Acute Kidney injury AKI Flashcards
define aki and what chracterises it
The syndrome arising from a rapidly falling GFR’
• Characterised by retention of both nitrogenous (e.g. urea and creatinine) and non-nitrogenous
waste products, as well as disordered electrolyte, acid-base and fluid homeostasis.
when diagnosing and classifying aki what 2 parameters do you look at
serum creatinine and urine output
describe difference between stage 1,2,3 of aki
1 creatinine rises above 26.5umol/l in 48hrs
2 creatinine rise 2-2.9 times from baseline
3 creatinine rises 3 times from baseline. or rrt regardless of serum creatinine, or creatinine greater than 353.6 umol/l
stage 3 no urine for 12 hrs, stage 1 and 2 0.5 ml/kg/hr for 6-12 hrs and for greater than 12 hrs respectively
what cells of kidney are very susceptable to hypotension and hypoxia
proximal tubular cells are
very susceptible to
hypotension and hypoxia
how much blood from co goes to kidney
Renal blood flow
20% of CO
what three ways can aki causes be classfied
pre renal, intrinsic (in the kidney), post renal(after exiting kidney
name some pre renal aki causes
volume depletion(hypovolaemia),
decreased effective volume,
altered intrarenal haemodynamics,
cardiac failure,
hepatorenal syndrome
what can alter intrarenal haemodynamics causing aki
- NSAIDs
2. ACEi-A2RB-induced
name some intrinsic causes of aki
acute tubular necrosis
acute glomerulonephritis
acute interstitial nephritis
vascular( renal artery or small vessel)
name some post renal aki causes
uteritic obstruction, bladder outflow obstruction
what can obstruct kidney post renally
- Papillary necrosis
- Tumours
- Retroperitoneal fibrosis
- Renal calculi
- Urinary retention
what are the seven functions of kidneys
excrete electrolytes clear waste products receptor site for hormones gluconeogenesis regulation of acid base state control water balance produce hormones
what hormones does kidney produce consider their functions
Vitamin D
- Erythropoetin stimulates rbc production
- Prostaglandins
what are the main functions affected by aki in kidneys
excretion of electrolytes
acid base regulation
control of water balance
clearance of waste products
if aki has caused fluid overload what can you expect to see, what may you find in patient
swelling of ankles,pitting oedma, swollen face worse when lying flat, pulmonary oedma which can be seen on xray
if aki effects electrolytes excretion what effect does this have on patient and what electrolyte are we worried about
patient can get hyperkalaemia
when potassium rises above 5.5 mmol/l. affects heart rhtym
as hyperkalaemia worsens how does ecg change
- 5-6.5 peaked t waves prolonged pr segment
- 5-8 loss of p waves, long qrs, st elevation, ectopic beats escape rhytms
greater than 8mmol ventricular fibrrillation, aystole, bundle branch blocks qrs proggresive widening
why would you request an abg for someone with AKI
because aki can cuase metabolic acidosis.
what do you expect to see in abg for someone with metabolic acidosis due to aki
acidic ph below 7.3
pco2 low
po2 normal or high
hco3 low
what are the typical symptoms of metabolikc acidosis
tachypnoeic/breathless
nausea
non specifically unwell
what is uraemia
retain metabolic watse products such as sulphate urea, creatinine, ammonia phisohate
what does retention of metabolic waste products cause
rentention can cause pericarditis, pleurisy (inflamed pleura), and/or encephalopathy (brain damage or malfunction)
what is the term for organs communicating with each other in aki
organ cross talk
how do you manage aki patients 4 main steps
1 exclude life threatening condition if present treat
2 identify the aetiology of aki (cause) hypovolaemic,sepsis,low bp,drug induced
3 supportive treatment (nutrition and ulcer prophylaxis)
4 avoidance of progression
avoid nephrotoxic drugs, hypovolaemia,hypotension
