Introduction:The aim of the present study was to assess the safety profile and outcomes of a ceftazidime-avibactam (CAZ-AVI)-based regimen and compare them with those of a tigecycline (TGC)-based regimen in intensive care unit (ICU) for the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP), which is classified into hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). Methods: Clinical and microbiological cure rates, 28-day survival rates, and safety evaluation findings were compared between patients treated with CAZ-AVI-based regimen and those treated with TGC-based regimen in this retrospective study. Conventional multivariate logistic regression analysis and regression adjustment analysis with propensity score (PS) were performed to control for confounding variables.Results: A total of 105 cases of critically ill ICU patients with CRKP-induced HAP or VAP were included in the present study from July 2019 to September 2020; 62 patients (59%) received TGC-based regimen and 43 patients (41%) received CAZ-AVI-based regimen. The most common concomitant agent in the CAZ-AVI group and TGC group was carbapenem (44.2% versus 62.9%, P = 0.058), while only a small proportion of the study population received CAZ-AVI and TGC monotherapy (20.9% versus 6.5%, P = 0.027). The clinical and microbiological cure rates of the CAZ-AVI group were superior to those of the TGC group [51.2% versus 29.0% (P = 0.022) and 74.4% versus 33.9% (P \ 0.001), respectively]. No significant differences in the 28-day survival rates were identified between the two groups (69.8% versus 66.1%, P = 0.695). Conventional multivariate logistic regression and PS analyses showed that patients who had used CAZ-AVI were more likely to have achieved a clinical cure [4.767 (95%CI 1.694-13.414), P=0.003;3.405 (95%CI 1.304-8.889), P=0.012] and microbiological success [6.664 (95%CI 2.626-16.915), P\0.001;7.778 (95%CI 2.717-22.265), P\0.001] than patients who used TGC. However, the difference in the 28-day survival rates between the two groups was not significant. According to the safety evaluation findings, the CAZ-AVI

Background: To assess the safety patterns and outcomes of ceftazidime-avibactam (CAZ-AVI) versus tigecycline (TGC) for the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) pneumonia defined as either hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP).Methods: Clinical and microbiological cure rates, 28-day survival rates, and safety evaluation were compared between patients treated with CAZ-AVI versus those treated with TGC in a retrospective study. Conventional multivariate logistic regression analysis and three propensity score (PS) analyses were performed to control for confounding variables.Results: A total of 105 cases were included in the study; 62 patients (59%) received TGC, and 43 patients (41%) received CAZ-AVI. Clinical cure rates and microbiological cure success of CAZ-AVI were superior to TGC [51.2% versus 29.0%(P=0.022) and74.4% versus 33.9%（P<0.001）, respectively]. There were no significant differences between the two groups with regard to 28-day survival rates (66.1% versus 69.8%, P=0.695). In analyses of conventional multivariate logistic regression and propensity score (PS) analysis, patients in the CAZ-AVI group were more likely to have achieved clinical cure and microbiological success compared with patients in the TGC group. However, the difference between the two groups with regard to 28-day survival rates were not significant. In terms of safety evaluation, generally, the CAZ-AVI group had a lower incidence of adverse reactions when compared with the TGC group.Conclusions: CAZ-AVI may be a suitable alternative to TGC for the treatment of HAP or VAP caused by CRKP in critically ill patients.