Renal/Urinary Flashcards
1
Q
What is the renal threshold for glucose in dogs and cats?
A
Dog: 180 mg/dL
Cat: 300 mg/dL
2
Q
What are the two main causes of hypocalcemia in dogs/cats with CKD?
A
1) hyperphosphatemia
2) Calcitriol deficiency
3
Q
Where is renin release?
A
Juxtaglomerular cells
Granular cells?
4
Q
Draw and label the juxtaglomerular apparatus. What are the three major components of juxtaglomerular apparatus?
A
1) Macula densa
2) Juxtaglomerular cells
3) Extra-glomerular mesangial cells
5
Q
In the kidney, where does ammoniagenesis mainly happen? Which amino acid is the source?
A
Proximal renal tubule
Glutamine
6
Q
True or False: Proteinuria is a negative prognostic indicator in both canine and feline CKD.
A
True
7
Q
What is the flow in the hemodialysis filter that can optimize the dialysis efficiency?
A
Countercurrent flow
8
Q
What are the four mechanisms of extracorporeal therapy?
A
Diffusion
Convection
Absorption
Seperation
9
Q
What is the diffusion based on to make the particles move?
A
Concentration gradient
Membrane charististics
10
Q
What is the mechanism behind convection in extracorporeal therapy?
A
Solvent drag
* Hydrostatic pressure gradient
11
Q
What are the four factors to consider when you determine the modality of the extracorporeal therapy?
A
Protein-binding
Molecular weight
Volume of distribution
Patient’s volume status
12
Q
What are the follow extracorporeal therapies based on?
Intermittent hemodialysis (IHD)
Hemoperfusion (HP)
Continuous venovenous hemofiltration (CVVH)
Continuous venovenous hemodialysis (CVVHD)
Continuous venovenous hemodiafiltration (CVVHDF)
Slow continuous ultrafiltration (SCUF)
A
Intermittent hemodialysis (IHD) - diffusion
Hemoperfusion (HP) - absorption
Continuous venovenous hemofiltration (CVVH) - convection
Continuous venovenous hemodialysis (CVVHD) - diffusion
Continuous venovenous hemodiafiltration (CVVHDF) - convection + diffusion
Slow continuous ultrafiltration (SCUF) - convection?
Therapeutic plasma exchange (TPE) - separation
13
Q
True or False: Smaller molecules are better removed by diffusion, and larger molecules are better removed by convection.
A
True
14
Q
True or False: During hemodialysis for ethylene glycol intoxication, only ethylene glycol is removed and the metabolites remains in the system.
A
False
Both ethylene glycol and its metabolites are removed
15
Q
How many percentage of colloid osmotic pressure contributes to the total osmotic pressure?
A
0.5%
16
Q
What are two types of water loss?
A
Obligatory water loss: water needed to excrete the daily renal solute load
Free water loss: water excreted unaccompanied by solute under the control of antidiuretic hormone [ADH]
17
Q
In dogs, how many percentage increase of osmolality will induce thirst?
A
1 - 3%
18
Q
Which molecule can be filtered through the glomerulus more easily, the positively charged or negatively charged one?
A
Positively charged one
Because glomerulus is negatively charged
19
Q
What is the size selectivity limit of glomerulus?
A
4 nm in diameter
20
Q
Which layer contributes to the glomerulus size selectivity?
1) Capillary endothelium
2) Glomerular basement membrane
3) Visceral epithelial cells (podocytes)
A
2) Glomerular basement membrane
The lamina rara interna and lamina rara externa contain polar non-collagenous proteins that contribute to the negative charge of the filtration barrier.
The lamina densa contains nonpolar collagenous proteins that contribute primarily to the size selectivity of the filtration barrier.
21
Q
The glomerulus has similar net filtration pressure than systemic capillary, but why glomerulus has such high filtration rate than capillary?
A
1) The glomerulus has much bigger surface area for filtration
2) The permeability for electrolytes are much greater (100x) than systemic capillaries
Both contribute to higher ultrafiltration coefficient Kf
22
Q
What are the changes in renal blood flow and GFR in each situation?
A
23
Q
What are the effects of norepinephrine, angiotensin II and dopamine and ADH on the renal blood flow and GFR?
A
NE: RBF↓ GFR↑
Angiotensin II: RBF↓ GFR↑
Dopamine: RBF↑ GFR no change
ADH: RBF↓ GFR↑
24
Q
True or False: norepinephrine, angiotensin II and ADH cause renal arterioles vasoconstriction, and stimulate the production of (PGE2 and PGI2), which counterbalances by their vasodilation effect.
A
True
25
True of False: ADH causes vasoconstriction on both afferent and efferent arterioles, and prostaglandin E2 cause vasodilation on both afferent and efferent arterioles.
False
ADH only cause vasoconstriction on efferent arterioles; prostaglandin E2 only cause vasodilation on afferent arterioles.
26
What is the equation for GFR?
27
What is normal GFR for dogs and cats? What about renal plasma flow (RPF) and filtration fraction (FF)?
1) GFR: Dog 3-5 ml/kg/min Cat 2.5-3.5 ml/kg/min
2) RPF: Dog 7-20 ml/kg/min Cat 8-22 ml/kg/min
3)FF: Dog 0.32-0.36 Cat 0.33-0.41
28
Name two substances that can used to evaluate GFR.
Creatinine
Inulin (a polymer of fructose)
29
Fill out the blank: In the kidneys, between perfusion pressures (MAP) of __________, GFR and RBF vary less than 10%. The ________ is the site to regulate the pressure.
80 - 180 mmHg
Afferent arterioles
30
What are the two autoregulation of nephrons? Which one is faster?
Myogenic mechanism
Tubuloglomerular feedback
Myogenic mechanism is faster
31
What is the RBF when compared to total cardiac output?
20% of cardiac output
32
How do you assess RBF based on RPF?
33
Which route does water mainly pass through in the renal tubule, paracellular route or transcellular route?
Transcellular route
34
Name four renal transport processes and an example for each one of them.
Passive diffusion -
Facilitated diffusion - glucose, amino acid
* it is a saturated process
Primary active transport - H+-ATPase at the luminal side, Na,K-ATPase at the basolateral side
Secondary active transport - (e.g. glucose-Na, Na-H)
35
True or False: Na is reabsorbed with glucose, amino acids, phosphate, and bicarbonate in the proximal renal tubule.
True
36
Which tubular transport maximum (Tmax) is the lowest, glucose, phosphate or amino acid?
Phosphate
37
Explain why during dehydration, patient's BUN may increase but not creatinine?
50% or urea is passively reabsorbed in the proximal renal tubule. When patient is dehydrated, tubular flow decreases, there is increased water reabsorption and subsequent urea reabsorption via the solvent drag.
38
True or False: The ascending limb of Henle’s loop is impermeable to water.
True
So NKCC2 can transport the electrolytes without carrying water → important step for urinary concentrating mechanism
39
There are three segments of collecting ducts, what are they? Which segment is permeable to urea?
Cortical, outer medullary, inner medullary
Inner medullar collecting duct is permeable to urea
* its urea permeability is increased by ADH
40
Why under normal condition, the medullary interstitium can maintain its hyperosmotic gradient?
The countercurrent exchange of vasa recta → can remove water while keep the solutes in the interstitium
41
Where is erythropoietin EPO produced in the fetus and adults?
Fetus: liver
Adults: peritubular cells in kidneys
42
Name three conditions that will increase renin release.
1) Decreased renal perfusion pressure
2) SNS stimulation & increased circulating catecholamines level
3) Decreased Cl concentration at the distal tubular flow
43
In the RAAS system, which step is the rate limiting step?
Renin converts 𝜶2-globulin angiotensinogen to angiotensin I
44
True or False: The release of renin is inhibited by a direct effect of angiotensin II on the granular cells.
True
45
How does angiotensin II cause increase proximal renal tubular sodium absorption?
Stimulating the Na-H antiporter in luminal membranes of proximal tubular cells.
46
Name 5 functions of angiotensin II
1) arterial vasoconstriction
2) inhibit renin
3) stimulate aldosterone production
4) stimulate ADH release
5) stimulate mesangial cells to produce PGE2, PGI2
6) Increase proximal renal tubular Na reabsorption
7) Cause afferent and efferent renal arterioles constriction
47
Where is kidney convert calcidiol to calcitriol?
Proximal tubular cells
48
Name 5 different types of diuretics, which part of the renal tubules do they work on and their MOA.
1) Carbonic anhydrase inhibitor - acetazolamide
2) Osmotic diuretic - mannitol
3) NKCC2 inhibitor - furosamide, torsamide
4) Thiazide - thiazide
5) Aldosterone receptor antagonist - spironolactone
49
What is MOA of Acetazolamide?
50
According to IRIS CKD staging, what is the UPC cutoff for proteinuria in dogs and cats? What about the cutoff for pre-hypertensive and hypertensive?
UPC
Dog: > 0.5
Cat: > 0.4
Blood pressure
Pre-hypertensive 140-159
Hypertensive 160-179
51
What is the creatinine range for grade II AKI?
1.7-2.5 mg/dL
52
According to IRIS AKI grading system, what is the definition of fluid responsive?
UOP > 1 ml/kg/hr over 6 hours, or creatinine decrease to baseline over 48 hours
53
What are the two subgrading for AKI in IRIS guidelines?
1) Non-oliguric or Oligo-anuric
2) Requiring RRT
54
According to IRIS AKI grading system, how many days does it normally take for grade I and II AKI to regain adequate renal function?
2-5 days
55
What are the three mechanisms of pathological causes of diuresis?
1) Failure of ADH to function
2) Pressure diuresis (e.g. hypertensive hypervolemic state)
3) Osmotic diuresis (e.g. glucosuria)
56
Among all classes of diuretics, which one reach its site of action from the blood instead of urinary space?
Spironolactone
57
What is the MOA of amiloride?
Epithelial sodium channels (ENaC) blockers → excrete water, retain K and H+
58
What is the MOA of acetazolamide?
Inhibits type II (cytoplasmic) and type IV (membrane) carbonic anhydrase at the proximal renal tubule → decrease reabsorption of sodium bicarbonate
59
How many percentage of Na is reabsorbed at the proximal renal tubule, loop of Henle, distal convoluted tubule and collecting duct, respectively?
Proximal renal tubule: 67% (2/3)
Loop of Henle: 25%
Distal convoluted tubule: 5%
Collecting duct: 3%
60
What are 4 types of renal tubular acidosis?
Type I (classic distal RTA): inability of distal renal tubule to excrete H+
- Hyperchloremic metabolic acidosis + increased urine pH (pH > 6.0)
- Ammonium chloride challenge test
Type II (proximal RTA): inability of proximal renal tubule to prevent loss of bicarbonate
- Mild metabolic acidosis + acidic urine or alkalotic urine (once plasma bicarbonate decreases; pH < 5.5)
- HCO3- fraction excretion > 15% after normalizing the plasma bicarbonate (normally is < 5%)
Type IV (hyperkalemic distal RTA): distal RTA and hyperkalemia secondary to hypoaldosteronism or aldosterone deficiency
Type III: a rare combination of proximal and distal RTA caused by carbonic anhydrase II deficiency and carbonic anhydrase inhibitors blocking the metabolism of bicarbonate and carbonic acid
61
List 5 lab abnormalities of Fanconi syndrome. Which segment is affected?
1) Proximal renal tubule
2) Glucosuria, proteinuria, aminoaciduria, phosphaturia, hypophosphatemia.
62
How many percentage of calcium is reabsorbed at the proximal renal tubule, loop of Henle, distal convoluted tubule and collecting duct, respectively?
Proximal renal tubule: 60-70% (paracellular)
Loop of Henle: 20% (paracellular)
Distal convoluted tubule: 10% (transcellular)
Collecting duct: almost none
63
The release of vasopressin is more sensitive to change in osmolarity or effective circulating volume?
osmolarity
An increase of only 1% in plasma osmolality will stimulate vasopressin release, whereas a drop in blood volume of approximately 10% is needed to stimulate vasopressin release
64
List 8 causes of Nephrogenic diabetic Insipidus (NDI).
Hypercalcemia
Hypokalemia
Pyelonephritis
Pyometra or gram (-) sepsis
Hyperthyroidism
Hypoadrenorcorticism (decreased Na → unable to maintain the interstitial concentration gradient)
Hepatic insufficiency (decreased urea production → unable to maintain the interstitial concentration gradient)
PSS (decreased urea production → unable to maintain the interstitial concentration gradient)
65
When performing desmopressin acetate trial, what is your interpretation if urine concentration does not change and remain hyposthesuria?
NDI or psychogenic polydipsia
66
What is the proposed mechanism of pulmonary disease causing SIADH?
1) tumors that ectopically produce ADH
2) diseases that interrupt the inhibitory impulses in vagal afferents from stretch receptors in the atria and great veins
67
What is the most significant clinical signs of SIADH?
Clinical signs associated with hyponatremia
* NO hypertension or edema will be present
* An increased BUN concentration typically excludes a diagnosis of SIADH
68
Name 3 novel urinary biomarker for glomerular injury and 3 for renal tubular injury.
Glomerular injury: urine CRP, urine IgG, podocin
Tubular injury: urine GGT & ALP (proximal renal tubule brush border), NAG, Neutrophil gelatinase associated lipocalin (NGAL)(multiple tissue, reabsorbed at proximal renal tubules), cystatin B (proximal renal tubule epithelial cells)
GFR
cystatin C (most nucleus cells)
69
What are the 4 phases of acute renal injury?
Initiation phase
Extension phase
Maintenance phase
Recovery phase
70
What are the most common lesions for CKD in dogs and cats, respectively?
Dog: glomerular disease/interstitial nephritis
Cat: lymphoplasmacytic tubulointerstitial nephritis
71
Fill in the blank: Typically, dogs with a urine protein-to-creatinine ratio of at least ____ are likely to have glomerular disease.
2
72
List 5 things that are associated with mortality in cats with CKD.
Plasma creatinine concentration
UPC
Urine albumin-to-creatinine ratio
Leukocytosis
Hyperphosphatemia
73
Fill out the blank: A urine sodium level of__________ is consistent with the action of aldosterone and supports the presence of poor renal perfusion.
less than 20 mEq/L
74
Fill out the blank: A urine sodium level of _________ with concurrent hyponatremia supports the diagnosis of SIADH.
more than 40 mEq/L
75
Name 3 contraindication for hemodialysis and peritoneal dialysis.
Hemodialysis: severe coagulopathy, severe hemodynamic instability, small patient size
Peritoneal dialysis: recent abdominal surgery, hypoalbuminemia, peritonitis
76
What is the definition of catheter-associated bacteriuria? What about catheter-associated UTI?
Catheter-associated bacteriuria
1) urine sample obtained aseptically from the urinary catheter or within 48 hours after urinary catheter removal
2) test positive for 1 species of bacteria at 10^5 CFU/ml
Catheter-associated UTI
1) Fever or clinical signs associated with UTI
2) test positive for 1 species of bacteria at 10^3 CFU/ml
77
What is the outer diameter of a 12 Fr urinary catheter?
4 mm
78
What is the MOA of fenoldopam?
D1 dopamine receptor agonist → cause vasodilation, especially at the renal capillary bed → increase renal blood flow
79
What is the MOA of diltiazem in treating oliguria?
Calcium channel blocker → cause afferent arteriole vasodilation → increase GFR
80
True or False: UTIs in intact male dogs are classified as complicated infections.
True
Because prostatic disease is commonly involved
81
What bacteria can facilitate struvite urolith formation when they present in the urine (name 3).
Staphylococcus spp
Proteus spp
Corynebacterium spp
Due to alkalinization of urine by urea metabolism by these organisms (urease)
82
True or False: Urine pH is often alkalotic with E. coli infections.
False
Acidic
83
What is the most common bacteria for acute prostatitis
E. coli
84
Name 3 uroliths that exist in acidic urine
Calcium oxalate
Purine
Cystine
85
Name two uroliths that are considered non-radiopaque.
Urate
Cystine
86
What is the full name for struvites
Magnesium ammonium phosphate hexahydrate
87
Which urolith cannot be dissolved by diet?
1) struvites
2) calcium oxalate
3) cystine
4) xanthine
calcium oxalate
88
What are the two important factors that promotes urethral healing?
1) Prevent urine extravasation
2) Good mucosal continuity
89
How long does it take for urethral mucosa to regenerate?
7 days
90
In male dogs and male cats, what are the urethrostomy recommended?
Male dog: scrotal urethrostomy
Male cat: perineal urethrostomy
91
How to differential hemoglobinuria from myoglobinuria with ammonium sulfate test?
80% ammonium sulfate solution is added to a urine sample and the mixture is observed for precipitation of the colored substance
Soluble → myoglobinuria
Insoluble → hemoglobinuria
92
What is the landmark on palpation when you place a urinary catheter in female dogs?
Urethral papilla
93
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the cut-off frequency for sporadic cystitis and recurrent cystitis?
Sporadic: < 3 eposides in 12 months
Recurrent: ≥ 3 episodes in 12 mouths
* A single recurrence of sporadic cystitis within the preceding 3 months should be approached recurrent cystitis
94
True or False: According to the ISCAID guidelines for the bacterial UTI in dogs and cats, NSAIDs are contraindicated in patients with sporadic cystitis as they can worsen the clinical signs.
False
NSAIDs (use with caution in cats) should be considered during the initial treatment period to help ameliorate clinical signs.
95
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the recommended first-line antibiotic and treatment duration?
Amoxicillin
3-5 days
96
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, post-treatment urine culture should be performed in sporadic cystitis 48 hours after the treatment is finished.
False
Post-treatment urinalysis or urine culture is NOT recommended for sporadic cystitis when clinical signs have resolved.
97
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the recommended duration of treatment for recurrent cystitis?
Re-infection:3-5 days
Persistent: 7-14 days
98
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, when to consider urine culture in patients with recurrent cystitis?
If patient gets 3-5 days treatment and clinically improved → no culture needed
If patient gets 7-14 days treatment → can consider culture after 5-7 days of treatment and 5-7 days after the treatment is finished
* Need a plan for either positive or negative results rather than just changing antibiotics
99
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the recommended first-line treatment and duration of treatment for pyelonephritis? When to recheck (urine culture)?
Fluroquinolone or cefpodoxime (3rd generation antibiotic)
10-14 days
1-2 weeks after the treatment is finished
* Consider serum breakpoint instead of urine breakpoint!
100
Antibiotic with what characteristic is most likely to cross the prostate-blood barrier (e.g. lipophilic vs hydrophilic, pKa, acidic & alkaline)?
Lipophilic, weak alkaline, high pKa
101
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the target organism for bacterial prostatitis before the culture result returns?
Enterobacteriaceae
102
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the recommended antibiotics for bacterial prostatitis before the culture result returns and the duration of treatment?
Fluoroquinolone, TMS
4-6 weeks
103
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the definition of subclinical bacteriuria?
Positive culture of bacteria in the cystocentesis urine WITHOUT clinical signs
* NOT based on urine sediment or cytology!
104
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the cut-off of CFU/ml to differentiate sporadic cystitis from subclinical bacteriuria?
You CAN'T differentiate them with bacterial cell count
105
True or False: Treatment of animals with pyuria or other cytological abnormalities without lower urinary tract signs is not recommended.
True
106
True or False: According to the ISCAID guidelines for the bacterial UTI in dogs and cats, routine catheter replacement to prevent bacteriuria or cystitis is not recommended.
True
107
True or False: According to the ISCAID guidelines for the bacterial UTI in dogs and cats, routine cytological evaluation and urine culture in patients with an indwelling urinary catheter is recommended to screen for UTI.
False
Unless there are clinical signs
108
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what should you do if a patient with an indwelling urinary catheter who develops signs of bacterial cystitis, but still requires the indwelling catheter in place?
1) Remove the urinary catheter
2) Collect urine by cystocentesis
3) Replace a new urinary catheter
4) After the clinical signs resolve with treatment, replace a new urinary catheter
* After clinically-apparent resolution of catheter-associated bacterial cystitis, if the catheter cannot be removed, it should be replaced with a new catheter, since colonization of the catheter is likely, even with clinically successful treatment.
* If this is not possible, the catheter should be removed, a new catheter placed and urine collected from the new catheter for culture. The !rst 3–5 mL of urine collected should be discarded before collecting the urine specimen for culture.
109
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, what is the recommendation for pre-operative screening for those patients that require urological surgery?
1) Urine culture to detect bacteriuria
2) If signicant bacteriuria is identified, treatment based on susceptibility result is indicated for 3–5 days duration immediately before the procedure
110
According to the ISCAID guidelines for the bacterial UTI in dogs and cats, if antibiotic is indicated in patients who receive medical treatment to dissolve uroliths, how long the duration of treatment should be?
7 days
* If bacterial cystitis is identified, antibiotic is recommended
* If a urease-producing bacterium (e.g. Staphylococcus pseudintermedius,Proteus spp.) is identified, antimicrobials should be administered
111
In human nephrology, what dose RIFLE stands for?
Risk
Injury
Failure
Loss of renal function
End-stage kidney disease
112
What is SDMA?
Symmetric dimethylarginine
It is produced by post‐translational methylation of arginine residues in proteins. It is filtered by the glomerulus and highly associated with GFR.
113
What are 5 phenotypes of cardiorenal syndrome?
Type I: acute cardiorenal syndrome
Type II: chronic cardiorenal syndrome
Type III: acute renocardial syndrome
Type IV: chronic renocardial syndrome
Type V: secondary cardiorenal syndrome
114
Name 3 ways to measure GFR.
Iohexel plasma clearance
Endogenous creatinine clearance
Renal scintigraphy
115
What is the equation to calculate fractional excretion of sodium?
Hemodynamic instability causing azotemia: FEna < 1%
Intrinsic renal damage causing azotemia: FEna > 1%
* When aldosterone is secreted, the kidneys can conserve sodium such that in hypovolemic states, the urine Na+ should be <20 mEq/L and may be as low as 1 mEq/L.5 Values of 20-40 mEq/L are equivocal, while >40 mEq/L of Na+ implies the kidneys are interpreting a normal blood volume
116
Describe percutaneous nephrostomy tube placement (using locking-loop pigtail nephrostomy catheters)
Each patient was placed in lateral recumbency with the affected kidney in the up position. Antimicrobials (cefazolin) were given (22 mg/kg [10 mg/lb], IV, at induction and q 2 h during the procedure) if patients were not currently being treated with antimicrobials. The area over the kidney was clipped of hair and aseptically prepared. A small stab incision was made in the skin for catheter penetration.
Modified Seldinger technique—Ultrasound guidance was used to perform pyelocentesis with an over-the-needle standard IV catheter or renal access needlec (dog, 18 gauge; cat, 22 gauge). Once the tip of the catheter was in the renal pelvis, the stylette was removed and an extension set and 3-way stopcock were attached to the catheter. Urine was drained and an equal amount of diluted contrast solutiond (50% contrast: 50% sterile saline [0.9% NaCl]) was infused into the renal pelvis to perform a pyelogram. Urine was submitted for microbial culture and antimicrobial susceptibility profiling. Under fluoroscopic guidance,e an angle-tipped hydrophilic guidewiref (dog, 0.035-inch-diameter wire; cat, 0.018-inch-diameter wire) was advanced through the catheter and coiled inside the renal pelvis. The catheter was removed over the wire, and the PNC (cat, 5Fg; dog, 6Fh) was advanced through the skin, into the renal parenchyma, and into the renal pelvis. For this process, the hollow cannula inside the PNC remained secure to keep the catheter rigid during renal penetration. Once the tip of the PNC was inside the renal pelvis, the cannula was immobilized as the catheter was advanced over the guidewire to form its loop. Once the loop of the pigtail was completely within the renal pelvis, the loop of the catheter was locked in place by pulling on the locking string at the catheter hub (Figures 1 and 2) and the string was carefully locked and secured. The cannula was removed from the catheter. The catheter was secured to the body wall by means of a purse-string and Chinese finger trap suture pattern and a second butterfly suture along the shaft of the catheter to the body wall. A sterile urine collection system was attached to the catheter for gravity drainage. A secure abdominal bandage was placed.
Reference:
2012 JAVMA Use of locking-loop pigtail nephrostomy catheters in dogs and cats: 20 cases (2004–2009)
117
What is the normal diameter of feline ureter?
0.4 mm
118
What sympathetic nerve and adrenergic receptor are in charge of the bladder function? What happen when it is activated?
Hypogastric nerve (leave the spinal cord at TS region)
Detrusor muscle relaxation (𝜷 receptor)
Urethral smooth muscle contraction (𝜶 receptor)
→ urine retention
119
What parasympathetic nerve and somatic nerve are in charge of the bladder function? Where do they originate from? What happen when they are activated?
Parasympathetic nerve - pelvic nerve
- Detrusor muscle contraction
- Inhibit sympathetic and pudendal nerve
Somatic nerve - pudendal nerve
- Striated urethral muscle contraction
S1-S3
120
How to close the cystotomy bladder?
Single layer, continuous or intermittent appositional pattern with monofilament absorbable suture
121
What is the MOA of Phenylpropanolamine (PPA; Proin)? What is the indication?
Cause release of NE and decrease the reuptake
𝜶1 agonist (mainly)
𝜷 agonist (weak)
Treat urethral sphincter hypotonus (or hormone responsive incontinence)
* Often in spayed female due to decrease estrogen
* Dose: 2 mg/kg BID
122
What is the MOA of bethanechol? What is the indication?
Cholinergic muscarinic receptor agonist
Lower motor neuron bladder, detrusor muscle atony
Dose: 2.5 - 25 mg/dog BID-TID
123
Explain the pathophysiology of detrusor muscle atony.
- Injury to the sacral spinal cord S1 - S3 or pelvic nerves
- Direct damage to the detrusor muscle (e.g. overdistension caused by mechanical or functional outflow obstruction of an acute or chronic nature). The muscle fibers of the detrusor transmit action potentials that initiate contraction via tight junctions. With overdistension, these tight junctions are interrupted, leading to an absent or ineffective contraction.
124
What is MOA of tamsulosin?
𝜶1A antagonist
125
What is the proposed pathophysiology of FIC in the review paper in JVECC 2015?
Imbalance between the sympathetic nervous system and the hypothalamic–pituitary–adrenal axis brought about by stressful situations
→ impaired blood flow & release of inflammatory mediators
→ edema, smooth muscle spasm, pain within the lower urinary tract
126
List 5 possible pathophysiology of post-obstructive diuresis (POD).
1) Medullary washout
2) Accumulation of osmotically active substances in the blood (osmotic diuresis)
3) Renal tubular damage/dysfunction
4) Antidiuretic hormone release
5) Increases in natriuretic factors brought about during the obstructive process
127
What are the pros and cons of each of the following urinary catheter:
Polypropylene
Polyvinyl
Polytetrafluoroethylene
Polyurethane
Polypropylene (Tomcat): most rigid, more reactive and irritating to tissue, more likely to cause urethral trauma
Polyvinyl (Red rubber): less rigid than tomcat, usually only comes with a side hole (not ideal for the initial un- blocking process), can be irritable
Polytetrafluoroethylene: firm at room temperature but soften when warmed to body temperature (meaning they can be left in place), less reactive to tissue
Polyurethane: firm at room temperature but soften when warmed to body temperature (meaning they can be left in place), cause least tissue reaction
128
What types of muscles does feline urethra composed of? What about dogs?
Proximal 1/3: smooth muscle
The rest 2/3: skeletal muscle
Dogs:
Proximal 2/3: smooth muscle
The rest 1/3: skeletal muscle
129
Which of the following mechanism is not used in peritoneal dialysis?
1) Diffusion
2) Convection
3) Ultrafiltration
2) Convection
130
In peritoneal dialysis, what is the normal glucose concentration in dialysate? What if patient is overhydrated?
Normal: 1.5%
Overhydrated: 2.5% or 4.25%
* Heparin (250– 1000 U/L) should be added to the dialysate for the first few days after catheter placement to help prevent occlusion of the catheter by fibrin deposition
131
Describe how many dialysate should be infused over how long? What is the indwelling time and drainage time?
Infusion volume: 20-40 ml/kg
Infusion time: 10-20 min
Indwelling time: 30-40 min
Drainage time: 10-20 min
Ideal retrieval percentage: 90-100%
132
What is the important to do at the beginning of each infusion to prevent bacterial contamination/infection?
At the beginning of every exchange, 2 mL of dialysate should first be flushed through the stopcock and into the outflow bag.18–20
This is referred to as the drain first protocol.
133
List 5 complications of PD.
1) Hypothermia
2) Outflow obstruction
3) Hypokalemia
4) Hypoalbuminemia
5) Dialysate leakage
134
What is the diagnostic criteria for peritonitis in patient with PD?
Meet at least 2 of the following criteria
1) Cloudy dialysate effluent
2) Detection of >100 inflammatory cells/𝜇L, or organisms in gram stain or cultures
3) Clinical signs of peritonitis
