Abstract and Introduction
Abstract
Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality worldwide, and since 1993, guidelines for management have been available. The process, which first began in the United States and Canada, has now been implemented in numerous countries throughout the world, and often each geographic region or country develops locally specific recommendations. It is interesting to realize that guidelines from different regions often interpret the same evidence base differently, and guidelines differ from one country to another, even though the bacteriology of CAP is often more similar than different from one region to another. One of the unique contributions of the 2007 US guidelines is the inclusion of quality and performance measures. In addition, US guidelines emphasize management principles that differ from some of the principles in European guidelines because of unique epidemiological considerations. In addition, certain therapy principles apply in the United States that differ from those in other regions, including the need for all patients to receive routine therapy for atypical pathogens, the emergence of community-acquired methicillin-resistant Staphylococcus aureus in some patients following influenza, and the need for all patients admitted to the intensive care unit to receive at least two antimicrobial agents. In the future, as guidelines evolve, there will be an important place for regional guidelines, particularly if these guidelines can recommend locally specific strategies to implement guidelines, which if successful, can lead to improved patient outcomes.
Introduction
Community-acquired pneumonia (CAP) is a common and potentially serious disease, ranked as the fifth leading cause of mortality globally. More importantly, it is the most common cause of mortality and of disability-adjusted life-years among all respiratory diseases [more common than chronic obstructive pulmonary disease (COPD)] and among infectious diseases [more common than human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS)]. Guidelines for management have been developed in many countries in the past 18 years following the initial publishing of CAP guidelines in North America in 1993. Guidelines were developed to synthesize large amounts of data about CAP and to serve as a tool for the evaluation and therapy of patients both in an out of the hospital. They were never intended to be a set of iron-clad rules, or a "cookbook" but, rather, a combination of expert interpretation of evidence-based data and opinion. When CAP guidelines first appeared in the United States, the therapy of this illness was heterogeneous, with many physicians choosing their own approach, but most were not using an organized synthesis of the available data. Since CAP guidelines first appeared, new problems have emerged, including an awareness of new pathogens (severe acute respiratory syndrome virus and H1N1 influenza), as well as the emergence of resistance among established pathogens (pneumococcus, Staphylococcus aureus). Additionally, despite an extensive number of published studies, management controversies remain, which guidelines have addressed, including who to admit to the hospital and intensive care unit (ICU), what prognostic scoring systems are best, what diagnostic testing should be done, and which therapies should be used and for how long. In the development of guidelines, information from thousands of studies was synthesized and evaluated to answer these questions. However, when different experts review the same data, they sometimes reach different conclusions and different recommendations. This may reflect the fact that, given their own individual expert experience, often influenced by the country in which they practice, and the economic resources available to them, they consider the same information to be of different relevance to their patients.