PassMedicine Flashcards
def of acute kidney injury
AKA acute renal failure
reduction in renal function
what is the inpatient mortality of AKI in the UK
25%
what are the causes of AKI divided into
1 prerenal
2 intrinsic
3 post renal
what are the prerenal causes of AKI
lack of blood flow to kidnets
1 hypovolaemia (secondary to D/V)
2 renal artery stenosis
what are the intrinsic causes of AKI
damage to kidney itself 1 glomerulonephritis 2 acute tubular necrosis 3 acute interstitial nephritis 4 rhabdomyolysis
what are the postrenal causes of AKI
obstruction causing urine to ‘back-up’
1 kidney stones in ureter or bladder
2 benign prostatic hyperplasia
3 external compression of ureter
risk factors of AKI
1 chronic kidney disease
2 heart failure/DM
3 history of AKI
4 nephrotoxic drugs
what drugs have nephrotoxic potential
NSAIDs
aminoglyclosides (gentamicin, streptomycin)
ACE inhibitors + ARBs
diuretics
symptoms and signs of AKI
reduced urine output
pulmonary/peripheral oedema
arrythmias (due to change in potassium)
how is AKI detected
1 rise in serum creatinine >26micromol/l in 48h
2 >50% rise in serum creatinine in last 7 days
3 a fall in urine output to <0.5ml/kg/hr for >6hrs
what drugs are used in hyperkalaemia treatment
1 IV calcium gluconate 2 combined insulin/dextrose infusion 3 nebulised salbutamol 4 calcium resonium 5 loop diuretics
how does combined insulin/dextrose infusion and nebulised salbutamol work against hyperkalaemia
causes short-term shift of K form extracellular to intracellular
how do calcium resonium and loop diuretics work against hyperkalaemia
removal of K from body
what must be stopped in AKI which due to increased risk of toxicity (but doesnt usually worsen AKI itself)
metformin
lithium
digoxin
what happens to H+ levels as K+ rises
hyperkalaemia is associated with acidosis because as potassium levels rise, fewer H+ ions enter the cells
what are causes of hypokalaemia with alkalosis
vomiting
diuretics
Cushings + Conns
A 35-year-old man presents with severe, episodic loin pain which radiates round to the front. He has blood+++, leucocytes ++ on the urine dipstick
renal colic
what is usually safe to continue in AKI
paracetamol warfarin statins aspirin clopidogrel BBs
what is primary hyperaldosteronism associated with
hypokalaemia
what stimulates ADH release
angiotensin II
what increases Na reabsorption in the renal distal tubule
aldosterone
what increases proximal tubule Na/H activity
angiotensin II
what is Granular appearance on immunofluorescence associated with
post-streptococcal glomerulonephritis
SLE nephropathy (class IV)
membranous glomerulonephritis
what can blood in the urine be split up into
microscopic
macroscopic
what does blood throughout voiding the bladder indicate
bleeding from bladder
what does blood at the end of voiding indicate
bleeding from terminal bladder or prostatitis
what are the two main causes of glomerulonephritis
IgA nephropathy
beurgers disease
what would you see in bloods with addisons
low Na
high Ka
what is the main cause of acute tubulointerstitial nephritis
drug hypersensitivity due to penicillin or NSAIDs
what are the symptoms of acute tubulointerstitial nephritis
fever
rash
painful joints
what would you expect urine output to be like with renal failure
oliguria ( decreased urine output)
what is the triad of nephrotic syndrome
proteinuria
low serum albumin
oedema
what is the 1st line treatment for nephrotic syndrome
low Na diet
diuretics
what is characteristic of nephritic syndrome
haematuria
proteinuria
HTN
oedema
what does TB of the kidney present with
haematuria
polyuria
nocturia
what would you expect to see in the urine with diabetic nephropathy
proteinuria
not haematuria
what is the triad of renal cell cancer
haematuria
flank pain
abdominal/flank mass
what is renal cell cancer also called
von grawitz tumour
what are symptoms of hypercalcaemia
increased urinary frequency, nocturia, constipation, polydipsia
what does bleeding throughout voiding indicate
lesion in bladder or above
what does bleeding at end of voiding indicate
terminal bladder or prostate lesion
what does bleeding at start of voiding indicate
urethral lesion
what causes tubulointerstitial nephritis
hypersensitivity reactions to drugs such as penicillin or NSAIDs
what is the first line imaging for renal stones
KUB USS
what is the gold standard for renal stones
CT
what drugs are safe to use in pregnancy
penicillins + cephalosporins
what are features of tubulointerstitial nephritis
anaemia
UTI
haematoma
what is the gold standard investigation for renovascular disease
renal arteriography
what is associated with Wegeners
cANCA
what is the most appropriate investigation for detecting EARLY renal impairment
microalbuminuria
how does renal failure cause secondary hyperparathyroidism
renal failure causes decreased Ca resorption and decreased PO4 excretion, this leads to low Ca and high PO4
low Ca causes a increase in PTH (secondary hyperparathyroidism) to compensate for the low Ca
PTH causes resorption which increases Ca to normal and increases PO4 causing hyperphosphataemia
what causes acute tubular necrosis
ischaema or nephrotoxins
what are features of acute tubular necrosis
will cause renal impairment and low urine output
later on it will recover and then increase urine output to greater than normal for a transient period
