Ch 37 UTO

Question 1

dilation of the renal pelvis and calices proximal to the point of obstruction

Answer 1

Hydronephrosis

Question 2

refers to blockage of urine flow due to a functional or structural derangement anywhere from the tip of the urethra back to the renal pelvis that increases pressure proximal to the site of obstruction

Answer 2

Obstructive uropathy

Question 3

functional or pathologic parenchymal damage in obstructive uropathy

Answer 3

Obstructive nephropathy

Question 4

Between the ages of 20 and 60 years, urinary tract obstruction was more frequent among

Answer 4

Women
uterine cancer and pregnancy

Question 5

Above the age of 60 years, UTO more common among?

Answer 5

Men
prostatic disease

Question 6

Acute Upper urinary tract [ureter or ureteropelvic junction (UPJ)] obstruction may present with

Answer 6

Renal Colic

Question 7

Acute Lower tract (bladder or urethra) obstruction may present with

Answer 7

Disorders of micturition

Question 8

A common renal complication of multiple myeloma

Answer 8

Myeloma kidney or myeloma cast nephropathy

Question 9

2 Intrinsic intramural processes that cause obstruction

Answer 9

1. failure of micturition
2. Failure of ureteral peristalsis (rare)

Question 10

Drug that cause intrinsic intramural obstruction by interfering with bladder contraction

Answer 10

Anticholinergic agents

Question 11

Drug which may mediate an α-adrenergic increase in urethral sphincter tone, resulting in increased bladder outlet resistance

Answer 11

Levodopa

Question 12

Chronic use of this drug
can cause severe cystitis with subsequent ureteral obstruction

Answer 12

Tiaprofenic acid (Surgam)

Question 13

Chronic infection of this organism leads to irreversible ureteral or bladder fibrosis and obstruction

Answer 13

Schistosomiasis (bilharziasis)

Question 14

Which ureter is affected more in the temporary form of obstruction usually observed in pregnancy

Answer 14

Right

Question 15

4 Conditions in pregnancy that may predispose to obstructive uropathy and acute kidney injury

Answer 15

1. multiple fetuses
2. polyhydramnios
3. incarcerated gravid uterus
4. solitary kidney

Question 16

Second most common cause of extrinsic obstructive uropathy in women

Answer 16

Cervical AdenoCA

Question 17

Preferred imaging to screen for obstructive uropathy in advanced cases of endometriosis

Answer 17

CT scan

Question 18

most common cause of urinary tract obstruction in men aged 50 years and older

Answer 18

BPH

Question 19

Top 2 most common causes of malignant genitourinary tumors causing urinary tract obstruction

Answer 19

1. Cervical CA
2. Bladder CA

Question 20

Chronic pancreatitis with pseudocyst formation causes

Answer 20

left ureteral obstruction

Question 21

Acute pancreatitis may result in

Answer 21

right-sided obstruction

Question 22

Most common vascular cause of urinary obstruction

Answer 22

Abdominal aortic aneurysm

Question 23

Retroperitoneal fibrosis usually involves which part of the ureter?

Answer 23

middle third

Question 24

Elevated levels of these 2 risk factor proteins are present in the urine from obstructed kidneys

Answer 24

1. neutrophil gelatinase-associated lipocalin (NGAL)
2. β2-microglobulin

Question 25

Preferred screening modality when obstruction is suspected

Answer 25

Ultrasonography

Question 26

Ultrasonography is both highly sensitive and highly specific in detecting hydronephrosis, with the rates approaching

Answer 26

90%

Question 27

Hydronephrosis detected as a dilated collecting system. On UTZ it appears as

Answer 27

anechoic central area surrounded by echogenic parenchyma

Question 28

False negative results in UTZ (UTO) - 8

Answer 28

1. first 48 hours of obstruction 2. When hydronephrosis is absent despite obstruction evaluated by CT 3. Dehydration 4. Staghorn calculi 5. Nephrocalcinosis 6. Retroperitoneal fibrosis 7. Misinterpretation of caliectasis as cortical cysts 8. Tumor encasement of the collecting system

Question 29

This new imaging technique provides information about renal stiffness related to fibrosis (i.e., chronic obstruction)

Answer 29

Renal elastography

Question 30

Imaging used to differentiate between obstructive or nonobstructive dilatation of the collecting duct system

Answer 30

Duplex doppler ultrasonography

Question 31

Diagnostic study of choice for the evaluation of the patient with acute flank pain

Answer 31

noncontrast-enhanced helical CT

Question 32

Can visualize a dilated collecting system without the requirement for contrast enhancement

Answer 32

Non contrast CT

Question 33

Exception to using a noncontrast CT

Answer 33

nephrolithiasis secondary to HIV protease inhibitors --> indinavir Reason: These stones are not radiopaque, and signs of obstruction may be minimal or absent thus the diagnosis may be missed with US and noncontrasted CT scan

Question 34

Imaging to establish the diagnosis in Nephrolithiasis 2° to HIV protease inhibitor --> Indinavir

Answer 34

Contrast-enhanced CT

Question 35

Imaging to diagnose upper urinary tract obstruction and providing information on the differential renal function (DRF) of both kidneys

Answer 35

Isotopic renography or renal scintigraphy

Question 36

Clearance of the isotope from the collecting system which indicate obstruction

Answer 36

T½: < 15 minutes (normal) > 20 minutes (obstruction) 15-20 minutes (equivocal)

Question 37

In patients with severely impaired renal function, use of gadolinium during MRI results ro increased risk of developing this toxicity

Answer 37

Nephrogenic systemic fibrosis (NSF)

Question 38

Because of the risk of NSF, gadolinium contrast media should be avoided in patients with what stage of CKD?

Answer 38

CKD stage 4 or 5

Question 39

Defines the functional effect of upper urinary tract dilatation by measuring the hydrostatic pressures in the renal pelvis and bladder during infusion of a saline and contrast mixture into the renal pelvis via a catheter

Answer 39

Whitaker test

Question 40

In whitaker test, what is the renal pelvic pressure that is considered obstructed?

Answer 40

Renal pelvic pressure (cm H2O): < 15: nonobstructed 15 - 22: equivocal > 22: obstructed

Question 41

This procedure defines the lower level of the obstruction

Answer 41

Retrograde pyelography

Question 42

This procedure establishes the proximal level of obstruction

Answer 42

Antegrade pyelography

Question 43

Blocks the hyperemic response

Answer 43

Indomethacin

Question 44

Critical to afferent vasodilation

Answer 44

Prostaglandins

Question 45

Obstruction of the left kidney augments?

Answer 45

1. AFFERENT renal nerve activity from the LEFT kidney 2. EFFERENT nerve activity to the RIGHT kidney

Question 46

2 phases of UUO

Answer 46

1. Early hyperemic phase 2. Late vasoconstrictive phase

Question 47

Afyer how many hours does renal blood flow declines progressively in unilateral obstruction?

Answer 47

3 hours

Question 48

After how many hours does renal plasma flow, GFR, and intratubular pressures have all dropped below normal values?

Answer 48

24 hours

Question 49

The only cell death at early time points following the onset of obstruction, such as at 24 hours occurs at?

Answer 49

the very tip of the papilla, where focal necrosis may be observed

Question 50

Following release of 24 hours of UUO, volume excretion from the postobstructed kidney, what happens tp the FeNa?

Answer 50

FENa may be twentyfold higher than normal

Question 51

What is the effect of obstruction on membrane expression of transporter proteins responsible for apical sodium entry and of basolateral sodium exit

Answer 51

downregulates

Question 52

major signaling mechanism by which obstruction downregulates Na+ transport

Answer 52

halt in urine flow

Question 53

Represents a particularly important mediator of salt wasting in bilateral obstruction

Answer 53

ANP

Question 54

This natriuretic peptide is markedly elevated in bilateral, but not in unilateral obstruction

Answer 54

ANP