Acute kidney injury Pt2 Flashcards
when in renal failure does uraemia start (GFR)
<15ml
symptoms of uraemia (9)
- pruitus
- nausea and vomiting
- lethargy
- confusion
- restless legs
- metallic taste
- neuropathy
- bleeding
- chest pain
acidosis symptoms (2)
breathlessness
confusion
hyperkalaemia symptoms
palpitations
chest pain
weakness
ECG signs of hyperkalaemia (5)
- peaked T waves
- flattered P waves
- lengthened PR interval
- widened QRS
- sine wave pattern (VF)
vitamin D deficiency symptoms
bone pain
fractures
anaemia symptoms
breathlessness
lethargy
faintness
tinnitus
presentations of renal failure (6)
- uraemia
- protein loss and Na+ retention
- acidosis
- hyperkalaemia
- anaemia
- vit d deficiency
electrolyte balances in AKI
hyponatremia (low Na+) hypocalcaemia (low Ca+) Hyperkalaemia (high K+) hypermagnesemia (high Mg) Hyperphosphatemia (high phosphate)
why do you get hyponatremia and hyperkalaemia
reduction in GFR means that less sodium is being filtered into the tubules, this decreases the activation of the sodium-potassium co-transporters in the distal convoluted tubule, decreasing the tubular secretion of potassium.
what does high serum K+ do to cell membranes
activates the potassium-proton pumps on cells so they release protons into the blood leading to metabolic acidosis
fraction of excreted sodium=
percentage of sodium filtered by the kidneys which is excreted in urine
a low FeNa <1% indicates
pre-renal or contrast induced nephropathy
FeNa >1% indicates
intrinsic AKI -sodium wasting
what happens to amylase in renal insufficiency
elevation in serum amylase when creatinine falls below certain threshold
low urine sodium leads to ____ osmolarity
high
which AKIs cause high urine osmolarity
pre-renal
post-renal
which AKIs cause low urine osmolarity
intrinsic
what detects fall in Bp
baroreceptors and macula densa cells
where are baroreceptors
carotid sinus
what do macula densa sense
filtrate sodium chloride
what do macula densa signal to
granular cells of the JGA
what does renin do
converts angiotensinogen (from liver) to angiotensin 1
what does ACE do
converts angiotensin 1 to 2
where does angiotensin 2 act
efferent arteriole constriction increasing GFR
aldosterone role
released from adrenal cortex causing Na+ reabsorption
what happens to drugs in renal failure (5)
- reduced clearance rate
- longer half life
- reduced plasma binding of acidic drugs
- reduced non-renal clearance (decreased activity of CYP450 enzymes)
- takes longer to reach steady state
how can hypertension progress kidney disease
afferent arteriole thickens via atherosclerosis reducing perfusion to kidneys and causing ischaemic injury –> deposition of extracellular matrix leading to glomerulosclerosis
extra glucose effect on kidneys
binds to vessels via non-enzymatic glycation leading to vessel wall thickening -by hyaline arteriosclerosis obstructing blood flow in efferent vessel and causing an increased GFR
kidney vessel most affected by glucose in diabetes
efferent arteriole
what is the direct effect of ACEi
cause efferent arteriolar dilation
extra effect of ACEi
inhibits breakdown of bradykinin to increase antihypertensive effects
can ARBs and ACEi further exacerbate renal hypoperfusion
yes
nephrotic syndrome (4) symptoms
proteinuria >3g/day
Oedema
hypoalbuminemia
hyperlipidaemia
nephritic syndrome (4) symptoms
haematuria
hypertension
raised creatinine
oliguria
why hyperlididaemia in nephrotic syndrome
occurs secondary to hypoproteinemia stimulation of protein synthesis in the liver overproduces lipoproteins
main site of damage in nephrotic syndrome
epithelial podocytes - loss of the pedible foot processes
name 3 primary causes of nephrotic syndrome
- minimal change nephritis
- focal segmental glomerulosclerosis
- membranous glomerulonephritis
most common nephrotic syndrome in children
minimal change nephritis
pathology of minimal change
T cells secrete cytokines damaging pedicle foot processes causing loss of negative charge and effacement
what can minimal change be associated with
Hodgkin’s lymphoma
symptoms of minimal change (4)
- foamy urine
- poor appetite
- swelling eyes, ankles, abdomen
- weight gain
most common nephrotic syndrome in adults
focal segmental glomerulosclerosis
how is focal segmental glomerulosclerosis characterised histologically
localised areas of scarring within the glomerulus
secondary FSGS associated with which diseases
- sickle cell disease
- HIV
- retrovirus
- heroin abuse
what happens to some of the filtered proteins and lipids in FSGS
they deposit into the interstitium causing hyalinosis and giving a glassy histological appearance -cause scarring
what is membranous GN
diffuse inflammation and thickening of the basement membrane by autoantibodies
what do immune deposits in membranous GN do
activate complement and the membrane attack complex causing cell damage
pattern of the basement membrane in membranous GN
spike dome pattern of the basement membrane
rule of 3s for membranous GN
1/3 resolve
1/3 respond to cytotoxics
1/3 develop CKD
name 4 causes of nephritic syndrome
- post-streptococcal GN
- Henoch-scholen purpura GN
- Vasculitis
- IgA nephropathy
when does post-strep GN occur post sore throat infection
1-2 weeks
main agent of post-strep GN
A streptococcus
when else can post-strep GN occur
4-6 weeks after a skin infection
pathology of post-strep GN
immune complex deposition of strep antigen deposited into kidney and transported into peritubular space -inducing a state of inflammation damaging glomerular basement membrane
symptoms of post-strep GN (5)
- dark urine
- peripheral oedema
- dyspnoea
- general malaise/headache
- weakness, anorexia, N&V
what is Henoch-scholen purpura GN
an acute IgA mediated vasculitis disorder
what is vasculitis
a group of disorders that destroy blood vessels by inflammation
where is the vessel damage in henoch-scholen (4)
skin
GI tract
joints
kidney
what age in Henoch Scholen purpura GN common in
3-10 years old
Henoch scholen purpura GN symptoms
- leg and arm purpura rash
- arthritis joint pain
- abdo pain, N&V
- GI bleeding
- nephritis
name 4 vasculitis’s
SLE
Small vessel
good pastures
ANCA
good pastures pathophysiology
anti-glomerular basement membrane antibodies specific to alpha-3 subunit of type 4 collagen
associations of Good pastures in rest of body
- pulmonary haemorrhage (haemoptysis)
- rapidly progressing GN
renal biopsy of Good pastures shows
IgG deposits on membrane
ANCA vasculitis associated with
small vessel vasculitis
clinical signs of ANCA
affects various organs
-skin lesions such as purpura and urticaria
IgA nephropathy also called
Berger’s disease/ mesangioproliferative GN
in IgA nephropathy where does it deposit
in the mesagium (smooth muscle surrounding capillaries)
typical presentation of IgA nephropathy
- young male recurrent episodes of macroscopic haematuria
- mucosal infection -upper respiratory tract
- renal failure
which has low complement levels IgA nephropathy or post-strep GN
post-strep GN
in which -post strep GN or IgA nephropathy is the main symptom proteinuria
post-strep GN
interval between respiratory tract infection and IgA nephropathy
1-2 days
% of patient with IgA nephropathy developing ESRF
25%
what marks a good prognosis in IgA nephropathy
frank haematuria
what marks a bad prognosis in IgA nephropathy (5)
male gender proteinuria hypertension smoking hyperlipidaemia
6 complications of CKD
anaemia renal bone disease hyperphosphatemia acidosis oedema uraemia
nephritic condition occuring in childhood following diarrhoea-inducing GI infection
haemolytic uremic syndrome
what cancer can cause AKI
myeloma
why can myeloma cause AKI
unregulated secretion of antibodies leading to protein filtration through the kidney coordinating damage
treatment of AKI
depends on cause
treatment of hyperkalaemia
- 10ml of 10% calcium gluconate
- 50ml of 50% glucose with 6-10 units of insulin (actrapid)
what does calcium gluconate do
protects the heart from life threatening arrhythmias
what does insulin do (in AKI)
encourages intracellular movement of potassium
signs and symptoms of AKI
- oliguria
- N&V
- Dizziness
- orthopnoea
- PND
- oedema (pulmonary and peripheral)
- tachycardia
- hypotension