Strategies of Treatment for Extensively Drug-Resistant Acinetobacter baumannii Infections: Single Centre Experience

Abstract

Objective: To describe treatment strategies employed in hospitalized patients at the "General Hospital Dr. Manuel Gea González" with infection by Extensively Drug-Resistant (XDR) Acinetobacter baumannii. Methodology:A retrospective analysis was carried out from January 1st 2012 to December 31st, 2014. Clinical data were collected, as well as group and doses of antimicrobial agents administered.Results: 39 patients were enrolled, the main infectious diagnosis was hospital acquired pneumonia (HAP) in 64%, followed by skin and soft-tissue infections (SSTI) in 23%. Thirty patients (77%) received tigecycline, while 83% of these received high doses. Thirty three percent of patients receiving meropenem had high dose. Twenty-nine patients (74.3%) received colistin and, from these, 61.5% was given a loading dose. Concerning the combined therapy, the following distribution was observed: 19 patients (48.7%) had triple therapy: meropenem, colistin and tigecycline (MCT), and 20 patients (51.3%) had double therapy including combinations of meropenem-colistin (MC), meropenem-tigecycline (MT) and tigecycline-colistin (TC). The sole adverse effect with the use of tigecycline was nausea in 20%. Twenty five percent of patients receiving colistin required dose adjustment after 5 days due to acute kidney injury (AKI). Outcomes: overall mortality was 33.3%, the mean of hospital stay at the intensive care unit (ICU) was 12.8 days (SD ± 16.2), while the total days of stay were 41 (SD ± 25.9). The lowest mortality (25.3%) was observed in the group receiving triple therapy (MCT), although this was no statistically significant. Conclusions:Triple combination therapy showed a trend to decreased mortality. The use of tigecycline at high doses and colistin at loading dose did not determine unfavorable clinical outcomes. It is necessary to perform randomized studies comparing different therapeutic strategies.