Session 11 Flashcards
Define Chronic kidney disease
The irreversible and sometimes progressive loss of renal function over a period of months to years
How does the kidney often respond to damage?
With fibrosis and scarring resulting to a decrease in functioning tissue
What is Chronic kidney disease strongly associated with?
An increase in cardiovascular morbidity and mortality
What are some of the different causes of Chronic kidney disease?
Immunologic eg glomerulonephritis Infection eg pyelonephritis Genetic eg polycystic kidney disease Hypertension Systemic disease eg Diabetes Idiopathic causes
What is the usual pathology of the kidney in Chronic kidney disease?
The Kidneys become smaller and shrunken, usually with a loss of the renal cortex. Tubules and Glomeruli are replaced with scar tissue
Except for in Polycycstic Kidney disease!
How can Chronic kidney disease cause Hypotension?
If the kidneys are damaged they may make less Renin which would cause a decrease in the levels of Angiotensin I to be converted to Angiotensin II (By ACE) so less vasoconstriction
What is the GFR in stage 1 of Chronic kidney disease?
> 90%
Early
Asymptomatic
What is the GFR in stage 2 of Chronic kidney disease?
60-89%
Asymptomatic
What is the GFR in stage 3 of Chronic kidney disease?
30-59%
Usually still asymtpomatic
What is the GFR in stage 4 of Chronic kidney disease?
15-29%
Symptomatic
What is the GFR in stage 5 of Chronic kidney disease?
<15%
Very symptomatic
Established renal failure
Patients usually have to go on dialysis
How can Creatinine clearance be misleading when used as a marker of renal function?
Creatinine clearance can still be relatively normal even with a GFR that is severely reduced (To around 40%)
How is GFR measured?
An equation is used to calculate eGFR
More accurate for seeing which patients have renal failure
What is Creatinine clearance determined by?
Muscle mass
Age
Gender
Ethinicity
What is the normal range for GFR?
80-120ml/min
How is Inulin clearance performed?
The patient is infused with a known amount of Inulin (An inert substance that is neither reabsorbed or secreted by the kidneys) until the plasma reaches a steady state
Then the amount excreted in the urine is measured
When is eGFR NOT useful?
In acute renal failure because the GFR is not staying constant
Only accurate in adults
How can you assess the cause of Chronic kidney disease?
Auto antibody screen
C reactive protein (Increased in response to infection)
ANCA (Anti-neutrophil cytoplasmic antibody)
Ultrasound scan (Size, obstruction)
How can Chronic kidney disease cause Anaemia?
The kidneys produce Erythropoietin (Stimulates bone marrow to make RBCs) so a decrease in kidney function means a decrease in Erythropoietin production so less is less effect on the bone marrow and less red blood cells are made
How can Chronic kidney disease cause Osteitis Fibrosa Cystica?
A decreased GFR causes an increase in phosphate due to it not being filtered normally (Stimulates a decrease in calcium)
The kidneys cannot hydroxylate vitamin D into its active form (Less calcium absorbed in the GIT)
Both lead to an increase in Parathyroid hormone
What is Osteitis Fibrosa Cystica?
Increased Osteoclast stimulation leading to bone breakdown causing them to fracture more easily
How can Chronic kidney disease progression be delayed?
Treat hypertension (To protect the renal function)
Use ACEi if Proteinuria is present
Lower lipid levels if Hypercholesterolaemia
What is Renal replacement therapy?
When the native renal function is no longer adequate to support health, the kidneys need to be replaced with either Dialysis or Transplantation
Usually when the GFR is <10 ml/min
~8% of renal function
What are some of the indications Dialysis is needed?
Uraemic symptoms (Malaise, tiredness, nausea) Acidosis Pericarditis Fluid overload Hyperkalaemia
What are the 2 types of Dialysis?
Haemodialysis (Can be done at hospital or home) Peritoneal dialysis (Can only be done at home)
What is needed in both types of Dialysis?
Highly purified water
What is an Arteriovenous fistula?
A connection between a vein and artery in the forearm is made. This causes the vein to become more muscular as blood flows from the artery to the vein.
Allowed for better cannulation
What artery and vein is usually used to make an Arteriovenous fistula?
The Cephallic vein and Radial artery of the forearm
What are the advantages of Haemodialysis?
Very effective
Only have treatment 3 days a week
What are the disadvantages of Haemodialysis?
Diet restrictions (Cannot drink much)
Limits travel
CVS instability
High costs
What does Peritoneal dialysis require?
The peritoneal membrane (Acts as a filter)
Peritoneal blood flow
Peritoneal dialysis fluid (Put into the Peritoneum and drained)
How is Peritoneal dialysis done?
Peritoneal dialysis fluid emptied into the Peritoneum through a catheter
Waste products diffuse through the Peritoneal membrane into the Peritoneal dialysis fluid from the blood
Peritoneal dialysis fluid drained
What are the advantages of Peritoneal dialysis?
Home technique
Easily learned
Allows more mobility
CVS stability
What are the disadvantages of Peritoneal dialysis?
Peritonitis
Frequent exchanges
Has to be done every day?
Is there an age cut off for renal transplant?
No, but co-morbidities do influence decisions
Where is the transplanted kidney placed?
In the Iliac fossa and can be connected to the Iliac vessels for blood supply.
The native kidney is left in!
What are the advantages of Kidney transplantation?
Restores function
Allows mobility
Improved survival
Cheaper than dialysis
What are the disadvantages of Kidney transplantation?
Not everyone is suitable Lack of donors Operation morbidity/mortality Life long immunosuppression Still have the original pathogenesis that is causing Chronic kidney disease
