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.

This observational study aims to assess the incidence, severity, and recovery of delirium in older adult patients treated with ceftazidime, cefepime, or ceftriaxone for infections. Delirium onset and severity will be monitored using the Confusion Assessment Method (CAM) and the Delirium Rating Scale (DRS-R98), alongside the Sequential Organ Failure Assessment (SOFA) scores, and National Early Warning Score (NEWS) for assessing the severity of infection. Key variables include the presence of delirium at Days 2, 4, and 6, and evaluating the severity of delirium and recovery time, as well as the impact of renal and hepatic dose adjustments. By examining these factors, the study seeks to provide insights into safer antibiotic use and dosing strategies in elderly patients, with the goal of reducing delirium risk and improving patient outcomes.

Inclusion Criteria:

• Older adult patients aged 65 years or above.
• Hospitalized patients in Alexandria university hospitals diagnosed with infection and treated with selected cephalosporins (Ceftriaxone, Ceftazidime, or Cefepime).
• Patients without a history of Pre-existing delirium prior to hospitalization.

Exclusion Criteria:

• Patients with contraindications or allergies to cephalosporins.
• Patients with septic shock.
• Current use of medications known to cause delirium (anticholinergics, benzodiazepines, or opioid analgesics).
• Current or recent substance abuse (patients with a history of alcohol or drug abuse within the past year, or currently undergoing withdrawal). 5. Recent surgical procedures (patients who have undergone major surgery, particularly those requiring general anesthesia, within the last 30 days).
• Electrolyte imbalance (patients with severe electrolyte disturbances such as hypernatremia, hyponatremia, hypercalcemia or hypocalcemia at the time of study entry).
• Patients with End-stage renal disease requiring dialysis.
• Patients with severe liver disease (e.g., Child-C).
• Pain management issues: Patients with severe, uncontrolled pain that might independently affect cognitive function.

Hospitalized patients aged 65 or older at Alexandria University Hospitals receiving Ceftriaxone, Ceftazidime, or Cefepime.