A systematic review and meta-analysis estimated that about one in three carbapenem-resistant Pseudomonas aeruginosa clinical isolates resists ceftazidime–avibactam, with regional variation in the proportion. The analysis pooled results from 36 studies, mapping where an important “last-line” combination may be losing ground. The report’s findings matter for antimicrobial stewardship and empiric therapy choices in ICUs and other high-risk settings where carbapenem-resistant Gram-negative infections are common. If resistance rates are material in a given region, clinicians may need to rely on susceptibility-guided strategies and reserve these combinations for narrower indications. The review also highlights the ongoing challenge of translating in vitro activity into real-world clinical effectiveness as resistance mechanisms evolve across health systems. For biotech and diagnostics, it supports continued demand for rapid susceptibility testing and companion diagnostics that can steer therapy before outcomes worsen.