1: Chronic Kidney Disease Flashcards
Define chronic kidney disease
Abnormalities kidney function or structure present for 3-months
What is the time-frame to diagnose CKD
3-months
How many categories of CKD are there
5
What is CKD categorised based on
eGFR
What is normal eGFR
More than 60
What is G1
eGFR >90 and evidence of renal dysfunction (haematuria, proteinuria, renal tubule disorder, disorder on imaging or biopsy)
What is G2
eGFR 60-90
What is G3a
eGFR 45-60
What is G3a referred to as
Mild-Moderate CKD
What is G3b
eGFR 30-45
What is G3b referred to as
Moderate-Severe CKD
What is G4
eFGR 15-30
What is G4 known as
Severe CKD
What is G5
eGFR <15
What is G5 known as
Renal Failure
Aside from GFR, how else can CKD be classified
Albuminuria
How is albuminuria measured
mg per 24h
Or, albumin: creatinine ratio
What is A1
a. <30mg/24h
b. A: Cr < 3
What is A2
a. 30-300 /24h
b. A: Cr = 3-30
What is A3
a. >300 / 24h
b. A: Cr = >30
What is the most common cause of CKD
Diabetes
What are 3 most common causes of CKD
- Diabetic neprhopathy
- HTN neprhopathy
- Glomerulonephritis
What are 5 RF for CKD
- Age
- DM
- HTN
- FH
- SAH
Why does SAH increase risk of CKD
Those with SAH have increased risk of CKD
How do patients present initially with CKD
Asymptomatic
What is required for CKD
Requires significant dysfunction of both kidneys to cause symptoms
What are 4 abnormalities that occur with CKD
- High uric acid
- High Potassium
- Sodium and fluid retention
- Loss ability to hydroxylate vitamin D
What 3 symptoms does increase retention of sodium and fluid lead to
Peripheral oedema
Pulmonary oedema
HTN
What 3 symptoms does K+ retention lead to
- Arrhythmias
- ECG changes
- Diarrhoea
- Muscle weakness
What are 3 ECG changes associated with high potassium
Tall tented T waves
Flat P wave
Broad QRS
What does loss of ability to hydroxylate vitamin D cause
Secondary hyperparathyroidism = renal osteodystrophy
What does a high concentration of uric acid cause
- Pericarditis
- Skin: pruritus, pigmentation
- Fatigue
- Weakness
- Neurological - hiccups, cramps, encephalopathy (seizures)
What is pathophysiological mechanism of CKD
CKD is caused by irreversible loss of neurons.
Loss of neurons causes shunting of filtrate to functional neurons called glomerular hyper filtration. Initially these neurons can tolerate it. However, over time results in glomerular sclerosis - leading to irreversible loss of neurons. Eventually so many neurons die to causes drop in GFR and oliguria. Drop in GFR means less excretion of waste products including uric acid that causes clinical manifestation of CKD.
When enough nephrons are lost in CKD what happens
Unable to produce renin = hypotension
Unable to produce EPO = anaemia
Unable to produce vitamin D = renal osteodystrophy
What does oliguria result in
Decreased excretion of fluid - causing fluid accumulation leading to HTN, peripheral oedema and pulmonary oedema
Explain why hyperkalaemia occurs in CKD
Reduced GFR causes build-up of potassium
Kidney damage - reduces renin secretion causing decrease action Na+-K+ ATPase and potassium retention
Why does metabolic acidosis occur in CKD
Impaired ability to secrete H+ and form HCO3-
Explain vitamin D disturbance in CKD
Loss of ability of kidney to hydroxylate 1a-vitamin D to 1,25-a hydroxy vitamin D
What does deficiency in active vitamin D mean
Reduced calcium absorption form the gut
What does hypocalcaemia stimulate
PTH release causing secondary hyperparathyroidism
What does drop in GFR mean for phosphate
Phosphate cannot be excreted - binds calcium and precipitate
Why does CKD cause anaemia
- Reduce EPO
- Uric acid has toxic effect on bone marrow
What is first-line investigation for CKD
eGFR
How is eGFR estimated
Cockcroft Gault Equation
What does cockcroft-gault equation use
Serum creatinine
Age
Gender
Ethnicity
What are 3 factors that can impact estimation of GFR
- Red meat 12-hours before
- Muscle mass
- Pregnant women
What is used to diagnose CKD
Albumin: Creatinine Ratio
A: Cr
What is used for monitoring CKD
Protein: Creatinine Ratio
P: Cr
What simple investigation is ordered in CKD
Urinanalysis
What may be present on urinalysis in CKD
Proteinuria
Haematuria
If positive proteinuria, what does this mean A:Cr must be
> 30mg/mmol
What is seen on U+Es in CKD
- High K+
When is a bone profile ordered in CKD
GFR <30
What will a bone profile show in CKD
- Low Calcium
- High Phosphate
- High PTH
When is a FBC ordered in CKD
Stage 3 CKD (GFR less than 45)
What anaemia is present in CKD
Anaemia of chronic disease
What are indications for Renal USS in CKD
- Accelerate progression
- Persistent haematuria
- Urinary tract obstruction
- PKD
- GFR <30
How often is A:CR and GFR monitored in renal disease patients
Every 3-months
When is a CKD patient referred to nephrologist
- Stage 4 or 5
- A:Cr > 70
- Proteinuria and haematuria
- Treatment-resistant HTN
- Suspect genetic cause
What are 3 important categories for slowing progression of CKD
BP
Lifestyle
DM
What is target BP in CKD
<140/90mmHg
What is target BP in CKD if diabetic or A:Cr >70
<130/80mmHg
What is given to control BP
ACEi (or ARB)
When is ACEi indicated in CKD
DM with A:Cr > 3
HTN and A: Cr > 30
CKD with A: Cr > 70
When should ACEI be stopped in CKD
- AKI
- Hyperkalaemia
- GFR drops below 45
If GFR drops below 45 in CKD, what is used as alternative to control BP
Furosemide
What HbA1c is aimed for in CKD
53 (7%)
What are 4 lifestyle measures for CKD
- Exercise
- Weight loss
- Limit dietary salt to 2g/day
- Smoking cessation
When should FBC be checked
GFR <60
How is anaemia in CKD managed
EPO
How is oedema managed in CKD
- Fluid restriction
- Salt restriction
- Loop diuretics: be careful as may worsen renal function
How is renal osteodystrophy managed
Vitamin D:
- 1,a- Calcidiol
- Or calcitriol
How are cramps or restless leg syndrome (due to high uric acid) managed in CKD
Sleep hygiene
Pregabalin/Gabapentin
What does CKD increase risk of
CVD
How is Cardiovascular risk reduced
All individuals with GFR less than 60 are given 20mg atorvastatin
When is RRT planned for
When risk of renal failure is 10-20% in one-year
What should all patients be listed for 6-months before anticipated start RRT
Deceased donor transplant
When is long-term dialysis usually started
6-months prior
What are the 3 types of RRT
Haemodialysis
Peritoneal dialysis
RRT
Explain haemodialysis
Blood passed over semi-permeable membrane with dialysis fluid flowing in opposite direction. Waste moves down concentration gradient
What is required for haemodialysis
AV Fistula
how often do individuals with attend for haemodialysis
3-times per week
what is peritoneal dialysis
Uses peritoneum as semi-permeable membrane
what are two types of transplantation
living donor
deceased donor
what has best outcomes
living donor
if a patient needs dialysis, but has not had it before, what is started
venovenous haemofiltration
when is venovenous haemofiltraiton seen
ITU
if a patient has a renal transplant, what 3 drugs are they put on
- Calcineurin Inhibitor
- Myclophenolate
- Prednisolone
