Acute kidney injury

Question 1

what does acute on chronic mean

Answer 1

refers to an acute injury suffered in addition to pre-existing chronic renal disease – the injury may or may not be related to the cause of pre-existing disease.

Question 2

What are the 3 categories of acute kidney injury

Answer 2

Haemodynamic
Intrinsic renal
post renal

Question 3

Describe how to resolve haemodynamic acte injury

Answer 3

correcting the underlying cause (often via fluids to restore renal perfusion)

Question 4

list 3 common causes of Haemodynamic acute kidney injury

Answer 4

hypovolaemia
anaesthesia
use of NSAIDs

Question 5

describe intrinsic renal injury

Answer 5

True renal damage – most commonly ischaemic /hypoxic or toxic in nature.

Question 6

List 3 nephrotoxins that can cause intrinsic renal injury

Answer 6

NSIADs
Ethylene Glycol
Lillies (cats)

Question 7

List 2 causes of post renal injury

Answer 7

urinary obstruction- blocked bladder
urinary leakage- uroabdomen

Question 8

What are the 4 phases of AKI- intrinsic

Answer 8

phase 1- asymptomatic- towards end of this phase azotaemia begins to develop
Phase 2- hypoxia and inflammatory responses propagate renal damag
Phase 3- can last up to 3 weeks
Phase 4- recovery phase, can last weeks to months- Na lost and svere polyuria –> can lead to hypovolaemia- kidney trying to fix itself

Question 9

What do you look for in the history that suggests AKI

Answer 9

Presence of a predisposing factor e.g. anaesthesia, toxin exposure
<1w history – anorexia, vomiting, PUPD, lethargy, diarrhoea.

Question 10

List what we see on clinical exam with AKI

Answer 10

renal pain +/- palpable enlargment
jaundice
signs associated with fluid loss
signs associated with concurrent illness e.g. sepsis

Question 11

If you see jaundice in an unvaccinated animal with renal pain and vomiting what should you think

Answer 11

Lepto

Question 12

what do we tend to see on biochem with AKI

Answer 12

azotaemia
Hyperphosphataemia (relatively marked)
Hyperkalaemia – to a possibly dangerous level
hypocalcaemia
Elevated hepatic parameters in Lepto

Question 13

what to we tend to see on urinalysis with AKI

Answer 13

Inappropriate USG- dilute when animal is dehydrated
Proteinuria
Glucosuria

Question 14

what is the normal size of kidneys

Answer 14

Dogs – 5.5 - 9.1x Aortic Diameter
Cats – 3 – 4.3cm in length

Question 15

when is peri-renal free fluid seen

Answer 15

lepto in dogs
or
lymphoma in cats

Question 16

what should you test every dog with a possible AKI for

Answer 16

Lepto
because it is zoonotic

Question 17

what do we see with lepto

Answer 17

renal damage
thrombocytopaenia
anaemia
electrolyte disturbances

25% of dogs get hepatic damage
75% get dyspnoea

Question 18

Describe how to diagnose lepto

Answer 18

SNAP lepto antibody test- (needs antibodies to have been generated, so early false negatives)

so if tests neg and has suggestive clinical signs - send off blood/urine samples for PCR

Question 19

Treatment of AKI

Answer 19

Fluid therapy
monitor urinary output, and fluid intakes - or via body weight

change fluid rate based on these - need to match losses

Question 20

define oliguria

Answer 20

<1ml/kg/hr in the hydrated and perfused patient

Question 21

define Anuria

Answer 21

little to no urine in the hydrated and perfused patient

Question 22

when is dialysis (renal replacement therapy) indicated

Answer 22

for the non-responsive patient to fluid therapy or acute poisoning e.g. lilly/ethylene glycol toxicity in cats.

Very expensive so not used much

Question 23

what is the complications associated with peritoneal dialysis

Answer 23

are moderate, including causing a septic abdomen.

Question 24

what is a good first line AB for suspected urinary tract infection

Answer 24

TMPS- for E.coli
Could use amoxyclav but getting moved to second line

Question 25

what is a good AB for lepto

Answer 25

doxycycline

Question 26

why should we avoid ACE inhibitors in AKI animas

Answer 26

they try to reduce blood pressure but they reduce afferent renal blood flow
which will damage kidneys further

Question 27

what is the prognosis of AKIs

Answer 27

depends on what problem is and the owner finances
Realistically – in the non-obstructive, non-infectious case, there is a 50/50 chance for a good outcome.

Question 28

What is haemodynamic acute kidney injury

Answer 28

it is reduced renal blood supply