PURPOSE:While pneumonia is the most important underlying risk factor for development of acute respiratory distress syndrome (ARDS), the relationship between specific causative organisms and development of ARDS has not been explored. Several case reports described the development of ARDS in patients with Legionella pneumonia.
METHODS:To determine the incidence, risk factors and outcome of ARDS among patients with Legionella pneumonia, we searched the Mayo Clinic Life Sciences System (MCLSS) database from 01/01/2003 to 12/31/2007. Electronic records of patients with active Legionella pneumonia based on the positive cultures and/or urinary antigen were reviewed. ARDS was diagnosed based on the criteria by the North American/European consensus conference definition.
RESULTS:We identified 15 patients with microbiologically proven Legionella pneumonia of whom 11 (73.3%) were admitted to the intensive care unit (ICU), 6 (40.0%) required mechanical ventilation and 5 (36%) met the criteria for ARDS. The diagnosis was made by culture in 2, urinary antigen in 10 and both in 3 cases. Two patients had positive bronchoalveolar lavage by direct fluorescent antibody staining (DFA). Age (median 42 vs 50 years, p=0.32) and gender (20% vs 33% female, p=0.60) were similar in patients with and without ARDS. Septic shock was present in 4 of the 5 patients with ARDS and only 1 without. Patients with ARDS had longer ICU length of stay (median 9 vs 1 days, P=0.03). Only one patient (from the ARDS group) died in the hospital.
CONCLUSION:In this retrospective study ARDS occurred in one third of patients with microbiologically proven Legionella pneumonia and was associated with prolonged length of ICU stay.
CLINICAL IMPLICATIONS:ARDS commonly occurs in patients with Legionella pneumonia and is almost always accompanied by septic shock.
DISCLOSURE:Marija Kojicic, No Financial Disclosure Information; No Product/Research Disclosure Information