Treatment with Ceftazidime-Avibactam for Lower Respiratory Tract Infections Caused by the Multidrug-Resistant Gram-Negative Bacteria in the Intensive Care Unit

Jingjing Pan,1,2,&ast; Haobo Kong,1,2,&ast; Zhi Geng,3,&ast; Min Liang,4 Shufeng Yu,1,2 Xuehui Fang5 1Department of Respiratory Intensive Care Unit, Anhui Chest Hospital, Hefei City, Anhui Province, People’s Republic of China; 2Department of Pulmonary and Critical Care Medicine, Anhui Chest Hospital, Hefei City, Anhui Province, People’s Republic of China; 3Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei City, Anhui Province, People’s Republic of China; 4Department of Tuberculosis, Anhui Chest Hospital, Hefei City, Anhui Province, People’s Republic of China; 5Anhui Chest Hospital, Hefei City, Anhui Province, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Shufeng Yu, Department of Respiratory Intensive Care Unit, Department of Pulmonary and Critical Care Medicine, Anhui Chest Hospital, 397 Jixi Road, Hefei City, Anhui Province, 230022, People’s Republic of China, Tel +86 13866705396, Email [email protected] Xuehui Fang, Anhui Chest Hospital, 397 Jixi Road, Hefei City, Anhui Province, 230022, People’s Republic of China, Tel +86 13637054095, Email [email protected]: Ceftazidime avibactam (CAZ-AVI) is recommended for treating severe infections caused by multidrug-resistant gram-negative bacteria (MDR-GNB). However, there are few real-world studies on the use of CAZ-AVI to treat lower respiratory tract infections (LRTIs) caused by MDR-GNBs in intensive care units (ICUs). This study aimed to evaluate the clinical characteristics of patients with LRTIs caused by MDR-GNB who were treated with CAZ-AVI in the ICU, and to investigate the independent risk factors for mortality.Patients and Methods: This single-center retrospective study included patients with LRTIs treated with CAZ-AVI in the respiratory ICU of a tertiary hospital in Anhui Province between December 2022 and November 2024. The primary outcomes were 28-day survival and independent risk factors for all-cause mortality.Results: A total of 71 patients were enrolled in the study and 56.3% (40/71) had 28-day survival outcomes. The Acute Physiology and Chronic Health Evaluation (APACHE) II score (odds ratio [OR]: 1.144, 95% confidence interval [CI]: 1.012– 1.293, p=0.032), coinfection with Aspergillus (OR: 42.753, 95% CI: 2.324– 786.555, p=0.011), and days of CAZ-AVI (OR: 0.851, 95% CI: 0.734– 0.986, p=0.032) were independent risk factors for 28-day all-cause mortality. Kaplan-Meier analysis demonstrated prolonged CAZ-AVI therapy (> 10 days) improved survival (p< 0.001), APACHE II scores > 24 correlated with increased 28-day mortality (p=0.0048), and Aspergillus coinfection significantly reduced survival rates (p=0.001). We also constructed a nomogram for predicting the risk of death in ICU patients treated with CAZ-AVI for LRTIs, with good discrimination and calibration.Conclusion: CAZ-AVI can be used to treat LRTIs caused by MDR-GNB in the ICU. Higher APACHE II scores and coinfection with Aspergillus were associated with 28-day mortality, whereas a longer course of therapy was a protective factor. The nomogram can help clinicians predict CAZ-AVI outcomes.Keywords: lower respiratory tract infections, multidrug-resistant gram-negative bacteria, ceftazidime avibactam, 28-day mortality, nomogram