Polymyxin B in The Treatment of Infections Caused by Multidrug-Resistant Gram-Negative Bacteria in Children: A Retrospective Case Series and A Literature Review.

Background: Multidrug-resistant Gram-negative bacteria (MRGN) pose a significant threat and require priority attention. Polymyxin B (PMB) retains substantial activity against MRGN and makes it potentially the last resort therapy for MRGN infections in children. To assess the effectiveness and safety of PMB in treating MRGN infections in Chinese children. Methods: Paediatric patients aged 0-18 years who were treated with PMB for MRGN infections were enrolled in the study. These cases were then compared with those identified in a literature review. In logistic regression, three independent variables were used for analyzing clinical effectiveness, and two for nephrotoxicity. Results: A cohort of 54 children was included in study and 24 eligible literature of 259 children were included in literature review. Out of the 54 patients, 53.7% showed favorable clinical responses, while 13.0% died during their hospitalization, of which 3.7% died within 30 days after receiving PMB. AKI was observed in 25.9% patients with 11.1% risk stage, 7.4% injury stage and 7.4% failure stage. The PMB co-administration with carbapenems was associated with significantly higher effectiveness (odds rate [OR] = 3.16, 95% confidence interval [CI]: 1.02-9.86, P = 0.05) and co-administration with potent diuretic (furosemide) may increase the risk of AKI (OR = 4.91, 95% CI: 0.96-24.98, P = 0.05). Conclusion: PMB has advantages in treating MRGN infections in paediatric patients, showing favorable clinical responses and pathogen clearance. AKI is a notable safety concern. The small sample size might hinder reliable identification of factors affecting clinical effectiveness and adverse effects.