Objective: To implement community-acquired pneumonia (CAP) guidelines at a public hospital in Brazil and to evaluate the impact of these guidelines on health care quality. Methods: A quasi-experimental study, with a before-and-after design, involving adult patients diagnosed with CAP and hospitalized between July of 2007 and October of 2008 in the general ward of the Marília School of Medicine Hospital das Clínicas, located in the city of Marília, Brazil. Results: During the study period, 68 patients were diagnosed with CAP: 48 before the implementation of the guidelines and 20 after their implementation. After the implementation of the guidelines, 85% of the cases were treated in accordance with the guidelines, and there was a significant increase in the use of antibiotic therapy for atypical bacteria in patients with severe CAP (6.3% vs. 75.0%; p < 0.001). Comparing the pre-implementation and post-implementation periods, we observed a trend toward a decrease in the mortality (35.4% vs. 15.0%; p = 0.09) and toward an increase in the recording of SpO2 in the medical charts of the patients (18% vs. 30%; p = 0.42). During the study period, the degree of severity was not recorded on the medical charts of most patients. In addition, the initiation of antibiotic therapy followed a pre-established schedule, regardless of the severity of the infection. Conclusions: This study showed that, although the development and implementation of CAP guidelines promoted the optimization of the treatment, there were no significant differences regarding the assessment of severity, SpO2 recording, or the initiation of antibiotic therapy. Therefore, strategies that are more effective are needed in order to modify variables related to the work of physicians and nurses.

Keywords: Guideline adherence; Pneumonia; Health care quality, access, and evaluation; Community-acquired infections.