Urinary system Flashcards
where are the kidneys located and how does the position of left and right vary?
retroperitoneal space
right more cranial
how does IV urography work?
dye collects and highlights kidneys, then moves to ureters and bladder
define nephron
functional unit of kidney
what is the function of the glomerulus and how does this happen?
filtration of blood into glomerular filtrate due to high pressure capillary bed between 2 arteries
in healthy animals proteins stay in the blood
what is the role of proximal convoluted tubule?
reabsorption of glucose, electrolyte control
what does the loop of henle do?
water reabsorption
what does the distal convoluted tubule do?
electrolyte and acid base regulation
where does ADH act in the kidneys?
distal convoluted tubule
what is the role of the collecting duct?
water reabsorption
define polydipsia
excess water intake
define glomerulonephritis
inflammation of glomeruli
define renal insufficiency
measurable reduction in kidney function
define renal disease
disease of the kidneys
how are free catch urine samples carried out? state advantages and disadvantages
caught in container midflow
adv- non-invasive
disadv- not sterile so may show bacteria not actually in sample
how are non-absorbable cat litter urine samples carried out? state advantages and disadvantages
collect after cat urinates as normal
adv- non-invasive, easy
disadv- non-sterile so may show bacteria not in sample
how are catheterisation urine samples carried out? state advantages and disadvantages
anaesthetised unless male dog
adv- more sterile, can accurately measure volume
disadv- more invasive
how are cystocentesis urine samples carried out? state advantages and disadvantages
needle inserted into bladder, blind or ultrasound guided
adv- sterile
disadv- invasive
what is the first sign of most kidney disease?
inability to concentrate urine
how is urine concentration measured?
USG with refractometer
what are the normal cat and dog values of USG?
cat- 1.035-1.060
dog- 1.015-1.045
define hypersthenuric USG and what values are seen for this?
appropriately concentrated urine
1.030
what is meant by sub maximally concentrated urine and what USG values are seen for cats and dogs?
some urine concentration taking place
cats- 1.012-1.035
dogs- 1.012-1.030
what is isosthenuric USG and what values are seen for this?
no modification of urine concentration
1.008-1.012
define hyposthenuric USG and what values are seen for this?
active dilution of urine, more dilute than filtrate
<1.008
what parameters are shown on dipstick analysis of urine?
pH glucose ketones protein blood WBC
what does microscopy of urine samples show?
crystals and casts in urine
what does cytology of urine show and what should be done after cytology?
cells and bacteria in urine
culture of bacteria to identify
what is urea derived from?
protein breakdown
what is creatinine derived from?
breakdown of muscle creatinine
what is the purpose of blood tests relating to kidneys?
shows levels of urea and creatinine which shows function of kidneys as they are excreted by the kidneys
why do blood tests to look at kidney function need to be fasted?
protein in recent meal falsely elevates urea
define azotaemia
high urea +/- creatinine in blood
what does presence of azotaemia show?
reduced glomerular filtration of blood
what are the causes of azotaemia?
pre-renal- inadequate renal perfusion
renal- reduced functional mass of kidneys from underlying kidney disease
post-renal- lack of excretion of waste products due to obstruction or rupture
how can you determine cause of azotaemia?
pre-renal- concentrated urine as water preserved
renal- poorly concentrated urine
post-renal- imaging
what other findings aside from urea and creatinine can indicate kidney disease and what are they caused by?
hyperphosphataemia- reduced renal excretion
hypokalaemia- kidney disease
anaemia- erythropoietin synthesised by kidneys so less in disease
what can radiography show about the US?
shape and size of kidneys
ureters, urethra, bladder
stones
what can be seen on ultrasounds of the US?
parenchymal detail (kidneys and prostate)
bladder wall morphology
causes of post renal azotaemia
what can cytology and biopsy of US show?
renal lymphoma
glomerular disease
commonly used on prostate
what is cystoscopy used for?
visualise LUT for collecting biopsies
laser lithotripsy of stones
define AKI
sudden onset kidney disease
what is the general cause of AKI and what are the effects of this?
sudden nephron damage
high levels of toxins present causing rapid illness
why does CKI present less severe illness?
gradual increase of toxins allows compensation
define anuria
no urine production
define oliguria
very small amounts of urine produced
define polyuria
excess urine production
define ischemia
impaired blood oxygen supply
what types of injury are kidneys susceptible to and why?
toxic and ischemic injury
highly metabolically active
what are causes of AKI?
toxic- NSAIDs, toxins
ischemia- hypoperfusion, hypovolaemia
infectious- leptospirosis, pyelonephritis
cutaneous and renal glomerular vasculopathy
define pyelonephritis
bacterial kidney infection
what are clinical findings of AKI?
acute kidney dysfunction azotaemia, uraemia general illness anuria, oliguria hyperkalaemia, cardiac arrhythmia hyperperfusion or hypoperfusion signs related to intoxicaton
define uraemia
clinical signs associated with azotaemia
how is AKI diagnosed?
history of short clinical illness
acute azotaemia with high phosphate and potassium
diagnosis of cause of azotaemia
urinalysis- concentration, casts, crystals, inflammatory cells, cultures`
what is initial treatment of AKI?
remove underlying cause- stop nephrotoxic drugs, treat for any ingestion of substances
supportive management- electrolytes, nutrition, analgesia
IVFT- crystalloids, correct hypovolaemia over 15 minutes, when euvolemic correct dehydration over 6 hours
what is ongoing treatment of AKI?
IVFT treat hyperkalaemia- crystalloids for renal perfusion, calcium gluconate to stabilise heart, glucose to stimulate insulin release and glucose and potassium uptake to cells treat cause keep BP over 80mmHg minimum appetite stimulants analgesia nutrition
what are complications associated with hyperkalaemia due to AKI?
cardiac arrhythmia or arrest
what is the prognosis for AKI for cats and dogs?
cats- 27-42%
dogs- 34-59%
up to 50% have CKD if survive
what are indications for euthanasia or dialysis for AKI cases?
persistent anuria, volume overload, unmanageable hyperkalaemia
define CKD
kidneys disease lasting over 3 months
what is the signalment of CKD?
cats
older patients
what is the aim of management of CKD and why?
protecting nephrons remaining and managing clinical consequences
damage is irreversible and progressive
what are causes of CKD?
chronic interstitial nephritis glomerulonephropathy untreated infection chronic obstructive disease congenital neoplasia
what findings tend to be in history of patients with CKD?
PUPD weight loss lethargy and weakness inappetence vomiting, diarrhoea, haematemesis, melaena signs associated with hypertension can be subtle or nonspecific
what does clinical exam show for patients with CKD?
low body muscle condition dehydration polyuric, very dilute urine weakness neck ventroflexion uraemic ulcers uraemic halitosis hypertensive retinopathy small irregular kidneys
what are the risks for organ damage associated with different systolic BP?
normotensive/<140- minimal
pre-hypertensive/140-159- low
hypertensive/160-179- moderate
severely hypertensive/>180- high
what organs are susceptible for damage due to high BP?
ocular
renal
cardiac
neurology
how is CKD diagnosed?
inappropriately concentrated urine with azotaemia (only when high level of GFR lost) SDMA test to approximate GFR anaemia high phosphate, low potassium hypertension renal ultrasound
what is initial management of CKD?
stop nephrotoxic drugs
treat underlying cause
correct fluid balance
what is long term treatment for CKD?
renal diet
control hypertension, proteinuria, hyperphosphatemia, hypokalaemia
feed RER
monitor BW
avoid protein calorie malnutrition
phosphate binders every meal to prevent absorption as makes feel ill
potassium supplements
long term regular monitoring
what is prognosis for CKD?
cats- often years
dogs- poor if significant clinical signs
determined once reversible issues addressed
what is nephrotic syndrome?
complication of glomerular disease
what is meant by LUTD?
diseases of bladder, urethra and prostate
define cystitis
bladder inflammation
what are clinical signs of cystitis?
reflect LUT pathology, inflammation, similar signs regardless of aetiology dysuria stranguria haematuria pollakuria periuria vocalisation licking prepuce inappetance lethargy
define dysuria
difficulty urinating
define stranguria
straining to urinate
define haematuria
blood in urine
define pollakuria
small frequent amounts of urine
define periuria
voiding in inappropriate places
what are causes of cystitis?
feline idiopathic cystitis bacterial UTI urolithiasis neoplasia drug induced catheters
what is triage for cystitis?
find out clinical signs of LUTD
are they able to pass urine as obstructions are emergency
define crystals
microscopic mineral precipitate
define crystaluria
crystals in urine
define uroliths
macroscopic urinary stone
what happens to fresh urine at room temperature if crystals are present?
crystals precipitate
what determines the type of crystal or urolith formed?
supersaturated compound
how do crystals and stones form?
high saturation of compounds is precipitation risk
crystal growth and aggregation leads to uroliths
how can you try to prevent formation of crystals and stones?
encourage water intake as more dilute urine the less risk of formation
what are the treatment options for crystals?
as long as symptomatic no treatment needed as microscopic so wont cause damage
abnormal types may need investigating
when are uroliths treated?
if symptomatic
what are the types of symptomatic uroliths?
nephroliths/kidney stones- UUT
ureteroliths- UUT
urethroliths- LUT
crystoliths- LUT
what effects do nephroliths have?
abdominal pain anorexia lethargy haematuria from irritation to pelvis lining pyelonephritis
what effects do ureteroliths have?
ureteric obstruction
post renal azotaemia
what affects do urethroliths have?
obstruction
unproductive urination
what affects do crystoliths have?
pollakuria
stranguria
dysuria
haematuria
how are symptomatic uroliths treated?
dissolving with diet or medication
surgical removal
treat associated infections
how can you identify type of urolith?
radiolucency and opacity
crystals present
stone analysis only definite way
radiography if 2-3 mm or bigger
what is the management for preventing uroliths?
encourage water intake
USG- under 1.033 for cats and 1.020 for dogs
encourage voiding
avoid obesity
dissolution diets- neutral pH to prevent formation of stones, only short term then back to normal diet
what are nursing considerations for uroliths?
monitor for unproductive urination as re obstruction possible
maintain hydration and urination
catheter care
analgesia- opioids, NSAIDs when wont get blocked again
what are potential causes of feline idiopathic cystitis/FIC?
young to middle aged overweight indoor, litter tray user multi animal household nervous dry diet stressors present sudden change in environment hypofunctioning GAG layer
what is meant by the GAG layer of the bladder?
protective layer lining the bladder
what tests are done if suspect FIC to rule out other causes?
urinalysis- exclude UTI
radiographs- look for uroliths, masses, strictures
ultrasound- assess UUT
how do non-obstructive FIC cats present?
LUTD signs- pollakuria, stranguria, dysuria, haematuria
able to void
how do obstructed FIC cats present?
urethral spasm or plug
unproductive urination
commonly recur
define urethral plug
accumulation of mucus, debris, organic matter due to inflammation in bladder lining
what is the consequence of obstructed UT?
back pressure on kidneys so cant filter blood- post renal azotaemia
hypokalaemia- bradydystrhythmia
pain
what is initial treatment for obstructed patient?
catheterise to relieve pressure
describe how to catheterise an obstructed patient
examine for stones, plugs, trauma
lubricate catheter
insert, can flush while doing this to aid process
suture in place
take urine sample for analysis
lavage bladder with warm 0.9% saline until clear to remove noxious secretions
what measures should be taken if placing indwelling catheter?
closed system, sterile handling
change bag daily, keep off floor
slack in system so no pulling
monitor UOP- hydration, electrolytes, infection
how do you calculate UOP?
weight of bag now- weight 4 hours ago= UOP over 4 hours
UOP over 4 hours/4= UOP over 1 hour
UOP over 1 hour/BW= UOP(ml/kg/hr)
what is management for FIC?
analgesia remove stress enough resources in house for number of cats encourage water intake urinary diet, wet food avoid obesity GAG supplements
define urinary incontinence
loss of normal voluntary control of micturition
what is the normal process of urination?
relaxation of urethral sphincter and contraction of bladder
what are the two types of neurogenic incontinence and how do these usually present?
upper motor neurone and lower motor neurone lesion
overflow incontinence
how does upper motor neurone lesion incontinence present?
spastic bladder, high muscle tone
hard to express
how does lower motor neurone lesion incontinence present?
flaccid bladder
easy to express
what are the causes of non-neurogenic incontinence?
urethral sphincter mechanism incomplete/USMI
anatomical defects
urge incontinence
dyssynergia
why does USMI cause incontinence?
sphincter function fails so leak in recumbency as bladder neck no longer compressed by pelvis which prevents leakage
what are predispositions for USMI?
neutering
obesity
intrapelvic bladder
large dogs
how is USMI treated?
tightening sphincter
stimulating sphincter contraction with alpha adrenergics, alpha agonists, oestrogens
urethral cuff
surgical repositioning of bladder
why do anatomical defects cause incontinence?
ureter voids to urethra so no urine storage
what is the cause of urge incontinence?
inflammation causing sudden contraction
why does dyssynergia cause incontinence?
failure of bladder contraction to coordinate with urethral relaxation
how is neurogenic incontinence managed?
treat disease
express bladder avoiding catheters where possible due to infection
how can anatomic cause of incontinence be treated?
laser to reposition bladder entry
surgical re-implantation
what history should be taken for surgical diseases of UT?
continence voiding urine, any abnormal times or location ease of urination volume, smell, appearance of urine frequency of urination drinking neuter status
what initial investigations are done for surgical disease of UT?
bloods- leukocytes, anaemia, urea, creatinine
urinalysis
radiography- stones, abnormalities
ultrasound- stones, masses, lesions, inflammation
what are general considerations when performing surgery on UT?
antibiotics especially if UTI present
minimise urine spilling with soaked lap pads
what equipment is required for surgery on UT?
fine instruments and suture material abdominal retractors retractors for bladder catheters cystotomy tubes suction spoons for stones magnification
when is surgery for renal neoplasia contraindicated?
pulmonary metastasis
bilateral neoplasia
what are clinical signs of renal neoplasia?
haematuria
palpable abdominal mass
other vague signs
what are common causes of renal trauma?
bite
RTA
when would subcutaneous ureteral bypass be performed?
ureter blocked and cant dissolve medically
what is a subcutaneous ureteral bypass?
tube placed in kidney and connected to bladder via under skin to give new ureter
what causes renal stones?
similar to uroliths, supersaturation of minerals
what is the treatment for renal stones?
diet to dissolve
antibiotics
surgery
what surgery be used to treat renal stones and what is a disadvantage of this?
nephrotomy (incision thorugh kidney) with tourniquet around renal vessels to reduce blood to incisions
may reduce renal function
how are ureters treated when damaged during spaying?
remove the damaged kidney and ureter
re implant ureter cutting off damaged part
define nephrectomy
removal of kidney
what are indications for nephrectomy?
renal neoplasia renal trauma chronic pyelonephritis idiopathic haematuria ureteral abnormalities one normally functioning kidney
how is nephrectomy performed?
midline laparotomy
kidney isolated and freed from peritoneum
renal artery and vein ligated
ureter ligated and transected adjacent to baldder
what is ureteral ectopia?
ureters opening to urethra not bladder, usually bilateral
what is signalment for ureteral ectopia?
congenital abnormality in dogs, normally female
how is ureteral ectopia treated?
neoureterostomy with close observation post op for stranguira
how is neoureterostomy performed?
incision through bladder wall and ureteral mucosa to lumen of ectopic ureter close to its entry to bladder wall
ureteral and bladder mucosa sutured to make new stoma
what is presentation for bladder stones?
haematuria
frequency and urgency to urinate
complete obstruction
how are bladder stones treated?
struvite and urate- medically dissolved
cystotomy for all other uroliths or any obstructing or causing clinical signs
prescription diet to prevent recurrence
how does bladder neoplasia present?
elderly animals
haematuria
frequency and urgency to urinate
obstruction
what are treatment options for bladder neoplasia?
most malignant
if effect trigone cant remove
partial cystectomy can aid palliative care
what is the consequence of ruptured bladder?
uroabdomen
post renal failure
how are bladder trauma treated?
IVFT to stabilise
surgical repair
what are indications for cystotomy?
removal of bladder stones
how is cystotomy carried out?
caudal midline laparotomy
exteriorise and isolate bladder with swabs
incision in ventral midline of bladder
what equipment is needed for cystotomy?
urethral catheter
volkmann spoon
what needs to be done following cystotomy for stone removal?
stones submitted for analysis of composition, culture and sensitivity
what are types of urethral disease?
urolithiasis incontinence FLUTD trauma neoplasia
what is the main consequence of urethral stones?
obstruction
how are urethral stones managed?
small pass unproblematically
relive obstructions
correct hypovolaemia, electrolyte imbalance, acid base balance
what are risk factors for USMI?
neutering
tail docking as affects spinal nerves
obesity
breeds- springers, mini poodles
how is USMI managed?
oestrogen or phenylpropanolamine to increase smooth muscle tone of sphincters
surgery if non responsive
what are the surgical options for USMI?
colposuspension
urethropexy
hydraulic artificial urethral sphincters
define urethropexy
support provided to urethra
what are risk factors for FLUTD?
middle aged overweight neutered indoor cats dry diet secondary to bladder disease
how is FLUTD managed?
usually medically
surgical if repeated episodes
what are surgical options for urethral neoplasia?
bypass urethra for palliation
usually too advanced for excision and mets present
define urethrotomy
incision into urethra
what is urethrotomy used for?
stones that wont flush into bladder
define urethrostomy
creation of permanent new opening
what is urethrostomy used for?
last resort for recurrent obstruction, severe trauma or stricture
where are urethrostomies mainly performed?
scrotal- dogs
perineal- cats
what are indications for tube cystotomy?
divert urine from urethral surgical sites
palliation of obstructions due to neoplasia
how are tube cystotomies carried out?
purse string suture in bladder
foley or mushroom tip catheter through stab incision in middle of suture
suture tightened
catheter passed through incision in abdominal wall
cystopexy performed
catheter sutured to skin and kept in place for 7 days
what is post op care for urethral surgery?
prevent interference
monitor short term haematuria
observe dysuria if no catheter
analgesia
what are the effects of benign prostatic hyperplasia?
dyschezia or dysuria
define dyschezia
difficult or painful defecation
what is signalment for benign prostatic hyperplasia?
older entire males
how is benign prostatic hyperplasia treated?
medical- anti-androgens
castration for definite treatment
define prostatitis
inflammation of the prostate gland
what are causes of prostatitis?
bacterial infection
often with BPH
what are signs of prostatitis?
dysuria
pyrexia
purulent penile discharge
how is prostatitis managed?
antibiotics
anit-androgens
castration
what are indications for prostatic abscesses?
entire males
usually with prostatitis
what are signs of prostatic abscesses?
male version of pyometra
dysuria
dyschezia
what is treatment for prostatic abscesses?
omentalisation following re-roofing and flushing of abscess to help healing
castration
rapid surgery and castration if burst with signs of sepsis
what are risks for prostatic neoplasia?
entire males
BPH
neoplasia
how is prostatic cysts treated?
de-roofing
omentalisation
castration
define catheterisation
inserting urinary catheter into urethra up to level of bladder
what are the two types of catheter?
temporary
indwelling
why are catheters used?
urine sample empty bladder to reduce contamination during surgery contrast insertion for radiography maintain urethral patency unblocking urethra monitoring UOP diverting urine preventing scalding
what are alternatives to catheterisation?
manual expression
free catch
cystocentesis
what are disadvantages of manual expression of urine?
can rupture bladder
not possible if tense
hard if overweight
not sterile
what are disadvantages of free catch urination?
time consuming
non sterile
what are advantages of cystocentesis?
sterile
what are disadvantages of cystocentesis?
higher risk
need to let animal void after
describe the features of portex catheters
rigid so traumatic
single use
side holes to allow drainage if end blocked but low pressure so hard to unblock
not designed for indwelling
describe the features of foley catheters
soft
inflatable balloon of sterile water to hold in place
preferred option for indwelling
too big for cats
multiple end ports for flushing, collection etc, externally large
describe features of jackson/tom cat catheters
good for unblocking
rigid
side holes make distal obstruction harder
not used indwelling as traumatic but can leave in short term
short so wont reach bladder
describe features of slippery sam catheters
open ended so good for unblocking
can be indwelling short term
atraumatic
risk hub detaching
describe how male dogs and cats are catheterised
restrain, may sedate
wash hands and put on sterile gloves and apron
expose penis from prepuce and prep with dilute iodine
lubricate catheter
can give lidocaine LA
insert until see urine
describe how to insert catheter in bitches and queens
sedate and place in sternal clip and clean vulva insert speculum in dogs to visualise urethral orifice, in cats use otoscope to visualise feed into urethral orifice insert until see urine
list equipment needed for catheterisation
catheter dilute iodine swabs lubricant containers for sample closed system if needed syringes sterile gloves and apron speculum
describe how to care for indwelling catheters
wash hands before and after empty bag every 4 hours or as needed measure UOP- hydration, kidney function check for swelling or pain check line remove as soon as no longer needed care for urine scalding monitor for UTI avoid patient interference
what are risks associated with catheterisation?
urethral rupture, trauma, inflammation, stricture
infection likely
obstruction of catheter by stones or kinks
what does cystotomy tube do?
urine from bladder to outside via abdominal wall
what does nephrostomy tube do?
urine from kidney to outside
what is normal UOP?
1-2ml/kg/hr
how do you calculate UOP?
(volume of urine/hours)/BW
how do you calculate expected normal UOP?
BW x normal UOP per hour x number or hours
how often should UOP be calculated in hospitalised patients?
every 4 hours
why do you need to measure UOP?
renal function information
what is the purpose of renal diets and what are their compositions?
minimise uremic episodes, prolong survival
restricted protein, phosphorus, sodium, supplemented by omega 3, antioxidants
