Nursing the CKD cat Flashcards
which species is more affected by chronic kidney disease?
cats (3x more prevalent than in dogs)
what type of disease is chronic kidney disease?
functional and/or structural disease of >3 months duration
what is the pathogenesis of chronic kidney disease?
gradual, progressive, irreversible nephron loss
what is the aim of chronic kidney disease management?
reducing workload of the remaining nephrons and preventing further damage
what is no nephron loss classed as?
normal kidney function
what is the loss of 50% of nephrons classed as?
subclinical kidney disease
what happens as a result of 67% kidney loss?
lose their concentrating ability
what USG indicates the kidneys have lost concentrating ability?
<1.030 in dogs
<1.035 in cats
at what percentage nephron loss do the kidney lose their concentrating ability?
67%
what occurs when there is 75% nephron loss?
become azotemic
at what nephron loss does the body become azotemic?
75%
at what stage of nephron loss do clinical signs of kidney disease appear?
75%
what occurs at 100% nephron loss?
incompatibility with life
what are the 2 main causes chronic kidney disease?
chronic interstitial nephritis
asymptomatic/undiagnosed initial kidney insult
what is chronic interstitial nephritis?
inflammation of the renal interstitium
what are the treatable and/or (partially) reversible causes of chronic kidney disease?
pyelonephritis
ureterolithiasis
what is pyelonephritis?
inflammation of the kidney and renal pelvis
what might cause pyelonephritis?
FIP, FIV, leishmaniosis
how can ureterolithiasis cause chronic kidney disease?
it is post-renal but causes renal damage
how might an asymptomatic insult lead to chronic kidney disease?
upregulate GFR rate –> compensatory hypertrophy of remaining nephrons
over time –> progressive nephron loss, progressive decrease in GFR
what are the main consequences of chronic kidney disease?
loss of water/electrolyte regulation
loss of acid/base regulation
failed excretion of uraemic solutes
impaired renal hormone synthesis
hypertension (cause vs consequence?)
what is the clinical manifestation of loss of water/electrolyte regulation?
PUPD, dehydration
hypokalaemia
what is the clinical manifestation of loss of acid/base regulation?
acidaemia - contributes to nausea, vomiting, inappetence
what is the clinical manifestation of failed excretion of uraemic solutes?
azotemia, hyperphosphataemia - contributes to nausea, vomiting, inappetence
contributes to renal secondary hyperparathyroidism
what is the clinical manifestation of impaired renal hormone synthesis?
lack of erythropoietin - anaemia
what is the clinical manifestation of hypertension?
end organ damage
which cats typically get chronic kidney disease?
mature-geriatric cats
when are young cats affected by chronic kidney disease?
due to congenital disorders (polycystic kidneys, malformation of kidneys)
when might we diagnose kidney disease in the sub-clinical phase
incidental finding - at time of pre-op profiles or geriatric wellness screening (bloods and urinalysis)
what should we discuss with the owner if kidney disease is suspected/diagnosed?
weight/condition changes - catabolic state
drinking/urination, appetite
demeanour, activity levels
vomiting +/- diarrhoea +/- haematemesis/melaena
signs associated with hypertension
medication admin - ease/problems
why might cats with chronic kidney disease have constipation?
secondary to dehydration
what signs are associated with hypertension?
neurological signs
blindness
why might we ask about drinking/urination?
to check for PUPD
what things should we be mindful of on assessment of a CKD cat?
hydration status
weakness (neck ventroflexion)
uraemic ulcers +/- halitosis
hypertensive retinopathy
small irregular kidneys on palpation
‘rubber jaw’
why might a cat with CKD show neck ventroflexion?
hypokalaemic myopathy
why do cats with CKD get ‘rubber jaw’?
due to renal secondary hyperparathyroidism
when might we have a clinical suspicion of CKD?
declining urinary concentration plus decline in weight
how do we diagnose CKD?
often combines diagnostic tools and functional tests
which tests may be undertaken for diagnosis of CKD?
USG
urine protein:creatinine ratio
serum creatinine and urea
GFR
SDMA
diagnostic imaging - U/S and radiography
what is the most indicative test of chronic kidney disease?
GFR
which parameters confirm reduced kidney function?
azotemia - increased urea and creatinine
WITH inappropriately concentrated urine
which other test may be used to diagnose chronic kidney disease?
symmetric dimethylarginine (SDMA)
what is the advantage of testing SDMA?
may identify kidney disease earlier than elevated urea/creatinine when used appropriately
how can we looks for structural disease of the kidney?
u/s - renal size and architecture
radiography - ureteroliths
what reversible causes of chronic kidney disease might we be able to see with imaging?
ureteric obstruction
pyelonephritis
lymphoma?
what is the most common cause of hypertension in cats and dogs?
chronic kidney disease
what is the target measurement for SBP?
<140mmHg
how many BP measurements should ideally be taken?
minimum 3, preferably 5-7 consecutive measurements
what can results from prolonged high BP?
ocular, target organ damage and neuro issues
how can we reduce the stress of taking blood pressure measurements in cats?
feline friendly room
long appointment
use headphones with doppler
tail measurement
feliway
consider medication e.g. gabapentin
how does ‘rubber jaw’ occur in CKD patients?
due to renal secondary hyperparathyroidism
how does renal secondary hyperparathyroidism result in bone resorption?
kidneys failing to excrete phosphorous –> raised serum phosphate
triggers increased PTH secretion to lower phosphate (ineffective as inadequate renal function to excrete phosphate efficiently anyway)
persistent PTH release –> bone resorption resulting from increased PTH activity
when is rubber jaw clinically most recognised?
in renal dysplasia
what is the overall effect of excess PTH?
demineralisation of calcium to correct balance in blood
(PTH increases calcium and decreases phosphate)
how does CKD result in hypokalaemia?
multiple factors - inappetence, GI losses, urinary losses
what does hypokalaemia cause?
weakness - neck ventroflexion
inappetence
how do we treat hypokalaemia in CKD cats?
potassium supplementation
which species commonly gets proteinuria as a result of CKD?
dogs
how do we identify proteinuria?
need urine protein:creatinine ratio (dipstick not sufficient)
what value is classed as proteinuria?
UPC >0.4
why do cats with CKD get anaemia?
multifactorial - lack of erythropoietin production, reduced RBC lifespan, GI losses (?)
what does anaemia contribute towards in CKD cats?
weakness
lethargy
inappetence
proportional to disease stage
what should be involved in the consultation for suspected CKD?
clinical history
weight, BCS
blood pressure, retinal exam
PCV, urea, phosphate, calcium, electrolytes
urinalysis
how often should CKD cats be re-seen?
every 3-6 months if stable
more frequently (as needed) if unstable
when is staging of CKD undertaken?
after diagnosis, once reversible problems have been addressed
why do we stage CKD?
in order to facilitate appropriate treatment and monitoring of the patient
what is IRIS staging?
an internationally recognised set of guidelines to CKD staging and treatment
what are the factors which contribute to IRIS staging of CKD?
creatinine
substage by proteinuria
substage by blood pressure
what are the most important therapies for CKD?
maintenance of hydration
feeding a renal diet
what is in a renal diet?
restricted protein content
low phosphate content
antioxidants
essential fatty acids
added potassium
bicarbonate to help acidosis
how can we encourage water intake in CKD cats?
water fountains
add water to food/feed wet food
trying different shaped/material bowls
multiple water bowls
keep water away from food
how can we help transition a cat onto a prescription renal diet?
don’t introduce in hospital
heat up food
mixing with existing diet, transition gradually
stabilise first - more important they eat non-renal than not eat at all
how can we manage hypertension in CKD patients?
amlodipine in cats
ACE inhibitors in dogs
how can we manage hyperphosphataemia in CKD patients?
renal diet
phosphate binders
how can we manage hypokalaemia in CKD patients?
renal diet
potassium supplementation
how can we manage proteinuria in CKD patients?
renal diet
ACE inhibitors
omega 3 PUFAs
anti-platelets (for cardiac issues)
