Real-world effectiveness of ceftazidime/avibactam versus polymyxin B in treating patients with carbapenem-resistant Gram-negative bacterial infections

Abstract

Objectives: To compare the effectiveness of ceftazidime/avibactam (CAZ/AVI) and polymyxin B against carbapenem-resistant Gram-negative bacteria (CRGNB) infections in western China.

Methods: The medical records of patients with CRGNB infections in this hospital from 2018-2022 were retrospectively reviewed. The data included demographic characteristics, laboratory results, antibiotic strategies and clinical outcomes.

Results: A total of 378 patients with CRGNB infections were enrolled, including 112 patients in the CAZ/AVI group and 266 patients in the polymyxin B group. The most common pathogen was carbapenem-resistant Klebsiella pneumoniae (44.44%). The rates of treatment failure at 28 days (65.04% vs. 45.54%; P = 0.000) and 28-day in-hospital mortality (20.30% vs. 9.82%; P = 0.014) in the polymyxin B group were higher than those in the CAZ/AVI group. Multivariable analysis revealed that multiple organ dysfunction syndrome (OR 2.730; P = 0.017), acute renal failure (OR 2.595; P = 0.020), higher Charlson comorbidity index (CCI) (OR 1.184; P = 0.011) and Acute Physiology And Chronic Health Evaluation (APACHE) Ⅱ scores (OR 1.149; P = 0.000) were independent risk factors for treatment failure, whereas CAZ/AVI therapy (OR 0.333; P = 0.002) had a protective effect. Multivariate Cox regression analysis revealed that CCI ≥ 5 and APACHE II score ≥ 15 were associated with a higher 28-day in-hospital mortality rate (P < 0.001).

Conclusion: CAZ/AVI therapy was associated with treatment success among patients with CRGNB infection. However, CAZ/AVI therapy did not improve 28-day in-hospital survival compared with polymyxin B. The CCI ≥ 5 and APACHE II score ≥ 15 affected 28-day in-hospital mortality of CRGNB-infected patients.

Keywords: Carbapenem-resistant Gram-negative bacteria; Ceftazidime/avibactam; Effectiveness; Mortality; Polymyxin B.