Etiologia, fatores de risco e terapia inapropriada em pneumonias associadas à ventilação em pacientes adultos internados em uma unidade de terapia intensiva de um hospital de ensino no Brasil

Abstract

Introduction: Ventilator-associated pneumonia (VAP) is one of the most common hospital-acquired infections in intensive care units (ICUs), contributing to an increased incidence of infections, mortality, and costs. Gram-negative bacilli (GNB) are the most common pathogens in these infections, but high frequencies of antibiotic-resistant microorganisms further aggravate the prognosis, as well as increased health spending in resource-poor countries. Aim: Evaluating the risk of inappropriate antibiotic therapy in the evolution of bacterial infections by resistant and multi-resistant GNBs to carbapenems and wide-spectrum cephalosporins in critical clinical patients affected with VAP. Methods: A prevalence survey of hospital infections was carried out in patients hospitalized at Clinic’s Hospital of the Federal University of Uberlândia (HC-UFU) in the period 2012-2014; the infections were defined according to clinical and microbiological criteria and the following resistance phenotypes were considered: non-fermenters (NF) resistant to carbapenems and Enterobacteriaceae resistant to 3rd and 4th generation of cephalosporins, according to "in vitro" results. The intrinsic and extrinsic risk factors of patients with VAP caused by GNB were evaluated through univariate and multivariate statistical analyses. The survival and the endemic curves were constructed. Results: In the three years of investigation, 2168 patients hospitalized in the ICU and 210 patients with VAP by GNB who were submitted to the epidemiological study according to the retrospective cohort model were identified. The incidence of infection in new patients was 55.1% and in total (new and old) of 91.2%; most of the infections were acquired in the ICU (81.2%) and the rest (18.8%) were acquired in other units. A total of 558 patients had VAP, 210 of them were caused by GNB in the first episode of infection, and the multivariate analysis identified that the inappropriate definitive therapy and the Charlson comorbidity score ≥ 3 were independent risk factors for 30-day mortality. Conclusion: VAPs were thus caused by resistant/multi-resistant BGNs associated with very high infection rates, given the limited available antibiotic therapeutic options for treatment of these infections and their association with mortality risk.