What treatment will reverse CNS symptoms in an elderly hypertensive patient with fever, dysuria, confusion, hyponatremia, hypocalcemia, and leukocytes in the urine?

Proper Antibiotics Will Reverse the CNS Symptoms

The correct answer is D: Proper antibiotics will reverse the CNS symptoms, as this elderly patient has a urinary tract infection with systemic manifestations (fever, dysuria, confusion, leukocytes in urine), and the European Association of Urology guidelines explicitly state that antibiotics should be prescribed when recent-onset dysuria is accompanied by systemic signs such as fever or clear-cut delirium. 1

Clinical Reasoning and Diagnostic Criteria

This patient meets the diagnostic criteria for UTI requiring antibiotic treatment based on the European Association of Urology algorithm 1:

• Recent-onset dysuria (present) 1
• Systemic signs of infection: fever and clear-cut delirium/confusion (both present) 1
• Leukocytes in urine confirming pyuria (present) 1, 2

The confusion in this case represents delirium secondary to systemic infection, not a primary electrolyte disturbance requiring correction before treating the underlying infection 1, 3.

Why Antibiotics Are the Priority

Treating the Underlying Infection

• The European Association of Urology guidelines emphasize that elderly patients with fever, rigors/shaking chills, or clear-cut delirium in the context of urinary symptoms warrant immediate antibiotic treatment 1, 3
• Delirium is defined as a disturbance in attention and awareness that develops over a short period and represents a direct physiological consequence of another medical condition—in this case, the UTI 1
• Systemic infection is the reversible cause of the CNS symptoms, and treating the infection will resolve the confusion 1, 3

Recommended Antibiotic Regimens

The European Association of Urology recommends the following first-line agents for elderly patients 3:

• Fosfomycin 3g single dose (optimal for elderly with renal impairment) 3
• Nitrofurantoin (avoid if CrCl <30-60 mL/min) 3
• Trimethoprim-sulfamethoxazole (only if local resistance <20%) 3
• Avoid fluoroquinolones unless other options exhausted due to increased adverse effects in elderly 3

Why the Other Options Are Incorrect

A. Correcting Hyponatremia (Na⁺ = 132)

• This is mild hyponatremia (130-134 mEq/L) and typically causes only mild symptoms like nausea, vomiting, or headache—not acute confusion 4
• Severe CNS symptoms (delirium, confusion, seizures) occur when sodium is <125 mEq/L, not at 132 mEq/L 4, 5
• The confusion is better explained by the systemic infection (fever + UTI) rather than this mild sodium abnormality 1, 4
• Diuretic-induced hyponatremia is common in elderly hypertensive women and may be contributing, but at 132 mEq/L, this is not the primary cause of acute confusion 6, 5

B. IV Calcium Gluconate (Ca²⁺ = 1.6)

• While this calcium level appears low, IV calcium gluconate is indicated for acute, symptomatic hypocalcemia with neuromuscular irritability, tetany, or seizures 7
• The FDA label states that calcium gluconate treats acute symptomatic hypocalcemia, but the primary CNS symptom here (confusion/delirium) is clearly related to the systemic infection, not hypocalcemia 7
• Hypocalcemia typically presents with neuromuscular irritability, not confusion 7

C. IV Fluids

• While IV fluids may be supportive, they do not address the underlying cause of the CNS symptoms, which is the systemic infection 1, 3
• The European Association of Urology guidelines emphasize treating the infection itself, not just providing supportive care 1, 3
• IV fluids alone will not reverse delirium caused by UTI 1

Critical Pitfalls to Avoid

Do Not Delay Antibiotic Treatment

• Never delay antibiotic treatment while pursuing correction of mild electrolyte abnormalities when systemic infection is present 1, 3
• The European Association of Urology algorithm prioritizes immediate antibiotic treatment when systemic signs are present 1

Distinguish True UTI from Asymptomatic Bacteriuria

• This patient has symptomatic UTI (fever, dysuria, confusion), not asymptomatic bacteriuria 1, 3, 2
• Asymptomatic bacteriuria occurs in 40% of institutionalized elderly but should never be treated 3, 2
• The presence of systemic signs (fever, delirium) distinguishes true infection requiring treatment 1, 3

Monitor for Complications

• Obtain urine culture with susceptibility testing to adjust therapy after initial empiric treatment 3
• Monitor renal function closely given hypertension and potential for medication-related nephrotoxicity 3
• Reassess mental status after 48-72 hours of appropriate antibiotic therapy 1, 3