Chronic Kidney Disease Flashcards
definition
reduction in glomerular filtration rate over a minimum period of 3 months
to diagnose chronic kidney disease what do you need
2 samples at least 90 days apart
what is reported for diagnosing chronic kidney disease
eGFR and creatinine levels because eGFR provides a more accurate estimation of renal function than creatinine alone
stages of chronic kidney disease
- G1
- G2
- G3a
- G3b
- G4
- G5
G1 : eGFR
greater than 90ml/min/1.73m2
G1 description
normal kidney function but urine findings or structural abnormalities or genetic trait point to kidney disease
G2: eGFR
60-89
G2 description
Middle reduced kidney function and urine findings or structural abnormalities or genetic trait point to kidney disease
G3a: eGFR
45-59
G3b; eGFR
30-44
Description of G3a and G3b
moderately reduced kidney function
G4; eGFR
15-29
G5; eGFR
less than 15
ALBUMIN CREATININE RATIO CATEGORIES
A1
A2
A3
A1
albumin creatinine ratio less than 3 mg/mmol
A2
albumin creatinine ration 3-30 mg/mmol
A3
albumin creatinine ratio greater than 30mg/mmol
normal glomerular filtration rate is between
100-125ml/min/1.73m2 however, this value is slightly less in females than males and declines with are
who is at increased risk of developing chronic kidney disease
those who have had acute kidney injury
people with acute kidney injuries should be monitored for what
the development of chronic kidney disease for at least 2-3 years after the acute kidney injury even if creatinine has returned to baseline
accelerated progression of chronic kidney disease
- a sustained decreased in glomerular filtration rate of 25% or more and a change in GFR category within 12months
OR - a sustained decreased in GFR or 15ml/min/1.73m2 per year
risk factors associated with chronic kidney disease progression
- cardiovascular disease
- proteinuria
- AKI
- hypertension
- diabetes
- smoking
- african or afro-carribean
- chronic use of NSAIDS
- untreated urinary outflow obstruction
blood pressure control in chronic kidney disease
- aim to keep systolic blood pressure below 140 and diastolic below 90mmHg
in people with chronic kidney disease and diabetes or people with chronic kidney disease with an albumin creatinine ratio of 70mg/mmol or more blood pressure control
aim to keep systolic less than 130 and diastolic less than 80
what should be used to control blood pressure
an ACE inhibitor or an angiotensin receptor blocked
do not modify the dose of the ACE inhibitor if
- the GFR decrease from pre-treatment baseline is less than 25% or
- the serum creatinine increase from baseline is less than 30%
if it exceeds these values then dosage should be reduced
cardiovascular disease and lipid lowering therapy in CKD
offer atorvastatin 20mg fro the primary or secondary preventing of CVD in people with CVDi
increasing the dose of atorvastatin
increase the dose if a greater than 40% reduction in non-HDL cholesterol is not achieved and eGFR is more than 30ml/min/1.73m2. If eGFR is less than 30ml/min/1.73m2 then consult a renal specialist
causes of chronic kidney disease
- hypertension
- diabetes mellitus
- glomerulonephritis
- polycystic kidney disease
- post-renal obstructive causes
hypertension is the
most common causes of chronic kidney disease
hypetension cuasing CKD pathophysiology
- atherosclerosis of arteries supplying the kidney cause narrowing of the lumen meaning less blood and oxygen gets to the kidney causing ischaemic injury of the glomerulus
- Macrophages and foam cells enter the glomerulus and secrete growth factors like TGF-B1 causing the mesangial cells to regress to there imitate state called mesangiocytes which secrete extra-cellular matrix causing glomerulosclerosis (hardening and scarggin) which reduces the kidneys ability to filter blood
2nd most common cause of chronic kidney disease
diabetes mellitus; hyperglycameia causes non-enzymatic glycation of the basement membrane which aprticualryl occurs at the efferent arteriole causing hyaline arteriosclerosis causing an obstruction of blood exiting the glomerulus which increases the pressure within the glomerulus causing hyper-filtration
- in response to this the mesangial cells lay down more structural matrix which causes expansion of the six of the glomerulus diminishing the ability of the kidney to filter blood
what does CKD present with in terms of calcium and phosphate levels
hypocalcaemia and hyperphospahtaemia
why does hypocalcaemia and phyerpphospahtaemia occur
there is reduced production of 1,25- dihydroxyvitamin D3 (calcitriol) because the kidney is responsibel for 1- hydroxylation of 25-hydrxyvitamin D3
- Calcitriol is responsible for increased GI absorption of calcium and re-absorption of calcium from the bone hence causing hypocalcaemia
- the hypocalcaemia causes secondary hyperparathyroidism but despite the increased PTH calcium levels cannot increase in response because of deficiency in calcitriol however, the re-absorption of phosphate in the kidneys can occur hence the huyperphopshataemia
treatment of hypocalcaemia and hyperphospahtaemia
- phosphate binders= sevalamer
- Cinaccalcet blocks production of PTH
- alfacidol which is an active vitamin D
what blood problem does chronic kidney disease cause
anaemia
why does chronic kidney disease cause anaemia
because the kidney are responsible for the production of erythropeatein which tells the bone marrow to make red blood cells, deficiency in red blood cells causes a normocytic anaemia
why is it a normocyitc anaemia
because there is no lack of iron or disease of red blood cells
symptoms of anaemia
fatigue and pallor
what else can chronic kidney disease cause
electrolyte abnormalities
the kidneys most critical excretion products are
sodium, potassium, hydrogen and magnesium, loss of renal function can cause elevated levels of all
loss of excretion of potassium can cause
hyperkalaemia which shoes tall tented T waves in ECG
what is classified as hyperkalaemia on ECG
anything greater than 5mm in the limb leads
inability to excrete hydrogen ions causes
a metabolic acidosis
treatment of anaemia in chronic kidney disease
check ferrite and iron stores aiming for:
ferritin greater than 100
TSATS GREATER THAN 20%
if low= oral iron therapy (veneer)
- erythropoiesis stimulating agent if haemoglobin is less than 100-110g/dl despite no iron or haematocrit deficiencies
inability to excreted nitrogenous waste products causes
uraemia/ azotemia
azotemia
is the build up of nitrogenous waste products in the blood, uraemia is the clinical symptoms caused by azotemia
symptoms of uraemia
pericarditis, encephalitis, bleeding, increased infection
why does uraemia cause increased infection
because white blood cells cannot degranulate
why does uraemia cause pericarditis
excuse the waste products physically irritate the pericardium
why does uraemia cause increased risk of bleeding
because platelets cannot adhere to one another
reduced glomerular filtration rate in chronic kidney disease causes
fluid overload and fluid shifts into the third space causing oedema
management of end stage renal disease
haemodialysis, peritoneal dialysis or renal transplant
long term management for all its chronic kidney dsieas
- avoid NSAIDS and don’t use gentamicin
- fluid restriction
- low potassium, phosphate and sodium diet
