title: Prognostic factors of severe Legionella pneumonia requiring admission to ICU.
abstract: Despite the fact that the epidemiology of community-acquired pneumonia and nosocomial Legionella infection is well known, there are no specific reports dealing with severe cases of Legionella pneumophila pneumonia admitted to intensive care units. We undertook a prospective study upon 84 patients with a reliable diagnosis of L. pneumophila pneumonia that required ICU admission. The study assessed the prognostic factors, clinical, radiological and outcome variables of both nosocomial (n = 33) and community-acquired (n = 51) cases of L. pneumophila pneumonia. The following variables were more common in nosocomial acquired as compared to community-acquired Legionella pneumonia: Chronic obstructive pulmonary disease (COPD) (64 versus 41%), cardiac disease (39 versus 10%), chronic renal failure (21 versus 4%), alcoholism (54 versus 18%), septic shock (33 versus 16%), and unilateral chest X-ray involvement (61 versus 39%). The crude mortality rate in this study was 30% (25 of 84) with no differences when comparing mortality between nosocomial (9, 27%) to community-acquired (16, 31%) types. The univariate analysis showed that cardiac disease, diabetes mellitus, creatinine > or = 1.8 mg/dl, septic shock, chest X-ray extension, mechanical ventilation, hyponatremia < or = 136 mEq/L, PACO2/FIO2 < 130, and blood urea levels > or = 30 mg/dl were factors related to poor outcome. On the other hand, the following two variables were related to better outcome: adequate treatment for Legionella and pneumonia improvement. The logistic regression analysis demonstrated that APACHE II score > 15 at admission (RR: 11.5; 95% CI 1.75 to 76.1; p = 0.025), and serum Na levels < or = 136 (RR: 21.3; 95% CI 1.11 to 408; p = 0.023), were the only independent factors related to death. On the other hand, improving pneumonia is associated with better outcome in Legionnaires' disease than for patients not having improving pneumonia (RR: 0.019; 95% CI: 0.036 to 0.106; p < 0.0001). A better understanding of the prognostic factors in cases of severe Legionella pneumonia will optimize our therapeutic approach in this disease and help to decrease both its mortality and morbidity rates.
authors.affiliation: Departament de Medicina, Universitat de Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: el-Ebiary
authors.forename: X
authors.initials: X
authors.lastname: Sarmiento
authors.forename: A
authors.initials: A
authors.lastname: Torres
authors.forename: S
authors.initials: S
authors.lastname: Nogué
authors.forename: E
authors.initials: E
authors.lastname: Mesalles
authors.forename: M
authors.initials: M
authors.lastname: Bodí
authors.forename: J
authors.initials: J
authors.lastname: Almirall
mesh_terms: D018806:APACHE; D003428:Cross Infection / Q000175:diagnosis; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007877:Legionnaires' Disease / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000401:mortality; D011379:Prognosis; D011446:Prospective Studies; D015996:Survival Rate