Icterus/HE in small animals Flashcards Preview

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Flashcards in Icterus/HE in small animals Deck (39):
1

In what form in newly formed unconjugated bilirubin?

insoluble in water, bound to albumin, dissociates from this before entering liver cell

2

What happens to bilirubin in the liver cell?

Conjugation with glucoronic acid making it water-soluble for excretion in urine (rate limiting step in hepatocyte)

3

What do bacteria in the lower urinary tract do?

convert bilirubin into urobilinogen --> enterohepatic circulation

4

Define pre-hepatic icterus

conjugation and uptake of bilirubin into liver overwhelmed

5

Define hepatic icterus

uptake, conjugation and excretion of bilirubin in hepatocytes overwhelmed

6

Define post-hepatic icterus

conjugation, excretion and uptake back into liver overwhelmed

7

What signs might show clinical signs of icterus? 4

-GIT
-neurologic
-renal/urinary
-haematologic

8

GIT signs 4

-vomiting and diarrhoea (common)
-acholic faeces (i.e. white)
-melaena
-ascites

9

Neuo signs of HE 6

-personality change
-ptyalism (drooling, cats)
-head pressing
-disorientation
-seizures
-stupor

10

Renal signs 6

Pu/PD (insufficient urea to concentrate)
pollakiuria
stranguria
dysuria
bilirubinuria

11

Define pollakiuria

excessively high daytime frequency of urination

12

Define stranguria

slow, painful urination caused by mm spasms of the urethra and bladder

13

Define dysuria

painful micturition

14

Haematologic signs 6

-yellow animal
-pale MM
-anaemia from GIT haemorrhage
-anaemia of chronic disease
-coagulation disorder
-haemolysis

15

DDx for pre-hepatic icterus

Haemolysis (IMHA, babesia infection, toxins - onions, lead , copper)

16

DDx for hepatic icterus - CAT 6 (in order of likelihood)

-suppurative cholangiohepatitis
-lymphoplasmacytic hepatitis
-hepatic lipidosis
-FIP
-toxins (acetaminophen=paracetamol, aspirin)
-neoplasia

17

DDx for hepatic icterus - DOG 4 (in order of likelihood)

-acute liver disease
-leptospirosis
-chronic hepatitis
-neoplasia

18

DDx for post-hepatic icterus (both dogs and cats) 3

-pancreatitis
-neoplasia (liver, duodenum, pancreas - i.e. close anatomic proximity)
-cholelithiasis (uncommon in cats/dogs)

19

How do you differentiate pre-hepatic and hepatic icterus? 2

PCV and TS (Prehepatic: PCV is low, TS normal. Hepatic - PCV usually normal, TS can be low if albumin is low)

20

How do you differentiate hepatic and post-hepatic icterus?

Imaging (what the bile duct looks like, what's blocking it perhaps, pancreatitis etc.)

21

Describe the workup for hepatic diseases - 8

-haematology, chemistry profile, UA
-liver function tests
-coagulation tests
-abdominal ultrasound
-aspirate effusion, cytology
-liver fine needle aspirate
-fine needle aspirate and culture of bile
-liver biopsy (histology, culture)

22

What is the most specific liver enzyme?

ALT (increased means increased numbers of hepatocytes are dying)

23

Where is AST present?

Liver but also the mm and intestines

24

What is AP and where is it found?

Alkaline phosphatase. Found in biliary duct cells (which are throughout the liver). Isoenzymes of this are cortisol-induced (dogs only) in bone, intestines, liver, placenta etc

25

Indications for liver failure on biochemistry - 4

-Low albumin
-Low cholesterol
-low glucose
-low BUN
(be sure to run a bile acid test as well)

26

Where are bile acids produced? From what?

in liver from cholesterol

27

How do bile acids return to the liver after secretion into small intestine?

enterohepatic circulation

28

How do you measure bile acids? When do levels of this change?

Take two measurements:
1st = fasted
Give food then take 2nd measurement
The rate limiting step ins the re-uptake of bile acids from the blood into hepatocytes. Levels are elevated in liver failure and PSS.

29

What is HE

ammonia and aromatic AA go directly into blood without passing through liver first means the CNS is exposed to shunted gut-derived toxins

30

Neurologic signs of HE - 5

-bizarre behaviour
-head pressing
-seizures
-intermittent blindness
-ptyalism (cats)

31

Signs of urate stone formation 3

dysuria, stranguria and haematuria

32

Clinical sign of HE

urate stone formation

33

Pathogenesis of urate stone formation

increased ammonium concentration in blood, decreased ability to convert uric acid to allantoin in the liver --> more urate excreted in urine

34

Most important diseases causing HE in CATS - 4

acute liver failure (toxic)
hepatic lipidosis
neoplasia
PSS (v rare in cats)

35

Most important diseases causing HE in DOGS - 3

PSS
liver failure (acute) - toxic, infectious
liver failure (chronic) - cirrhosis

36

In hepatic acidosis, how can FFA and Tg be processed by liver? When doesn't this work? Treatment?

-B oxidation
-redistribution to other organs via lipoproteins (especially VLDLs)
-doesn't work if diet is protein-deficient. Treatment therefore requires force-feeding (stomach tube) diet which is high in protein.

37

How do you test for liver function?

bile acids (remember 2 readings). Not liver enzymes as these won't tell you if the whole liver is working.

38

What are classic biochemistry signs for HE? 3

low glucose and urea, high bile acids (latter confirms hepatic dysfunction)

39

DDx for seizures/strong reaction to normal diazepam dose, decreased mentation, lethargy, weakness, inappetence?

INTRACRANIAL:
- anomaly (hydrocephalus, lissencephaly)
-infection (distemper, toxoplasma, parasites)
-idiopathic epilepsy
-trauma

METABOLIC:
-EXOGENOUS - toxic - medications
-ENDOGENOUS - HE because PSS, uraemia, electrolyte disturbances, hypoglycaemia