Hepatic Surgery Flashcards

1
Q

where does the liver sit within the abdomen?

A

cranially, with 2/3rds of it mass to the RHS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how is the liver divided?

A

4 lobes - left, right, caudate and quadrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the liver attached to?

A

diaphragm, right kidney, lesser curvature of the stomach and proximal duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

which major vessel runs through the liver?

A

caudal vena cava - firmly attached to liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where does the liver receive blood from?

A

hepatic portal vein (from digestive tract and spleen) - 70-80%

hepatic artery - oxygenated blood - 20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

where does the oxygen supply to the liver come from?

A

50% hepatic portal vein and 50% hepatic artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how does blood leave the liver?

A

drains into hepatic veins which exit at the dorsal border of the liver into the caudal vena cava

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is one of the main challenges of hepatic surgery?

A

high vascularity of the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

when do we start to see clinical signs of hepatic impairment?

A

not until 70-80% of functional hepatic tissue is lost - large functional reserve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what might we see if synthesis and clearance of proteins (albumin) is impaired?

A

albumin-bound drugs and anaesthetic agents, ascites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the main functions of the liver?

A

synthesis and clearance of proteins (albumin)

metabolism of nutrients

production/activation of clotting factors

clearance of toxins (ammonia, drugs)

immunoregulation

GI function

storage - vitamins, fats, glycogen, copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what might occur as a result of impaired metabolism of nutrients?

A

hypoglycaemia, lethargy, weight loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what might occur as a result of impaired clearance of toxins?

A

excessive sensitivity to drugs, neurological signs, PUPD, anorexia, vomiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what might occur as a result of impaired production/activation of clotting factors?

A

clotting problems, haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what might occur as a result of impaired immunoregulation?

A

endotoxaemia, sepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what might occur as a result of impaired GI function?

A

weight loss, diarrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are some of the non-specific signs you might see with impaired liver function?

A

PUPD, lethargy, weight loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

where are bile acids synthesised?

A

in the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how are bile acids excreted?

A

into hepatic ducts - converge to form common bile duct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what happens to bile when the body is not digesting?

A

bile drains from the liver and passes via the cystic duct to the gall bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what happens to bile in the gallbladder?

A

storage and concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how does bile exit the gallbladder?

A

flows out via the cystic duct to the common bile duct and into the duodenum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what are the main functions of bile acids?

A

help with digestion and absorption of fat

neutralise gastric acid and inhibit gastric acid secretion to prevent intestinal ulceration

24
Q

what diagnostic testing might be carried out for suspected hepatic dyfunction?

A

blood testing - haematology, biochemistry, blood gas/electrolytes, dynamic bile acid testing

urinalysis

imaging - radiography, U/S, CT, MRI, scintigraphy

25
Q

how might we medically manage patients with hepatic dysfunction to help with stabilisation before surgery?

A

prescription diet
oral abs
oral lactulose

26
Q

what should be ascertained about the patients blood before surgery?

A

complete coagulation profile - platelet count, activated partial thromboplastin time, prothrombin time

27
Q

why should a complete coagulation profile be carried out before hepatic surgery?

A

hepatic insufficiency can lead to clotting abnormalities, which could exacerbate risk of haemorrhage

28
Q

how can we mitigate abnormal coagulation test results?

A

advisable to pre-treat patient with vitamin K or fresh frozen plasma

29
Q

why are abs indicated for hepatic surgery?

A

due to presence of of bacteria in liver and risk of endotoxaemia/sepsis

30
Q

what is an appropriate ab choice for a patient undergoing hepatic surgery?

A

broad-spectrum ab e.g. potentiated amoxycillin or 2nd gen cephalosporin (while awaiting C&S results from liver/bile/gallbladder)

31
Q

which types of drugs should be avoided in patients with hepatic insufficiency?

A

drugs than undergo hepatic metabolism

32
Q

what general patient care is important to consider in patients with hepatic insufficiency?

A

pupd - regular water replenishment and toileting trips
anorexia - tempt to eat

33
Q

what are the different methods for liver biopsy?

A

u/s guided percutaneous FNA/tru-cut
open surgical technique
laparoscopic technique

34
Q

what is the advantage of open/laparoscopic liver biopsies?

A

more accurate
yield a better sample
allows for gross visualisation and examination of the abdominal organs

35
Q

what are the indications for a partial/complete hepatic lobectomy?

A

removal of benign/malignant masses, abscess, liver lobe torsion

36
Q

what are the risks of partial/complete hepatic lobectomy?

A

haemorrhage
liver failure
portal hypertension

37
Q

what is cholecystectomy?

A

removal of the gallbladder

38
Q

what is cholecystoenterostomy?

A

rerouting of the gallbladder into the duodenum

39
Q

what are the indications for cholecystectomy/cholecystoenterostomy?

A

biliary tract rupture and bile peritonitis

diseases causing extrahepatic biliary tract obstruction e.g. gallbladder mucocele, choleliths, pancreatitis, neoplasia

40
Q

what are the main perioperative considerations during hepatic surgery?

A

hypotension - arterial line ideal

hypothermia - often difficulty regulating temperature

significant risk of haemorrhage even if coagulation abnormalities identified and mitigated

IVFT throughout surgery

care with premedication and induction choice - avoid heavy hepatic metabolism

ventilation if facilities available

perioperative abs indicated

41
Q

what are the post-operative care considerations after hepatic surgery?

A

intensive nursing required for critical animals

pain scoring and adequate analgesia

monitoring - physical parameters, BP, signs of haemorrhage, bile leakage

minimum database - haem and biochem

abs if infection present

nutrition - prescription liver diet

monitor for sepsis/SIRS

42
Q

what is a portosystemic shunt?

A

an anomalous blood vessel which connects the hepatic portal vein with the systemic venous circulation, thereby passing the liver and diverting some of the portal blood supply away from the liver

43
Q

what can occur as a result of poor liver development due to PSS?

A

reduced protein production
altered fat and protein metabolism
reticuloendothelial dysfunction

44
Q

how long should a patient be starved for a bile acid stim test?

A

at least 12 hours

45
Q

how long should be left inbetween the pre-prandial and postprandial blood samples in a bile acid stim test?

A

as close to 2 hours as possible

46
Q

what diet should be fed to patients with PSS?

A

highly digestible
high biological value of protein
fatty acids, vitamins and minerals to meet the minimum requirements of the individual
e.g. purina HP, royal canin hepatic, hills l/d

47
Q

why should patients undergoing corrective PSS surgery be starved for no longer than 8 hours?

A

due to reduced glycogenolysis and gluconeogenesis reserve

48
Q

why should patients undergoing corrective PSS surgery have a peripheral and central IVC placed?

A

peripheral for drug admin and IVFT

central for blood sampling, glucose monitoring

49
Q

what blood parameter should be measured very regularly/closely during PSS surgery?

A

blood glucose - predisposition to hypoglycaemia, often paediatric patients

50
Q

how can we reduce risk of complications due to haemorrhage during PSS surgery?

A

ascertain clotting times pre-surgery

blood cross matching and correct blood type available for transfusion

51
Q

why is it advantageous to have access to sympathomimetics during PSS surgery?

A

hypotension likely unresponsive to fluid therapy

reduced proteins in blood due to impaired liver function means blood has less oncotic pressure - fluids given are rapidly lost to the extravascular space

52
Q

what should we be monitoring after after the PSS has been occluded?

A

portal hypertension

53
Q

what post-operative monitoring is required after PSS surgery?

A

ideally ICU-level nursing - often not possible

temperature - prone to hypothermia, shivering will use up glucose unnecessarily

blood pressure (15-30 min intervals) - colloids helpful part of IVFT if unresponsive to crystalloids

glucose monitoring every hour until patient awake

pain score hourly, analgese accordingly (no NSAIDs)

54
Q

which type of drug should be avoided in patients who have had PSS corrective surgery?

A

NSAIDs - risk of GI ulceration associated with portal hypertension

55
Q
A