SM_243: Hydronephrosis / Nephrolithiasis Flashcards
Hydronephrosis is ___
Hydronephrosis is a descriptive term referring to the dilation of the renal pelvis and calyces
Obstructive uropathy is ___
Obstructive uropathy is structural impedance to the flow of urine anywhere along the urinary tract
Obstructive nephropathy is ____
Obstructive nephropathy is damage to the renal parenchyma resulting from obstruction of urine flow anywhere along the urinary tract
Describe presentation of acute obstruction
Acute obstruction
- Flank pain
- Lower abdominal pain
- Groin pain
- Penile, testicular, clitoral pain
- Inner thigh pain
- Nausea / vomiting
- Fever and chills (infection)
Describe laboratory tests for obstruction
Obstruction laboratory tests
- Serum: azotemia, hyperkalemia
- Urine: hematuria, proteinuria, pyuria, urinary casts, crystalluria, elevated urinary sodium, decreased osmolality, decreased urine to plasma creatinine ratio
Anuria results from ____ obstruction
Anuria results from bilateral obstruction
Describe acute obstruction
Acute obstruction
- Phase I: RBF and ureteral pressure rise (1-1.5 hours)
- Phase II: decreased RBF, increased ureteral pressure (1.5-5 hours)
- Phase III: decreased RBF, decreased ureteral pressure (> 5 hours)
Describe gross changes in kidney due to obstruction
Gross changes in kidney due to obstruction
- Hydronephrosis variable: extrarenal vs intrarenal collecting system
- Compression of papillae: calyceal blunting
- Thinning of parenchyma
Describe histological changes in kidney due to obstruction
Histological changes in kidney due to obstruction
- Dilation of tubules and flattening of epithelium
- Glomeruli eventually enlarge, Bowman’s capsule thickens, hyalization
Describe presentation of chronic obstruction
Chronic obstruction
- Intermittent flank pain
Weight gain, edema, malaise, anorexia, headaches, fatigue, dysuria - Uremia: m.s. changes, tremors, bleeding
- Obstructive symptoms: weak intermittent stream, overflow, incontinence
- Irritative symptoms: frequency, urgency nocturia
- Polyuria: poor concentrating ability
Describe diangosis of obstruction
Obstruction diagnosis
- Intravenous urogram: delayed nephrogram, delayed pyelogram, hydronephrosis, columning, forniceal rupture
- Ultrasonography: dilated collecting system continuity of calcyes and pelvis, anechoic central areas in normally echogenic renal sinus, chronic obstruction with parenchyma thinning
- Diuretic renography: Technetium 99m mercaptoacetyltriglycine, > 20 min
- Whitaker test: percutaneous renal pelvis pressure transducer, bladder pressure transducer, saline / contrast infued, > 22 cm H20
___ is gold standard for diagnosing obstruction and occurs when ___ cm H20
Whitaker test is gold standard for diagnosing obstruction and occurs when > 22 cm H20
Describe postobstructive diuresis
Postobstructive diuresis
- Polyuria after release of bilateral obstruction
- Physiologic release of urea, sodium, water
- Pathologic impaired concentrating ability and sodium resorption
Describe symptoms of infection in obstruction
Infection in obstruction
- Fever, chills, rigors
- Tachycardia
- Hypotension = sepsis
- Leukocytosis, pyuria, bacteriuria
Bactermia in obstruction involves ____, ____, and ____
Bactermia in obstruction involves pyelolymphatic urine backflow, pyelovenous urine backflow, and forniceal rupture (extravasation)
Treatment for obstruction and infection includes ____, ____, and ____
Treatment for obstruction and infection includes antibiotics, IV fluids, and drainage via percutaneous nephrostomy or ureteral stenting
Urolithiasis formation involves ____, ____, and ____
Urolithiasis formation involves supersaturation, crystallization, and aggregation
Describe physical chemistry of urolithiasis
Urolithiasis physical chemistry
- Solubility product (Ksp): point at which saturation is reached and crystallization occurs
- Formation product: urine metastable with respect to CaOx, inhibitors / matrix / nucleation /; etc
- Inhibitors: Mg, citrate, etc
- Complexors: citrate, Mg
- Promoters: glycosaminoglycans, Tamm-Horsfall protein
Describe types of kidney stones
Kidney stones
- Calcium oxalate (most common)
- Uric acid
- Struvite (infection stones)
- Calcium phosphate
- Cystine
Initial evaluation of nephrolithiasis includes ____, ____, and ____
Initial evaluation of nephrolithiasis includes urinalysis, urine culture, and serum studies
Hypercalciuria is ___
Hypercalciuria is increased urinary excretion of Ca
- Present in 50-70% of kidney stone patients
Describe treatment for hypercalciuria
Hypercalciuria treatment
- Idiopathic hypercalciuria (HCTZ, chlorthalidone, moduretic): fluids, low salt diet, thiazide diuretics
- Secondary hypercalciuria: parathyroidectomy, correct underlying disease
Describe treatment for hyperoxaluria
Hyperoxaluria treatment
- Low oxalate diet
- Increased Ca intake
- Calcium citrate
- Pyridoxine
- Magnesium oxide
Describe causes of hyperuricosuria
Hyperuricosuria causes
- Gout
- Increased purine intake
Increased turnover of nucleic acids: hematologic malginancies, hemolytic anemia, rhabdomyolysis, psoriasis
Increased uric acid synthesis: alcohol consumption
Inborn errors of metabolism
Uricosuric agents
Hyperuricosuria treatment involves ____, ____, and ____
Hyperuricosuria treatment involves low purine diet, alkaline urine, and allopurinol (if gout)
Describe struvite stones
Struvite stones
- Urease producing bacteria use urease to supply their demand for nitrogen
- Urea represents principal excretory nitrogenous product in urine
- Bacteria split urea with urease to NH3
- NH3 used to form glutamate and glutamine
____, ____, ____, and ____ are urease-producing bacteria
Proteus, Klebsiella, Pseudomonas, and Staphylococcus are urease-producing bacteria
Struvite stone treatment involves ___ and ___
Struvite stone treatment involves stone free and antibiotics
Cystinuria is caused by ____ and leads to____
Cystinuria is caused by inborn error of transport of dibasic amino acids and results in supersaturation and stone formation
- Dibasic amino acids: cystine, ornathine, lysine, arginine
Describe treatment of cystinuria
Cystinuria treatment
- Potassium citrate: alkalinize to 6.5 - 7
- Low salt diet
- Thiola: mixed disulfide
- 3L of urine: dilution
Three points in the ureter that a stone will most likely not pass are ___, ___, and ___
Three points in the ureter that a stone will most likely not pass are ureteral pelvic junction, iliac vessels, and ureteral vesical junction
Patient may die from post-obstructive diuresis if not recognized or managed correctly due to ___
Patient may die from post-obstructive diuresis if not recognized or managed correctly due to hyponatremia
Septic patient with hydronephrosis and obstructing stone in proximal ureter should be managed with ____ or ____
Septic patient with hydronephrosis and obstructing stone in proximal ureter should be managed with ureteral stent or percutaneous nephrostomy tube
It is important to relieve obstruction because obstruction causes ___ and ___
It is important to relieve obstruction because obstruction causes AKI and CKD
Hypercalciuria is ___, ___, or ___
Hypercalciuria is absorptive (from GI tract), renal leak, or primary hyperparathyroidism
