The goal of this observational study is to learn if the use of ceftazidime, cefepime, and ceftriaxone impacts the incidence of delirium in elderly patients (aged 65 and older) with infections. The main questions it aims to answer are: Does the administration of these antibiotics increase the incidence of delirium in elderly patients? How do renal and hepatic dose adjustments affect the likelihood of delirium? Researchers will observe elderly patients receiving either ceftazidime, cefepime, or ceftriaxone for infection management to see if these antibiotics contribute to the onset of delirium, and then assessing the severity of the delirium. Participants will: Be assessed for delirium using the CAM (Confusion Assessment Method) at 2, 4, and 6 days after starting treatment. Have their QSOFA (Quick Sequential Organ Failure Assessment) and NEWS (National Early Warning Score) tracked to evaluate their overall health status. Undergo dose adjustments based on renal and hepatic function as part of their treatment. Use the DRS.R89 score to assess delirium if it occurred.