Acute Renal Failure Flashcards
Frothy urine is indicative of which renal abnormalities
Proteinuria such as in nephrotic syndrome
Recurrent frank haematoma is indicative of what
IgA glomerulonephritis in young people
Renal tract cancer in elderly people
Haematuria at the beginning of the urine stream is suggestive of what
Urethral bleeding
Haematuria at the end of the urine stream is suggestive of what
Bladder or prostate bleeding
Haematuria throughout the urine stream is suggestive of what
Glomerular bleeding
What can happen in the kidneys following a streptococcal throat. Infection
Post-infective glomerulonephritis
Dysmorphic red cells in the urine suggest what
Glomerular bleeding
Eosinophils and leukocytes in the urine are suggestive of what
Interstitial nephritis
Polymorphonuclear cells in the urine suggest what
Inflammation from bacterial infection
Red cell casts in the urine suggest what
Bleeding usually due to glomerulonephritis
White cell casts in the urine suggest what
Acute infection - usually bacterial
What do hyaline or fine granular casts in the urine suggest
They are normal findings, but may be raised in proteinuria
Fatty casts in the urine are suggestive of which condition
Nephrotic syndrome
Large waxy casts in the urine suggest what
Chronic kidney disease
Where are urinary casts made
In the DCT and collecting ducts
What are urinary casts primarily made of
Tubular mucoprotein aka Tamm-Horsfall protein
Pigmented casts in the urine are suggestive of what
Haemoglobinuria or myoglobinuria
Describe the structure of calcium oxalate crystals and which conditions might make them appear in the urine
Square envelope shape
Most common component in kidney stones
Describe triple phosphate crystals and when they might be present in the urine
Coffin lid shape
Found in alkalin urine eg in a proteus UTI such as klebsiella
Describe the structure of Uric acid crystals and when they would be present in the urine
Diamond shape
Found in hyperuricaemia eg in gout
Can also be caused by tumour lysis syndrome
Describe the shape of cystine crystals and when they would be present in the urine
Hexagonal with sharp edges
Present in cystinuria (inherited metabolic disorder)
What is the first sign of diabetic nephropathy
Microalbuminuria
What might be seen on histology in ATN
Dilated tubules
Loss of tubular epithelium
Mitosis figures in tubular epithelial nuclei
What are the histology all features of acute interstitial nephritis
Leucocytic infiltrate into the interstitial (esp eosinophils)
Normal glomeruli
What are the histological features of crescentic glomerulonephritis
Crescent shaped cluster of acute inflammatory cells w/in the Bowmann’s capsule displacing the glomerular tuft
name the three broad groups of AKI
PRERENAL- decr fluid/blood to kidneys so decr GFR
INTRINSIC - damage to parenchyma
POSTRENAL - urinary tract obstruction
which part tof the glomerular vasculature does angiotensin II act
it is a powerful vasoconstrictor of the vas efferens
how might third space sequestration cause AKI and how might it manifest
PRERENAL - compression of renal veins (if >70mmHg also arteries)
manifests as:
- resp comprimise
- decr cardiac output
- intestinal ischaemia
- hepatic dysfunction
what is the most common cause of intrinsic ARF
acute tubular necrosis
how does rhabdomyolysis cause AKI
haem from myoglobin damages proximal tubules, and obstructs tubules as forms casts.
volume depletetion may also occur as fluid accumulates within the damaged muscles.
what 4 electrolyte abnormalities are present in rhabdomyolysis
hyperkalaemia
hyperphosphataemia
hyperuricaemia
hypocalcaemia as calcium is deposited in muscle (hyper in recovery as this is released)
describe three methods of preventing rhabdomyolysis induced AKI
fluid repletion
forced alkaline diuresis
mannitol forced diuresis
how can radiocontrast nephropathy be preventd
low osmolarity contrast media prehydration with IV fluids antioxidants N-acetyl-cysteine diuretics IV NaCO3
name three types of ATIN
drug induced
infection related
inflammatory
whihc drugs can cause ATIN
penecillins cephalosporins sulfonamides rifampicin frusemide NSAIDs
which viral infection can cause ATIN
Hautavirus
name a bacterial infection which can cause ATIN
legionella leptospira streptococci mycoplasma brucella chlamydia
which inflammatory conditions are associated with ATIN
Sjogrens
SLE
Wegener’s granulomatosis
sarcoidosis
which type of ATIN presents with eosinophiluria and eosinophilia
drug induced
which type of ATIN might present with neutrophilic cellular infiltrate
infection induced from acute pyelonephritis
what is TINU syndrome
uveitis with TIN
usually presents in childhood
in adults more common in females
thought to be related to autoantibodies to CRP
which is the main diagnostic test for post renal causes of AKI
US
looks for hydronephros or hydroureter
what are the main tubular functions in the kidney
concentration of urine
acidification of urine
therefore in obstruction there is a loss of concentration and a loss of acidification capacity leading to polyuria and metabolic acidosis
what are the treatments of post renal AKI
post obstructive diuresis
replace electrolytes
correct metabolic acidosis
what is a normal anion gap acidosis indicative of and what might have caused is
bicarbonate loss
caused by diarrhoea and renal tubular acidosis
what is an increased anion gap suggestive of and what might have caused it
increased acid production
caused by:
- lactic acidosis
- DKA
- renal failure
- methanol
- ethylene glycol
what are the signs of metabolic acidosis
muscle weakness
altered mental state
kussmaul breathing
hypotension (from negative ionotropic effect)
what are the effects of hyperkalaemia
muscle weakness
constipation
cardiac : loss of p wave, tall tented T, wide QRS
what can be administered IV in hyperkalaemia to protect cardiac muscle
Ca gluconate
10mls of 10% over 10 mins
Ca antagonises K in cardiac muscles
Dextrose insulin as glucose co-transported with K
SABA - IV salbutamol works via the glucose K co-transporter
what must not be given to patients with bilateral renal artery stenosis
ACE inhibitors as causes a dramatic drop in GFR
list 4 causes of high renin states
1 volume depletion (D&V, diuretics)
2 fluid overload (cirrhosis, nephrotic syndrome)
3 low cardiac output (CCF)
4 renal hypoperfusion (renal artery stenosis)
which is the most common causative organism in acute pyelonephritis
e. coli
what are the three predisposing conditions for papillary necrosis
diabetes
urinary tract obstruction
analgaesic abuse
list some causes of hyperosmolar hyponatraemia
renal failure
hyperglycaemia
mannitol therapy
list some causes of hyponatraemia with a normal osmolarity
also known as pseudohyponatraemia
seen in severe hyperlipidaemia and paraproteinuria
hyposmolar hyponatraemia can be further sub divided into what
HIGH ADH
LOW ADH (renal failure, primary polydipsia)
what can cause primary polydipsia
anti-psychotic induced thirst
hypothalamic lesions
beer drinkers
which type of diuretic might be used in hyponatraemia
loop diuretics
what is osmotic demylination syndrome
a complication of rapid correction of severe hyponatraemia
what are Bence Jones proteins
light chains from IgG found in myeloma
light chain disease can cause cast nephropathy
give two examples of osmotic diuretics and what they do
mannitol, glycerol
exert an osmotic effect in the glomerulus as they are not reabsorbed
give two examples of loop diuretics and what they do
furosemide and bumetenide
they bind to NKCC2 co-transporters in the THICK ascending limb, this inhibits Na K and Cl reabsorption which decreases the medullary hypertonicity.
They also alter the transcellular voltage and reduce reposition of calcium and magnesium
THESE ARE STRONG DIURETICS
give two examples of thiazide diuretics and how they work
bendroflumethazide and indapamide
these reversibly bind inhibit the NCC apical NaCl co-transporter in the DCT allowing more sodium in and potassium out
they are weak diuretics
can raised rate and cholesterol levels
can also lead to the depletion of Na K Cl Mg
give two examples of potassium sparing collecting duct diuretics
amiloride and triamterene
blocks ENaC and therefore sodium reabsorption and potassium secretion
how does aldosterone affect the collecting duct
promotes sodium reabsorption and potassium secretion
how does spironolactone work?
it blocks aldosterone receptors in the collecting duct reducing sodium reabsorption.
can lead to:
hyperkalaemia
gynaecomastia (as anti andrgogenic)
list two drugs that can cause hypokalaemia
thiazide diuretics
loop diuretics
list three drugs that can cause hyperkalaemia
ACEI
Angiotensin receptor blockers
sprinoloactone
which drugs may cause irreversible renal damage
aminoglycosides (Gent)
NSAIDS
which drug may falsely elevated serum creatinine
trimethoprim
which drugs can cause rhabdomyolysis
statins calcineurin inhibitors ( cyclosporin and tocrolimus)
