What is the recommended emergency department disposition for a patient with a 5mm ureteral stone and impaired renal function?

Emergency Department Disposition for a 5mm Ureter Stone with Impaired Renal Function

A patient with a 5mm ureteral stone and elevated creatinine (1.5) should be admitted to the hospital for urgent urological intervention due to the high risk of obstructive uropathy and potential for permanent renal damage.

Assessment of Clinical Situation

Stone Characteristics

• Size: 5mm stones represent a critical threshold:
  • Stones >5mm have only a 50% chance of spontaneous passage 1
  • 5mm stones specifically have only a 65% spontaneous passage rate within 20 weeks 2
  • Average passage time for 4-6mm stones is 22.1 days 1

Evidence of Renal Impairment

• Creatinine of 1.5 indicates:
  • Impaired renal function
  • Likely obstructive uropathy
  • Risk of progressive kidney injury if obstruction persists

Management Algorithm

Step 1: Immediate Evaluation

• Confirm stone location with non-contrast CT (gold standard imaging) 3
• Obtain urinalysis to assess for infection 3
• Obtain urine culture if infection is suspected 3
• Complete blood count to evaluate for systemic infection 3

Step 2: Disposition Decision

• Admit for urgent intervention if:
  • Elevated creatinine (as in this case)
  • Evidence of infection/sepsis
  • Intractable pain
  • Solitary kidney
  • Bilateral obstruction

Step 3: Intervention Options

1. Urgent decompression options:

   • Ureteral stent placement
   • Percutaneous nephrostomy tube

2. Definitive management options (after stabilization):

   • Ureteroscopy (URS) - preferred for 5mm stones 3
   • Shock wave lithotripsy (SWL) - alternative option 3

Rationale for Hospital Admission

1. Obstructive uropathy: The elevated creatinine indicates kidney function impairment from obstruction, which requires prompt intervention to prevent permanent damage

2. Low spontaneous passage probability: 5mm stones have only a 65% chance of spontaneous passage 2, and passage may take weeks

3. Risk of complications: Continued obstruction can lead to:

   • Worsening renal function
   • Pyelonephritis
   • Urosepsis
   • Permanent kidney damage

Important Caveats

• If purulent urine is encountered during intervention, the procedure should be aborted, drainage established, and antibiotics administered 3

• Blind basketing (stone extraction without direct visualization) should never be performed due to risk of ureteral injury 3

• In patients with bleeding disorders or on anticoagulation, ureteroscopy is preferred over other interventions 3

• The patient should be monitored for signs of infection, as untreated bacteriuria combined with obstruction can lead to urosepsis 3