Chronic kidney disease Flashcards
What is meant by chronic kidney disease?
irreversible and significant loss of renal function
How do we measure the filtration (excrete out) function of the kidney?
eGFR from creatinine blood test
How do we measure the filtration (keep in) function of the kidney?
blood/protein in urine
How do we assess the anatomy of the kidney?
histology/radiography
Define the stages of CKD in terms of eGFR
Stage 1 >90 Stage 2 60-89 stage 3a 45-59 stage 3b 30-44 stage 4 15-29 Stage 5 <15
How is eGFR measured?
serum creatinine
3 problems with serum creatinine for eGFR
need to lose about 60% GFR for a rise in Screatinine
muscle mass
other sources eg steak dinner
What substances cross GBM bit reabsorbed in PCT?
glucose
low molecular weight proteins
What substances do not cross GBM?
cells eg RBC, WBC
high molecular weight proteins eg albumin
Should there be blood or protein in the urine?
no
How do we quantify protein in the urine?
protein creatinine ratio - PCR
Define CKD
Presence of kidney damage (abnormal blood, urine or x-ray findings) or GFR <60mls/min/1.73msquared for more than 3 months
List the complications of CKD
Acidosis Anaemia Bone disease CVS Death and dialysis Electrolyte fluid overload gout hypertension iatrogenic issues
What are CKD complications more likely with?
worsening eGFR
List some causes of CKD
diabetes, glomerulonephritis, PKD, myeloma
renovascular disease eg atherosclerosis, renal artery stenosis
hypertension
persistent decreased renal perfusion eg heart failure and cirrhosis
chronic exposure to nephrotoxins eg NSAIDS
List some symptoms and signs of CKD
cognitive impairment hypertension pallor - anaemia peripheral oedema pulmonary oedema anorexia, vomiting polyuria, haematuria, proteinuria, oliguria, nocturia, frothy urine itch, cramps unilateral small kidneys, cystic kidneys etc
What would give evidence of previous renal disease?
raised creatinine/urea
LUTS
proteinuria/haematuria
hypertension
What would you ask in a history for CKD?
FH - PKD
systemic eg malignancy, hypertension, DM
Drugs eg NSAIDS, aminoglycosides, ACEI
pre/post renal factors eg V&D, heart failure, diuretics
uraemic symptoms eg pruritus, weight loss, fatigue, nausea
Examination in CKD
vital signs eg bp, fever volume status - overload eg raised JVP, oedema deplete eg skin turgor skin eg rash cardiac murmurs bruits, palpable organs pulses bones and joints obstruction eg bladder
Blood chemistry CKD
U+E and FBC
bicarbonate, calcium, phosphate, LFT, CK, Ig
Urine tests for CKD
urine dip, urine PCR or ACR, 24 hour collection
How would we do renal histology?
with a biopsy
What imaging would be done for CKD?
USS, CT, MRI, plain radiography, nuclear medicine
Positives and negatives of USS in CKD
positive - no radiation, not invasive
negative - no functional data, not tell about chronicity of disease, operator dependent
How can we manage CKD to slow that rate of decline
Bp control lipid control control acidosis protein restriction control proteinuria - ACEI/ARB
Identify how we would assess the complications of CKD
Acidosis - bicarbonate and H+ anaemia - FBC, film, haematinincs bone disease - ca, phosphate, albumin, PTH CVS - chest pain, bp, cholesterol death and dialysis - urea, creatinine, GFR electrolytes - and K+ fluid overload - bp, oedema, JVP, CXR gout hypertension - bp +/- 24 hour tape iatrogenic issues - medications
What GFR will acidosis be seen?
not until <20mls/min
When is acidosis most marked?
in tubular interstitial disease
How is metabolic acidosis treated?
oral sodium bicarbonate
Problems with metabolic acidosis
worsens renal bone disease
hyperkalaemia risk
Why does anaemia occur in CKD?
Reduced erythropoietin production
reduced RBC survival
increased blood loss
When would we usually treat anaemia in CKD?
<10mls/min GFR or symptomatic
How is anaemia treated?
iron replacement
ESA therapy
What does a reduced GFR lead to in terms of bone disease?
hyperphosphataemia
Why does CKD affect vitamin D and calcium reabsorption?
less renal tissue - less activated vit D
therefore less calcium reabsorption
Consequence of high phosphate and low calcium in CKD
high PTH
secondary hyperparathyroidism - can become tertiary
What is high phosphate associated with?
vascular and cardiac calcification
How do we treat renal bone disease?
control phosphate - diet, phosphate binders
normalise calcium and PTH - active vitamin D analogues, parathyroidectomy, calcimetics
What increases CV risk in CKD?
hypertension diabetes lifestyle smoking hyperlipidaemia renal bone disease
Why is hyperkalaemia found in CKD?
usually exchanged for sodium to be excreted in DCT
reduced sodium delivery as GFR falls
also ACEI, ARB, diet etc
Acute treatments of hyperkalaemia
stabilise - calcium gluconate
shift - insulin dextrose, salbutamol
remove - dialysis, calcium resonium
Chronic treatments of hyperkalaemia
diet
drug modifications
Why does CKD lead to fluid overload?
unable to excrete excess sodium load leading to sodium and water retention
Treatment of fluid overload
sodium restriction
loop diuretics
fluid restriction
Blood pressure aims for CKD patients with and without proteinuria
with : <125/75
without: 130/80
What causes uraemic pericarditis?
build up of own urea toxin
What drugs can cause AKI on top of CKD?
contrast, antibiotics
5 preparations steps for ESRD+RRT
education and info MDT select modality planning access deciding when to start
