Give Antibiotics
In this elderly patient with fever, confusion, positive urinalysis (nitrites and leukocyte esterase), and focal genitourinary symptoms consistent with UTI, antibiotics are the intervention most likely to reverse the CNS status. 1
Clinical Reasoning for Antibiotic Priority
This patient meets the specific criteria for true UTI requiring treatment rather than asymptomatic bacteriuria:
- Systemic signs of infection present: Fever is a key diagnostic criterion (the patient has documented fever) 1
- Positive urinalysis markers: Both nitrites and leukocyte esterase are present, indicating active infection 1
- Altered mental status WITH systemic signs: The combination of fever, rigors/shaking chills, and clear-cut delirium with no other localizing source of infection justifies antimicrobial treatment 1
The European Urology Association specifically recommends treating altered mental status with focal genitourinary symptoms as complicated UTI requiring 7-14 days of empiric therapy, particularly in patients with confirmed infection and systemic manifestations such as fever 1
Why Not the Other Options?
Fluids (Option A)
While dehydration should be addressed concurrently, fluids alone will not reverse CNS status caused by active infection. 1 The confusion may persist or worsen initially despite fluid administration if the underlying infection is not treated. 1
Correcting Hyponatremia (Option C)
The sodium level of 132 mEq/L represents mild hyponatremia (130-134 mEq/L range). 2 Severe symptoms requiring emergency correction occur when sodium is less than 125 mEq/L. 2 This patient's confusion is far more likely attributable to the active UTI with fever than to mild hyponatremia, which typically causes only mild symptoms like nausea, vomiting, and headache—not acute delirium. 2
Empiric Antibiotic Regimen
Initiate empiric antibiotics immediately with options including: 1
- Amoxicillin plus aminoglycoside
- Second-generation cephalosporin plus aminoglycoside
- Third-generation cephalosporin IV
Treatment duration should be 7-14 days for complicated UTI. 1
Critical Pitfalls to Avoid
Do not delay antibiotic treatment while pursuing other interventions. Untreated UTI can progress to urosepsis, particularly in elderly patients with multiple comorbidities. 1
Do not expect immediate resolution of confusion with antibiotics alone. Delirium has a fluctuating course and may take days to resolve even with appropriate antimicrobial therapy. 1 The confusion may initially persist or worsen despite treatment. 1
Address contributing factors concurrently: While antibiotics are the primary intervention, also correct the hyperglycemia (which may worsen with infection and stress) and provide adequate hydration. 1 However, these are supportive measures—the definitive treatment is antimicrobial therapy for the underlying infection.
Monitoring Parameters
- Resolution of fever 1
- Improvement in mental status (though delirium may fluctuate) 1
- Clinical stability and hemodynamic parameters 1
The cortical atrophy noted on MRI is a chronic finding unrelated to the acute presentation and does not change the management approach. 3