When should a patient with kidney stones be referred to a urologist or emergency department?

When to Refer Patients with Kidney Stones to a Urologist or Emergency Department

Patients with kidney stones should be referred to the emergency department immediately if they have severe pain unresponsive to analgesia within one hour, signs of infection/sepsis, or complete obstruction, while referral to a urologist is indicated for recurrent/extensive nephrolithiasis, stones >10mm, or stones failing to pass with conservative management.

Emergency Department Referral Criteria

Immediate ED Referral Required For:

• Patients with acute renal colic who cannot be assessed within 30 minutes should be sent to the emergency department 1
• Failure of pain control with analgesia within one hour requires immediate hospital admission 1
• Patients with shock or fever must be admitted to hospital immediately due to risk of sepsis 1
• Patients with signs of urinary tract infection with obstruction (fever, chills) as this represents a urologic emergency 2
• Abrupt recurrence of severe pain after initial relief warrants immediate admission 1
• Patients with high-grade obstruction seen on imaging 3
• Patients with a single kidney and acute obstruction 1

Clinical Assessment Findings Requiring ED Referral:

• Abnormal vital signs, particularly tachycardia, hypotension, or fever 1
• Inability to tolerate oral fluids or medications 4
• Severe pain requiring intravenous narcotics (these patients are more likely to return to the ED) 5
• Patients over 60 years with flank pain (to rule out abdominal aortic aneurysm) 1
• Women with delayed menses and flank pain (to rule out ectopic pregnancy) 1

Urologist Referral Criteria

Referral to Urologist Recommended For:

• Recurrent or extensive nephrolithiasis 1, 6
• Stones that fail to pass with conservative management after an appropriate trial period 4
• Proximal ureteral stones (these have higher rates of ED revisits) 5
• Stones >10mm in diameter (less likely to pass spontaneously) 4
• Patients with anatomical abnormalities of the urinary tract 4
• Patients with solitary kidney and kidney stones 1
• Patients with bilateral obstructing stones 1
• Patients with persistent hematuria after stone passage 3
• Patients with high-risk metabolic conditions for stone formation 4

Management Algorithm Before Referral

Initial Assessment:

• Diagnose based on history of abrupt onset of severe unilateral flank pain radiating to groin/genitals 1
• Perform urinalysis - presence of hematuria supports diagnosis (>80% of renal colic cases) 1
• Examine abdomen to establish site of maximal tenderness and exclude other conditions 1
• Check vital signs to exclude shock and systemic infection 1

Pain Management:

• Administer analgesia promptly - diclofenac 75mg intramuscular injection is preferred 1
• Follow up by phone within one hour to assess pain control 1
• If pain is not controlled within one hour, arrange immediate hospital admission 1

Follow-up and Investigations:

• All patients with suspected renal colic should receive follow-up imaging to confirm diagnosis 1
• Renal ultrasonography is recommended as first-line imaging, especially in pregnant patients 4
• Patients managed at home should increase fluid intake and strain urine to catch any passed stones 1
• Medical expulsive therapy (alpha-blockers) should be considered for stones ≤10mm in the distal ureter 1, 4

Common Pitfalls to Avoid

• Failing to recognize signs of infection with obstruction, which is a urologic emergency requiring immediate intervention 2
• Delaying referral for patients with fever and flank pain 1
• Inadequate pain management - pain should be controlled within 30 minutes 1
• Missing alternative diagnoses in atypical presentations (abdominal aortic aneurysm in older patients, ectopic pregnancy in women of childbearing age) 1
• Failing to arrange appropriate follow-up imaging to confirm stone passage 1
• Not recognizing that younger patients (<30 years) have higher rates of ED revisits and may need closer follow-up 5

Special Considerations

• Patients with known chronic kidney disease and nephrolithiasis should be referred to nephrology 1
• Patients with uric acid stones may benefit from oral chemolysis with urinary alkalinization 1
• Patients on antithrombotic therapy require special consideration before interventional procedures 1
• Pregnant patients with kidney stones should always have renal ultrasound as the first imaging modality 4