{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:35:55Z","timestamp":1760060155818,"version":"build-2065373602"},"reference-count":45,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2025,8,5]],"date-time":"2025-08-05T00:00:00Z","timestamp":1754352000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Ceftazidime\u2013avibactam (CAZ-AVI) is a second-generation intravenous \u03b2-lactam\/\u03b2-lactamase inhibitor combination. In recent years, substantial evidence has emerged regarding the efficacy and safety of CAZ-AVI. However, data on its use in critically ill patients remain limited. Background\/Objectives: This multicenter, retrospective, observational cohort study was conducted across four Intensive Care Units (ICUs) in three hospitals in the Marche region of Italy. The primary objective was to evaluate the 30-day clinical outcomes and identify risk factors associated with 30-day clinical failure\u2014defined as death, microbiological recurrence, or persistence within 30 days after discontinuation of therapy\u2014in critically ill patients treated with CAZ-AVI. Methods: The study included all adult critically ill patients admitted to the participating ICUs between January 2020 and September 2023 who received CAZ-AVI for at least 72 h for the treatment of a confirmed or suspected Gram-negative bacterial (GNB) infection. Results: Among the 161 patients included in the study, CAZ-AVI treatment resulted in a positive clinical outcome (i.e., clinical improvement and 30-day survival) in 58% of cases (n = 93\/161), while the overall mortality rate was 24% (n = 38\/161). Relapse or persistent infection occurred in a substantial proportion of patients (25%, n = 41\/161). Notably, acquired resistance to CAZ-AVI was observed in 26% of these cases, likely due to suboptimal use of the drug in relation to its pharmacokinetic\/pharmacodynamic (PK\/PD) properties in critically ill patients. Furthermore, treatment failure was more frequent among immunosuppressed individuals, particularly liver transplant recipients. Conclusions: This study demonstrates that the mortality rate among ICU patients treated with this novel antimicrobial combination is consistent with findings from other studies involving heterogeneous populations. However, the rapid emergence of resistance underscores the need for vigilant surveillance and the implementation of robust antimicrobial stewardship strategies.<\/jats:p>","DOI":"10.3390\/antibiotics14080797","type":"journal-article","created":{"date-parts":[[2025,8,6]],"date-time":"2025-08-06T10:13:51Z","timestamp":1754475231000},"page":"797","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Ceftazidime\u2013Avibactam in Critically Ill Patients: A Multicenter Observational Study"],"prefix":"10.3390","volume":"14","author":[{"given":"Olivieri","family":"Silvia","sequence":"first","affiliation":[{"name":"Infectious Diseases, Via Murri, 15, 63023 Fermo, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sara","family":"Mazzanti","sequence":"additional","affiliation":[{"name":"Infectious Diseases Clinic, Via Conca 71, 60126 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabriele","family":"Gelo Signorino","sequence":"additional","affiliation":[{"name":"Infectious Diseases Clinic, Via Conca 71, 60126 Torrette, Italy"},{"name":"Department of Biomedical Sciences and Public Health, Medical School, Polytechnic University of Marche, Via Tronto 10\/A, 60020 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francesco","family":"Pallotta","sequence":"additional","affiliation":[{"name":"Department of Biomedical Sciences and Public Health, Medical School, Polytechnic University of Marche, Via Tronto 10\/A, 60020 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrea","family":"Ficola","sequence":"additional","affiliation":[{"name":"Infectious Diseases Clinic, Via Conca 71, 60126 Torrette, Italy"},{"name":"Department of Biomedical Sciences and Public Health, Medical School, Polytechnic University of Marche, Via Tronto 10\/A, 60020 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Benedetta","family":"Canovari","sequence":"additional","affiliation":[{"name":"Infectious Diseases Unit, Azienda Ospedaliera Ospedali Riuniti Marche Nord, 61121 Pesaro, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vanessa","family":"Di Muzio","sequence":"additional","affiliation":[{"name":"Hospital Pharmacy, AUO delle Marche, Via Conca 71, 60126 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michele","family":"Di Prinzio","sequence":"additional","affiliation":[{"name":"Hospital Pharmacy, AUO delle Marche, Via Conca 71, 60126 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Elisabetta","family":"Cerutti","sequence":"additional","affiliation":[{"name":"Department of Anesthesia, Transplant and Surgical Intensive Care, AUO delle Marche, Via Conca 71, 60126 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Abele","family":"Donati","sequence":"additional","affiliation":[{"name":"Anesthaesia and Intensive Care Clinic, AUO delle Marche, Via Conca 71, 60126 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrea","family":"Giacometti","sequence":"additional","affiliation":[{"name":"Infectious Diseases Clinic, Via Conca 71, 60126 Torrette, Italy"},{"name":"Department of Biomedical Sciences and Public Health, Medical School, Polytechnic University of Marche, Via Tronto 10\/A, 60020 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Francesco","family":"Barchiesi","sequence":"additional","affiliation":[{"name":"Department of Biomedical Sciences and Public Health, Medical School, Polytechnic University of Marche, Via Tronto 10\/A, 60020 Torrette, Italy"},{"name":"Infectious Diseases Unit, Azienda Ospedaliera Ospedali Riuniti Marche Nord, 61121 Pesaro, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lucia","family":"Brescini","sequence":"additional","affiliation":[{"name":"Infectious Diseases Clinic, Via Conca 71, 60126 Torrette, Italy"},{"name":"Department of Biomedical Sciences and Public Health, Medical School, Polytechnic University of Marche, Via Tronto 10\/A, 60020 Torrette, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"626","DOI":"10.1097\/QCO.0000000000000599","article-title":"Risk stratification for multidrug-resistant Gram-negative infections in ICU patients","volume":"32","author":"Burillo","year":"2019","journal-title":"Curr. 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