Polymyxin for treatment of ventilator-associated pneumonia in a setting of high carbapenem resistance

Abstract

Objectives To analyse the use of polymyxins for the treatment of ventilator-associated pneumonia (VAP) at a teaching hospital where carbapenem-resistant gram-negative bacteria are endemic. Patients and methods This was a historical cohort study of patients receiving polymyxins to treat VAP in ICUs at a public university hospital in southern Brazil between January 1, 2017 and January 31, 2018. Results During the study period, 179 cases of VAP were treated with polymyxins. Of the 179 patients, 158 (88.3%) were classified as having chronic critical illness. Death occurred in 145 cases (81.0%). Multivariate analysis showed that the factors independently associated with mortality were the presence of comorbidities (P<0.001) and the SOFA score of the day of polymyxin prescription (P<0.001). Being a burn patient was a protective factor for mortality (P<0.001). Analysis of the 14-day survival probability showed that mortality was higher among the patients who had sepsis or septic shock at the time of polymyxin prescription (P = 0.028 and P<0.001, respectively). Acinetobacter baumannii was identified as the etiological agent of VAP in 121 cases (67.6%). In our cohort, polymyxin consumption and the incidence density of VAP were quite high.

Genetic, antimicrobial resistance profile and mortality rates of Acinetobacter baumannii infection in Brazil: A systematic review

“…In addition, 10 other studies were excluded, mainly because of inappropriate study type (n=5), descriptive studies (n=4) or for not having identified A. baumannii (n=1). Finally, 5 articles [ 11 - 15 ] were included in the final review: four from PubMed [ 12 - 15 ] and one from BVS [ 11 ]. A manual search was performed in the references of the included articles and resulted in no further studies to be included.…”

“…Risk factors of A. baumannii infection were assessed in 3 studies [ 12 ,14,15]. Moreover, the use of invasive devices, previous antibiotic therapy, use of nasogastric tube, and hemodialysis increased the risks of infection [ 15 ]. Biofilm formation was described in 1 study, in which most isolates (76.8%) presented with this feature [ 12 ]…”

“…A. baumannii- associated mortality rates were reported in 3 studies, ranging from 43.7%to 81% [ 11 ,14,15]. One study identified an association of A. baumannii infection with poor prognosis [ 11 ] and another study indicated higher mortality of patients with A. baumannii -associated sepsis and septic shock that received polymyxin [ 15 ]. Respiratory infection, age (>60 years), and noradrenaline administration constituted the main risk factors for mortality in those with A. baumannii infection [ 11 ].…”

“…Notably, patients infected or colonized by the ST25 strain that harbored bla OXA-23 had a 100% mortality rate [ 13 ]. Previous use of cephalosporins and carbapenems associated with a six-fold increase in the risk of carbapenem-resistant A. baumannii infection; comorbidities and higher scores on the Sequential Organ Failure Assessment (SOFA) significantly predicted patients mortality [ 15 ].…”

“…Since then, several studies have identified this pathogen with a similar resistance profile in several Brazilian states [ 16 ]. Results from these investigations revealed that A. baumannii harbored a high prevalence of bla OXA-23 , followed by bla OXA-51 ; bla OXA-143 was found in A. baumannii isolates in Brazil and other Latin American countries [ 12 , 15 , 17 , 18 ].…”