Clinical efficacy and nephrotoxicity of intravenous colistin sulfate in the treatment of carbapenem-resistant gram-negative bacterial infections: a retrospective cohort study

Background: Carbapenem-resistant gram-negative bacteria (CR-GNB) are becoming increasingly important bacterial pathogens in critically ill patients. Several clinicians use Intravenous colistin sulfate to treat infections due to CR-GNB, although the clinical data is limited. The aim of our retrospective observational study was to evaluate the effectiveness and nephrotoxicity of intravenous colistin sulfate in the treatment of CR-GNB infections.Methods: Fifty critically ill intensive care patients with infections due to CR-GNB were retrospectively enrolled between January 2020 and December 2021 in the Zhejiang Provincial People's Hospital. Favorable clinical response rate, bacterial clearance rate, nephrotoxicity, and 28-day mortality were evaluated.Results: The overall favorable clinical response rate was 58%, the bacterial clearance rate was 40%, and the 28-day all-cause mortality was 44%. Temperature, neutrophil count, C-reaction protein (CRP), procalcitonin (PCT), creatinine (Cr), and lactate levels were also significantly decreased (P<0.05). The major adverse reaction is nephrotoxicity, and renal function was evaluated on the day before and after treatment with colistin sulfate. Possible nephrotoxicity was observed in three patients (6%). Backward logistic regression was conducted to determine risk factors for the nephrotoxicity of colistin sulfate, the result showed there were no significant differences in the duration and dose of colistin sulfate.Conclusions: Our results provide evidence for the positive clinical efficacy and safety of colistin sulfate. Appropriate use of colistin sulfate may be viable and safe in the treatment of severe infections caused by CRGNB.