Urinary Flashcards
What is azotemia
increase in concentration of non-protein nitrogenous compounds (urea, creatinine) in the blood above normal levels. can be due to renal or non-renal causes
what is uremia
azotemia with clinical signs of polysystemic consequences of renal failure. It is a clinical syndrome
What is renal disease
functional or morphological impairment of both kidneys, irrespective of extent. May regress, remain stable or progress. NOT renal insufficiency or failure
What is renal insufficiency
exists when the kidney’s ability to concentrate or dilate urine is impaired as a result of underlying renal disease. Only when 2/3 of total functional nephrons irreversibly damaged
What is renal failure
clinical syndrome that occurs when kidneys are no longer able to maintain their regulatory, excretory and endocrine functions, resulting in retention of nitrogenous wastesa and derangements of fluid, electrolyte and acid-base homeostasis. Renal failure can be classified as acute or chronic, based on time course and whether reversible or not
What is acute renal renal failure
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What is acute renal renal failure
rapid onset of azotemia associated with renal pareencymal dz/injury over hours to days.
What are the clinical signs of acute renal failure?
- oliguria/anuria (most cases)
- declining GFR
- rapid increase in azotemia, acidemia, electrolyte disturbances like hyperkalemia
- absence of anemia
- normal function prior to onset of illness
Is acute renal failure reversible?
potentially
What is chronic renal failure?
gradual onset of azotemia caused by renal parenchyma disease or injury that occurs over a prlonged duration of monts to years. Results in irreversible renal structural lesions
What is seen clinically with chronic renal failure?
- gradual onset of PU/PD
- anemia
- gradually worsening azotemia
- kidneys small and irregular
- may be exacerbated by prerenal and postrenal factors
What is nephritis?
inflammation within the kidneys
What is nephropathy?
developmental or degenerative pathological process in the kidney
What is nephrotic syndrome?
disease affecting the glomerulus and characterized by
- proteinuria without inflam urinary sediment
- hypoalbuminemia
- hypocholesterolemia
- accumulation of fluid in interstitial tissues or body cavities
What are two main categories of glomerular disease?
glomerulonephritis and amyloidosis
What
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What is dysuria?
Painful or difficult urination
What is stranguria?
Slow or painful urination with signs of straining
What is pyuria
the presence of excessive numbers of white blood cells in the urine (>0-3)
What is pollakiuria?
frequent urination, usually small amounts
What is hematuria
Blood in the urine. May be macroscopic or microscopic
What is incontinence?
loss of voluntary control of urination
What is proteinuria?
Presence of increased amounts of protein in the urine
What is polyuria?
increased volume of urination >2ml/kg/hr (>50ml/kg/d)
What is polydipsia?
increased drinking >100ml/kg/day (dog)
>45 ml/kg/day (cat)
What is micturition?
The process of storage and excretion of urine from the body
What is oliguria?
Urine production less than 1ml/kg/hr
What is anuria?
Absence or lack of urine production
What is isosthenuria?
urine with a consistent concentration of soultes that is similar to plasma. USG: 1.008-1.012
What is hyposthenuria?
urine with a consistent concentration of solutes less than that of plasma, resulting in a USG:
What is baruria?
urine with a concentration of solutes greater than plasma (dog >1.030, cat >1.035, horse and cow >1.025)
What is enuresis?
Urinary incontinence when asleep
What is nocturia?
Excessive urination during the night
What is uroabdomen?
chemical peritonitis resultin from free urine within the abdominal cavity
What is urolithiasis?
Formation of urinary calculi
What is urinary tract infection?
microbial infection of any portion of the urinary tract that is normally sterile (includes everything except distal urethra.
Whta is cylindruria?
presence of casts in urine
What are diagnostic tests for determining renal function?
- GFR determination
What is GFR?
rate at which the glomerulus forms the ultrafiltrate of plasma across Bowman’s space
What are indicators for determining the combined or individual kidney GFR?
- evaluate suspected renal insufficiency
- to assess function of each kidney if nephrectomy of one is indicated
- to establish baseline measurements prior to use of a potentially nephrotoxic drug
What is normal urine production
2ml/kg/hr
What are ways to estimate GFR
- evaluating azotemia
- endogenous or exogenous creatinine clearance tests
- nuclear scintigraphy
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What are ways to estimate GFR
- evaluating azotemia
- endogenous or exogenous creatinine clearance tests
- nuclear scintigraphy
- iohexol clearance
Why is serum urea and creatinine concentratrion a very crud index of GFR?
because renal azotemia does not occur until at least 75% of nephrons are nonfunctional.
Which is more reliable? Creatinine or BUN?
creatinine because affected by fewer non-renal variables
Why is creatinine a better crude index of GFR than urea?
because it is produced at a constnt rate, freely filtered by the glomerulus but not reabsorbed by the renal tubules and it is affected by fewer non-renal factors.
What two things affect serum creatinine levels?
- muscle wasting
2. muscle necrosis
does diet affect serum creatinine?
no
Where does urea come from?
the hepatic urea cycle
Where does urea come from?
the hepatic urea cycle
Is the Azostix dipstick for urea reliable?
no can be very unreliable
What are three reasons that urea is a poor estimate of GFR
- urea production and excretion does not occur at a constant rate
- some reabsorption by the renal tubules does occur
- serum urea concentatrion is affected by too many non-renal factors
What are 5 causes of increased serum urea that are not renal?
- dehyration–more urea reabsorbed
- high protein diet
- bleed into GI tract
- increased tissue catabolism (fever,starvation, sepsis)
- administration of drugs that increase protein catabolism (e.g. steroids)
What are three causes of decreased serum urea (not renal)?
- low protein diet
- administration of anabolic steroids that decrease protein catabolism
- liver insufficiency
When is there renal azotemia (% of GFR reduced)`
when GFR is
When is there renal azotemia (% of GFR reduced)`
when GFR is
What is the USG with renal azotemia?
The USG is
What are exceptions to the rule that only renal azotemia has poorly concentrated urine?
Diseases that impair the ability of the kidney to concentrated urine, leading to PU/PD and is associated with prerenal azotemia
- diabetes mellitus
- hypoadrenocorticism
What is postrenal azotemia?
azotemia that results from interferences with excretion of urine from the body as a result of
- obstruction of the excretory pathway that affects both kidneys
- tear or rupture in excretory pathway
What are the key features of postrenal azotemia
The USG and degree of azotemia are variable but there are tpyically clinical findings: distended turid bladder, unproductive stranguria, hydronephrosis and fluid-filled abbdomen with history or recent trauma
What are the key features of postrenal azotemia
The USG and degree of azotemia are variable but there are tpyically clinical findings: distended turid bladder, unproductive stranguria, hydronephrosis and fluid-filled abbdomen with history or recent trauma
What is the GFR and clinical features associated with altered glomerular permeability to plasma proteins?
GFR is variable, proteinuria with urine P/Cr ratio >1
What is the GFR and clinical features associated wuth renal insufficiency?`
- GFR
What is the GFR and clinical signs associated with renal failure?
- GFR
What is the renal clearance test that is a gold standard from GFR determination?
Nuclear scintigraphy–can calculate individual kidney GFR and total combined renal GFR
What is the renal clearance test that is a gold standard from GFR determination?
Nuclear scintigraphy–can calculate individual kidney GFR and total combined renal GFR
What is the minimum database for disorders of the urinary system?
- signalment and history
- physical examination
- routine laboratory data: UA, CBC, and serum biochemistry
What is signalment made up of?
- breed
- age
- gender
- environment
- diet
Why is important to get a general history?
- general attitude and activity level (non-specific) can accompany urinary diseases
2 .disturbances of the GI tract are among earliest and most common seen with upper urinary tract disorders - important to ask about current and past drug treatments
What are specific questions to ask regarding urinary problems?
- PUPD
- pollakiuria
- stranguria
- urinary retention
- discolored or odiferous urine
- hematuria
- dysuria
- urinary incontinence
- oliguria or anuria
10 urethral or vaginal discharge
What 7 changes can be seen on the serum biochem panel with renal disease?
- azotemia
- hypoalbuminemia
- hyperphosphatemia
- hypercalcemia or hypocalcemia
- electrolyte abnormalities
- metabolic acidsois
- increased amylase and lipase ~2x increase
What are three ways a urine sample can be collected?
- voided sample
- cystocentesis
- urethral catheterization
What is a disadvantage with cystocentesis?
can have varable degree of iatrogenic hematuria that cannot be readily distinguished from disease-induced hematuria
What is a disadvantage of free catch or catheterization?
May be contaminated by variabmle amounts of epithelial cells, bacteria and debris from the LUT
What changes can be seen in urinalysis with urinary system disease?
- altered states of concentration
- proteinuria
- hematuria
- pyuria
- casts
- crystalluria
- bacteriuria
What are 6 additional tests that can be done to further investigate urinary system disease?
- imaging studies
- urine culture and sensitivity
- additional renal function tests
- spot or 24-hour urine collections
- cytology and histopathology of kidneys or masses with in the urinary tract
- specialized studies: cystometroram, urethral pressure profilometry
What are three types of imaging studies that can be done?
- plain or contrast radiographs
- abdominal ultrasound
- special imaging (CT/MRI)
What are 4 reasons imaging studies might be donw
- suspected urolithiasis
- UTIs
- urinary neoplasia
- micturition disorders
What are 4 reasons imaging studies might be donw
- suspected urolithiasis
- UTIs
- urinary neoplasia
- micturition disorders
What urine should you use to analyze?
fresh (1hr) urine at room temperature
What are the three components of a routine urinalysis
- physical examination
- chemical (dipstick)
- sedimentation
Why can urine be cloudy?
- cells
- crystals
- protein
- lipid
- sperm
- mucus
What does orange urine mean?
bilirubin
What does red urine mean?
increased RBCs
myoglobin
hemoglobin
What can discolour urine (besides blood/hemoglobin etc)
certain drugs or dietary constituents
What can cause abnormal urine odor?
- ketonuria
2. increased ammonia
Does hyposthenuria suggest renal failure?
no. it is an active process performed by the renal tubules
When can glucosuria occur?
- hyperglycemia
2. renal tubular damage
When can glucosuria occur?
- hyperglycemia
2. renal tubular damage
When can ketonuria be seen?
- starvation
- diabetes mellitus
- fever
- lactation
- pregnancy
When can bilirubinuria be seen?
prehepatic, hepatic or posthepatic dz. can be normal in canine urine but is alwasys abnormal in feline urine
How do you distinguish hemoglobinuria, myogloninuria and hematuria?
spin the urine down and look at the sediment and supernatant. With hematuria the supernatant is yellow and there are RBCs in the sediment. With hemoglobinuria the supernatant is red and the plasma of blood is red. With myoglonuria, the supernatant is red and the blood plasma is normal
What are 3 causes of hematuria?
- sampling trauma
- contamination from genital tract disease
- hemorrhage or inflammation within the urinary tract
What protein are dipsticks most sensitive for? What don’t they detect?
- albumin
2. Bence-jones proteins
What protein are dipsticks most sensitive for? What don’t they detect?
- albumin
2. Bence-jones proteins
What are normal sediment levels of red blood cells and white blood cells?
red: 0-5/hpf
white:
When can increased white blood cells be seen?
- inflammation
- infection
- neoplasia
- urolithiasis
What are 3 parasites that can be seen in urine?
capillaria plica, capillaria felis-cati, dioctophyma renale
what are the three types of casts?
- hyaline
- cellular
- granular casts
What must you keep in mind when interpreting proteinuria?
- urine sediment
2. USG
What test detects all proteins?
sulfosalicyclic acid
What test detects all proteins?
sulfosalicyclic acid
When is a urine protein/creatinine ratio indicated?
when urine sediment is inactive and significant proteinuria is suspected
What is the normal PC ratio (protein/creatinine)? What is indcative of proteinuria provided urine sediment is inactive?
- 1
What can radiographs be used to do?
- reveal kidney size
- detect bladder
- detect radiodense uroliths
When is excretory urography indicated?
- evaluate abnormalities in renal size, shape, location
- assess renal perfusion and patency of excretory pathway
- invaestigate suspected rupture/tears
- investigate congenital anomalies
- detect radiolucent uroliths
When is intravenous pyelography contraindicated?
- dehydrated patients
- patients receiving other nephrotoxic drugs
- patietns with known sensitivity to contrast media
What are retrograde contrast enhanced urinary studies?
cystourethrogram & vaginocystourethrogram
What are indications for retrograde contrast enhanced urinary studies?
- rule out urethral obstruction or rupture
- evaluate congenital anomalies
- ID mucosal or mural lesions in the urethra and bladder
what is ultrasonography used for
- evaluate the architecture of the kidneys, bladder, prostate, assocated sublumbar and iliac lymph nodes, and for detection of hydronephrosis
what is ultrasonography used for
Evaluate the architecture of the kidneys, bladder, prostate, assocated sublumbar and iliac lymph nodes, and for detection of hydronephrosis
What is the gold standard to urine culture and sensitivity?
quantitative aerobic culture on a sample derived by cystocentesis (collected before antimicrobial therapy and not refrigerated for extended periods of time
What are the two basic methods for antimicrobial sensitivity
- Kirby-Bauer
2. MIC (gold standard)
What are 4 indications for renal biopsy?
- To differentiate glomerulonephritis afrom amyloidosis
- suspected neoplasia
- to determine prognosis for ARF
- for definitive diagnosis of other renal disorders
What are 3 complications of renal biopsy?
- hemorrhage
- renal infection (issue for cats!)
- rarely hydronephrosis if blood clot obstructes renal pelvis
What are indications for enoscopy (urethroscopy/cystoscopy?)
- susected anatomic abnormalities
2. to biopsy a mass
When are urodynamic procedures performed?
to investigate certain disorders of micturition
What is the difference between azotemia and uremia
Azotemia is a lab finding of increased non-protein nitrogenous waste in blood above normal levels. it is a lab finding and can have extra renal as well as renal causes. uremia is the clinical signs of polystemic consequences of renal failure. uremia animals are always azotemic but not vice-versa
What is meant by the terms a) lower urinary tract and b) upper urinary tract?
a) LUT: bladder + urethra
b) UUT: kidney + ureter
When is a urine protein/creatinine ratio indicated?
when urine sediment is inactive and significant proteinuria is suspected
What is meant by the terms a) lower urinary tract and b) upper urinary tract?
a) LUT: bladder + urethra
b) UUT: kidney + ureter
What is the GFR and what methods are available for determining GFR?
GFR is glomerular filtration rate: the rate at which the glomerulus forms the ultrafiltrate of plasma within the Bowman’s capsule.
- evaluate azotemia
- endogenous or exogenous creatinine clearance tests
- nuclear scintigraphy
- iohexol clearance
What are the indications for performing a urine protein creatinine ratio?
when urine sediment is inactive and significant proteinuria is suspected
What are the indications and contraindications of renal biopsy
indications:
1. differentiate glomerulonephritis and renal amyloidosis
2. suspected neoplasia
3. to determine prognosis for ARF
4. for definitive diagnosis of other renal disorders
Contraindications (internet)
- solitary kidney, 2. coagulopathy, 3. severe systemic hypertension
- renal lesions associated with fluid accumulation (e.g., hydronephosis, renal cysts and abscesses)
(From facebook: Contraindications
for kidney biopsy include a lack of one kidney,
pyonephrosis, presence of perirenal abscesses, polycystic
kidney disease (PKD), hydronephrosis, big renal cysts,
severe kidney insufficiency, uncontrolled hypertension,
blood coagulation disorders, severe anemia, extensive
pyelonephritis, terminal kidney insufficiency and severe
respiratory-circulatory insufficiency).
what do a high number of cats signify when seen on urinalysis?
renal tubular damage
What are some findings on the history, on a CBC and a physical examination that might help distinguish ARF and CRF?
- anemia (CRF)
- polyuria (&polydipsia) (CRF) vs oliguria/anuria (ARF)
- rapid vs slow onsest of azotemia
- kidneys small and irregular (CRF)
What are the steps to determine if significant hematuria?
- dipstick test
- examine sediment
- rule out hemoglobinuria, myoglobinuria, bilirubinuria
- rule out pseudohematuria (pgiments) or intermittent hematuria
- localize source (1. history & physical exam, 2. urogenital examination, 3. observe micturition, 4. urethral catheterization, 5. minimum data base
what are contraindications to cystocentesis
coagulopathy
infection?
What are the steps to determine if significant hematuria?
- dipstick test
- examine sediment
- rule out hemoglobinuria, myoglobinuria, bilirubinuria
- rule out pseudohematuria (pgiments) or intermittent hematuria
- localize source (1. history & physical exam, 2. urogenital examination, 3. observe micturition, 4. urethral catheterization, 5. minimum data base, 6. coagulation testing, 7. systemic blood pressure, 8. diagnostic imaging, 9. exploratory laparotomy
what are contraindications to cystocentesis
coagulopathy
infection?
what are teh 3 components of nephrotic syndrome?
- proteinuria
- hypoalbuminemia
- hypercholesterolemia/hyperlipoproteinemai
- subQ edema or body cavity effusions
what can the sulfosalicyclic acid turbidity testing be used for?
for lower protenuria vales and can measure tamm-horsfall and bence jones protein
what UP/C ratio is abnormal in dogs and cats, what is normal?
> 0.5 for dog, >0.4 for cat
what UP/C ratio is abnormal in dogs and cats, what is normal?
> 0.5 for dog, >0.4 for cat
3 causes of prerenal, renal and postrenal hematuria
prerenal
- thrombocytopenia
- vWD
- warfarin toxicosis
renal
- renoliths
- pyelonephritis
- renal telangiectasia
postrenal
- cystolith
- cystitis
- inflammatory bladder polyps
what is pseudohematuria
changes in urine colour due to pigments
what are causes of hemoglobinuria and myoglobinuria?
- IMHA
2. muscle damage
how can ovserving animal urinate help localize source of hematuria?
if ad begining or not with urinating then likely urethra or later
if at end likely bladder
if throughout then kidney or pladder
3 causes of prerenal, renal and postrenal proteinuria
prerenal: elevated serum protein
renal: glomerulonephritis, amyloidosis
post renal: hemorrhage into LUT.
how is proteinuria quantified?
dipstick
sulfosalicyclic acid sedimentation test
microalbuminuria
when is it indicated to do a UPC ratio of urine?
high protein with inactive sediment
prgnostic value of knowing if is glomerulonephritis or amyloidosis
because variable outcome for gomerulonephritis but amyloidosis is generally progressive and fatal. diagnose by biopsy
prgnostic value of knowing if is glomerulonephritis or amyloidosis
because variable outcome for gomerulonephritis but amyloidosis is generally progressive and fatal. diagnose by biopsy
What are the 5 major mechanisms for PU/PD
- primary idiopathic psychogenic polydipsia
- secondary psychogenic polydypsia
- central diabetes insipidus
- nephrogenic diabetes inspidus
- renal medullary washout
What are contraindications for performing a modified water test
- documented renal disease
- dehydration
- hypercalcemia
what stage in the work-up for a patient for PU/PD is it appropriate to perform a modified water deprivation test
If the underlying cause is unknown after exploring other avenues and there are no clear contraindications
what are the appropriate treatments for a dog with a) central diabetes insipidus
b) idiopathic nephrogenic diabetes insipidus
a. long acting ADH analog DDAVP
b. treat underlying cause or give thiazide diuretic–increased sodium ans water reabsorption
what are some causes of hypercalcemia that can lead to PU/PD
Hyperparathyroidism Osteomyelitis Granulomatous Idiopathic neoplasia youth addisons renal disease vit D
why should you not have an owner restrict the water intake of an animal suspected to PU/PD prior to evaluating the animal and performing a minimum database
Failure to recognize other polyuric syndromes can lead to incorrect diagnosis or result in significant patient morbidity (hypercalcemia, early renal failure, hypoadrenocorticism)
why is it important to do a urine culture in a patients with PU/PD even if the urine sediment is quite
because they have dilute urine that is not as good at preventing infection and they don’t completely void bladder and endocrine diseases like diabetes mellitus and cushings can cause decreased immune response
