A prospective multicenter study assessed how adherence to antibiotic therapy recommendations affected outcomes in patients with severe community-acquired pneumonia. The study involved 529 patients with community-acquired pneumonia hospitalized in the intensive care unit. The average age of the patients was 59.9 ± 16.1 years, the average score on the APACHE II scale was 18.9 ± 7.4 and the overall mortality rate was 27.9%. The American Society of Infectious Diseases (IDSA) recommendations on antibiotic therapy were followed in 57.8% of cases.

The most common causative agents of pneumonia were Streptococcus pneumoniae and Legionella spp. According to the results of a unidirectional analysis, among the patients receiving empirical treatment in accordance with the recommendations of the IDSA, the mortality rate was 24.2%. The corresponding indicator in patients receiving other therapy was 33.2%. In other words, there was a relative decrease in mortality of about 30% and an absolute decrease of 9%.

One possible explanation for the results is a faster appointment of effective antibiotic therapy when following up on recommendations. As the multivariate analysis shows, 4 factors were independently associated with death. These included age (odds ratio [OR] 1.7), severity of disease rated on the APACHE II scale (OR 4.1), immunosuppression (OR 1.9) and non - compliance with recommendations (OR 1.6). As you can see, the latter factor increased the probability of death by 60%.

In 15 (75%) of the 20 cases of infection caused by Pseudomonas aeruginosa, antibiotic therapy on admission was inadequate (including 8 out of 15 patients treated according to IDSA recommendations). Chronic obstructive pulmonary disease (OS 17.9), neoplasms (OS 11.0), recent use of antibiotics (OS 6.2) and radiological signs of rapid progression of pneumonia (OS 3.9) have been shown to support the disease of Pseudomonas aeruginosa.

Adherence to the recommendations of the American Society of Infectious Disease antibiotic therapy improves the outcome of severe community-acquired pneumonia. It is important that compliance with the recommendations does not entail additional costs. In patients with chronic obstructive pulmonary disease, neoplasms and previous antibiotics, the range of empiric antibiotic therapies should include P.aeruginosa.