Session 11 Flashcards
(38 cards)
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
