RESULTS

Indicators encouraging influenza vaccination and appropriate antibiotic selection had the most robust evidence. Rapid delivery of antibiotics also showed significant reduction in mortality, though the actual timing (4 versus 8 hours) varied between studies. Other measures, such as performance of blood cultures, pneumococcal vaccination, smoking cessation, and oxygenation assessment, demonstrated less obvious clinical benefit.

CONCLUSIONS

There is inherent value in setting standards of care for high-impact conditions such as CAP, but these standards should be chosen on the basis of high-quality research. Public reporting of the current measures is problematic, as it implies they represent best practices for CAP despite relatively weak evidence.

Comment évaluer, orienter et suivre un patient ayant une pneumonie aiguë communautaire ? Une exacerbation de bronchopneumopathie chronique obstructive ?

L'objectif de cette revue est de présenter une analyse bibliographique de la littérature de ces cinq dernières années concernant les pneumonies aiguës communautaires (PAC) et les exacerbations aiguës de bronchopneumopathies chroniques obstructives (EABPCO). La PAC et l'EABPCO sont des pathologies fréquentes grevées d'une mortalité et/ou morbidité encore élevée de nos jours. La connaissance des facteurs de risque d'évolution compliquée et l'identification des signes de gravité souvent liés au risque de mortalité permettent d'orienter le patient pour un traitement ambulatoire, en hospitalisation conventionnelle ou en secteur de réanimation ; des règles prédictives ont été établies dans ce sens. La littérature concernant les critères de sortie d'hospitalisation et le suivi des patients est plus pauvre.

Updated review of blood culture contamination

Blood culture contamination represents an ongoing source of frustration for clinicians and microbiologists alike. Ambiguous culture results often lead to diagnostic uncertainty in clinical management and are associated with increased health care costs due to unnecessary treatment and testing. A variety of strategies have been investigated and employed to decrease contamination rates. In addition, numerous approaches to increase our ability to distinguish between clinically significant bacteremia and contamination have been explored. In recent years, there has been an increase in the application of computer-based tools to support infection control activities as well as provide clinical decision support related to the management of infectious diseases. Finally, new approaches for estimating bacteremia risk which have the potential to decrease unnecessary blood culture utilization have been developed and evaluated. In this review, we provide an overview of blood culture contamination and describe the potential utility of a variety of approaches to improve both detection and prevention. While it is clear that progress is being made, fundamental challenges remain.

Assessment of analysis of urinary pneumococcal antigen by immunochromatography for etiologic diagnosis of community-acquired pneumonia in adults

The limitations of conventional microbiologic methods (CMM) for etiologic diagnosis of community pneumococcal pneumonia have made faster diagnostic techniques necessary. Our aim was to evaluate the usefulness of the immunochromatography (ICT) technique for detecting urinary Streptococcus pneumoniae antigen in the etiologic diagnosis of community-acquired pneumonias (CAP). This was a prospective study on in-patients with CAP in a tertiary hospital conducted from October 2000 to March 2004. Apart from using CMM to reach an etiologic diagnosis, we determined pneumococcal antigen in concentrated urine by ICT. We also determined the urinary pneumococcal antigen (UPA) content in patients from two control groups to calculate the specificity of the technique. One group was comprised of in-patients diagnosed with chronic obstructive pulmonary disease (COPD) or asthma, with respiratory infection, and without pneumonia; the other group included fractures. We studied 959 pneumonia patients and determined UPA content in 911 (95%) of them. We diagnosed the etiology of 253 cases (28%) using CMM; S. pneumoniae was the most common etiologic agent (57 cases). ICT analysis was positive for 279 patients (31%). Using this technique, the percentage of diagnoses of pneumococcal pneumonias increased by 26%, while the overall etiologic diagnosis increased from 28 to 49%. The technique sensitivity was 81%; the specificity oscillated between 80% in CAP with nonpneumococcal etiology and 99% for patients with fractures without infections. Determination of UPA is a rapid, simple analysis with good sensitivity and specificity, which increased the percentage of etiologic diagnoses. Positive UPA may persist in COPD patients with probable pneumococcal colonization or recent pneumococcal infections.

Blood cultures do not change management in hospitalized patients with community-acquired pneumonia

OBJECTIVES

To determine if blood cultures identify organisms that are not appropriately treated with initial empiric antibiotics in hospitalized patients with community-acquired pneumonia, and to calculate the costs of blood cultures and cost savings realized by changing to narrower-spectrum antibiotics based on the results.

METHODS

This was a retrospective observational study conducted in an urban academic emergency department (ED). Patients with an ED and final diagnosis of community-acquired pneumonia admitted between January 1, 2001, and August 30, 2003, were eligible when the results of at least one set of blood cultures obtained in the ED were available. Exclusion criteria included documented human immunodeficiency virus infection, immunosuppressive illness, chronic renal failure, chronic corticosteroid therapy, documented hospitalization within seven days before ED visit, transfer from another hospital, nursing home residency, and suspected aspiration pneumonia. The cost of blood cultures in all patients was calculated. The cost of the antibiotic regimens administered was compared with narrower-spectrum and less expensive alternatives based on the results.

RESULTS

A total of 480 patients were eligible, and 191 were excluded. Thirteen (4.5%) of the 289 enrolled patients had true bacteremia; the organisms isolated were sensitive to the empiric antibiotics initially administered in all 13 cases (100%; 95% confidence interval = 75% to 100%). Streptococcus pneumoniae and Haemophilus influenzae were isolated in 11 and two patients, respectively. The potential savings of changing the antibiotic regimens to narrower-spectrum alternatives was only 170 dollars.

CONCLUSIONS

Appropriate empiric antibiotics were administered in all bacteremic patients. Antibiotic regimens were rarely changed based on blood culture results, and the potential savings from changes were minimal.

Community-acquired pneumonia: a practical approach to management for the hospitalist

Community-acquired pneumonia (CAP) is common, and inpatient physicians should be familiar with the most current evidence about and guidelines for CAP management. Our conclusions and recommendations include: Streptococcus pneumoniae is the most common identified cause of CAP requiring hospitalization, whereas Legionella pneumophila is a common cause of severe CAP. The chest radiograph remains an essential initial test in the diagnosis of CAP and should be supplemented by blood cultures sampled prior to antibiotic therapy and sputum for gram stain and culture if a high-quality specimen can be rapidly processed. Once the diagnosis is made, the Pneumonia Severity Index (PSI) should be used to optimize the location of treatment and to provide prognostic information. Absent other mitigating factors, patients in PSI risk classes I, II, and III can safely be treated as outpatients. Hospitalized patients with CAP should be treated promptly with empiric antibiotics. Nonsevere pneumonia should be treated with a parenteral beta-lactam plus either doxycycline or a macrolide. Patients admitted to the intensive care unit should be treated with a beta-lactam plus either a macrolide or a fluoroquinolone as well as be evaluated for pseudomonal risk factors. Most patients with nonsevere CAP reach clinical stability in 2-3 days and should be considered for a switch to oral therapy and discharge shortly thereafter. Patients should receive pneumococcal vaccination, influenza vaccination, and tobacco cessation counseling prior to discharge if eligible. Multiple quality indicators are measured and publicly reported in the management of CAP, which provides hospitals with an opportunity to improve care processes and patient outcomes.

Clinical and bacteriologic efficacy of telithromycin in patients with bacteremic community-acquired pneumonia

This retrospective analysis was performed to determine the clinical and bacteriologic efficacy of the ketolide antibacterial telithromycin in patients with community-acquired pneumonia (CAP) with pneumococcal bacteremia. Patients 13 years old with radiologically confirmed CAP and a positive blood culture for Streptococcus pneumoniae at screening were analyzed from eight multicenter Phase III/IV clinical trials. In four open-label, non-comparative studies, patients received telithromycin 800 mg once daily for 7-10 days. In four randomized, controlled, double-blind, comparative studies, patients received telithromycin 800 mg once daily for 5-10 days or a comparator antimicrobial (amoxicillin 1000 mg three times daily, clarithromycin 500 mg twice daily, or trovafloxacin 200 mg once daily) for 7-10 days. In total, 118 patients (telithromycin, 94/1061 [8.9%]; comparator, 24/244 [9.8%]) had documented pneumococcal bacteremia. Those who were treated with telithromycin achieved a clinical cure rate of 90.2% (74/82, per-protocol population); S. pneumoniae was eradicated in 77/82 (93.9%) bacteremic patients who received telithromycin and 15/19 (78.9%) comparator-treated patients. Clinical cure was also observed among telithromycin-treated bacteremic patients who were infected with penicillin- or erythromycin-resistant strains of S. pneumoniae (5/7 and 8/10, respectively). In conclusion, telithromycin achieves high clinical and bacteriologic cure rates in CAP patients with pneumococcal bacteremia.

Neumonías comunitarias graves del adulto

Las neumonías agudas comunitarias son causa frecuente de hospitalización y mortalidad. El reconocimiento inmediato de las formas graves según criterios simples, clínicos, radiológicos y de laboratorio, es una etapa esencial para un tratamiento rápido en el servicio de reanimación con el fin de controlar los fallos orgánicos. La obtención de muestras apropiadas para realizar estudios microbiológicos precede al tratamiento antibiótico, que se debe instaurar con rapidez después de diagnosticar la neumonía. Pese a las técnicas de identificación, sólo la mitad de las neumonías se documentan adecuadamente. El tratamiento antibiótico, en principio empírico, integra los gérmenes patógenos, tanto extracelulares como intracelulares, que producen neumonías con mayor frecuencia; siempre debe ser activo contra el neumococo, la bacteria implicada más a menudo. La asociación de un betalactámico y un macrólido o una fluoroquinolona es la que mejor responde a este objetivo. En las recomendaciones más comunes, las fluoroquinolonas activas contra los neumococos sustituyen a los fármacos precedentes. En el caso excepcional de los pacientes con factores de riesgo especiales, el tratamiento empírico debe tener en cuenta Pseudomonas aeruginosa. La gravedad de parte de las neumonías comunitarias justifica el que se recurra a tratamientos complementarios. Se debe evaluar de nuevo el tratamiento antibiótico en las 72 horas siguientes a su instauración, a fin de valorar su eficacia, adaptar el tratamiento en caso necesario y simplificarlo. El mantenimiento de antibióticos de amplio espectro expone al paciente a efectos secundarios y contribuye a producir resistencias bacterianas. En cuanto a las neumonías neumocócicas, las fluoroquinolonas activas contra el neumococo podrían representar una alternativa en caso de que el neumococo desarrolle resistencia a los betalactámicos. La mortalidad persistente de las neumonías sigue siendo notable. Esto debe fomentar la mejora del tratamiento inicial y la búsqueda de nuevas opciones terapéuticas.

The JRS guidelines for the management of community-acquired pneumonia in adults: an update and new recommendations

Community-acquired pneumonia (CAP) continues to be a major medical problem. Since CAP is a potentially fatal disease, early appropriate antibiotic treatment is vital. Epidemiologic studies have shown that in the combined cause-of-death category, pneumonia ranks fourth as the leading cause of death in Japan. Therefore, the Japanese Respiratory Society (JRS) provided guidelines for the management of CAP in adults in 2000. Because of evolving resistance to antimicrobials and advances in diagnosis, treatment and prevention of CAP, it is felt that an update should be provided every three years so that important developments can be highlighted and pressing questions can be answered. Thus, the guidelines committee updated its guidelines in 2005. The basic policy and main purposes of the JRS guidelines include; 1) prevention of bacterial resistance and 2) effective and long-term use of medical resources. The JRS guidelines have recommended the exclusion of potential and broad spectrum antibiotics, fluoroquinolones and carbapenems, from the list of first-choice drugs for empirical treatment. In addition, the JRS guidelines have recommended short-term usage of antibiotics of an appropriate dose and pathogen-specific treatment using rapid diagnostic methods if possible.

Pneumonia in hospitalized children

Pneumonia is one of the most common infections in the pediatric age group and one of the leading diagnoses that results in overnight hospital admission for children. Various micro-organisms can cause pneumonia, and etiologies differ by age. Clinical manifestations vary, and diagnostic testing is frequently not standardized. Hospital management should emphasize timely diagnosis and prompt initiation of antimicrobial therapy when appropriate. Issues of particular relevance to inpatient management are emphasized in this article.

Do emergency department blood cultures change practice in patients with pneumonia?

STUDY OBJECTIVE

Although it is considered standard of care to obtain blood cultures on patients hospitalized for pneumonia, several studies have questioned the utility and cost-effectiveness of this practice. The objective of this study is to determine the impact of emergency department (ED) blood cultures on antimicrobial therapy for patients with pneumonia.

METHODS

We performed a prospective, observational, cohort study of consecutive adult (age > or =18 years) patients treated at an urban university ED between February 1, 2000 and February 1, 2001. Inclusion criteria were radiographic evidence of pneumonia, clinical evidence of pneumonia, and blood culture obtained. Blood cultures were classified as positive, negative, or contaminant based on previously established criteria. Additionally, data were collected on antimicrobial sensitivities, empiric antibiotic therapy, antibiotic changes, and reasons for changes.

RESULTS

There were 3,926 ED visits with blood cultures obtained for any reason, of which 3,762 (96%) were available for review. Of these, 414 of 3,762 (11%) patients met pneumonia study inclusion criteria, and blood cultures identified 29 of 414 (7.0%) patients with true bacteremia. In the 414 patients, blood culture results altered therapy for 15 patients (3.6%) with suspected pneumonia, of which 11 (2.7%) patients had their coverage narrowed; only 4 (1.0%) patients had their coverage broadened because of resistance to empiric therapy. For the 11 patients with bacteremia whose therapy was not altered, culture results actually supported narrowing therapy in 8 (1.9%) cases, but this was not done.

CONCLUSION

Blood cultures rarely altered therapy for patients presenting to the ED with pneumonia. More discriminatory blood culture use may potentially reduce resource utilization.

Quality of antibiotic use for lower respiratory tract infections at hospitals: (how) can we measure it?

BACKGROUND

To assess and improve the quality of antibiotic use in patients with community-acquired pneumonia (CAP) and acute exacerbation of chronic bronchitis or chronic obstructive pulmonary disease (AECB), a valid set of quality indicators is required. This set should also be applicable in practice.

METHODS

Guidelines and literature were reviewed to derive potential indicators for quality of antibiotic use in treating hospitalized patients with lower respiratory tract infection (LRTI). To assess the evidence base of each indicator, a literature review was performed. Grade A recommendations were considered valid. For grade B-D recommendations, an expert panel performed a consensus procedure on the indicator's relevance to patient health, reduction of antimicrobial resistance, and cost containment. To test applicability in practice, feasibility, opportunity for improvement, reliability, and case-mix stability were determined for a data set of 899 hospitalized patients with LRTI.

RESULTS

None of the potential indicators from guidelines and literature were supported by grade A evidence. Nineteen indicators were selected by consensus procedure (12 indicators for CAP and 7 indicators for AECB). Lack of feasibility and of opportunity for improvement led to the exclusion of 4 indicators. A final set of 15 indicators was defined (9 indicators for CAP and 6 indicators for AECB).

CONCLUSIONS

A valid set of quality indicators for antibiotic use in hospitalized patients with LRTI was developed by combining evidence and expert opinion in a carefully planned procedure. Subjecting indicators to an applicability test is essential before using them in quality-improvement projects. In our demonstration setting, 4 of the 19 indicators were inapplicable in practice.

Pneumonies communautaires graves de l'adulte

Les pneumonies aiguës communautaires sont des causes fréquentes d'hospitalisation et de mortalité. La reconnaissance immédiate des formes sévères sur des critères simples, cliniques, radiologiques et biologiques, est une étape importante pour une prise en charge rapide en réanimation afin de contrôler les défaillances d'organes. Les prélèvements appropriés microbiologiques précèdent l'antibiothérapie qui doit être instituée très rapidement après le diagnostic de pneumonie. Malgré les techniques d'identification, la moitié seulement des pneumonies sont documentées. Cette antibiothérapie, initialement probabiliste, intègre les germes pathogènes les plus souvent responsables, extra- et intracellulaires ; elle doit toujours être active sur le pneumocoque, bactérie la plus fréquente. L'association d'une β-lactamine et d'un macrolide ou d'une fluoroquinolone répond le mieux à cet objectif. Les fluoroquinolones actives sur le pneumocoque se sont substituées aux précédentes dans les plus récentes recommandations. Dans le cas exceptionnel des patients ayant des facteurs de risque particuliers, le traitement probabiliste doit prendre en compte Pseudomonas aeruginosa. La gravité d'une partie des pneumonies communautaires justifie le recours à des traitements adjuvants. L'antibiothérapie doit être réévaluée dans les 72 heures dans le but d'apprécier son efficacité, de l'adapter éventuellement et de la simplifier. La poursuite des antibiotiques à large spectre expose le patient à des effets indésirables et contribue aux résistances bactériennes. Pour les pneumonies dues au pneumocoque, les fluoroquinolones actives sur le pneumocoque pourront constituer une alternative en cas d'évolution importante des résistances du pneumocoque aux β-lactamines. La mortalité persistante des pneumonies reste sévère. Ceci doit stimuler l'amélioration de la prise en charge initiale et faire rechercher de nouvelles thérapeutiques.

Processes of care for community-acquired pneumonia

Clinical and economic outcomes in hospitalized patients with CAP directly are related to the way that certain processes of care are executed at the local-hospital level. For each process of care, a clear and evidence-based recommended course of action should be stated. Having an unambiguous action plan helps to develop process-of-care indicators and to educate healthcare workers. Improving processes of care is a secure way to improve outcomes in hospitalized patients with CAP.

New developments in the diagnosis of bloodstream infections

New techniques have emerged for the detection of bacteria in blood, because the blood culture as gold standard is slow and insufficiently sensitive when the patient has previously received antibiotics or in the presence of fastidious organisms. DNA-based techniques, hybridisation probes, and PCR-based detection or protein-based detection by mass spectroscopy are aimed at rapid identification of bacteria and provide results within 2 h after the first signal of growth in conventional blood cultures. Also, detection of microorganisms directly in blood by pathogen-specific or broad-range PCR assays (eubacterial or panfungal) shows promising results. Interpretation is complex, however, because of detection of DNA rather than living pathogens, the risk of interfering contamination, the presence of background DNA in blood, and the lack of a gold standard. As these techniques are emerging, clinical value and cost-effectiveness have to be assessed. Nevertheless, molecular assays are expected eventually to replace the current conventional microbiological techniques for detection of bloodstream infections.

Diagnosis of infection in sepsis: An evidence-based review

OBJECTIVE

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for the diagnosis of infection in sepsis that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis.

DESIGN

The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee.

METHODS

The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591.

CONCLUSIONS

Obtaining a precise bacteriological diagnosis before starting antibiotic therapy is, when possible, of paramount importance for the success of therapeutic strategy during sepsis. Two to three blood cultures should be performed, preferably from a peripheral vein, without interval between samples to avoid delaying therapy. A quantitative approach is preferred in most cases when possible, in particular for catheter-related infections and ventilator-associated pneumonia. Diagnosing community-acquired pneumonia is complex, and a diagnostic algorithm is proposed. Appropriate samples are indicated during soft tissue and intraabdominal infections, but cultures obtained through the drains are discouraged.

Management of community-acquired pneumonia in persons with spinal cord injury

STUDY DESIGN

Retrospective case series.

OBJECTIVES

Respiratory disorders are the leading cause of death in persons with spinal cord injury (SCI), but the epidemiology and medical management of pneumonia in persons with chronic SCI is not well characterized. We describe the clinical presentation of persons with SCI with community-acquired pneumonia (CAP), characterize its management and compare practice to recommendations for CAP in the general population.

SETTING

Three United States Veterans Affairs Medical Centers with specialized SCI services.

METHODS

Chart abstraction was performed for all persons with chronic SCI seen at participating centers for treatment of CAP during a 2-year period. Collected data included presenting signs and symptoms, laboratory and imaging results, initial antibiotic therapy, secretion mobilization techniques, in-patient vs outpatient management, length of stay, and mortality.

RESULTS

In all, 41 persons with SCI received treatment for CAP during the study period. A total of 32 (78.0%) patients were admitted for treatment; two (4.8%) required intubation and mechanical ventilation. Initial antibiotic coverage met guideline recommendations for only half of inpatients and infrequently provided adequate antipseudomonal coverage. Microbiologic testing was performed on 26 cases (63.4%) and demonstrated a specific pathogen in only five cases (12.2% of total). Three cases (7.3%) died during treatment for CAP, and 16 (42.1%) of 38 CAP survivors died within a median follow-up of 3 years.

CONCLUSION

The majority of chronic SCI patients who present to specialized SCI centers with CAP are admitted for treatment. Short-term mortality is comparable to CAP in the general population.

The changing face of pleural empyemas in children: epidemiology and management

OBJECTIVE

Empyema remains a significant cause of morbidity in children. This study evaluates the changes that have affected the outcome in children with pleural empyema, including the emergence of resistant organisms, the introduction of the pneumococcal conjugate vaccine, and earlier treatment with video-assisted thoracoscopy (VATS).

METHODS

A retrospective chart review was performed on all patients who were discharged with a diagnosis of empyema and community-acquired pneumonia over a 10-year period (1993-2002) at Texas Children's Hospital in Houston, Texas. Data collected included demographic information, clinical presentation, radiographic studies, laboratory data including culture results, and hospital course.

RESULTS

A total of 230 charts were available for review. The mean age of the patients was 4.0 +/- 3.6 years. Of the pleural fluid cultures performed, 32% (69 of 219) were positive. An additional 27 patients had a cause identified by blood culture. The first penicillin-nonsusceptible Streptococcus pneumoniae was identified in 1995, and the first methicillin-resistant Staphylococcus aureus was identified in 1998. After the universal use of the pneumococcal conjugate vaccine, 3 major changes have occurred (1999-2000 vs 2001-2002): 1) the number of patients admitted with empyema (per 10 000 admissions) has decreased from 23 to 12.6; 2) the prevalence of S pneumoniae has decreased from 66% (29 of 44) to 27% (4 of 15); and 3) S aureus has become the most common pathogen isolated (18% vs 60%), with 78% of those being methicillin resistant. The use of early VATS (<48 hours after admission) versus late VATS (>48 hours after admission) significantly decreased the length of hospitalization (11.49 +/- 6.56 days vs 15.18 +/- 8.62 days).

CONCLUSIONS

The microbiologic cause of empyema has changed with an increasing incidence of S aureus, particularly methicillin-resistant S aureus. The use of VATS for initial therapy of empyema results in decreased duration of fever and length of hospitalization.

Community-acquired pneumonia in casualty

PURPOSE OF REVIEW

Community-acquired pneumonia, because of its substantial treatment costs, incidence, and mortality, is an aggressively researched diagnosis. In this review, we highlight new developments in the diagnosis, etiology, pathophysiology, treatment, and prevention of community-acquired pneumonia published since April 2002.

RECENT FINDINGS

The combined end points of improved patient care and conservation of health care resources have prompted several studies examining current professional society community-acquired pneumonia guidelines. In general, patients treated with the recommended third-generation cephalosporin and macrolide or an antipneumococcal fluoroquinolone when indicated have fared better, including reduced overall costs, inpatient days, and mortality, than those receiving alternative treatments. Etiologic identification efforts by traditional methods, blood and sputum cultures, are being questioned owing to poor success rates and, even when positive, are being underused or ignored in antibiotic selection and patient management. Newer diagnostic tests are becoming commercially available, along with tests for biologic markers that have been only recently identified as contributors to, or prognosticators of, community-acquired pneumonia. Because antibiotic resistance remains a major obstacle to successful patient treatment, prevention or mitigation of community-acquired pneumonia is gaining increasing popularity through more aggressive pneumococcal and influenza vaccination of at risk groups, even before hospital discharge from a community-acquired pneumonia admission.

SUMMARY

Although prevention is our best defense, current community-acquired pneumonia treatment guidelines are effective for treatment and cost containment. However, they should be scrutinized in light of clinical utilization data now entering the literature regarding their testing recommendations. Providers should consider encouraging focused culturing of sicker patients and those with significant comorbidities.

Predicting Bacteremia in Patients with Community-Acquired Pneumonia

It is recommended that blood cultures be performed on all patients admitted to the hospital with pneumonia. Questions regarding the cost-effectiveness of this practice have emerged. We used data on 13,043 Medicare patients hospitalized with pneumonia to determine predictors of bacteremia. Predictors included recent antibiotic treatment, liver disease, and three vital-sign and three laboratory abnormalities. Patients were stratified into three groups on the basis of the likelihood of bacteremia. We then created a decision support tool that recommends performing no blood cultures on patients with low likelihood of bacteremia, one blood culture on patients with moderate likelihood of bacteremia, and two blood cultures on patients with higher likelihood of bacteremia. This tool was then applied to a validation cohort of 12,771 patients with pneumonia. Use of the decision support tool would result in 38% fewer blood cultures being performed when compared with the standard practice of performing two blood cultures for each patient and identified 88 to 89% of patients with bacteremia. A simplified tool performed similarly overall but was less sensitive than was the first tool among pneumonia severity index Class V patients. These tools may allow clinicians to target patients with pneumonia in whom blood cultures are most likely to yield a pathogen.

Blood cultures in ambulatory patients who are discharged from emergency with community-acquired pneumonia

OBJECTIVES

To determine the factors that predict whether or not ambulatory patients with community-acquired pneumonia (CAP) treated in an emergency room (ER) setting will have blood cultures drawn and the factors that predict a positive blood culture.

METHODS

Prospective observational study of all patients with a diagnosis of CAP, as made by an ER physician, who presented to any of seven Edmonton-area ERs over a two-year period.

RESULTS

Seven hundred ninety-three (19.2%) of 4124 patients with CAP had blood cultures drawn. The site-specific blood culture rates ranged from 7.8% to 25% (P<0.001); 41 of 793 (5.1%) were positive. Streptococcus pneumoniae accounted for 58.5% of the isolates while Staphylococcus aureus and Escherichia coli each accounted for 14.6%, or six patients each. Only two of the 24 patients with S pneumoniae bacteremia were subsequently admitted to hospital while all six of the patients with S aureus were admitted. Only one of the six patients with E coli bacteremia was treated at home. No factors were predictive of positive blood cultures on multivariate analysis.

CONCLUSIONS

Physicians are selective in ordering blood cultures on patients with ambulatory pneumonia who present to an ER, and the positivity rate of 5.1% is quite high. No factors are predictive of positive blood cultures on multivariate analysis, thus clinical judgment has to prevail in the decision to perform blood cultures. Breakthrough bacteremia can occur with microorganisms susceptible to the antibiotics that the patient is receiving.

Community-acquired pneumonia

This seminar reviews important features and management issues of community-acquired pneumonia (CAP) that are especially relevant to immunocompetent adults in light of new information about cause, clinical course, diagnostic testing, treatment, and prevention. Streptococcus pneumoniae remains the most important pathogen; however, emerging resistance of this organism to antimicrobial agents has affected empirical treatment of CAP. Atypical pathogens have been quite commonly identified in several prospective studies. The clinical significance of these pathogens (with the exception of Legionella spp) is not clear, partly because of the lack of rapid, standardised tests. Diagnostic evaluation of CAP is important for appropriate assessment of severity of illness and for establishment of the causative agent in the disease. Until better rapid diagnostic methods are developed, most patients will be treated empirically. Antimicrobials continue to be the mainstay of treatment, and decisions about specific agents are guided by several considerations that include spectrum of activity, and pharmacokinetic and pharmacodynamic principles. Several factors have been shown to be associated with a beneficial clinical outcome in patients with CAP. These factors include administration of antimicrobials in a timely manner, choice of antibiotic therapy, and the use of a critical pneumonia pathway. The appropriate use of vaccines against pneumococcal disease and influenza should be encouraged. Several guidelines for management of CAP have recently been published, the recommendations of which are reviewed.

Evaluation of outcomes in community-acquired pneumonia: a guide for patients, physicians, and policy-makers

Community-acquired pneumonia (CAP) is a key target for research and quality improvement in acute medicine. However, many of the outcome measures used in prognostic and antibiotic studies are not validated and do not capture features of outcome that are important to patients. Substitutes for traditional outcome measures include a recently validated patient-based symptom questionnaire (the CAP-Sym) and process-of-care measures. The interpretation of outcomes also depends on the quality of the study design and methods used. This paper discusses the advantages and disadvantages of outcome, process-of-care, and economic measures in CAP and the interpretation of these measures in randomised and observational studies. A core set of measures for use in clinical CAP research and performance measurement is proposed.