Renal Medicine Flashcards
3 tubes leaving kidney
artery
vein
ureter
what does the glomerulus filtrate
plasma
what does the glomerulus connect to
collecting duct
what controls the pressure of glomerulus filtration
afferent and efferent blood vessels
what causes changes changes in afferent and efferent blood vessels
muscular traps squeeze vessels open and shut so ml/hour constant
what is the effect of the renal artery having a high BP
the renal artery will shut off to reduce the pressure going into the glomerulus
maintain same pressure difference despite high BP to maintain filtration
act of renin
reduce BP
low BP means short of circulating volume so retain more fluid
how does the glomerulus filtrate
it is a membrane with holes in it
what cannot filter through the glomerulus
cells and proteins
what does cells and proteins in urine indicate
disease
particularly of the glomerulus
what is the role of the collecting duct system
secretion and reabsorption of electrolytes
- modify the electrolyte
what is the role of the collecting tubule
fluid reabsorption
- modify volume
diabetes insipidus
pee a lot of normal type urine
polyuria
pee too much
dysuria
pain when passing urine
haematuria
blood in urine
- microscopic
- stained red
proteinuria
protein in urine
- should not be if glomerulus is working well
- holes too small for proteins
- more leaky if inflammed
uraemia
waste products that should be extracted by kidney are not so accumulate in blood
3 measuring renal function
serum UREA
serum creatinine
24 hr urine collection
urea level in urine
waste product from body
constant level
increase in urea also increase water excretion
- dehydration
- poor renal function
not a good marker to use
serum creatinine in urine
good general guide to renal function
should be generally low
if kidney not working well then will rise
24hr urine collection
Creatinine clearance – best measure
Faff procedure to carry out
EGFR is mainly used in clinic
4 consequences of renal failure
loss of renal excretory function
loss of water and electrolyte balance
- cannot modify or concentrate amount in system
loss of acid base balance
- loss H ions or base
- compensate by ventilation partially
- CO2 removal from body is same as removing H ions from Kidney
loss of renal endocrine function
3 endocrine functions of the kidney
Erythropoietin
- Become anaemic (lack of RBC)
calcium metabolism
- less production of vitamin D dependent factors
- not normal Ca metabolism
renin secretion
2 types of renal failure
acute
chronic
acute renal failure
rapid loss of renal function
usually over hours or days
- infection
- trauma e.g. accident
muscle injury causes muscle proteins to be broken down and circulate in blood stream to kidneys
swamp glomerulus as too many proteins
block holes so not able to filter plasma effectively
- medicines – can be toxic
sudden and quick
pt notice as become unwell
need tx till kidney can recover
chronic renal failure
gradual loss of renal function
usually over many years (10-20years)
3 possible causes of acute renal failure
infection
trauma
medicine
3 sites where renal failure can occure
pre-renal
renal
post-renal
pre-renal causes of renal failure
hypoperfusion of the kidney
- not get enough oxygen
- not able to metabolise properly
- significant drop in BP
shock
- resuscitate but BP low for several hours
- BP and normal cardiac output is too low
renal artery or Aorta disease
- aneurisms can cause burst
- blood flow to kidney lowers
renal
renal causes of renal failure
disease of kidney itself
- chronic disease – uncommon
- drug damage – certain combinations
- trauma – usually defended due to where they sit anatomically
- rhabdomyolysis – muscle protein breakdown, block glomerulus
Glomerulonephritis
- most common in children
- Autoimmune
- Inflammation of antibodies to cells in kidney
Renal diabetic disease
- Large cause of renal failure in adults
Glomerulonephritis
- most common in renal failure of children
- Autoimmune
- Inflammation of antibodies to cells in kidney
rhabdomyolysis
muscle protein breakdown, block glomerulus
post renal causes of renal failure
renal outflow obstruction
cannot pee urine out so therefore cannot make more
- stones
- prostate blockage of urinary tract (in males)
what is the creatinine level in acute renal failure
above 200μmol/L
usually 80μmol/L
what is the process of acute renal failure
Anuric initially (no urine) with volume overload
- Accumulate fluid
- —–Ankle oedema (if ambulatory), sacral oedema (if bed bound)
- Pulmonary oedema & breathlessness
- Raised Jugular Venous Pressure (JVP)
- Weight gain
Gradually progresses to polyuria (none to a lot of urine production)
- Healing restores filtration before concentration ability
- —–Become dehydrated before concentration ability returns
development of Hyperkalaemia (high K+)
- Can lead to cardiac arrest
- —-K makes nerves excitable or unexcitable
- —–Needed to make muscles contract
development of Uraemia and Acidosis (slower process)
- High urea
- low bicarbonate
- increased respiratory excretion of CO2
4 disease stages of acute renal failure
anuric (no urine) with volume overload
gradually progresses to polyuria
development of hyperkalaemia (high K+)
deverlopment of uraemia and acidosis
most common way to treat acute renal failure
Usually pre-renal cause
- Catastrophic drop in BP
Give support till kidney function comes back and then recover
Usually reversible with time Renal support until recover - Dialysis -------Artificial replacement of some aspects of renal function - Nutrition
primary causes of chronic renal failure
Glomerulonephritis
Polycystic kidney disease
primary chronic renal failure cause site
kidney itself
secondary chronic renal failure causes
Diabetes (30%)
Hypertension (20%)
Drug therapy
Vasculitis
Renal artery disease/aorta disease
glomerulonephritis signs
Haematuria/proteinuria
- glomerulus inflamed, spaced between holes become decreased, so increased leaking of blood cells and protein
Gradual progression to
- Hypertension
- —–Overactive system angiotensin system
- Chronic renal failure
- ——gradually destroying glomerulus
nephrotic syndrome is
complication of Glomerulonephritis
- excessive loss of protein in urine (>3g in 24hrs)
- —-hypoalbuminaemia
- loss of plasma oncotic pressure
- —-suck of fluid into BV is reduced so not get fluid moving into BV from tissue
- tissue swelling (oedema)
Hypercoagulable state
- Loss of clotting factor proteins – AT3 deficiency
- dehydration raises other coagulation factors concentrations
nephrotic syndrome signs (4)
excessive loss of protein in urine (>3g in 24hrs)
—–hypoalbuminaemia
loss of plasma oncotic pressure
—–suck of fluid into BV is reduced so not get fluid moving into BV from tissue
tissue swelling (oedema)
Hypercoagulable state
- Loss of clotting factor proteins – AT3 deficiency
- dehydration raises other coagulation factors concentrations
2 drugs that impact renal disease
NSAIDs
Nephrotoxic drugs
NSAIDs effect on renal disease
Inhibit glomerular blood flow
- Opening of BV into glomerulus and closing to keep pressure constant controlled by prostaglandins
Inhibited by NSAID
Cause interstitial nephritis
Avoid in renal disease if possible
example of nephrotoxic drug
cyclosporin
renal vascular disease
Reduced blood flow to the kidney
- Atheroma of renal artery/aorta
- —-Atherosclerosis of aorta is common cause
- ——-Worse in narrowing branches
causes:
Hypertension – narrowing of renal artery
-Renal artery is first branch after neck of aorta (atherosclerosis of aorta)
Microangiopathy
microangiopathy is
- Immune reaction causing small blood vessel damage, RBC damage and thrombosis microscopic stop of BV
- E Coli 0157
2 causes of renal valvular dusease
Hypertension – narrowing of renal artery
-Renal artery is first branch after neck of aorta (atherosclerosis of aorta)
microangiopathy
renal artery disease is
Junction of renal artery Comes off at 90 degrees
- Flow hard
so Damage to surrounding mucosa
Prone to atherosclerosis
- lead to problems with renal blood flow
- hypertension
3 types of immune mediated renal damage
Multiple Myeloma
Goodpasture’s Syndrome
Vasculitis
- SLE and variants Lupus
multiple myeloma of the kidney
immune mediated renal damage
Plasma cell tumour
- B cells committed to making antibodies
- Excess light chain production ‘clogs’ kidney Tubular nephritis results
- Start to proliferate outwith control
- —-Make more and more and more
- Crush and clog up kidney
- Largely effects bones (more) and kidneys
Goodpasture’s syndrome
immune mediated renal damage
Anti-glomerular basement membrane antibody (anti-gbm)
- Wrong genetic makeup and - come across infection – make antibody
vasculitis
immune mediated renal damage
- SLE, lupus
Inflammation of blood vessels – smaller ones tend to clog and shut down if in kidney, causes function issue
what causes polycystic kidney disease
Gene mutation (PKD1,2 or 3)
- Inherited (AD or AR) or spontaneous
- Dominate or recessive
what is polycystic kidney disease
Multiple cysts in the renal parenchyma
Enlarged kidney (cysts make size increase)
Progressive destruction of normal kidney (squash away remaining functioning kidney tissue)
Gradual renal failure
when is end stage renal disease
when eGFR is <15ml/min
creatinine is 800-1000μmol/L
eGFR
estimated glomerular filtration rate
calculated from electrolytes
what impacts the time taken to reach end stage renal disease
- underlying cause
- modifying factors
what is a normal value for eGFR
90ml/min
kidney damage stage 1
eGFR 90+
normal or minimal kidney damage with normal GFR
kidney damage stage 2
eGFR 60-86ml/min
mild decrease in GFR
kidney damage stage 3
eGFR 30-59ml/min
mild decrease in GFR
kidney damage stage 4
eGFR 15-29ml/min
severe decrease in GFR
kidney damage stage 5
eGFR <15ml/min
kidney failure
protein or albumin in urine are high, cells or casts seen in urine
4 ways to manage chronic renal failure
reduced the rate of decline
- Eliminate nephrotoxic drugs
- —–Non-steroidals taken regularly for rheumatoid - reduce
- Control hypertension
- Control diabetes
- Control vasculitic disease
- ——Steroids/other immune suppressant drugs
Correct Fluid Balance
- Restrict fluid intake
- restrict salt, potassium, protein
Correct deficiencies
- Anaemia (erythropoietin)
- Calcium (vitamin D)
REMOVE outflow obstruction
- Renal stones (calculi)
- prostate enlargement
TREAT infection
- Chronic renal system infection
- —Make progressively worse
- — Speed up rate to complete failure
3 signs of chronic renal failure
anaemia
hypertension
- caused by renal failure but also causes renal failure
renal bone disease
- low Ca, high PO4
- hyperparathyroidism
- osteomalacia
- —-caused by low Ca level resorption of bone
symptoms of chronic renal failure
Insidious
- May be few
- Non-specific, hard for pt to define, over long time maybe unnoticed
Polyuria
Nocturia
Tired and weak
nausea
what is the purpose of carrying out renal replacement therapy
replace functions of the kidney
- not a cure
always have health deficit if kidneys not woring
2 types of renal malignancy
Renal Cell Carcinoma
- Renal tubular cell tumour
- Abdominal mass & haematuria
- Commoner in men, smokers
- Hypertension (renin) polycythaemia (EPO)
Transitional Cell carcinoma
- Usually bladder – ureter/kidney possible
- Haematuria – often asymptomatic
dentistry and renal disease
Few direct oral problems
General health may dictate treatment timing
CARE with prescribing
- CHECK all drugs with renal physician
- avoid NSAIDs, some tetracyclines
- reduce dose of most others
growth may be slow in children
- tooth eruption may be delayed
secondary effects of anaemia
- Oral ulceration
- ‘dysaesthesias’ – painful mucosa and tongue
white patches
- uraemic stomatitis
oral opportunistic infections
- Fungal and viral infections/reactivations
- Prone to post-op infections
dry mouth & taste disturbance
- fluid restriction and electrolyte disturbance
bleeding tendencies
- Platelet dysfunction
renal osteodystrophy - lamina dura lost
- bony radiolucency
- Secondary hyperparathyroidism increases osteoclast activity
