NEPHROLITHIASIS Diagnosis & Treatment

Transcription

1 Learning Objectives NEPHROLITHIASIS Diagnosis & Treatment Jai Radhakrishnan, MD, MS Professor of Clinical Medicine Columbia University Management of the first episode of renal colic: Optimal Imaging Treatment issues Pain Intervention Discharge Managing Recurrent stones Biochemical workup Treatment according to type of stone Pathogenesis Stone Facts Urine is normally super - saturated NIDUS Stone promoters Stone inhibitors Prevalence 12 percent of the population will have a urinary stone during their lifetime White men> white women> black women> and black men Estimated cost: 2 billion dollars/year 1,825,000 office visits in Prevalence: White Males Growth of the U.S. Kidney Stone Belt in Response to Projected Climate Change STONE BELT PNAS 2008;105: Curhan GC et al. J Urol 1994 Apr;151(4): by The National Academy of Sciences of the USA

2 Composition Case 1: The first stone A 25 year old male with no past medical history presents with acute L flank pain ( like I pulled a muscle ) Family history is notable for kidney stones in his maternal uncle Physical exam, chemistries, and blood counts are normal. Urinalysis: Trace protein and heme, 0-2 RBC s QUESTION: What is the next step? 1. Discharge from ED-urine is normal 2. KUB and intravenous urogram 3. CT urogram (without contrast) 4. Renal ultrasound Clinical Presentation Acute, colicky flank pain radiating to the groin Exam: CVA tenderness may be present Hematuria Seen in 90% Absence does not rule out stones Presence in a pt with flank pain is not diagnostic of stone Radiological Diagnosis of Stones Helical non-contrast CT USG + KUB Intravenous Urogram Renal Colic: Differential Diagnosis Radiological Diagnosis of Stones Helical non-contrast CT: the study of choice Faster and more sensitive than IVP Does not require contrast Can visualize uric acid stones Diagnosis of urinary tract abnormalities which predispose to stones R/o conditions which may masquerade as renal colic.

3 Role of Plain Abdominal Xray (KUB) Role of Renal USG To see if stone is radioopaque Radiolucent: Uric acid, indinavir. High specificity (>90 percent), Sensitivity 11 to 24 percent Usually 1 st step in pregnant patients with colic (MR can also be used) For the follow up of stones to monitor growth Case 1: The first stone ANSWER: What is the next step? 1. Discharge from ED-urine is normal 2. KUB and intravenous urogram 3. CT urogram (without contrast) 4. Renal ultrasound CT urogram shows a 9 mm radio-opaque stone in the R ureteropelvic junction. QUESTION 2: How would you treat the patient? 1. Aggressive IV fluids and narcotics 2. Aggressive IV Fluids and NSAIDS 3. NSAIDs and tamsulosin 4. Call Urology Management of Renal Colic: IV Fluids No difference in pain scales when no fluids vs. 3 liters IVF for 6 hours Scandinavian Journal of Urology & Nephrology 1983;17(2): No difference in pain/rate of passage when 3L NS vs. 20ml/hour J Endourol Oct;20(10):713-6 Management of Renal Colic Ketorolac vs. meperidine? Am J Emerg Med Jan;17(1):6-10.

4 Expulsive Therapy: α-antagonists Expulsive Therapy: Calcium Channel Blocker-Nifedipine Ann Emerg Med Nov;50(5):552-6 Ann Emerg Med Nov;50(5):552-6 Likelihood of Passage of Ureteral Stones 5 mm 68% (95% CI: 46% to 85%) >5 mm and 10 mm 47% (95% CI: 36% to 59%) Repeat imaging to confirm stone passage Urologic Intervention? INDICATIONS Stone size >10 mm/persistent Obstruction Infection Uncontrolled pain, nausea/vomiting TECHNIQUES Extracorporeal shock wave lithotripsy Ureteroscopic removal Percutaneous Nephrolithotomy [Open surgery] 2007 Guideline for the Management of Ureteral Calculi. J Urol Dec;178(6): ESWL: Extracorporeal Shock Wave Lithotripsy Proximal stones < 2cms Contraindications Bleeding tendencies Pregnancy Uncontrolled HTN UTI Morbid obesity Long Term Risks??Renal Insufficiency?HTN Ureteroscopic removal Fragmentation of stone by laser, electrohydraulic, or ultrasound. Most stones can be treated.

5 Percutaneous Nephrolithotomy Large proximal stones CT urogram shows a 9 mm radio-opaque stone in the R ureteropelvic junction. QUESTION 2: How would you treat the patient? 1. Aggressive IV fluids and narcotics 2. Aggressive IV Fluids and NSAIDS 3. NSAIDs and tamsulosin 4. Call Urology Case 1: The first stone The stone is endourologically removed. Management After First Stone Episode -Laboratory evaluation Creatinine, HCO3, calcium and phosphate. Urine analysis, urine culture 24-hour collections are not generally needed Except in children (cystine, hyperoxaluria) What workup do you need to do? 1. No workup hour urine for stone risk analysis 3. Urine culture, basic metabolic profile, phosphate 4. Let the stone clinic handle this. Management After First Stone Episode - Evaluation of risk factors Occupation/Environment Management After First Stone Episode -Referral to Stone Clinic Children Solitary kidney Family history Diet: protein, purines, Na, fluid, Ca, oxalate Medications: Triamterene Indinavir, Sulfonamides Carbonic anhydrase inhibitors. Triamterene Struvite stones Abnormal renal function RTA` Indinavir

6 Case 1: The first stone What workup do you need to do? 1. No workup hour urine for stone risk analysis 3. Urine culture, basic metabolic profile, phosphate 4. Let the stone clinic handle this. Urine culture is negative BMP, Phosphate are normal. Stone analysis: Calcium oxalate. What diet advice do you give the patient? 1. 2 liters water, no special diet 2. 2 liters water, low salt, low protein, normal calcium 3. 2 liters water, low calcium 4. Drink lots of beer (+pretzels to avoid hyponatremia) Water >2.2 Liters Liters Which Beverage? Decreased Risk Coffee Tea Beer Wine Increased Risk Grapefruit juice J Urol Mar;155(3): Curhan GC et al. Am J Epidemiol 1996 Feb 1;143(3): Comparison of Two Diets for the Prevention of Recurrent Stones in Idiopathic Hypercalciuria Risk of Stones with Calcium+D Supplementation HR 1.17 [CI 1.02 to 1.34] Borghi L., N Engl J Med 2002; 346: N Engl J Med Feb 16;354(7):669-83

7 Timing of Calcium Supplement and Urinary Oxalate Effect of Low-carbohydrate High-protein Diets Kidney Int May;65(5): Reddy ST Am J Kidney Dis Aug;40(2): Management After First Stone Episode -Therapeutic Recommendations for Calcium Stones Increase urine volume to 2-2.5L/day Diet: Na <2g/day Protein <8oz/day Oxalate as low as possible Do not restrict dietary calcium Calcium supplements may increase risk Management After First Stone Episode -Recurrence Rate after the First Episode What diet advice do you give the patient? 1. 2 liter water, no special diet 2. 2 liters water, low salt, low protein, normal calcium 3. 2 liters water, low calcium 4. Drink lots of beer (+pretzels to avoid hyponatremia)

8 Case Review Emergency management Indications for referral to stone clinic Preventive strategies to start Case 2: Recurrent Stones The patient followed your instruction to adequately hydrate himself and reduce salt and protein intake. However, he experienced 3 further episodes of colic and analysis of one stone revealed calcium oxalate. How would you work up this patient? What specific treatment can you recommend based on your investigations? Workup of Recurrent Stone Formers Urine (24 hour) collections for Calcium Oxalate Citrate Uric acid ph Cystine at least once Urine culture if struvite/staghorn. The Report Calcium Stones: Pathogenesis & Treatment All patients: Urine volume >2L/day Dietary restriction: Na, Protein, oxalate Hypercalciuria Thiazides Hypocitraturia K- or Mg-K-citrate Hyperoxaluria Dietary restriction of oxalate Hyperuricosuria Dietary restriction of purine Allopurinol Primary hyperparathyroidism Parathyroidectomy Distal RTA NaHCO3 therapy Uric Acid Stones A 50-year-old male presents with the third episode of renal colic. The stone is 100% uric acid. 24 hour urine shows ph 5.5, normal levels of uric acid, calcium citrate and oxalate. The most important component of treatment is: 1. Raising urine ph 2. Reducing urinary uric acid levels with allopurinol 3. Increasing urine volume 4. Low purine diet Ann Intern Med Apr 2;158(7):535-43

9 Uric Acid Stones Pathogenesis Low urine ph Hyperuricosuria Radiolucent stones Treatment of Uric Acid Stones All patients Restrict animal protein and salt Alkalinize urine K-citrate K-Mg-citrate Urine volume not critical Hyperuricosuria Allopurinol Struvite Stones The most important component of treatment is: 1. Raising urine ph 2. Reducing urinary uric acid levels with allopurinol 3. Increasing urine volume 4. Low purine diet Urease-producing organisms (Proteus) MgNH 4 PO 4 Surgical treatment and antibiotics Guess the stone A 24-year-old male new to your practice has a history of stones since age 6. He does not have his records. Urinalysis is shown on the right. What kind of stones is he likely to have?: 1. Struvite 2. Cystine 3. Calcium phosphate 4. Uric Acid Cystine Stones Hereditary disorder(recessive) of dibasic amino acids May present with staghorn calculi Hexagonal crystals in the urine Treatment High Fluid Intake Alkalinize urine ph>7.5 Penicillamine Mercaptopropinylglycine

10 Conclusions Kidney stones are common. For renal colic, non-contrast CT urogram is the optimal imaging technique. After the first stone, lifestyle changes should be instituted A biochemical workup and specific treatment plan should be performed for recurrent stone formers. E N D Footer text is edited under "view/header and footer" menu May 22, 2013 Page 56