Kidney disease Flashcards
Most common cause of CKD?
Diabetes
Main key functions of the kidneys?
Waste excretion Acid/base balance Salt/water homeostasis BP control Glycaemic control Secretion of hormones (e.g. EPO)
Organs that undergo gluconeogenesis?
Liver
Kidneys
Most common cause of AKI?
Ischaemia
Different pathogenic factors leading up to CKD?
Glomerulosclerosis Tubular Atrophy Interstitial fibrosis Loss of renal mass Loss of renal function?
What is one of the most important factors that determines kidney damage when ultrasounding the kidneys?
Kidney size
Mechanisms of CKD progression?
Haemodynamic:
- RAAS pathway
- Hypertensive vascular damage
Inflammatory:
- Pro-fibrotic cytokines
Mode of action of CKD in terms of glomerular function? How do ACE inhibitors and AR antagonists work to prevent this?
Glomerulosclerosis leads to loss of number of functioning glomeruli, leads to increased blood flow to remaining nephrons, this then leads to intraglomerular hypertension and more glomerulosclerosis.
ACE inhibitors prevent the increased intraglomerlar hypertension
Risks of using a ACE inhibitor in someone with hypertension caused by disseminated atheroma?
Will decrease renal perfusion to the point of AKI
one important molecule associated with the inflammatory pathway in CKD?
TGF-β
Process of inflammation in CKD?
Mechanical vascular stretching and Angiotensin II lead to increased TGF-β
Plasminogen activator inhibitor 1 expression that leads to:
- abnormal matrix deposition
- decreased NO
Decreased NO leads to hypertension, Proteinuria and interstitial fibrosis.
Effects of CKD?
Reduced GFR
- Retention of nitrogenous waste products
- Hyperphosphataemia
- Salt/Water retention (oliguria)
Impaired Tubular function
- Disturbed fluid balance (polyuria)
- Acidosis and hyperkalaemia
Hormonal deficiency
- Anaemia (EPO)
- Vit D deficiency, hyperparathyroidism (calcitriol)
As pH goes up what does potassium do?
Goes down
Why do CKD patients have anaemia?
Iron deficient:
- Diet
- Occult GI loss
Chronic disease:
- EPO deficiency
Treatment of anaemia in CKD?
Parenteral iron
recombinant EPO replacement
HIF stabilisers
Examples of features of chronic kidney disease mineral bone disorder (CKD MBD)?
Periosteal reabsorption
Browns tumour
Tumoral Calcinosis
What causes CKD MBD?
Failure of the phosphate and calcium regulation system, regulated in the kidneys in part by calcitriol.
Pathogenesis of CKD MBD?
on diagram
Decreased calcitriol causes decreased GI calcium absorption. (and increased PTH itself)
This leads to a reduction in serum calcium and this increases the production of PTH:
Increased PTH:
- causes an increase in calcitriol production (leading to increased serum calcium and decreased potassium)
- Causes the resportion of calcium and phosphate from bone to release it into the bloodstream
Leads to increased serum Ca++ and increased serum phosphate.
With the passage of time the parathyroid gland becomes hyperplastic and pathogenically releases PTH irregardless of the calcium levels in the bloodstream
Management of CKD MBD?
Vit D replacement
Dietary Phosphate restriction
Phosphate binders
Calcimimetics
Parathyroidectomy
GFR of end-satge renal disease?
About 5
Management of end-stage renal disease?
Conservative management
Dialysis (replacement therapy)
Transplantation
Types of renal replacement therapy?
Haemodialysis
Peritoneal dialysis
What are the aims of haemodialysis
Remove nitrogenous waste
Correct imbalances in:
- Serum electrolytes
- Hydration status
- Acid/Base
What does haemodialysis not do?
Correct hormonal imbalances
Avoid cardiovascular risk associated with CKD
Two factors that cause movement of waste products in dialysis?
DIffusion from blood to diasylate
Ultrafiltration: H2O essentially being pumped through the semi permeable membrane dragging other waste products with it.
Risks of peritoneal dialysis?
The two fluids can equilibrate and the body can absorb teh waste products it was previously excreting.
Advantages of peritoneal dialysis?
User friendly
Can be done anywhere by someone who knows how to
Genes responsible for Polycystic kidney disease?
Pkd 1 and 2
Who is eligible for kidney transplantation?
Progressive irreversible kidney failure
No current infection
No current malignancy
Proof of compliance with treatment
Life expectancy without a transplant of
What do you assess for when seeing someone for renal transplant?
Vessel quality
Space
History and examination - fit enough
Types of Renal donors?
Cadaveric organ:
- Brainstem death (heart beating)
- Cardiac death donor (non-heart beating)
Live donation
If a potential donor is ABO incompatible, what are the options?
- Do a ABO incompatible transplant (push receivers immune system so that it will not reject organ) - remove antibodies etc
- paired/sharing scheme, gives to someone else who has a compatible kidney.
If a donor has several renal arteries does this make them less suitable for a transplant, why?
Yes it does, will increase risk for patient as have to do more ‘plumbing’ in surgery
Risks to surgery?
Excess bleeding
Thrombosis
Collections - form around kidney, lymphatic leakage.
Infection
Ureteric complications (leak, stenosis)
Kidney may not work
How is immunosuppression obtained following transplant?
Steroids
Calcineurin inhibitors - inhibit IL2
Antiproliferative agent - MMF
Sometimes an induction agent
