CKD Flashcards
what is the most common kidney disease in dogs and cats?
CKD
is CKD more prevalent in dogs or cats?
3 x more prevalent in cats
what is the definition of CKD?
functional and/or structural disease of the kidneys of >3 months duration
what is the result of CKD?
gradual, progressive and irreversible nephron loss leading to reduced ability to filter toxins from the body
what can therapeutic intervention do for CKD patients?
help slow disease progression
prolong good quality of life
what is the aim of CKD management?
reducing workload of remaining nephrons
prevention of further kidney damage
what level of nephron loss is there with normal kidney function?
none-50% loss
what disease signs are seen with 50% nephron loss?
none - disease still subclinical
what what level of nephron loss do kidneys loose urine concentrating ability?
67%
what happens to the kidneys at 67% nephron loss?
lose concentrating ability
what USG is seen in cats once they reach 67% nephron loss?
<1.035
what USG is seen in dogs once they reach 67% nephron loss?
<1.030
what happens to the kidneys at 75%% nephron loss?
become azotemic and clinical signs seen
at what level of nephron loss are clinical signs and azotemia seen?
75%
what happens between 75 and 100% nephron loss?
decreasing quality of life which then becomes incompatible with life
what are the majority of CKD cases caused by?
chronic interstitial nephritis
what is chronic interstitial nephritis?
inflammation of renal interstitium
what should be excluded when diagnosing CKD?
treatable or partially reversible causes
what are the main treatable/reversible causes of CKD?
pyelonephritis
ureterolithiosis
what may CKD be caused by other than chronic interstitial nephritis?
an asymptomatic or undiagnosed initial insult which leads to a reduction in glomerular filtration rate
what is pyelonephritis?
inflammation of kidney and renal pelvis with infectious cause (e.g. FIP/FIV)
how does ureterolithiasis cause kidney injury?
post renal obstruction but causes damage as waste products back up into kidney
what is caused by reduction in glomerular filtration rate?
compensatory hypertrophy of remaining nephrons which over time leads to progressive nephron loss as the process is damaging
overall reduction in GFR
is compensatory hypertrophy of nephrons effective?
initially yes - individual nephrons can increase GFR.
Over time this is damaging
what are the main consequences of CKD?
loss of water/electrolyte regulation
loss of acid/base regulation
failed excretion of uraemic solutes
impaired renal hormone synthesis
hypertension
what are the clinical manifestations of loss of water/electrolyte regulation due to CKD?
PUPD
dehydration
hypokalaemia
what are the clinical manifestations of loss of acid/base regulation due to CKD?
acidaemia leading to nausea, vomiting, dehydration and inappetance
what are the clinical manifestations of failed excretion of uraemic solutes due to CKD?
azotemia
hyperphosphataemia
what is caused by hyperphosphataemia?
nausea
vomiting
dehydration
inappetance
renal secondary hyperparathyroidism
what are the clinical manifestations of impaired renal hormone synthesis due to CKD?
lack of erythropoetin (EPO)
anaemia
what are the clinical manifestations of hypertension due to CKD?
end organ damage
what age of patient is affected by CKD?
increasing incidence with age
<1 year old may be affected
what patients are typically affected by CKD?
mature-geriatric cats
what is the usual cause of patients under 1 year being affected by CKD?
congenital disorders e.g. malformation or polycystic kidneys
how long will signs of CKD last for?
weeks to months
when may CKD be identified?
long term signs
incidental diagnosis in subclinical phase
how may CKD be diagnosed in the subclinical phase?
pre-op sceening profiles
geriatric wellness screening bloods and urinalysis
what should be discussed with an owner when taking patient history if CKD is suspected?
weight or condition changes
drinking and urination (PUPD)
appetite changes
change to demenour or activity levels
any GI signs
signs associated with hypertension
ease of medication administration
what GI signs may be seen with CKD?
vomiting
diarrhoea
haematemesis
melaena
constipation secondary to dehydration
what should you assess about a patient with suspected CKD?
hydration status
weakness
presence or uraemic ulcers/uraemic halitosis
hypertensive retinopathy
palpation of kidneys
presence of rubber jaw
what signs may suggest weakness in CKD patients?
neck ventroflexion
what is neck ventroflexion in CKD patients caused by?
hypokalaemic myopathy
how may kidneys appear on palpation if the patient has CKD?
small and irregular
what is rubber jaw caused by?
renal secondary hyperparathyroidism
how is CKD diagnosed?
combination of diagnostic tools and functional tests
what tests are used to diagnose CKD?
USG
urine protein:creatinine ratio
serum creatinine and urea
GFR
symmetric dimethylarginine (SDMA)
imaging (xray or US)
what is the earliest indication of CKD?
weight loss
reduction in urine concentration
what is the most sensitive test for CKD?
GFR
at what level of nephron loss is azotemia seen?
75%
what is azotemia?
increased blood urea and creatinine
at what level of nephron loss is inappropriately concentrated urine seen?
67%
what clinical signs are seen at 67% GFR loss?
inappropriately concentrated urine
what clinical signs are seen at 75% GFR loss?
azotemia
what clinical signs confirm CKD diagnosis?
azotemia and submaximally concentrated urine
what USG is submaximally concentrated urine in cats?
<1.035
what USG is submaximally concentrated urine in dogs?
<1.030
what is urinalysis also used to assess?
urine infection
urine protein
what is the benefit of SDMA testing for CKD?
may identify kidney disease earlier than elevated urea or creatinine
how can kidneys be elevated for structural disease?
US
xray
what can be shown about kidneys on US?
renal size and architecture
what can be shown about kidneys on xray?
ureteroliths
what may be found on imaging of kidneys?
reversible causes
what are some reversible causes of CKD that may be seen on imaging?
ureteric obstruction
pyelonephritis
lymphoma
what are the main complications associated with CKD?
hypertension
renal secondary hyperparathyroidism
hypokalaemia
proteinuria
anaemia
what percentage of cats with CKD have hypertension?
20-60%
what is the most common cause of hypertension in cats and dogs?
CKD
what is the target systolic BP for cats and dogs?
120-140 mmHg
what is seen with persistent hypertension?
occular damage
target organ damage
neuro issues
how many BP measurements should be taken for an average?
minimum 3
ideally 5-7
how can stress be reduced for patients under going BP measurement?
quiet room
minimal/gentle handling
feliway
headphones for doppler
patience
what size BP cuff should be used?
40% of limb circumference
what effect does CKD have on phosphate?
increased levels of serum phosphate
what hormone responds to increased serum phosphate?
parathyroid hormone
what effect does parathyroid hormone have on phosphate?
under normal circumstances it should reduce phosphate levels
what is the effect of parathyroid hormone on calcium?
increase release of calcium from bones to increase serum Ca2+
why is parathyroid hormone ineffective in reducing phosphate levels during CKD?
inadequate renal function to excrete the increased phosphate
how does CKD cause secondary hyperparathyroidism?
CKD leads to increased serum phosphate
parathyroid hormone released in response
actions of paratyroid hormone ineffective as renal function is inadequate and phosphate cannot be released
PTH continues to be released due to high phospate levels
leads to bone reabsorption due to calcium releasing effects of PTH
why is bone reabsorption seen with hyperphosphataemia?
PTH releases calcium from bone
PTH released in response to hyperphosphataemia leads to demineralisation of bone and bone reabsorption
what is the commonly seen sign of renal secondary hyperparathyroidism?
rubberjaw
when is rubber jaw most commonly seen?
renal dysplasia
what is renal dysplasia?
kidney not fully developed in utero
what is hypokalaemia in CKD due to?
inappetance
GI losses
urinary losses
what is caused by hypokalaemia in CKD?
weakness
neck ventroflexion
inappetance
in how many cats with CKD is hypokalaemia seen?
20-30%
how is hypokalaemia treated?
K+ supplementation
in what animals is proteinuria more commonly seen with CKD?
dogs
what urine:protein creatinine ratio indicates CKD?
> 0.4
what causes proteinuria in CKD?
glomerulus is damaged leading to protein loss into urine
what is needed to diagnose proteinuria?
urine:protein creatinine ratio (UPC)
in how many CKD patients is anaemia seen?
30-60%
how does CKD lead to anaemia?
multifactorial:
lack of erythropoetin production
reduced RBC lifespan
GI losses
what are the signs of anaemia in CKD patients?
weakness
lethargy
inappetance
proportional to disease sateg
what parameters should be recorded on CKD patient review?
hydration
BP
K+
Ca+
USG
weight
what is involved in a CKD clinic?
history
weight and BCS
BP
retinal exam
testing
what history questions are crucial in CKD consults?
appetite
drinking (PUPD)
GI signs
what tests may be done regularly in patients with CKD?
BP
PCV
urea
creatinine
phosphate
calcium
electrolytes
urinalysis
how often should CKD patients be seen?
if stable: 3-6 months depending on stage
if unstable: as needed
what are the IRIS guidelines?
international guidelines for diagnosis, management and treatment of CKD
when is IRIS staging performed?
following CKD diagnosis
what is the aim of IRIS staging?
facilitate appropriate treatment and monitoring
what is involved in IRIS staging?
creatinine level
substage by proteinuria
substage by BP
what must be done before testing for IRIS stage of CKD?
address reversible problems
describe IRIS stage 1
non-azotemic
inability to concentrate urine
elevated SMDA
describe IRIS stage 2
mild azotemia
may not have any clinical signs
describe IRIS stage 3
moderate azotemia
some extrarenal signs
describe IRIS stage 4
increasing risk of systemic signs and uraemic crisis
what is an emphasis of IRIS management of CKD patients?
hydration
what are the main areas of therapy for CKD patients?
maintain hydration
feed renal diet
what is the most effective CKD management strategy?
feeding a renal diet
what effect can dehydration have on CKD?
advance disease
what are the key components of a renal diet?
low phosphate
low protein
antioxidants
essential fatty acids
K+ supplementation
bicarbonate
why should CKD diets be low phosophate?
reduction of hyperphosphataemia
kidneys cannot remove as well
why should CKD diets be low protein?
kidneys not handling protein as well
leak from glomerulus into urine
why should CKD diets have antioxidants?
protection against organ damage
why should CKD diets have essential fatty acids?
support bloodflow and GFR
why should CKD diets have bicarbonate?
prevention of acidosis
what are the main options for improving hydration of CKD patients?
fountain
shallow bowl
multiple bowls
fresh water
wet food or adding water to food
try different bowls / materials / sizes
keep water away from food
what is the aim of CKD therapy?
supportive and symptomatic treatment of disease consequences
what factors may need treatment in CKD?
hypertension
hyperphosphataemia
hypokalaemia
proteinuria
how can hypertension be managed?
amlodipine (cats)
ACE inhibitors (dogs)
how can hyperphosphataemia be managed?
renal diet
phosphate binders
what is the role of phosphate binders?
prevent absorption
how can hypokalaemia be managed?
renal diet
potassium supplementation
how can proteinuria be managed?
renal diet
ACE inhibitors
omega 3 PUFAs
antiplatelets
what is the role of antiplatelets?
prevention of cardiac issues
