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

PURPOSE: 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. PATIENTS AND METHODS: 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). RESULTS: 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. CONCLUSION: 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.