Definition/Key Clinical Features
Differential Diagnosis
Best Tests
Best Therapy
Best References

Definition/Key Clinical Features

• Acute nephrolithiasis (renal colic)
• Severe pain, abrupt in onset
• Constant, rather than colicky
• Localized to flank or radiating from flank to groin
• May be associated with nausea and vomiting
• Microscopic or macroscopic hematuria
• Atypical presentations
• Midanterior abdominal pain
• Obstruction without pain or hematuria
• Progressive renal failure
• Urosepsis
• Adynamic paralytic ileus
• Passage of most kidney stones < 5 mm diameter within 48 hr
• Intervention to effect passage of stone required in 20% of patients
• Chronic and recurrent nephrolithiasis
• Recurrence in 40% of males within 5 yr of first stone; 60% within 10 yr
• Recurrence rate in females about two thirds of the rate in males
• Chronic nephrolithiasis often asymptomatic
• Cumulative occurrence of a symptomatic event is 50% over 5 yr
• Calcium stones most common (calcium oxalate > calcium phosphate)

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Differential Diagnosis

• Sloughed renal papilla
• Clot
• Fungal ball

• Calcium-containing stones
• Tubular disorders (renal tubular acidosis)
• Hypercalcemia and hypercalciuria
• Hyperoxaluria
• Hyperuricosuria
• Reduced urine volume
• Abnormalities in excretion of inhibitors of stone formation
• Presence of promoters of stone formation
• Uric acid stones
• Persistently acid urine
• Gout
• Struvite stones
• Urinary tract infection by ectoenzyme urease-secreting organisms
• Proteus
• Pseudomonas
• Klebsiella
• Providentia
• Serratia
• Staphylococcus
• Cystine stones
• Cystinuria
• Drug-induced stones
• Indinavir
• Nelfinavir

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Best Tests

• Laboratory studies
• Urinalysis
• Stones or gravel
• Crystalluria
• Hematuria
• Urine culture and sensitivity
• Imaging studies
• Flat abdominal film
• Helical CT scan
• Obtain if hematuria absent or stone not seen on abdominal film
• Superior to intravenous urography in diagnosing acute nephrolithiasis
• Ultrasonography
• May fail to identify stones < 5 mm diameter
• Cannot define degree or site of obstruction
• Intravenous urography (IVU)

• Laboratory studies
• Urinalysis
• Crystallographic analysis
• Urine and stone culture
• Fasting urinary pH
• 24-hr urine levels
• Calcium
• Phosphate
• Uric acid
• Sodium
• Citrate
• Oxalate
• Cystine
• Creatinine
• Urea nitrogen
• Urine volume
• Plasma levels
• Calcium
• Phosphate
• Uric acid
• Creatinine
• Bicarbonate
• Urea nitrogen
• Imaging studies
• Flat abdominal film
• Initial study of choice
• Useful for monitoring in situ stones
• Non–contrast-enhanced spiral CT
• IVU
• Shows site of obstruction
• Allows assessment of urine flow
• Ultrasonography

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Best Therapy

• Emergent care
• Suspected stone with fever, urinary tract infection, or both
• Hospital admission
• Intravenous antibiotics
• Removal of stone after infection stabilized
• Supportive therapy
• Analgesia
• Hydration
• Hospital admission
• Urinary tract obstruction
• Severe pain
• Intractable vomiting
• Therapy for confirmed nephrolithiasis with total obstruction
• Nephrostomy and percutaneous lithotripsy
• Extracorporeal shock wave lithotripsy (ESWL)
• Retrograde basket removal
• Surgery

• Prevention of renal stone formation and growth
• Specific treatment of underlying disorders
• Adequate hydration
• Reduction of concentration of stone-forming constituents in urine
• Dietary modification
• Drugs
• Urinary alkalinization/acidification
• Correction of mechanical or structural abnormalities associated with urinary tract stasis
• Invasive therapy
• ESWL
• First choice for most renal and proximal ureteral stones
• Percutaneous nephrostolithotomy/open surgery
• Stones > 2 cm diameter or complex calculi
• Cystine stones that are relatively resistant to ESWL
• Anatomic abnormalities (e.g., horseshoe kidney, ureteropelvic junction obstruction)
• Stones within caliceal diverticula

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Best References

Bihl G, et al: Lancet 358:651, 2001 [PMID 11530173]

Coe FL, et al: N Engl J Med 327:1141, 1992 [PMID 1528210]

Consensus Conference: JAMA 260:977, 1988 [PMID 3294456]

Delvecchio FC, et al: Curr Opin Urol 13:229, 2003 [PMID 12692447]

Rivers K, et al: Urol Clin North Am 27:203, 2000 [PMID 10778464]

October 2006