What information should be included in a urology referral for a patient with kidney stones?

Essential Information for Urology Referral for Kidney Stones

Include imaging results, stone characteristics, clinical status, laboratory values, and treatment history in every urology referral for kidney stones to enable appropriate surgical planning and risk stratification.

Imaging Documentation

• Provide non-contrast CT scan results showing stone size (measured in millimeters), exact anatomic location (upper/middle/lower calyx, renal pelvis, or ureteral position), stone density in Hounsfield units, and presence/degree of hydronephrosis 1
• Include stone burden calculation (cumulative diameter if multiple stones present) and specify whether stones are in lower pole versus non-lower pole locations, as this affects treatment selection 1
• Document any anatomic abnormalities such as horseshoe kidney, pelvic kidney, duplicated collecting system, ureteropelvic junction obstruction, or history of prior urological surgery, as these require specialized surgical approaches 1

Stone Characteristics

• Send previous stone analysis results if available, as stone composition (calcium oxalate, calcium phosphate, uric acid, struvite, cystine) directly determines surgical approach and post-treatment prevention strategies 1
• Note radiographic appearance on plain X-ray (radiopaque versus radiolucent), which helps predict stone composition and influences treatment planning 1

Clinical Status and Symptoms

• Document presence or absence of infection signs including fever, positive urinalysis, or positive urine culture results, as infected obstructing stones require urgent intervention to prevent urosepsis 1, 2
• Specify pain control status—whether symptoms are well-controlled or intractable, as this affects urgency of referral 1
• Note any neurological symptoms or bone pain that might suggest metastatic complications requiring additional workup 1

Laboratory Values

• Include serum creatinine, BUN, and estimated GFR to assess renal function, as progressive renal insufficiency may require nephrology co-management and affects surgical risk stratification 1
• Provide urinalysis results and urine culture if infection is suspected based on clinical or laboratory findings 1
• Include CBC and platelet count if there are symptoms suggesting anemia, thrombocytopenia, or infection, particularly for procedures with significant hemorrhage risk 1
• Send serum electrolytes if reduced renal function is suspected 1

Treatment History

• Detail all prior interventions including dates of previous shock wave lithotripsy (SWL), ureteroscopy (URS), or percutaneous nephrolithotomy (PCNL), along with outcomes and any complications 1
• Document duration of conservative management attempts, including medical expulsive therapy (MET) with alpha-blockers, and whether the stone has changed position on serial imaging 1
• Note any residual fragments from prior procedures, as these require different management strategies 1

Medical History Relevant to Stone Disease

• Include history of recurrent stones, number of prior episodes, and time intervals between episodes to establish risk stratification (low versus moderate-to-high risk) 1
• Document metabolic evaluation results if available, including 24-hour urine collection showing calcium, oxalate, citrate, uric acid, cystine, and volume 1
• List relevant comorbidities including diabetes, obesity, metabolic syndrome, chronic kidney disease stage, and any genetic conditions associated with stone formation 1
• Note current medications, particularly those affecting stone formation or surgical risk (anticoagulants, immunosuppressants, medications causing drug stones) 1

Urgency Indicators

• Flag any of these requiring urgent/emergent referral: evidence of urinary tract infection with obstruction, intractable pain despite medical management, solitary kidney with obstruction, bilateral obstruction, or acute kidney injury 2
• Specify if patient has failed conservative management beyond 4-6 weeks, as prolonged obstruction risks irreversible kidney injury 1

Special Populations

• For pediatric patients, note age and any history of urological abnormalities, as children have different treatment algorithms 1
• For pregnant patients, clearly state gestational age and any pregnancy-specific complications 1
• For patients with suspected cystine or uric acid stones based on imaging characteristics (radiolucent stones), highlight this as it affects treatment selection 1

Common Pitfalls to Avoid

• Never assume small stones will pass spontaneously if hydronephrosis is present—obstruction changes risk-benefit calculations and may require intervention regardless of stone size 2
• Do not delay referral for suspected infection with obstruction, as this can rapidly progress to urosepsis 2
• Avoid sending referrals without imaging documentation, as urologists cannot plan appropriate treatment without knowing exact stone characteristics 1
• Do not omit prior stone analysis results if available, as this information is critical for preventing recurrence and may influence acute management 1