Renal Overview Flashcards
What is polyuria
pee too much
What is dysuria
pain on passing urine
What is haemapuria
passing blood in urine
What is proteinuria
protein in urine
What is uremia
when waste products should be excreted by the kidney are starting to accumulate in the blood
How is renal function measured
serum urea
serum creatine
24 hour urine collection
How is serum urea used to measure renal function
o goes up in renal dysfunction but also rises with dehydration meaning it isn’t a good indicator
How is serum creatine used to measure renal function
o good general guide to renal function
o should be relatively low
o if kidney is not working then it will rise
How is urine collection used to measure renal function
o creatine clearance – best measure
What are the consequences of renal failure
loss of renal excretory function loss of water and electrolyte balance loss of acid base balance loss of renal endocrine function calcium metabolism renin secretion
Why is there a loss of water and electrolyte balance in renal failure
o unable to modify electrolytes within the collecting duct and so losing more than you should do
Why is there a loss of acid base balance in renal failure
o losing hydrogen ions
o this can upset the acid base balance
o can be compensated by ventilation (breathing more acid)
What renal endocrine functions are lost
erythropoietin
calcium metabolism
renin secretion
What are the two types of renal failure
acute and chronic
What is acute renal failure
o happens suddenly
o often due to infection, trauma or damage to the kidneys
o rapid loss of renal function
o usually over hours or days
What is chronic renal failure
o gradual loss of renal function
o usually over many years
What can causes of renal failure be split into
prerenal
renal
post renal
What are the prerenal causes
hypoperfusion of the kidney
shock
renal artery or aorta diseases
What are the renal causes
chronic disease
drug damage
trauma
rhabdomyolysis
What is rhabdomyolysis
o protein taken from muscle round to kidney blocking glomerulus
What are post renal causes
renal outflow obstruction
o stones
How is acute renal failure defined
It is the rapid loss of renal function resulting in a Creatine > 200umol/L. The normal is usually 80.
How does acute renal failure present
anuric initially with volume overload
gradually progresses to polyuria
development of hyperkalaemia
development of uremia and acidosis
What does anuric and volume overload result in
ankle oedema (if ambulatory), sacral oedema (if bed bound)
pulmonary oedema and breathlessness
raised jugular venous pressure (JVP)
weight gain
What does hyperkalaemia result in
can lead to cardiac arrest as it alters the nerves excitability
What does the development of uremia and acidosis result in
high urea
low bicarbonate
increased respiratory excretion of CO2
o raised respiratory rate
What are the causes of acute renal failure
usually prerenal
Is acute renal failure reversible
Usually reversible with time
Renal support is required until recovery
dialysis
nutrition
What are the primary causes of chronic renal failure
glomerulonephritis
polycystic kidney disease
What are the secondary causes of chronic renal failure
diabetes (30%) hypertension (20%) drug therapy vasculitis renal artery disease/aorta disease
What is seen in glomerulonephritis
Haematuria/proteinuria in an otherwise healthy individual
There will be a gradual progression to hypertension and chronic renal failure due to the damage to the glomerulus system meaning that you will not be producing angiotensin and renin
What is nephrotic syndrome due to
Complications of glomerulonephritis
What happens in nephrotic syndrome
Complications of glomerulonephritis:
excessive loss of protein in the urine
loss of plasma oncotic pressure
tissue swelling (oedema) due to the lack of oncotic pressure to draw the fluid back into the vessels
hypercoagulable state
Why is there a hypercoaglulable state in glomerulonephritis
antithrombin is lost in the urine, leading to a higher activity of Factor II and Factor X and in increased tendency to thrombosis.
Why are NSAIDs bad for renal disease
NSAIDs inhibit glomerular blood flow and cause interstitial nephritis due to their inhibition of prostaglandins
They should be avoided in renal disease if possible.
What other drugs can result in renal disease
Nephrotoxic drugs can also result in renal disease e.g cyclosporin.
What are different renal vascular diseases
reduced blood flow to kidney
microangiopathy
What is reduced BF to kidney due to
atheroma of renal artery and aorta
hypertension – narrowing of renal artery
What is micrangiopathy
immune reaction causing small blood vessel damage, RBC damage and thrombosis
o E.Coli 0157 association
What is polycystic kidney disease due to
gene mutation (PKD 1,2 or 3) o inherited (AD or AR) or spontaneous
what can polycystic kidney disease lead to
o enlarged kidney
o progressive destruction of normal kidney
o gradual renal failure
What is end stage renal disease defined by
eGFR <15ml/min
creatine 800-1000umol/L
What is the time taken for end stage renal disease dependent on
underlying cause
modifying factors
What is the grading for kidney disease
The kidney damage can be graded
1 is normal and 5 is kidney failure
How is chronic renal failure managed
reduce rate of decline correct fluid balance correct deficiencies remove outflow obstruction treat infection
how do you reduce rate of decline of chronic renal failure
eliminate the nephrotoxic drugs control hypertension control diabetes control vasculitis disease o steroids/other immune suppressant drugs
How do you correct fluid balance
restrict fluid intake
restrict salt, potassium and protein
How do you correct deficiencies
anaemia (erythropoietin)
calcium (vitamin D)
How do you remove outflow obstruction
renal stones (calculi)
prostate enlargement
What infections do you treat when managing chronic renal failure
chronic renal system infection
What are the signs of chronic renal failure
anaemia
hypertension
renal bone disease
What are the causes of renal bone disease in chronic renal failure
o low Ca, high PO4
o hyperparathyroidism
o osteomalacia
What are the symptoms of renal failure
insidious o may be a few polyuria nocturia tired and weak nausea
What is renal replacement therapy
Have to replace the functions of the kidney but it is not a cure as the kidneys still do not work
When should be care taken in dentistry regarding renal disease
Care should be taken with prescribing
check all drugs with renal physician
avoid NSAIDs and tetracyclines
reduce dose of most others
What is the effect of renal disease in children
Growth may be slow in children and tooth eruption may be delayed
What are the secondary effects of anaemia
oral ulceration
‘dysaesthesias’ – painful mucosa and tongue
Why may white patches be seen in the mouth
uraemic stomatitis
What may be seen in patients with renal disease
oral opportunistic infections
dry mouth and taste disturbances
bleeding tendencies
renal osteodystorphy
Why may you see a dry mouth and taste disturbance
o fluid restriction and electrolyte disturbance
What are the oral opportunistic infections
o fungal and viral infections/reactivations
o prone to post-op infections
Why is there bleeding tendencies
o platelet dysfunction
What will be seen in the mouth regarding renal osteodystrophy
o lamina dura lost
o bony radiolucency
secondary hyperparathyroidism increases osteoclast activity
