12.7.1: Chronic kidney disease Flashcards
Fill in the blanks for CKD
K+ normal or decreased
USG <1.035 (inappropriately dilute)
Fill in the blanks for ARF
K+ elevated, there is metabolic acidosis
USG usually 1.008-1.015
What are some possible underlying causes for CKD?
- Polycystic kidney disease
- Pyelonephritis
- Toxins
- Glomerulonephritis
- Neoplasia
- Amyloidosis
- FIP
Often no cause is identified - this is age-related degeneration.
Common presenting signs of CKD
- PUPD
- Anorexia
- Weight loss
- Dehydration
- Pallor
- Vomiting
- Diarrhoea
- Mucosal ulcers
- Uraemic breath
Comorbidities that might provide renal insult, over time leading to CKD
- Hyperthyroidism
- Hypercalcaemia
- Heart disease
- Periodontal disease
- Cystitis
- Urolithiasis
- Diabetes
- Previous AKI
- Nephrotoxic drugs
What are some nephrotoxic drugs?
- NSAIDs
- Aminoglycosides e.g. gentamicin
- Sulphonamides
- Polymixins
- Chemotherapeutics
True/false: in Chronic Kidney Disease, nephron damage is progressive, but if caught early enough, may be reversible.
False
In Chronic Kidney Disease, nephron damage is progressive and irreversible.
Describe how renal hyperparathyroidism (osteodystrophy) could develop in CKD
- Reduce metabolism and excretion of parathyroid hormone -> renal hyperparathyroidism (osteodystrophy)
- This is uncommon but possible
Explain why you may see anaemia with CKD and which type of anaemia this will be
- Reduced renal function -> reduced EPO production
- Reduced EPO -> non-regenerative anaemia
Uraemic crisis
Build-up of urea and other toxins usually excreted in kidneys to intolerable levels. Due to:
* End-stage CKD
* AKI
* Acute on chronic AKI (e.g. ischaemic/toxic insult exacerbating existing CKD)
Clinical signs of uraemic crisis
- Vomiting/nausea
- Anorexia
- Lethargy
- Depression
- Oral ulcers
- Melena (GI ulcers)
- Anaemia
- Weakness
- Hypothermia
- Muscle tremors
- Seizures
Renal insufficiency vs renal failure
Renal insufficiency: reduced functional ability of the kidneys but they are compensating (coping).
Renal failure: the animal is unable to compensate for its reduced renal function.
These definitions have largely been replaced by IRIS staging.
IRIS staging of CKD
Stage 1 - No azotaemia with normal creatinine
Stage 2 - Mild azotaemia with normal/elevated creatinine
Stage 3 - Moderate azotaemia
Stage 4 - Severe azotaemia
What do we use to quantify a patient’s CKD using IRIS staging? Explain both staging and substaging.
- Stage 1-4 based on creatinine or SDMA -> looking for consistent elevation in the hydrated patient
- Substage is based on proteinuria and systolic BP
What should you do before attempting to IRIS stage a patient?
- Properly hydrate them first
- Remember that abnormal on IRIS staging may fall within normal lab values so check for this
How could we diagnose early stage CKD?
- Often we don’t pick CKD up this soon
- Abnormal renal imaging/known insult
- Persistent elevation/increased creatinine/SDMA
- Persistent renal proteinuria
How could we diagnose late stage CKD?
Which of the following is a marker of GFR?
a) serum phosphate
b) total ionised calcium
c) serum creatinine
d) serum potassium
C) Serum creatinine
Describe why serum creatinine is a marker of GFR
Describe why SDMA is a marker of GFR
Breed predispositions to chronic kidney disease - dogs
- Westies
- Boxers
- Shar Pei
- Bull terriers
- Cocker spaniels
- CKCS
Breed predispositions to chronic kidney disease - cats
- Persian
- Abyssinian
- Siamese
- Ragdoll
- Burmese
- Russian Blue
- Maine Coon
Almost all purebreds have CKD at higher prevalence than DSHs for example.
Broad treatment principles for CKD
- Treat the underlying cause if possible/ known
- Slow progression by managing risk factors
- Focus on controlling proteinuria, hypertension, and hyperphophataemia as these are linked to worse prognosis
- Diet is very important Stage 2 onwards
- Later stages: treat secondary anaemia, acidosis, nausea; maintain hydration and adequate nutrition
- See recommendations for each substage
Treatment of a uraemic crisis
Causes of CKD aside from ageing / fibrosis
Primary causes of hypertension
- Stress / environment
- Idiopathic (prevalence >12% in healthy cats >10 y.o.)
Secondary causes of hypertension
- Iatrogenic (e.g. glucocorticoids)
- Systemic disease including CRF, Cushing’s, hyperT4, hypoT4, DM, obesity, phaeochromocytoma, primary hyperaldosteronism
Hypertension can result in end organ damage. Which organs are affected?
- Eyes
- Heart
- Brain
- Kidneys
Describe how hypertension affects chronic renal failure
Treatment of hypertension and CRF
How quickly should we aim to reduce blood pressure if an animal is hypertensive?
- Aim to reduce to <150 mmHg over a few weeks
- Quicker (in hours) if there are severe ocular / CNS signs
Which drugs would we start with when treating hypertension in the dog? How is this different in the cat?
You started a hypertensive patient on treatment. When should you recheck and what will you look for? How will you continue to monitor them?
Pyelonephritis
bacterial infection of the renal pelvis and parenchyma.
Prevalence and diagnosis of pyelonephritis
Which antibiotics would you use to treat UTIs / pyelonephritis? Which should you avoid in the patient with CKD?
Clinical presentation and diagnosis of polycystic kidney disease (PKD)
Characteristics of renal neoplasia and how this could lead to signs associated with CKD
Causes, clinical signs and treatment of Fanconi syndrome
Clinical signs and diagnosis of protein losing nephropathy
Which species is primary glomerular disease more common in: dogs or cats? What are some possible causes of this in cats?
More common in dogs.
When seen in cats, often caused by:
* Neoplasia
* Systemic inflammatory disease
* Chronic FeLV
* FIV
* FIP
Examples of primary glomerular disease seen in dogs
Diagnosis of primary glomerular disease
Pathogenesis and clinical presentation of nephrotic syndrome
Treatment of nephrotic syndrome
Treatment of glomerular disease
Factors that inform prognosis of chronic renal failure
Indications for renal biopsy
Only perform a renal biopsy if it will alter patient management (generally not CKD) - for example:
* Protein losing nephropathy (if unexpected / doesn’t respond to treatment)
* AKI - causes and prognosis
* Mass lesions
Contraindications for renal biopsy
- Late stage CKD
- Severe anaemia / azotaemia
- Uncontrolled hypertension / coagulopathy
- Severe hydronephrosis / many large cysts
- Pyelonephritis / perirenal abscess
- NSAIDs in the last 5 days
CKD is a very common condition especially in older cats. It can be the result of aging change or have an underlying cause (if the latter, treat this if possible). What does IRIS staging allow us to do?
IRIS staging allows us to:
Identify CKD and advise appropriate treatment focusing on:
* Appropriate nutrition and hydration
* Controlling hypertension
* Minimising proteinuria
* Controlling serum phosphate
It also allows us to offer information regarding prognosis.
Best results = close monitoring, patient compliance, owner commitment.
