Medical treatment of Urolithiasis Dr Wael

Renal Stone disease Dr. Wael El-Reshaid Consultant Nephrologist Faculty of Medicine Case A 24 year old man presented to the emergency room with severe colicky pain in the left lower abdomen of 12 hours duration. He is afebrile and his investigations were as follow: s-creatinine: Urinalysis: 74 µmol/l excess RBCs / HPF 6-8 WBCs / HPF Plain KUB shows 7 mm stone opposite L1 – L2 on the left side 1. What is the differential diagnosis of : a) right lower abdominal pain b) left lower abdominal pain 2. What are the possible clinical presentations of a patient with renal stone disease? 3. What are the types of renal stones and their incidence ? 4. What are the factors the lead to formation of renal stones ? 5. What are the expected findings in terms of: a) Laboratory investigations b) Radiological imaging 6. Outline the management of a patient with acute renal colic. 7. Outline the management of a patient with recurrent stone disease. Differential diagnosis Left abdominal quadrant pain: - Renal colic - Intestinal colic / sigmoid colon - Ovarian cyst / ectopic pregnancy (females) Right abdominal quadrant pain: As above + appendicular origin Possible presentations of renal stones - asymptomatic. - colicky pain with typical radiation. (  passage of stone ) - hematuria. - complications: obstruction or infection Incidence of renal stones • 1-2 / 1000 population /yr. • Male / female: 2 - 3 x • peak onset: 3 rd decade • peak incidence: 5 - 6th decade Types of renal stones • • • • • • Calcium oxalate Calcium oxalate + apatite Mg NH4 PO4 ( struvite ) Uric acid Cystine Calcium PO4 40 % 30 % 10 - 20 % 5 - 10 % 1-2% 1% Pathogenesis of renal stones 1) formation product ( Kf ): ion activity product at which salt crystals spontaneously nucleate. a) fluid intake. b) 24 hr urine excretion of salt. 2) urinary PH: Ca PO4 stones form at PH: 6 -7 ( HPO4 ) but not at PH < 5.8 ( H2PO4 ). 3) presence or absence of urinary inhibitors: Mg complexes oxalate citrate complexes Ca++ Laboratory investigations a) serum: electrolytes, creatinine, Ca++, PO4 , albumin, uric acid. b) urinalysis + PH. c) 24 hr urine: creatinine, volume, PH, Na+. Ca++, oxalate, uric acid, Mg, citrate. Cystine ( if indicated ). d) Stone analysis: Radiological investigations 1. X-rays of kidneys : all stones radioopaque except uric acid ( radioluscent ) 1. Ultrasound 2. IVU ( if indicated ). Acute renal colic - Fluids - Analgesics - Anti-spasmolytics - Anti-emetics - Seiving the urine for stones - Urological consultation if obstruction Calcium oxalate / apatite ↑ calcium normal calcium ↑ PTH normal PTH hypercalciuria normal U- calcium hyperuricosuria hyperoxaluria hypocitraturia idiopathic ↑ vit D normal vit D Acidosis No acidosis (distal RTA ) Non calcium stones Struvite (infection) Ureas splitting bacteria e.g. Proteus cysteine Uric acid ↑ serum or urinary uric acid normal Management of Renal Stones • • • • • • Encourage fluid intake ( 2 – 3 l / d ) Decrease “ salt “ Treat underlying disease ( sarcoidosis, MM… etc. ) Treat urinary tract infection Change urinary PH ( if indicated ) Infection or total obstruction Surgical intervention