Efeitos da administração de amicacina inalatória na prevenção da pneumonia associada a ventilação mecânica: estudo prospectivo e randomizado

Abstract

Background: Ventilator-associated pneumonia (VAP) is the most frequent nosocomial infection in intensive care units (ICU), and it is associated with higher mortality and longer hospitalizations. Several prophylactic strategies have been studied, among them the use of inhaled antibiotics. So, we evaluated if prophylactic nebulization with amikacin reduces the incidence of VAP in ICU. Methods: We conducted a prospective, randomized, single center, open-label study, in the Intensive Care Unit of the University Hospital of the Universidade Federal de Juiz de Fora. Inclusion criteria were patients aged 18 years or older, tracheal intubation and mechanical ventilation (MV) for less than 24 hours, and expectation of MV for more than 48 hours. Patients were randomized to receive nebulized amikacin (500 mg, bid), or saline (bid), for 7 days, or until extubation or death. The primary outcome was VAP incidence in 28 days. Continuous variables were compared using t test or Mann-Whitney U test, and categorical variables were compared using chi-square test. Cox proportional-hazards regression was performed with adjustments for potential confounders. Results: We included 27 patients, 13 in the amikacin group. VAP incidence was not significantly different between amikacin and control groups (10,8/1000 vs. 16,6/1000 MV days, p =0,77). Regarding the secondary outcomes, the prophylaxis with amikacin did not reduce the incidence of tracheobronchitis (VAT) (12,2/1000 vs. 5,5/1000 MV days, p =0,63), the VAP ratio (7,7% vs. 21,4%, p =0,32), the VAT ratio (7,7% vs. 7,1%, p =0,95), the lenght of stay in the ICU (6,3 vs. 3,3 days out of ICU at day 28, p =0,33), the ICU mortality (46,2% vs. 71,4%, p =0,18), and the hospital mortality (53,9% vs. 71,4%, p =0,35). Conclusions: Prophylactic nebulized amikacin was not effective in reducing the incidence of VAP, and did not improve the clinical evolution of ICU patients.