A 78-year-old man is brought to the clinic by his son for a routine follow-up. The patient… — USMLE Step 2 CK

A $78$ -year-old man is brought to the clinic by his son for a routine follow-up. The patient has a history of advanced Parkinson disease and neurogenic bladder, which is managed with a chronic indwelling urethral catheter. The son reports that over the past week, the urine in the collection bag has become notably turbid and foul-smelling. The patient is otherwise acting at his baseline; he has had no fevers, chills, abdominal pain, or changes in oral intake. Vital signs are temperature $37.0^\circ\text{C}$ ( $98.6^\circ\text{F}$ ), blood pressure $132/82\text{ mm Hg}$ , pulse $74\text{/min}$ , and respirations $14\text{/min}$ . Physical examination demonstrates a soft, non-tender abdomen and no costovertebral angle tenderness. There is no leakage or erythema around the urethral meatus.

A urinalysis is obtained directly from the catheter port:

Test	Result
Color	Turbid
Specific gravity	$1.015$
Leukocyte esterase	Positive
Nitrites	Positive
WBC	$50\text{/hpf}$
Bacteria	Many

A urine culture grows $>100,000\text{ CFU/mL}$ of *Klebsiella pneumoniae*. Which of the following is the most appropriate next step in management?

Reassurance and continued observationCevap
B
Exchange the indwelling catheter and observe
C
Initiate oral ciprofloxacin
D
Initiate oral nitrofurantoin
E
Bladder irrigation with sterile saline

Cevap

Reassurance and continued observation

The correct management is reassurance and continued observation. This patient has asymptomatic bacteriuria (ASB) in the setting of a chronic indwelling urinary catheter. Virtually all patients with chronic indwelling catheters will develop bacteriuria within

2

4

weeks. The presence of cloudy, foul-smelling urine, pyuria (positive leukocyte esterase and elevated WBC count), and positive nitrites on urinalysis are expected findings of chronic colonization. They do not distinguish ASB from catheter-associated urinary tract infection (CAUTI). A diagnosis of CAUTI requires the presence of systemic signs of infection (e.g., fever, altered mental status, hemodynamic instability) or localized urinary symptoms (e.g., flank pain, pelvic discomfort) with no other identifiable source. In the absence of these symptoms, treatment with antibiotics is contraindicated, as it does not prevent future symptomatic infections and strongly promotes antimicrobial resistance.

Adım Adım Çözüm

Evaluate the patient's clinical symptoms in the context of a chronic indwelling catheter.

The patient has turbid, foul-smelling urine but no systemic signs of infection (normal temperature and hemodynamics) or localized symptoms.

Determining the presence of true symptoms is required to distinguish clinical infection from expected bacterial colonization.

Interpret the urinalysis and urine culture results.

The urinalysis demonstrates pyuria and the culture is positive for a high bacterial load of Klebsiella pneumoniae.

While these findings indicate the presence of bacteria and inflammation, they are nearly universal in patients with chronic catheters and do not confirm an active infection.

Determine the appropriate management plan based on the diagnosis of asymptomatic bacteriuria (ASB).

The diagnosis is ASB, which requires reassurance and observation without antimicrobial therapy or catheter exchange.

Antibiotic treatment of ASB does not improve outcomes, fails to prevent future infections, and actively contributes to antimicrobial resistance.

Anahtar Kavram

Cloudy, foul-smelling urine and pyuria are expected findings in patients with chronic indwelling urinary catheters and do not constitute indications for antibiotic therapy in the absence of systemic or localized signs of infection.

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

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