Delirium Secondary to Urinary Tract Infection

Question

A 71-year-old woman has 2 days of fever, dysuria, and suprapubic pain, and since this morning has been disoriented with fluctuating attention; last week she was fully alert and independent. Temperature is 38.6 °C. Urinalysis shows nitrites and 60 white cells per high-power field. Leukocytes are 16.5 × 10⁹/L, sodium 132 mmol/L, and corrected calcium 2.06 mmol/L. Which of the following is the most appropriate next step in management?

Accepted Answer

A. Start empiric intravenous antibiotics — This is hyperactive-hypoactive fluctuating delirium precipitated by an acute urinary tract infection in an older adult, and the cornerstone of treatment is prompt identification and correction of the underlying cause. The fever, dysuria, suprapubic pain, pyuria with positive nitrites, and leukocytosis all point to a urinary source, and starting empiric intravenous antibiotics after sending blood and urine cultures treats both the infection and the delirium. Older brains have reduced cholinergic reserve and impaired cerebral autoregulation, so systemic inflammation with cytokine release readily produces acute global cerebral dysfunction, and delirium is often the only presenting sign of infection in this age group. The mild hyponatremia at 132 mmol/L is far too modest to cause encephalopathy, since symptomatic hyponatremia usually requires a sodium below about 125 mmol/L, and hypertonic saline is reserved for seizures or severe symptomatic hyponatremia because overcorrection risks osmotic demyelination. The calcium of 2.06 mmol/L is only marginally low and is asymptomatic without tetany, Chvostek or Trousseau signs, or QT prolongation, so intravenous calcium is unnecessary and would not improve cognition. Antipsychotics such as haloperidol are reserved for severe agitation that threatens patient or staff safety after non-pharmacologic measures have failed, and they treat the symptom while leaving the cause untreated, with risks of extrapyramidal effects and QT prolongation. Supportive delirium care includes reorientation, restoring the sleep-wake cycle, providing glasses and hearing aids, early mobilization, adequate hydration, avoiding urinary catheters and physical restraints, and reviewing anticholinergic and sedative medications.

Delirium Secondary to Urinary Tract Infection

Explanation

Why each option

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