Initial Management of Kidney Stones
The initial management of a kidney stone centers on immediate pain control with NSAIDs, aggressive hydration to achieve at least 2.5 liters of urine output daily, and assessment for infection or obstruction that would require urgent intervention. 1
Immediate Assessment
Exclude Infection and Obstruction
- Obtain urinalysis with both dipstick and microscopic evaluation to assess for pyuria, bacteriuria, and pH abnormalities that suggest infection 1
- Send urine culture immediately if urinalysis suggests infection or if the patient has recurrent UTIs 1
- Check serum chemistries including electrolytes, creatinine, and uric acid to assess for systemic involvement 1
- A urinary tract infection in the setting of obstruction is a urologic emergency requiring immediate drainage, usually with a ureteral stent 2
Imaging
- Non-contrast CT scan is the standard imaging modality for stone diagnosis 3
- Renal ultrasonography is the recommended first-line imaging in pregnant patients 4
- Review imaging to quantify stone burden and location, as this determines treatment approach 1
Acute Pain Management
- Use NSAIDs as first-line therapy for renal colic 1
- Reserve opioids only for severe uncontrolled pain that fails to respond to NSAIDs 1
- About 90% of stones causing renal colic pass spontaneously, so conservative management is appropriate for most patients 2
Hydration Protocol
- Mandate immediate fluid intake sufficient to produce at least 2.5 liters of urine daily, which reduces stone recurrence by approximately 50% 1
- Encourage water, coffee, tea, and orange juice, while strictly avoiding sugar-sweetened beverages, particularly colas acidified with phosphoric acid 1
- High fluid intake is the most powerful and economical means of prevention and should be initiated immediately 5
Medical Expulsive Therapy
- Medical expulsive therapy (MET) with alpha-blockers like tamsulosin is considered first-line therapy for uncomplicated distal ureteral stones 10 mm or less in diameter 6, 4
- This facilitates spontaneous stone passage and is appropriate when stones do not resolve with observation alone 4
Stone Recovery and Analysis
- Instruct the patient to strain urine to recover stone material for analysis 2
- Stone analysis should be obtained at least once when material is available, as this guides long-term prevention strategies 1
Indications for Urgent Intervention
High-grade obstruction, failure of oral analgesics to relieve pain, or infection with obstruction requires hospitalization and possible urgent urologic intervention 2. Surgical options include extracorporeal shock wave lithotripsy, percutaneous nephrolithotomy, ureteroscopy, ureteral stents, or nephrostomy tubes depending on stone size and location 4, 2.
Initial Dietary Counseling
Even during acute management, begin counseling on:
- Maintaining normal dietary calcium at 1,000-1,200 mg daily from food sources 1, 7
- Limiting sodium intake to 2,300 mg (100 mEq) daily 1, 7
- Reducing animal protein intake to 5-7 servings per week 1
- Avoiding calcium supplements, which increase stone risk by 20% compared to dietary calcium 1