A pilot study of the clinical significance and outcomes of infections in the ICU caused by colistin-resistant Klebsiella pneumoniae

Abstract

The objective was to study the risk factors, outcomes of infections caused by colistin-resistant K. pneumonia (CRKP) and to evaluate the  sensitivity of these microorganisms to antibacterial agents to determine the most adequate antibiotic therapy options.Materials and methods. Klebsiella pneumoniae strains isolated in the ICU of an acute care hospital between October 2020 and August 2022 were included in the study. Microorganisms were identified using an automatic analyzer PHOENIX. The determination of antibiotic sensitivity was studied by the method of serial micro-dilutions in agar with the determination of MIC EUCAST criteria were used to interpret sensitivity. Detection of carbapenemases was carried out by PCR. Clinical efficacy of starter therapy was evaluated as recovery/improvement and no effect.Results. The infection was characterized by a severe course in 58.9 % of patients, with SOFA scores ranging from 1 to 16 points (mean 5.8 points). 88.2  % of patients had received prior antibiotics, most commonly carbapenems. CRKP infections occurred more frequently in older men with comorbidity. The clinical efficacy of initial antibiotic therapy was 41.2 %. In 47.1 % of cases, there was no effect, which required adjustment of therapy. Excluding patients in whom it was impossible to evaluate the effect, eradication was achieved in 33.3 % of patients. 64.6 % of patients were discharged or transferred to another hospital; 6 patients died between 5 and 41 days after diagnosis of CRKP infection. Fatal outcome was more frequent in women ( p=0.042), patients with higher comorbidity index (p=0.027), in case of sepsis and/or septic shock ( p=0.011), and in earlier detection of CRKP after hospitalization ( p<0.001).Conclusion. The efficacy of initial antibiotic therapy after detection of CRKP infection has been shown to be associated with patient  survival and reduced risk of mortality with an odds ratio of 3.5. We also identified risk factors for mortality in CRKP infection: comorbidity, sepsis, duration of hospitalization and female gender.