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NephrolithiasisAka: Urolithiasis, Kidney stone, Renal Calculi, Ureteral Calculus, Renal Colic

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  1. Epidemiology
    1. Prevelance: 0.2% in U.S.
    2. Life-time risk
      1. Males: 10-12%
      2. Females: 3-5%
    3. Recurrence of nephrolithiasis: 50%
    4. Peak age 20-50 years
    5. Gender associations: Overall Male:Female ratio 4:1
      1. Males: Calcium oxalate
      2. Females: Struvite
      3. Both: Urate Stones and Cystine Stones
  2. Pathophysiology
    1. Stone formation is inhibited by Citrate
    2. Women have much higher levels of citrate than men
    3. Low citrate levels are related to most stone forms
  3. Risk Factors
    1. See Nephrolithiasis Risk Factors
  4. Types of Stones
    1. Calcium Nephrolithiasis (75%)
      1. Calcium oxalate (70%)
      2. Calcium Phosphate (5-10%)
    2. Uric Acid Nephrolithiasis (10-15%)
    3. Struvite (15-20%)
    4. Cystine (1%)
    5. Drug-Induced (1%)
      1. Indinavir
      2. Triamterene
  5. Symptoms: Renal Colic
    1. Severe Abdominal Pain of sudden onset
      1. Unilateral flank pain
      2. Lower Abdominal Pain
    2. Associated symptoms
      1. Nausea and Vomiting
  6. Symptoms related to stone location
    1. Kidney
      1. Vague flank pain
      2. Hematuria
    2. Proximal Ureter
      1. Flank pain
      2. Upper Abdominal Pain
      3. Renal colic
    3. Mid-Ureter
      1. Flank pain
      2. Anterior Abdominal Pain
      3. Renal colic
    4. Distal ureter (Ureteropelvic junction)
      1. Dysuria
      2. Urinary frequency
      3. Anterior Abdominal Pain
      4. Flank pain
      5. Renal colic
  7. Differential Diagnosis
    1. Acute onset of symptoms
      1. Urinary Tract Infection
      2. Acute Prostatitis
      3. Musculoskeletal spasm
      4. Acute Constipation or other acute bowel disorder
    2. Chronic intermittent or insidious onset of symptoms
      1. Bowel disease
      2. Interstitial Cystitis
      3. Inguinal Hernia
      4. Testicular mass
      5. Urothelial or Renal Mass
      6. Benign prostatitic hyperplasia
  8. Radiology
    1. See Nephrolithiasis Imaging
  9. Labs
    1. Initial diagnostics
      1. Urinalysis
        1. Microscopic or Gross Hematuria in 90% of cases
      2. Urine Culture
    2. Evaluation of single stone former without risk
      1. Chemistry panel
        1. Serum electrolytes
        2. Serum Calcium
        3. Serum Phosphorus
      2. Renal Function tests
        1. Blood Urea Nitrogen
        2. Serum Creatinine
      3. Serum Uric Acid
      4. Stone Analysis (nidus and outer layer)
        1. Stone analysis is critical
        2. Microscopic Crystal Analysis
          1. Envelope shape crystal: Calcium oxalate
          2. Diamond shape crystal: Uric Acid
          3. Coffin-lid shape crystal: Struvite
          4. Hexagon shape crystal: Cystine
      5. Urinalysis
      6. Urine Culture (when indicated)
    3. Evaluation of recurrent stone formation
      1. See those labs listed above
      2. Parathyroid Hormone level
      3. 24 hour Urine Collection
        1. Urine pH
          1. Gouty diathesis pH < 5.5
          2. Struvite Calculi form in alkaline urine
        2. Urine Sodium
        3. Urine Creatinine
        4. Urine Calcium (Hypercalciuria >300 mg/day)
        5. Urine Uric Acid (Hyperuricosuria >750 mg/day)
        6. Urine Oxalate (Hyperoxaluria >40 mg/day)
        7. Urine Citrate (Hypocitraturia <320 mg/day)
        8. Urine Magnesium (Hypomagnesuria <50 mg/day)
        9. Other urine labs to consider
          1. Urine pHosphorus
          2. Urine Calcium Oxalate (Supersaturation)
          3. Urine Calcium Phosphate
  10. Management: Indications for Urology Consultation
    1. Failure to pass stone
      1. Unpassed stone after several days
      2. Large calculus
        1. Calculi <5 mm pass spontaneously in 90% of cases
        2. Calculi 10 mm pass spontaneously <10% of cases
    2. Fever and urosepsis
      1. Emergent management required
    3. Intractable pain and Vomiting
    4. High grade ureteral obstruction
    5. Severe pain requiring Narcotics >2 days
    6. Recurrent stone formation
    7. Occupation (unable to return to work until clear)
      1. Police officer
      2. Firefighter
      3. Train engineer
      4. Airline pilot
  11. Management: General
    1. See Prevention below
      1. Fluid and dietary measures apply to both acute management and prevention
    2. See Specific Types
      1. Calcium Nephrolithiasis
      2. Uric Acid Nephrolithiasis
    3. Adequate Analgesics
      1. NSAIDs
        1. Highly effective in renal colic
          1. Cordell (1994) Ann Emerg Med 23(2):262
          2. Cordell (1996) Ann Emerg Med 28:151
        2. NSAIDs compared with Opioids
          1. Equal to or more effective than Opioids
          2. Less Vomiting than with Opioids
          3. Holdgate (2004) BMJ 328:1401
      2. Opioids often required for adequate analgesia
    4. Medications to shorten course (standard of care)
      1. Nifedipine (Procardia)
        1. Hollingsworth (2006) Lancet 368:1171
      2. Tamsulosin (Flomax)
        1. Becoming standard of care (not yet FDA approved)
        2. Other alpha blockers are probably effective
        3. Increases chance of passing ureteral stone to >80%
        4. Preferred over Nifedipine
        5. Porpiglia (2004) J Urol 172:568
  12. Management: Specific Stone Therapy
    1. See Urate Stones
    2. See Calcium Stones
    3. See Struvite Stones
    4. See Cystine Stones (Cystinuria)
  13. Management: Interventions
    1. Anatomic directed stone therapy
      1. Stone above Illiac crest
        1. Extracorporeal Shock Wave Lithotripsy (ESWL)
        2. Pushback and Extracorporeal Shock Wave Lithotripsy
        3. Antegrade or retrograde Ureteroscopy
        4. Percutaneous nephrostomy tube
        5. Open surgery (See Below)
      2. Stone below Illiac Crest
        1. Pushback and Extracorporeal Shock Wave Lithotripsy
        2. Cystoscopy and stent placement
        3. Ureteroscopy and Stone Manipulation (Loop, basket)
        4. Open surgery (See Below)
    2. Available Interventions
      1. Ureteroscopy
        1. Ureteral stone
      2. Ureterorenoscopy
        1. Renal stones <2 cm
      3. Extracorporeal Shock Wave Lithotripsy (ESWL)
        1. Radiolucent calculi
        2. Renal stones <2 cm
        3. Ureteral stones <1 cm
      4. Percutaneous Nephrolithotomy
        1. Renal stones >2 cm
        2. Proximal ureteral stones >1 cm
      5. Open Surgery Procedures in refractory cases
        1. Anatomic nephrolithotomy
        2. Partial nephrectomy
        3. Illeal ureter
  14. Prevention
    1. Maintain fluid intake >2.5 Liters per day
      1. Ingest 8 to 12 ounces fluid at bedtime
      2. Recommended fluids
        1. Water
        2. Citrus juice
    2. Maintain Urine volume > 2 Liters per day
      1. Periodically measure urine output in a 2 liter bottle
    3. Dietary restrictions
      1. Limit animal protein to 8 ounces per day (or <1 gram/kg/day)
      2. Limit sodium intake to 2-4 grams per day
      3. Limit Oxalate Containing Foods
      4. Limit high sugar or fat content (Obesity predisposes to stone formation)
      5. Avoid excessive Vitamin C
    4. Dietary increases or no restriction
      1. Increase vegetable Dietary Fiber
      2. Maintain calcium intake at at least 1000 mg/day
        1. No Dietary Calcium restriction (unless absorptive Hypercalciuria)
        2. Calcium binds oxalate in intestine
  15. References
    1. Goldfarb (1999) Am Fam Physician 60(8):2269
    2. Houshiar (1996) Postgrad Med 100(4):131
    3. Mobley (Feb 1999) Hospital Medicine, p. 21-38
    4. Portis (2001) Am Fam Physician 63(7):1329
    5. Segura (1997) J Urol 158:1915
    6. Teichman (2004) N Engl J Med 350:684
    7. Trivedi (1996) Postgrad Med 100(6):63

Kidney Calculi (C0022650)

Definition (MSH)Stones in the KIDNEY, usually formed in the urine-collecting area of the kidney (KIDNEY PELVIS). Their sizes vary and most contains CALCIUM OXALATE.
ConceptsPathologic Function (T046)
ICD9592.0
EnglishCALCULUS KIDNEY, Calculus of kidney, Kidney Calculi, KIDNEY CALCULUS, KIDNEY STONE, Kidney stones, nephrolith, Renal Calculi, Renal calculus, Renal calculus or stone, Renal stone, Renal stones, Stone in kidney
Spanishcalculo renal, nefrolito, piedra renal
Parent ConceptsUrinary Calculi (C0042018), Nephrolithiasis (C0392525), kidney morphologic (C0549592), Calculus of kidney and ureter (C0156257), Kidney Diseases (C0022658), Kidney Calculi (C0022650), Urolithiasis (C0451641)
SourcesAOD, CCS, COSTAR, CSP, CST, DXP, ICD9CM, MEDLINEPLUS, MSH, MTH, MTHICD9, NCI, NDFRT, OMIM, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)


Nephrolithiasis (C0392525)

Definition (CSP)condition marked by the presence of renal calculi, abnormal concretions within the kidney, usually of mineral salts.
Definition (MSH)Formation of stones in the KIDNEY.
ConceptsDisease or Syndrome (T047)
ICD9592.0
EnglishCALCULUS DISORDERS, Nephrolithiasis, Renal stone - uric acid
Spanishnefrolitiasis
Parent ConceptsKidney Diseases (C0022658), Urinary Calculi (C0042018), Urolithiasis (C0451641), Reason not stated concept (C1276325), Ambiguous concept (C1274012)
SourcesAOD, COSTAR, CSP, CST, DXP, MSH, MTH, MTHICD9, OMIM, QMR, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)


Urolithiasis (C0451641)

Definition (MSH)Formation of stones in any part of the URINARY TRACT, usually in the KIDNEY; URINARY BLADDER; or the URETER.
ConceptsDisease or Syndrome (T047)
EnglishUrinary Lithiasis, Urolithiasis
Spanishlitiasis urinaria, urolitiasis
Parent ConceptsBLADDER ABNORMALITY (C0149632), Abnormal urine (C0235639), Nephrolithiasis (C0392525), Urologic Diseases (C0042075), Duplicate concept (C1274013)
SourcesCOSTAR, CSP, CST, MSH, MTH, OMIM, SCTSPA, SNOMEDCT
Derived from the NIH UMLS (Unified Medical Language System)



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