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