Search

PURPOSE OF REVIEW This article reviews recent literature and experience in the diagnosis of nonresolving and slowly resolving pneumonia as it pertains to malignancy. RECENT FINDINGS Malignancy must be considered as an important cause of pneumonia that resolves slowly or has incomplete resolution. Airway obstruction is more common than malignant infiltration as a cause of pneumonia that does not resolve appropriately. Infection due to resistant or unusual organisms must also be considered in the differential diagnosis. SUMMARY Nonresolving pneumonia remains an important clinical challenge. Bronchoscopic evaluation in conjunction with computed tomography and PET scanning is still the most important technique for diagnosis.

PURPOSE Long-term oxygen therapy (LTOT) is widely used to treat chronic obstructive pulmonary disease (COPD) and other conditions with severe hypoxemia, imposing a large financial burden on the American health care system. METHODS To better understand oxygen prescription and its use in a multiethnic community hospital, we completed a prospective, observational study with a survey design in our multicultural population to better recognize patient understanding of oxygen indications and utilization. RESULTS The survey was conducted at three outpatient pulmonary clinics. Among the 94 respondents (42% men and 58% women; age 71.8 ± 13 yr), 64% were current or former smokers. Sixty-one percent had primary diagnoses other than COPD, most commonly interstitial lung disease and congestive heart failure. One-third used oxygen for

Purpose of review The current article reviews recent literature and summarizes the current understanding, diagnosis, risk, predictors, and management of radiation pneumonitis. Recent findings We discuss the different parameters that contribute to radiation toxicity, the potential biomarkers that predict the risk, and mitigators of radiation pneumonitis. Summary Radiotherapy aims to provide care and a better quality of life in cancer patients however with complications. Radiation pneumonitis is important to recognize to appropriately plan and care for this population.

Multiple pulmonary nodules are a common finding especially with the implementation of lung cancer screening. Available guidelines address the management of solitary pulmonary nodules. The management of the multiple pulmonary nodules would differ based on the characteristic of the nodules, their distribution, and the history of the patients as well.Most of the recent publications on multiple pulmonary nodules consist of individual case reports or case series. Robust population studies are lacking.In this article, we propose an approach for management of multiple pulmonary nodules which needs to be validated.

This article reviews the current literature for the purpose of developing a practical approach for the diagnosis and management of primary tracheal tumors.Because of nonspecific symptoms, tracheal tumors remain a diagnostic challenge. Currently available management strategies are not being optimally utilized due to lack of physician awareness and knowledge. The use of newer diagnostic modalities has increased diagnostic accuracy resulting in earlier detection in recent years. This review describes currently available diagnostic modalities along with relatively newer ones such as virtual bronchoscopy, anatomic Optical Coherence Tomography, spectroscopic techniques, and endobronchial ultrasonography. We will review and discuss management strategies including surgical options, adjuvant therapies, and interventional pulmonary techniques including their role in palliation.Early detection along with improved surgical and interventional pulmonology techniques has led to a decline in the death rates from tracheal cancer in recent years. However, further studies are required to define the role of chemotherapeutic agents, combination therapies, and novel techniques such as tracheal transplantation, in the management of primary tracheal tumors. More robust evidence-based studies are needed to provide evidence for clinical practice guidelines for the treatment of primary tracheal tumors.

Purpose of review Despite the fact that primary pulmonary lymphoma (PPL) is a rare lung tumour, significant advances addressing clinical features, histological diagnosis, prognostic criteria and therapeutic management of this disease have been made within the past decade. Recent findings Monoclonality and phenotyping of alveolar lymphocytes are suggestive of mucosa-associated lymphoid tissue (MALT). Detection of MALT-1 gene rearrangements in bronchoalveolar fluid cells using fluorescence in-situ hybridization techniques helps to confirm the diagnosis of MALT PPL. Fine needle aspiration-computed tomography guided biopsies as well as transbronchial/cryobiopsies provide adequate tissue material for histological evaluation. Recent publications also provide a better appreciation of newer chemotherapeutic approaches, including fludarabine and mitoxantrone with or without ritubximab for the treatment of MALT, as well as complete surgical resection if local disease is present. Prognostic factors influencing survival and optimal therapy for MALT have not been well defined, but the use of tumour microvascular density appears promising. Summary This review outlines the implications of recent findings for clinical practice and research progress of PPL. Larger, multicentre and well designed studies are imperative to optimize the current diagnostic and therapeutic approach for this disease.

The Standards for the Diagnosis and Treatment of Patients with COPD document 2004 updates the position papers on chronic obstructive pulmonary disease (COPD) published by the American Thoracic Society (ATS) and the European Respiratory Society (ERS) in 1995 1, 2. Both societies felt the need to update the previous documents due to the following. 1) The prevalence and overall importance of COPD as a health problem is increasing. 2) There have been enough advances in the field to require an update, especially adapted to the particular needs of the ATS/ERS constituency. 3) It allows for the creation of a “live” modular document based on the web; it should provide healthcare professionals and patients with a user friendly and reliable authoritative source of information. 4) The care of COPD should be comprehensive, is often multidisciplinary and rapidly changing. 5) Both the ATS and the ERS acknowledge the recent dissemination of the Global Initiative of Obstructive Lung Disease (GOLD) 3 as a major worldwide contribution to the battle against COPD. However, some specific requirements of the members of both societies require adaptation of the broad GOLD initiative. Those requirements include specific recommendations on oxygen therapy, pulmonary rehabilitation, noninvasive ventilation, surgery in and for COPD, sleep, air travel, and end-of-life. In addition, special emphasis has been placed on issues related to the habit of smoking and its control. ### Goals and objectives The main goals of the updated document are to improve the quality of care provided to patients with COPD and to develop the project using a disease-oriented approach. To achieve these goals, both organisations have developed a modular electronic web-based document with two components. 1) A component for health professionals that intends to: raise awareness of COPD; inform on the latest advances in the overall pathogenesis, diagnosis, monitoring and management of COPD; and …

Background: While the optimal role of spiral CT angiography (CTA) in the diagnosis of pulmonary embolism (PE) remains controversial, this technology is already being widely utilized in the community setting. Objectives: To assess the impact CTA has had on angiography utilization rates and the overall diagnostic rate of PE. Methods: All patients evaluated for PE during a 4-year period were studied. PE was defined as either a high-probability V/Q scan, a positive conventional angiogram, or a CTA with emboli in the segmental or larger pulmonary vessels. Diagnostic rates of PE per 1,000 hospital admissions were determined and analyzed for time periods before and after the introduction of CTA. CT reports were compared with their concurrent chest radiograph (CXR) reports and additional findings that were not apparent on CXR were abstracted. Results: The diagnostic rate of PE per 1,000 hospital admissions was 1.8 prior to the introduction of CTA and increased to 2.8 per 1,000 admissions after the introduction of CTA (p < 0.0001). Total costs for diagnostic testing per PE diagnosis made went from $2,518 to $2,572. While the number of PE diagnosed by V/Q scan remained constant, the number of PE diagnosed by conventional angiography decreased while the number diagnosed by CTA increased. In patients with intermediate probability V/Q scan results, the percentage of patients receiving subsequent angiography (conventional or CTA) increased from 17 to 26% (p = 0.043). When conventional angiography was performed, CT imaging of the chest still had to be ordered for other reasons 38% of the time. Additional information was obtained in 78% of cases when CTA was performed. Conclusions: Increased utilization of CTA was associated with an increase in angiography utilization rates and diagnostic rates of PE, was cost effective, and often provided additional, useful, and unanticipated diagnostic information.

A 60-year-old man undergoes chest radiography during an evaluation for pneumonia, and a 1.5-cm nodule is discovered. He is a heavy smoker but has no history of lung disease. The results of a physical examination are unremarkable. How should he be evaluated?

Pneumonia that fails to resolve after 10 to 14 days of antibiotic therapy can lead physicians to call for consultation or unnecessary invasive diagnostic procedures. Understanding the infectious and noninfectious causes of pneumonia and their normal times to resolution is enormously helpful in the judicious evaluation of and timely intervention in this very challenging condition.

Intensive care units (ICUs) comprise up to 10% of all hospital beds in the United States and consume as much as 34% of hospital resources. This is over 1% of the gross domestic product (GDP) 7 or nearly $64 billion per year. 15 There are between 50,000 and 100,000 patients in an ICU on any given day in the United States and the demand for critical care beds will continue to grow as the population ages. 21 Managed care and reduced reimbursement for services have forced hospitals to focus on these high-cost areas and reassess the best approach to improving patient care outcomes in the most cost-effective way. 8,9,11 This article addresses various staffing and organizational models that are either being introduced or considered for intermediate or long-term implementation. Recent experience at the authors' institution has resulted in a critical care model that offers 24 hours per day, 7 days a week on-site coverage by qualified intensivists and maintains significant input from primary care physicians and other specialists caring for the patient. This model is outlined here. There are few evidence-based outcome studies available to guide health care delivery. 26 The authors describe the advantages to an organized multidisciplinary team approach to critical care delivery and review the existing data to support this approach.

The finding of a solitary pulmonary nodule (SPN) on a chest radiograph is a common problem in pulmonary medicine. SPNs are seen in 0.09 to 0.2% of chest radiographs and are caused by a variety of conditions, ranging from benign granulomas to lung cancer (1–3). Because solitary nodules are often malignant and because 5-yr survival after resection of a solitary bronchogenic carcinoma is 40 to 80%, it is important to promptly identify malignant nodules to ensure optimal treatment (4, 5). Similarly, it is important to avoid the morbidity and mortality associated with thoracotomy in patients with benign disease. Therefore, the goal of the evaluation and management of solitary pulmonary nodules is to promptly identify and bring to surgery all patients with operable malignant nodules while avoiding thoracotomy in patients with benign nodules. Traditional approaches have emphasized assessment of the probability of malignancy, the so-called Bayesian approach. The Bayesian approach estimates the prevalence of malignancy in the population, assesses risk factors predictive of malignancy as demonstrated by history and chest radiograph, and selects a management strategy based on the adjusted probability of malignancy. The development of new diagnostic tests and surgical techniques requires that this traditional approach be reevaluated. This commentary will focus on the role of newer imaging methods in this process and on strategies for SPNs of indeterminate origin.

Infection with either Streptococcus sanguis or Streptococcus pneumoniae type 25 causes acute pneumonitis in rats. Pneumonia caused by S. sanguis resolves over the course of 8 d, whereas pneumonia caused by S. pneumoniae type 25 progresses to fibrosis. To examine the role of apoptosis in these models, we performed assays with the terminal deoxynucleotidyltransferase-uridine nucleotide end-labeling technique on tissue sections from rat lungs at various times, and quantified the results with image analysis. Apoptosis was a feature of both the acute and resolving stages of pneumonia. The pattern and extent of apoptosis were similar in both models during the acute stage, and the number of apoptotic nuclei increased in both models through 4 d after infection. Although there were differences in the cellular pattern of apoptosis after 2 d and 4 d of infection, the extent of apoptosis was the same in both models. After 8 d, major differences were observed. In the resolving model, apoptosis was limited primarily to an abscess in the base of the lung. In the nonresolving model, apoptosis was persistent. We also found that cyclin-dependent kinase-5 expression is upregulated during apoptosis induced by bacterial infection. These data indicate that the location and timing of apoptosis may determine whether pneumonia resolves or progresses to fibrosis.

We hypothesized that a "closed" intensive care unit (ICU) was more efficient that an "open" one. ICU admissions were retrospectively analyzed before and after ICU closure at one hospital; prospective analysis in that ICU with an open ICU nearby was done. Illness severity was gauged by the Mortality Prediction Model (MPM0). Outcomes included mortality, ICU length of stay (LOS), hospital LOS, and mechanical ventilation (MV). There were no differences in age, MPM0, and use of MV. ICU and hospital LOS were lower when "closed" (ICU LOS: prospective 6.1 versus 12.6 d, p < 0.0001; retrospective 6.1 versus 9.3 d, p < 0.05; hospital LOS: prospective 19.2 versus 33.2 d, p < 0.008; retrospective 22.2 versus 31.2 d, p < 0.02). Days on MV were lower when "closed" (prospective 2.3 versus 8.5 d, p < 0.0005; retrospective 3.3 versus 6.4 d, p < 0.05). Pooled data revealed the following: MV predicted ICU LOS; ICU organization and MPM0 predicted days on MV; MV and ICU organization predicted hospital LOS; mortality predictors were open ICU (odds ratio [OR] 1.5, p < 0.04), MPM0 (OR 1.16 for MPM0 increase 0.1, p < 0.002), and MV (OR 2.43, p < 0.0001). We conclude that patient care is more efficient with a closed ICU, and that mortality is not adversely affected.

All forms of aerobic life are faced with the threat of oxidation from molecular oxygen (O2) and have evolved antioxidant defenses to cope with this potential problem. However, cellular antioxidants can become overwhelmed by oxidative insults, including supraphysiologic concentrations of O2 (hyperoxia). Oxidative cell injury involves the modification of cellular macromolecules by reactive oxygen intermediates (ROI), often leading to cell death. O2 therapy, which is a widely used component of life-saving intensive care, can cause lung injury. It is generally thought that hyperoxia injures cells by virtue of the accumulation of toxic levels of ROI, including H2O2 and the superoxide anion (O−2), which are not adequately scavenged by endogenous antioxidant defenses. These oxidants are cytotoxic and have been shown to kill cells via apoptosis, or programmed cell death. If hyperoxia-induced cell death is a result of increased ROI, then O2 toxicity should kill cells via apoptosis. We studied cultured epithelial cells in 95% O2 and assayed apoptosis using a DNA-binding fluorescent dye, in situ end-labeling of DNA, and electron microscopy. Using all approaches we found that hyperoxia kills cells via necrosis, not apoptosis. In contrast, lethal concentrations of either H2O2 or O−2 cause apoptosis. Paradoxically, apoptosis is a prominent event in the lungs of animals injured by breathing 100% O2. These data indicate that O2 toxicity is somewhat distinct from other forms of oxidative injury and suggest that apoptosis in vivo is not a direct effect of O2.

Community-acquired pneumonia is an important public health concern and a recent focus of clinical practice guidelines. What has become clear from this renewed focus of attention is that a subgroup of patients with community-acquired pneumonia have severe disease with a differing spectrum of pathogens and prognosis. This article reviews the definition, bacteriology, diagnostic approach, and treatment of patients categorized as having severe community-acquired pneumonia. Although some of what is discussed is controversial and the literature in this area continues to expand, we focus on an evidence-based approach to this clinical problem.

Clinical and radiologic signs and symptoms of gram-negative infections are often muted or obscured by a concurrent disease, and therefore, are not reliable for predicting the infecting organisms. Thus, initial therapy is nearly always empiric and based on the clinician's judgment that a patient's pneumonia is likely to be caused by particular pathogens. The choice of an appropriate regimen requires careful consideration of the extent and severity of coexisting illness and debilitation, the severity of the pneumonia, and the level of care required.

The elderly are more susceptible to pneumonia and more likely to die from this infection than younger populations. Older patients with pneumonia requiring hospitalization are more likely to develop complications necessitating longer hospital stays. This article focuses on features of common lower respiratory tract infections and physiologic and immunologic characteristics of elderly patients that might obscure classic clinical presentation of pneumonia. Treatment factors unique to elderly patients with severe pneumonia are also discussed.

Monoclonal antibodies directed against the endotoxins produced by gram-negative organisms have been developed for the treatment of patients with sepsis. Phase 3 clinical trials in which two of these agents, E5 and HA-1A, have been evaluated have suggested possible benefit in terms of improved survival and reversal of organ dysfunction for certain subgroups. Since monoclonal antibodies are expected to be expensive, cost-effectiveness analysis is necessary to assess the joint clinical and economic impact. Cost-effectiveness studies based on the clinical data from these phase 3 trials have suggested that monoclonal antibodies may represent a cost-effective approach to the treatment of sepsis. However, an increase in the number of questions concerning the clinical efficacy of these agents and their ultimate impact on survival mandates the need for further clinical and economic investigation.

Pneumonia is both more prevalent in the elderly and more severe. This article reviews the approach to nonresolving or slowly resolving pneumonia in the elderly. Specific attention will be given to the natural history of commonly occurring pneumonias in this age group, related host defense impairments, unusual infectious causes of slowly resolving pneumonia, and noninfectious mimics of pneumonia.

anorexia. Leptin, a 167 amino-acid protein synthesized and secreted by white adipose tissue, is a component of a lipostatic signaling pathway that alters energy balance by central and peripheral mechanisms. In this study, the authors investigated the relationship of plasma leptin to both inflammation and energy balance in COPD patients (27 with emphysema and 15 with chronic bronchitis as classified by high-resolution CT). They employed both a cross-sectional and cohort prospective design. In the cross-sectional study, the relationship between the concentrations of plasma leptin and soluble tumor necrosis factor receptors 55 and 75 was examined. A significant correlation was found between leptin and tumor necrosis factor receptor 55 levels in patients with emphysema but not in patients with chronic bronchitis. In the prospective study, an inverse relationship between plasma leptin levels, baseline dietary intake, and response to nutritional therapy was reported. These results indicate leptin levels may be influenced by circulating cytokines, and that circulating leptin levels may, in turn, alter the patients’ ability to respond to nutritional intervention.

Critical care is an important consideration in the current health care debate and with good reason. Many citizens question the enormous expenditures incurred in the intensive care unit (ICU), along with the rationale for prolonged and expensive treatment for patients for whom survival is a remote possibility. An estimated 1% of our entire gross domestic product (GDP) is spent in our ICUs, and about 40% of Medicare dollars are spent on the last year of a patient’s life. The ICU also is where we care for a higher proportion of older patients as well as underor noninsured patients. Consequently, debates about ‘‘death panels’’ and end-of-life care are often centered in ICUs, where stark choices are presented to dying patients, their families, and medical staff. Many of us who work in critical care often feel that we are delivering costly care to patients who are unlikely to recover. This is an inevitable dilemma but perhaps not an unsolvable one. For more than a decade, the concept of ‘‘regionalization’’ has been proposed as a way to make ICUs more efficient and more cost-effective. Although some variant of critical care is available in almost every part of the country, accessibility, quality, and resources are far from evenly distributed. Most people prefer the convenience of receiving care locally—from physicians they are familiar with and have confidence in. Changes in the delivery of critical care services have been made at a relatively rapid pace such that only the most experienced of centers are able to effectively care for the most critically ill patients. Given this, consideration should be given to regionalizing most critical care services such as practiced in trauma and pediatric critical care. The Regional ICU concept posits that, since resources and personnel are more concentrated in more densely populated areas, we should concurrently concentrate them in larger facilities, which may be less convenient but are also almost certainly better equipped to handle the most complex medical problems. Such regional ICUs would

Sepsis remains an uncommon, but potentially devastating problem in the previously healthy pregnant patient. Although septic sequelae, including organ failure and shock, are unusual, they are likely to lead to morbidity and mortality as high, or higher, than in the general population. At the present time, hemodynamic support, surgery, and antimicrobial therapy aimed at reducing polymicrobial aerobic and anaerobic infection remain the gold standard of therapy. New antimediator and anti-inflammatory therapies offer promise of improved survival in the general and obstetric population with severe sepsis.

This article focuses on the features of common lower respiratory-tract infections in the elderly, specifically those age-associated physiologic and immunologic changes that alter the classic clinical picture of infection. Attention is directed at the epidemiology and clinical features of pneumonia in community, institutionalized, and hospitalized individuals. Those treatment factors unique to an elderly patient are discussed.

We evaluated the conditions of 33 patients who completed an outpatient pulmonary rehabilitation program to determine what types of improvements occurred, and whether these changes were related to the baseline degree of ventilatory impairment, to determine whether rehabilitation was beneficial to patients, regardless of the degree of underlying lung dysfunction. Endurance measurements, including sustained submaximal performance on a cycle ergometer and the 12-minute walk distance (1,349 +/- 625 feet to 1,700 +/- 670 feet) increased significantly (p less than 0.01), as did multiple educational and subjective parameters. Maximal exercise performance on a graded cycle test improved very little, with a decline in the ventilatory equivalent for oxygen consumption (VE/VO2) being the only significant change (48.2 +/- 28.3 L/ml to 36.6 +/- 8.7 L/ml). Of the observed changes, only one endurance measurement, the sustained submaximal exercise performance, correlated with FEV1 (r = 0.5, p less than 0.01), but only if it was expressed as an absolute number (liters) and not as percent predicted. Lung function did not correlate with changes in the 12-minute walk distance, in maximal exercise performance on the cycle ergometer or with changes in educational and subjective parameters. We conclude that because the magnitude of change in both physiologic and psychologic parameters was not directly related to lung function, the benefits of rehabilitation can extend to all patients with chronic lung disease, regardless of the severity of preexisting pulmonary dysfunction.

OBJECTIVE To determine whether the iv infusion of prostaglandin E1 (PGE1) could modify the early influx of neutrophils into bleomycin-injured lungs and if that would affect subsequent development of inflammation and fibrosis. BACKGROUND AND METHODS In vivo controlled animal study performed in a university hospital pulmonary research laboratory. Male Syrian golden hamsters (100- to 110-g body weight) were divided into four treatment groups: a) No treatment; b) intratracheal bleomycin plus PGE1 infusion; c) bleomycin plus saline infusion; d) PGE1 infusion only. PGE1 (180 ng/hr.100 g) or saline were infused iv 3 to 25 hr after intratracheal instillation of bleomycin sulfate (0.5 U/0.5 mL.100 g). Total and differential counts of cells recovered by lavage, lavage fluid protein, and lung total protein and hydroxyproline levels were measured from 6 hr to 30 days later. RESULTS PGE1 infusion reduced the influx of neutrophils 6 hr after bleomycin injury by 53% compared with saline infusion (p less than .0001), but increased inflammatory cell traffic after 24 hr for 15 days. At 4 days, protein recovered in lung lavage fluid was also decreased in PGE1-treated, bleomycin-injured animals, reflecting reduced injury to lung permeability barriers. Accumulation of lung collagen in the PGE1-treated, bleomycin-instilled hamsters tended to be lower than in the bleomycin-injured, saline-infused group at 15 and 30 days, although these differences did not achieve statistical significance. Despite this fact, greater than 33% of the animals in the PGE1-treated group died, possibly indicating an increased risk of sepsis in these animals. CONCLUSIONS PGE1 infusion can decrease early neutrophil traffic and reduce injury to the lung permeability barriers. However, this treatment augments late inflammatory events and does not significantly alter the development of fibrosis.

Background Prior case series have shown promising diagnostic sensitivity for CT scan-guided bronchoscopy. Methods This was a prospective randomized trial comparing CT scan-guided bronchoscopy vs conventional bronchoscopy for the diagnosis of lung cancer in peripheral lesions and mediastinal lymph nodes. All procedures were performed using a protocolized number of passes for forceps, transbronchial needles, and brushes. Cytologists and pathologists were blinded as to bronchoscopy type. Patients with negative results underwent open surgical biopsy (for nodules or lymph nodes) or were observed for ≥ 2 years if they had a nodule Results Fifty patients were enrolled into the study (CT scan-guided bronchoscopy, 26 patients; conventional bronchoscopy, 24 patients). Two patients, one from each arm, dropped out of the study. Ultimately, 36 patients were proven to have cancer, and 27 of these patients (75%) had their diagnosis made by bronchoscopy. The sensitivity for malignancy of CT scan-guided bronchoscopy vs conventional bronchoscopy for peripheral lesions was similar (71% vs 76%, respectively; p = 1.0). The sensitivity for malignancy of CT guided bronchoscopy vs conventional bronchoscopy for mediastinal lymph nodes was higher (100% vs 67%, respectively) but did not reach statistical significance (p = 0.26). On a per-lymph-node basis, there was a trend toward higher diagnostic accuracy with CT scan guidance (p = 0.09). The diagnostic yield was higher in larger lesions (p = 0.004) and when CT scanning confirmed target entry (p = 0.001). Conclusion We failed to demonstrate a significant difference between CT scan-guided bronchoscopy and conventional bronchoscopy for the diagnosis of lung cancer in peripheral lesions and mediastinal lymph nodes. Further study of improved steering methods combined with CT scan guidance for the diagnosis of lung cancer in peripheral lesions is warranted.

Systemic sepsis and pneumonia are common predisposing factors for ARDS, which can serve as the initial manifestation of the multisystem organ failure syndrome. Primary pneumonia that necessitates ICU admission leads to ARDS in approximately 10% of patients. Systemic infection can also lead to ARDS, but when bacteremia alone is present, the risk is low (probably less than 5%). If the septic syndrome with a hemodynamic and end-organ response develops, the ARDS may follow in as many as 40% of patients. When multiple risk factors for acute lung injury are present, the risk of developing ARDS rises dramatically. The septic syndrome, acute lung injury, and multiorgan failure are closely tied to one another because bacterial cell walls can activate inflammatory mediators, such as interleukin-1 and tumor necrosis factor, which can in turn lead to the septic syndrome and inflammatory injury to the lung. Clinical features, more than serum markers, have been the best predictors of whether lung injury will follow sepsis, indicating that the mere presence of mediators alone cannot cause ARDS and that there are individual susceptibility factors in the effects of these mediators. With the advent of monoclonal antibodies and new anti-inflammatory drugs, prevention of progression from sepsis to multiorgan failure may become possible. Pneumonia is the most common infection that complicates ARDS once it is established, and the mortality rate may approach 90%. The existence of acute lung injury, its predisposing conditions, coexisting illnesses, and the therapeutic interventions used for patients with lung injury all can interfere with lung host defenses and set the stage for bacterial infection of the already-injured lung. This infection appears to add to the propagation of the multiple system organ failure that has already begun. In the future, it may become possible to prevent this infection, which would be a welcome development, because currently, we are stymied in our efforts to diagnose and treat pneumonia in the setting of acute lung injury. Preventive efforts will follow from an understanding of the pathogenesis of pneumonia and in the future may include topical antibiotics, selective digestive decontamination, and prophylactic passive immunotherapy.

1990;97;170-181 Chest M S Niederman, D E Craven, A M Fein and D E Schultz Pneumonia in the critically ill hospitalized patient. http://chestjournal.chestpubs.org/content/97/1/170.citation can be found online on the World Wide Web at: The online version of this article, along with updated information and services ) ISSN:0012-3692 http://chestjournal.chestpubs.org/site/misc/reprints.xhtml ( without the prior written permission of the copyright holder. reserved. No part of this article or PDF may be reproduced or distributed Chest Physicians, 3300 Dundee Road, Northbrook, IL 60062. All rights of been published monthly since 1935. Copyright1990by the American College is the official journal of the American College of Chest Physicians. It has Chest

PURPOSE OF REVIEW Community-acquired pneumonia is associated with significant morbidity and mortality and is the most common cause of death from infectious diseases in North America. The purpose of this review is to highlight recent advances in epidemiology, risk factors, severity criteria and antibiotic therapeutic regimens used for community-acquired pneumonia management. RECENT FINDINGS All guidelines recommend early and appropriate empiric therapy directed against common typical organisms, such as Streptococcus pneumoniae, and other atypical organisms, but clinicians should be aware of newer emerging pathogens such as community-acquired methicillin-resistant Staphylococcus aureus and Gram-negative pathogens. SUMMARY The optimum outcome in community-acquired pneumonia can be achieved by careful risk stratification using prediction rules together with appropriate antibiotic regimens. The mainstay of community-acquired pneumonia prevention is influenza and pneumococcal immunization. Promotion of smoking cessation will also help curtail the incidence of pneumococcal disease.