Acute Kidney injury AKI

Question 1

define aki and what chracterises it

Answer 1

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.

Question 2

when diagnosing and classifying aki what 2 parameters do you look at

Answer 2

serum creatinine and urine output

Question 3

describe difference between stage 1,2,3 of aki

Answer 3

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

Question 4

what cells of kidney are very susceptable to hypotension and hypoxia

Answer 4

proximal tubular cells are
very susceptible to
hypotension and hypoxia

Question 5

how much blood from co goes to kidney

Answer 5

Renal blood flow

20% of CO

Question 6

what three ways can aki causes be classfied

Answer 6

pre renal, intrinsic (in the kidney), post renal(after exiting kidney

Question 7

name some pre renal aki causes

Answer 7

volume depletion(hypovolaemia),

decreased effective volume,

altered intrarenal haemodynamics,

cardiac failure,

hepatorenal syndrome

Question 8

what can alter intrarenal haemodynamics causing aki

Answer 8

1. NSAIDs

2. ACEi-A2RB-induced

Question 9

name some intrinsic causes of aki

Answer 9

acute tubular necrosis
acute glomerulonephritis
acute interstitial nephritis
vascular( renal artery or small vessel)

Question 10

name some post renal aki causes

Answer 10

uteritic obstruction, bladder outflow obstruction

Question 11

what can obstruct kidney post renally

Answer 11

• Papillary necrosis
• Tumours
• Retroperitoneal fibrosis
• Renal calculi
• Urinary retention

Question 12

what are the seven functions of kidneys

Answer 12

excrete electrolytes
clear waste products
receptor site for hormones
gluconeogenesis
regulation of acid base state
control water balance
produce hormones

Question 13

what hormones does kidney produce consider their functions

Answer 13

Vitamin D

• Erythropoetin stimulates rbc production
• Prostaglandins

Question 14

what are the main functions affected by aki in kidneys

Answer 14

excretion of electrolytes
acid base regulation
control of water balance
clearance of waste products

Question 15

if aki has caused fluid overload what can you expect to see, what may you find in patient

Answer 15

swelling of ankles,pitting oedma, swollen face worse when lying flat, pulmonary oedma which can be seen on xray

Question 16

if aki effects electrolytes excretion what effect does this have on patient and what electrolyte are we worried about

Answer 16

patient can get hyperkalaemia

when potassium rises above 5.5 mmol/l. affects heart rhtym

Question 17

as hyperkalaemia worsens how does ecg change

Answer 17

5. 5-6.5 peaked t waves prolonged pr segment
6. 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

Question 18

why would you request an abg for someone with AKI

Answer 18

because aki can cuase metabolic acidosis.

Question 19

what do you expect to see in abg for someone with metabolic acidosis due to aki

Answer 19

acidic ph below 7.3
pco2 low
po2 normal or high
hco3 low

Question 20

what are the typical symptoms of metabolikc acidosis

Answer 20

tachypnoeic/breathless
nausea
non specifically unwell

Question 21

what is uraemia

Answer 21

retain metabolic watse products such as sulphate urea, creatinine, ammonia phisohate

Question 22

what does retention of metabolic waste products cause

Answer 22

rentention can cause pericarditis, pleurisy (inflamed pleura), and/or encephalopathy (brain damage or malfunction)

Question 23

what is the term for organs communicating with each other in aki

Answer 23

organ cross talk

Question 24

how do you manage aki patients 4 main steps

Answer 24

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

Question 25

when do you use renal replacement therapy rrt

Answer 25

Indication: life threatening complication of AKI

Question 26

name life threatening complications of AKI (aim for 5)

Answer 26

pulmonary oedema severe, severe metabolic acidosis, severe hyperkalaemia
uraemic pericarditis
uraemic encephalopathy

Question 27

outline the principles of rrt

Answer 27

blood from patient goes to blood pump, pumped through effluent which removes water and electrolytes and waste products, goes to air detector and back to patient

Question 28

name three veins that can be used for rrt and what type of catheter do you use

Answer 28

dual lumen catheters, internal jugular vein, femoral vein, subclavian vein