Nephrolithiasis

Orson W. Moe, MD
Khashayar Sakhaee, MD
Naim M. Maalouf, MD
University for Texas Southwestern Medical Center, Dallas, TX

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 if bilateral or unilateral functional kidney
• Urosepsis (usually with obstruction)
• Adynamic paralytic ileus
• Passage of most kidney stones, increases with smaller size and distal location
• Medical expulsive therapy is useful but surgical intervention to effect passage of stone required in 10% of patients
• Chronic and recurrent nephrolithiasis
• Recurrence in 50% of males within 5 yr of first stone; 75% within 10 yr
• Chronic nephrolithiasis often asymptomatic
• Calcium stones most common (calcium oxalate > calcium phosphate), followed by uric acid

back to top

Differential Diagnosis

• Sloughed renal papilla
• Clot
• Fungal ball
• Non-renal intraabdominal processes

• Calcium-containing stones
• Hypercalciuria
• Hypocitraturia
• Hyperoxaluria
• Hyperuricosuria
• Reduced urine volume
• Imbalance of promoters vs. inhibitors of stone formation
• Uric acid stones
• Persistently unduly acidic urine
• Hyperuricosuria
• Struvite stones
• Urinary tract infection by ectoenzyme urease-secreting organisms
• Proteus
• Pseudomonas
• Klebsiella
• Providentia
• Serratia
• Staphylococcus
• Cystine stones
• Cystinuria
• Drug-induced stones
• Indinavir
• Nelfinavir
• Others

back to top

Best Tests

• Laboratory studies
• Urinalysis
• 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 with pH
• Stone analysis
• 24-hr urine levels
• Urine volume
• Calcium
• Phosphate
• Uric acid
• Sodium
• Potassium
• Citrate
• Oxalate
• Cystine (not routinely)
• Creatinine
• Urea nitrogen
• Sulfate
• pH
• Ammonium
• Titratable aciditiy
• Plasma levels
• Calcium
• Phosphate
• Uric acid
• Creatinine
• Electrolyte
• Urea nitrogen
• Imaging studies
• Flat abdominal film
• Non–contrast-enhanced spiral CT
• Ultrasonography
• IVU

back to top

Best Therapy*

• Supportive therapy
• Analgesia
• Hydration
• Intravenous antibiotics if infection present
• Hospital admission
• Urinary tract obstruction
• Intractable pain
• Non passage
• Therapy for confirmed nephrolithiasis with total obstruction
• Medical expulsive therapy
• 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 depending on the stone type
• 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

back to top

Best References

Coe FL, Evan A, Worcester E: J Clin Invest 115:2598-608, 2005 [PMID 16200192]

Evan A, Lingeman J, Coe FL, Worcester E: Kidney Int 69:1313-8, 2006 [PMID 16614720]

Moe OW: Lancet 367:333-44, 2006 [PMID 16443041]

Cameron MA, Sakhaee K, Moe OW: Pediatr Nephrol 20:1587-92, 2005 [PMID 16133066]

Tracy CR, Pearle MS: Curr Opin Urol 19:200-4, 2009 [PMID 19188774]

* To obtain additional drug information, click on the DrugInfo tab in the left column, or click on the following link: http://search.medscape.com/drug-reference-search?queryText=

April 2010