Kidney stones with step2 Flashcards
(124 cards)
1
Q
What stones form in acidic urine?
A
Uric acid and cystine stones.
2
Q
What stones form in alkaline urine?
A
Calcium oxalate stones. + calcium phosphate.
Ammoniummagnesium phosphate
3
Q
Most common stones in kidney?
A
Calcium oxalate.
4
Q
Calcium oxalate stones can result from …….
A
Idiopatic hypercalciuria. Ethylene glycol (antifreeze) ingestion, vit. C abuse, hypocitraturia, fat malabsorbtion (Crohn disease, bowel resection).
5
Q
What kidney stones are seen in Crohn disease?
A
Calcium oxalate.
6
Q
What is mechanism of stones formation in Crohn disease?
A
Fat malabsorbtion –> fat binds calcium and oxalate is left free to be absorbed and deposited in kidney.
7
Q
What diuretic is used to treat calcium stones?
A
Thiazides.
8
Q
Ammonium magnesium phosphate stones type? Where are founded?
A
Staghorn calculi in renal calyces.
9
Q
Ammonium magnesium phosphate stones formed in what pH?
A
Alkaline.
10
Q
What causes ammonium magnesium phosphate stones? Pathophysiologic mechanism?
A
Infections. Urease positive m/o –> hydrolyze urea to ammonia –> urine alkalinization.
11
Q
What are urease positive m/o?
A
Proteus mirabilis, Proteus vulgaris, Klebsiella, Staph. saprophyticus.
12
Q
Staghorn calculi act as nidus for ……..
A
Urinary tract infections.
13
Q
What is a treatment of ammonium magnesium phosphate stones? (2 ones).
A
Surgical removal, eradication of pathogen. (antibiotics alone are not enought)
14
Q
Uric acid stones formed in ……… urine pH.
A
Low/acidic.
15
Q
What stones are most common in gout?
A
Uric acid stones.
16
Q
What state in leukemia/myeloproliferative diseases causes uric acid stones?
A
Hyperuricemia.
17
Q
Uric acid stones 3 causes?
A
- Hot, arid climate, 2. Low urine volume, 3. Acidic pH.
18
Q
Most common type of stones due to low urine volume?
A
Uric acid stones.
19
Q
How to treat uric acid stones?
A
Hydration, alkalinization of urine, allopurinol for gout.
20
Q
How is alkalinizated urine?
A
With potassium bicarbonate.
21
Q
What stones are radiolucent?
A
Uric acid stones.
22
Q
What stones are radiopaque?
A
Calcium oxalate/phosphate, ammonium magnesium phosphate, cystine (faintly radiopaque).
23
Q
Cystine stones are formed in …… urine pH.
A
Low/acidic.
24
Q
What stones formation is due to genetic defect?
A
Cystine.
25
What is mechanism of cystine stone formation?
Decreased reabsorbtion of cystine in PCT --> cystinuria --> cystine is poor soluble --> stones form in urine.
26
In what age mostly occurs cystine stones?
Childhood.
27
What other molecules are poorly absorbed due to cysteine transport defect in PCT?
Ornithine, Lysine, Arginine.
28
Staghorn calculi is formed from ....
Ammonium magnesium phosphate. Cystine (may be formed, e.i. not always)
29
What is treatment (3 ones) of cystine stones ?
Low sodium diet, alkalinization of urine, hydration.
30
Urine crystals in calcium oxalate stones?
Envelope or dumbell shaped.
31
Urine crystals in calcium phosphate stones?
Wedge shaped prism.
32
Urine crystals in ammonium magnesium phosphate stones?
Coffin lid.
Stoghorn
33
Urine crystals in uric acid stones?
Rhomboid or rosettes.
34
Urine crystals in cystine stones?
Hexagonal.
35
Envelope shaped urine crystals are seen in ........
Calcium oxalate.
36
Wedge shaped prism urine crystals are seen in ........
Calcium phosphate.
37
Coffin lid urine crystals are seen in ........
Ammonium magnesium phosphate stones.
38
Rhomboid or rosettes urine crystals are seen in ........
Uric acid stones.
39
Hexagonal urine crystals are seen in ........
Cystine stones.
40
hypercalcemia -> hypercalciuria --> think about what stones?
calcium oxalate/calcium phosphate
41
Crohn disease - what stones?
calcium oxalate/calcium phosphate
42
calcium oxalate/calcium phosphate - treatment?
hydrochlorotiazide (calcium-sparing diuretic
43
staghorn stone -> think about what 2 types?
clasically - amonium magnesium phosphate
also, may be in cystine stones
44
most common type in adults?
calcium oxalate/calcium phosphate
45
second mos common?
amonium magnesium phosphate
46
third most common?
uric acid
47
in children?
cystine
48
genetic defect - what stone?
cystine
49
COLA - stone?
cystine
50
what is COLA?
cystine, ornithine, lysine, arginine
51
treatment to all stones?
adequate hydration
52
why in amonia stones colic is not common? what symptoms then?
Struvite stones are often large and may fill the renal pelvis. Although patients may have mild flank pain due to recurrent infection, acute renal colic is uncommon as these large stones do not travel down the ureter.
53
3 locations of obstruction?
Ureteropelvic junction, intersection of ureter and iliac artery (uzstringa virs iliac artery); vesicoureteral junction (kur slapimtakis ieina i pusle)
54
uric acid crystals in stones versus urate crystals in gout?
Uric acid crystal are morphologically distinct from the needle-shaped monosodium urate crystals seen in synovial fluid in acute gout.
Uric acid stone: rhomboid shaped crystals
Needle-shaped monosodium urate crystals IN SYNOVIAL FLUID IN ACUTE GOUT.
55
why hematuria in stones?
Kidney stones usually cause disruption of the ureteral epithelium with resulting gross or microscopic hematuria due to the presence of free RBCs in the urine
56
stones versus GN bleeding?
Hematuria due to the presence of free RBCs in the urine.
GN: formation of RBC casts due to trapping of RBC cells by precipitating Tamm-Horsfall protein; the cells are typically dysmorphic due to mechanical and osmotic trauma as they pass through the nephron.
57
urolithiasis. what shows urine analysis?
Inspection of urine sediment in patients with acute ureterolithiasis may identify crystals corresponding to the type of stone.
58
what urine gravity in stones?
commonly occur in concentrated urine (eg, >1.015)
A specific gravity of ≤1.003 indicates dilute urine (stones form in concentrated urine)
59
UW. Calcium stone. Disease -> Hypercalciuria?
eg, sarcoidosis
60
UW. Calcium stone. Disease -> hyperoxaluria?
eg, Crohn disease
61
UW. Calcium stone. Disease -> hyperuricosuria?
gout
62
UW. Calcium stone. Disease -> hypocitraturia?
distal renal tubular acidosis).
63
Most common cause of calcium stones?
Most kidney stones are made up of calcium salts and are idiopathic, but conditions that increase calcium excretion increase the risk of stone formation.
Primary hyperparathyroidism leads to increased bone resorption, decreased urinary phosphate reabsorption, and increased 1,25-dihydroxyvitamin D formation, all of which result in hypercalcemia and hypophosphatemia
Despite the increased fractional reabsorption of calcium induced by PTH, net urinary calcium excretion is elevated due to the increased filtered calcium load, raising the risk for stone formation.
64
Obstruction at the ureteropelvic junction - symptoms?
flank or upper abdominal pain
65
obstructing stone at the ureterovesical junction usually presents with ....
lower abdominal or groin pain.
66
why low calcium diet leads to stones?
Dietary calcium binds oxalate in the gut to form unabsorbable calcium oxalate. Low-calcium diets lead to increased absorption of free oxalate, which is then excreted in the urine; the resulting hyperoxaluria promotes the formation of calcium oxalate stones.
67
How increased diet sodium leads to calcium stones?
Calcium passively follows the reabsorption of sodium and water in the renal tubules. Increased dietary sodium intake leads to reduced sodium reabsorption in the proximal tubule and lowers calcium reabsorption (leading to hypercalciuria).
68
amonia stones - morphology of kidney?
Patient has a large staghorn calculus in the renal pelvis associated with dilation of the collecting system and atrophy of the renal cortex
69
urease positive bacteria alkalinizes the urine (pH usually >7) and facilitates precipitation of magnesium ammonium phosphate crystals.
.
70
how kidney looks like in case of amonia stones?
The kidneys are often atrophic due to recurrent infection and/or chronic obstructive nephropathy.
71
uric acid stones on xray?
Stones – check X-ray. Uric acid – radiolucent, thus x-ray will be normal
72
what is soluble and what is insoluble?
solube - urate; insolube - uric acid
low pH favours formation of uric acid over urate
73
uric acid stones. what leads to low urine pH?
CHRONIC DIARRHEA (GI BICARBONATE LOSS)
Metabolic syndrome/DM
74
Chronic diarrhea -> loss of HCO3 -> chronic metabolic acidosis. how kidney compensate and how incr. risk for uric acid stones?
The kidneys compensate by increasing the excretion of hydrogen ions (H+) and reabsorption of bicarbonate in the collecting ducts. This lowers urine pH (acidic urine), increasing the conversion of soluble urate ion into insoluble uric acid.
Conversely, alkalinization of the urine with potassium citrate favors formation of urate and can prevent, and in some cases dissolve, uric acid stones.
75
Cystinuria - what inheritance?
AR
76
FA2. what stones most common?
calcium oxalate
77
FA2. stones risk factors?
family history, low fluid intake, gout, medications (alopurinol, chemotherapy, loop diuretics), postcolectomy/postileostomy, specific enzyme deficiencies, type I RTA (caused by alkaline urinary pH and hypocitrauria), hyperparathyroidism
78
FA2. stones symptoms?
acute onset of severe, colicky flank pain that may radiate to the groin and is assoc. with nausea and vomiting.
79
FA2. what body position when pain due to stones?
unable to get comfortable and shift position frequently (as opposed to those with peritonitis, who lie still).
80
FA2. What show urinalysis?
Gross or microscopic hematuria (85 proc.)
81
FA2. what gold standard for diagnosis?
noncontrast abdominal CT
82
FA2. diagn. algo.
We have clinical suspicion of stones. What evaluate next?
is patient pregnant?
83
FA2. diagn. algo.
suspect stones --> patient pregnant ->?
Do kidney UG
84
FA2. diagn. algo.
suspect stones --> patient IS NOT pregnant ->?
CT scan of abdomen/pelvis
85
FA2. diagn. algo.
suspect stones --> evaluate whether pregnant/nonpregnant --> do instrumental. What evaluate?
assess diameter of stone
86
FA2. diagn. algo.
size of stone < 10 mm. what next?
Medical management:
Alpha blocker or Ca chanel blockers
Analgesia
Hydration
87
FA2. diagn. algo.
size of stone >= 10 mm. what next?
Urologic management
88
FA2. diagn. algo.
size of stone >= 10 mm. --> urologic management --> according what?
again evaluate size 20 mm
=< 20 mm or > 20mm
89
FA2. diagn. algo.
size of stone >= 10 mm. --> urologic management --> =< 20 mm --> what management?
Shock wave lithotripsy or ureteroscopy
90
FA2. diagn. algo.
size of stone >= 10 mm. --> urologic management --> > 20 mm --> what management?
Percutaneous nephrolithotomy
91
FA2. What value or xray?
plain x ray of abdomen are still usefull for following the progression/treatment of larger stones.
92
FA2. Best initial treatment? 2
Hydration and analgesia
93
FA2. treatment. what medication and why?
alpha 1 receptors blockers (tamsulosin) and CCB (eg nifedipine) REDUCE URETERAL SPASM and facilitate passage of ureteral stone < 10mm, reducing need for analgetics.
94
FA2. treatment methods varies according what?
size and diameter of the stone
95
FA2. treatment.
if stone < 5 mm --> treatment?
may pass spontaneously
96
FA2. treatment.
if stone < 10 mm --> treatment?
Higher rate of spontaneous passage with alfa blockers or CCB.
97
FA2. uric acid and urate crystals difference?
In gout, urate crystals are needle shaped.
Uric acid nephroliths are pleomorphic
98
FA2. Most common cause of calcium oxalate?
idiopathic hypercalciuria
99
FA2. urinary pH in calcium oxalate?
Ca oxalate precipitates with HYPOCITRATURIA, which is often assoc. with decr. pH
100
FA2. calcium oxalate. 3 main treatment?
Hydration, dietary sodium restriction, thiazide diuretics
101
FA2. calcium oxalate. why do not decrease Ca intake when treat?
can lead to hyper oxaluria
and risk for osteoporosis
102
FA2. calcium oxalate. what additional treatment?
May also give citrate supplements, but pH must not be raised too high
103
FA2. Calcium phospahte. causes?
same as oxalate - most common idiopathic hypercalciuria.
Also cause may be related to hyperparathyroidism, immobility syndromes that results in high bone loss
104
FA2. Ca phosphate. xray?
same as oxalate - radiopaque
105
FA2. Ca phosphate. precipitates at what pH?
at high pH
oxalate - at low pH ????
106
FA2. Ca phosphate. what 2 treatment what 1 avoid?
hydration and sodium restriction.
Thiazides - only if for idiopatic. If hyperparathyroidism - ovoid
same as for oxalate - dont decrease Ca intake
107
FA2. strutive stones - what have in history?
recurrent UTI
108
FA2. strutive stones on xray?
radiopaque
109
FA2. strutive stones in what urinary pH?
high pH
110
FA2. strutive stones. treatment? 3
Hydration
Treat UTI if present
Surgically remove staghorn stone (ANTIBIOTICS ARE NOT ENOUGH)
111
FA2. uric acid. causes?
gout, xantine oxidase deficiency, high purine turnover
112
ammonium magnesium = struvite.
.
113
FA2. uric acid. urinary pH?
low pH
114
FA2. uric acid. treatment? 2 general
hydration
Alkalize urine
115
FA2. uric acid. treatment FIRST LINE.
restrict dietary purines
116
FA2. uric acid. treatment if stones recur despite dietary restrictios?
consider allopurinol
117
FA2. Cystine. imaging Xray or CT?
partially radiopaque, so not always seen on xray --> may need CT
118
FA2. Cystine. in what urinary pH?
low
119
FA2. Cystine. main treatment?
hydration, sodium restriction
Alkanize urine
120
FA2. Cystine. if stones recur despite treatment? 2
consider penicillamine or tiopronin
121
FA2. treatment.
5-20 mm?
shock wave lithotripsy or ureteroscopy
122
FA2. treatment.
>20 mm?
percutaneous nephrolithotomy
123
FA2. treatment. dietary?
to prevent calcium - inc. fluid intake (most important), normal calcium intake, decr. sodium intake
if cause by hyperoxaluria - decr. oxalate intake
124
FA2. treatment. indications for urologic consult?
Stone size > 9mm, refractory pain/vomiting, signs of sepsis or complete obstruction.
