Clinical Efficacy of Polymyxin B in Patients Infected with Carbapenem-Resistant Organisms

Carbapenem-resistant organisms (CROs) pose great challenges for clinical treatment. Polymyxin B (PMB) is one of the "last resort" choices of CRO infections. We explored the possible factors affecting PMB efficacy.This retrospective study involved CRO-infected patients treated with PMB for ≥72 h. The endpoint indicator was clinical efficacy. We compared the characteristics (demographics, pathogenic bacteria, PMB treatment) between patients who had "clinical success" (CS) and "clinical failure" (CF).A total of 191 patients were enrolled: 110 in the CS group and 81 in the CF group. The total cumulative dose for the CS group was higher than the CF group [1100 (700-1443.75) vs 800 (500-1112.5) mg; P = 0.001]. Treatment duration in the CS group was longer than the CF group [11 (8-14) vs 8 (6-11) days; P < 0.000]. Multivariate logistic regression analysis showed mechanical ventilation, vasoactive agents, multiple-site infection, and total cumulative dose to be independently associated with clinical efficacy. Cox survival analysis for 30-day mortality also showed that the use of vasoactive agents and the total cumulative dose of PMB could influence survival time and mortality rate independently.PMB had good efficacy and a low prevalence of adverse reactions. The total cumulative dose, duration of PMB treatment, mechanical ventilation, vasoactive agents, and multiple-site infection were factors associated with the clinical efficacy of PMB.