KLE-Liver Flashcards
(159 cards)
1
Q
What are the ligaments that attach the liver to the abdominal wall
A
Falciform
Round
2
Q
What are the ligaments that attach the liver to the diaphragm
A
Coronary ligament
Triangular ligament
3
Q
What is the functional unit of the liver
A
Lobule
4
Q
Describe the lobule structure
A
Hexagonal w/ central vein and portal veins at 6 corners
5
Q
What are the liver components for the following:
Arterioles
Capillaries
Venules
A
Arterioles= terminal branches of -hepatic artery -Portal vein Capillaries = sinusoids Venules = central vein
6
Q
What are the 3 zones of the acinus
A
divisions that correspond to the distance from arterial O2 supply
Zone 1 = closest, most oxygenated
Zone 2 = middle, middle oxygenation
Zone 3 = furthest, least oxygenated
7
Q
What is significant about acinus zone 3
A
Most susceptible to ischemic injury
Contains highest concentration of CYP450 enzymes
8
Q
What are Kupffer cells
A
- Part of the reticuloendothelial system
2. Remove bacteria before vena cava
9
Q
What structure drains bile
A
Canaliculi
10
Q
Where is bile produced and stored
A
Produced = hepatocyte Stored = gallbladder
11
Q
How is bile drained to the gallbladder
A
- Canaliculi drain bile into bile duct
- Bile ducts converge to form hepatic duct
- Hepatic duct joined by cystic and pancreatic duct
- Empties into duodenum
12
Q
What structure controls the flow of bile released from common hepatic duct
A
Sphincter of Oddi
13
Q
What medication can increase biliary pressure and how
A
Opioids contract the sphincter of Oddi
14
Q
What effect do opioids have on the common hepatic bile duct
A
Causes contraction of the sphincter of Oddi, increasing biliary pressure
15
Q
What are 3 functions of bile
A
- Absorption of fat and fat-soluble vitamins (DAKE)
- Excretory pathway for bilirubin and products of metabolism
- Alkalization of duodenum
16
Q
What vitamins are absorbed by bile
A
Fat-soluble vitamins = DAKE
Vitamins D, A, K, E
17
Q
What is cholecystokinin (CCK)
A
it stimulates the gallbladder to contract increasing flow of bile into duodenum following fat and protein consumption
18
Q
Where is cholecystokinin produced
A
duodenum
19
Q
What is the lymphatic structure of the liver
A
Lymph and proteins drain into the space of Disse (between hepatocytes and sinusoids)
They then empty into lymphatic ducts
20
Q
What organ is responsible for half of the lymph production in the body
A
Liver
21
Q
What percent of CO and volume does the liver receive
A
CO = 30% Volume = 1,500 mL/min
22
Q
What percent of blood flow and O2 supply does the hepatic artery supply the liver
A
Blood flow = 25%
O2 supply = 50%
23
Q
What percent of blood flow and O2 supply does the portal vein supply the liver
A
Blood flow = 75%
O2 supply = 50%
24
Q
The hepatic artery is a branch of which artery
A
Celiac artery
25
How does splanchnic vascular resistance affect hepatic flow
Portal vein is a product of splanchnic circulation
| Increased splanchnic vascular resistance reduces portal vein BF
26
What are examples of causes of decreased portal vein flow
1. SNS stimulation
2. Pain
3. Hypoxia
4. Hypercarbia
27
What is the equation of portal perfusion pressure
Portal perfusion pressure = portal vein pressure - hepatic vein pressure
28
What is the normal pressure for the following:
Portal vein
Sinusoid
Portal vein = 7-10 mmHg
| Sinusoids = 0 mmHg
29
What are diagnostic pressure for portal HTN at the following sites:
Portal vein
Sinusoids
Portal vein = >20-30 mmHg
| Sinusoids = >5 mmHg
30
How does the hepatic artery compensate for decreased portal vein flow
Washout of vasodilators (adenosine) increase hepatic artery flow
31
What is the equation for hepatic artery perfusion pressure
hepatic artery perfusion pressure = MAP - hepatic vein pressure
32
5 perioperative factors that reduce liver blood flow
1. Increased splanchnic vascular resistance (SNS stim, pain)
2. Factors increasing CVP (PPV, excess hydration)
3. Some beta-blockers (propranolol)
4. Intrabd procedures
5. Laparoscopic surgery (pneumoperitoneum)
33
How does propranolol affect liver blood flow
reduces CO and increases splanchnic vascular resistance
34
The celiac artery provides blood flow to which 3 organs
1. Liver
2. Spleen
3. Stomach
35
The superior mesenteric artery provides BF to which 3 organs
1. Pancreas
2. Small intestines
3. Colon
36
What organ is supplied by the inferior mesenteric artery
colon
37
What is the liver responsible for synthesizing
1. Coagulation proteins
| 2. Plasma proteins
38
What are 4 coagulation protein categories that the liver is responsible for synthesizing
1. Procoagulants
2. Anticoagulants
3. Fibrinolytics
4. Thrombopoietin
39
What procoagulants are NOT synthesized by the liver
1. von Willebrand factor
2. Factor 3
3. Factor 4 (Ca++)
40
Where is factor 8 produced
Liver sinusoidal cells and endothelial cells (NOT hepatocytes)
41
Where are most protein coagulation factors produced
The hepatocytes of the liver
42
Vitamin K is required for synthesizing which factors
2, 7, 9, 10
43
What anticoagulant factors are synthesized in the liver
1. Antithrombin
| 2. Proteins S, C, Z (vit K dependent)
44
What fibrinolytics and thrombopoietin factors are synthesized in the liver
```
Fibrinolytics = plasminogen
Thrombopoietin = stimulates plt production
```
45
Which plasma protein is not produced by the liver
immunoglobulins
46
How does hepatic function affect protein binding of drugs
Protein synthesis is decreased, so drugs will have a higher Vd and free fraction
47
How is vascular oncotic pressure affected by liver dysfunction
Impaired protein synthesis reduces plasma proteins and ultimately vascular oncotic pressure
48
What are the metabolic responsibilities of the liver
Metabolism of
1. CHO
2. Proteins
3. Lipids
49
What is the liver's role in glucose and insulin regulation
1. Utilizes glycogenesis and glycogenolysis to increase or decrease serum glucose
2. Clears insulin from circulation
50
What is the liver's response with hyperglycemia
Glycogenesis
| Glucose => glycogen (storage)
51
What is the liver's response to hypoglycemia
Glycogenolysis:
glycogen (storage) => glucose
Gluconeogenesis:
non-CHO => glucose (w/ AA, pyruvate, lactate, glycerol)
52
What does hyperglycemia stimulate the release of
insulin from pancreatic beta cells
53
What does hypoglycemia stimulate the release of
Glucagon from pancreatic alpha cells
Epi from adrenal medulla
54
How is protein processed by the liver
1. AA deamination allows proteins conversion to CHO and fats
55
What is the result of protein metabolism
CHO and fats
| Large quantities of ammonia
56
How is ammonia cleared
The liver converts it to urea which is eliminated by the kidneys
57
Metabolic processing of lipids by the liver
1. Energy storage from triglycerides
2. Energy release by beta-oxidation of fatty acids
3. Synthesis of cholesterol, phospholipids, and lipoproteins
58
What is the process of bilirubin production
old hgb goes to spleen => turned to heme => becomes unconjugated bilirubin
59
How is bilirubin transported to the liver and from where
Unconjugated bilirubin is lipophilic and transported bound to albumin from spleen to liver
60
What does the liver do to unconjugated bilirubin
conjugates bilirubin to glucuronic acid, increasing water solubility
61
What is the ultimate fate of conjugated bilirubin
excretion into bile, metabolized by intestinal bacteria and elimination in stool
62
What liver function tests indicate synthetic function issues
PT
| Albumin
63
What liver function tests indicate hepatocellular injury
AST
| ALT
64
What liver function test indicates hepatic clearance effectiveness
Bilirubin
65
What liver function tests indicates biliary duct obstruction
1. Alkaline phosphatase
2. Y glutamyl transpeptidase
3. 5'-nucleotidase
66
Which liver function test for synthetic function is very sensitive for acute hepatic injury
PT (half-life = 4-6 hrs)
67
With which hepatocellular LFTs can hepatitis and cirrhosis be considered
Result interpretation
1. Marked elevation of both = hepatitis
| 2. AST/ALT ratio >2 = cirrhosis or alcoholic liver disease
68
What are confounding factors for elevated bilirubin
Hemolysis or hematoma absorption
69
What is the most specific LFT for biliary obstruction
5'-nucleotidase
| Bile duct obstructions increases systemic levels
70
What are 3 categories of liver disease
1. Prehepatic
2. Hepatocellular injury
3. Cholestatic
71
Which LFTs are altered in prehepatic causes of liver dz
1. unconjugated bilirubin increased
72
Causes of prehepatic liver dz
hemolysis
| hematoma absorption
73
Which LFTs are altered in hepatocellular injury r/t liver dz
1. bilirubin increased
2. AST/ALT increased
3. PT increased
4. albumin dec chronic injury
5. Alk phos increased
74
What are 6 causes of liver dz r/t hepatocellular injury
1. Cirrhosis
2. Alcohol abuse
3. Drugs
4. Viral infxn
5. Sepsis
6. Hypoxemia
75
Which 7 LFTs are altered in liver dz d/t cholestatic causes
1. conj bili increased
2. AST/ALT late inc
3. PT late inc
4. Albumin late dec
5. Alk Phos always inc
6. Y glutamyl transpeptidase inc
7. 5'-nucleotidase
76
What are causes of liver dz r/t cholestasis
1. biliary tract obstruction
| 2. Sepsis
77
Which hepatitis types cause cirrhosis
B and C
| C most common
78
When does drug-induced hepatitis typically present
2-6 weeks after insult
79
What is the most common cause of acute liver failure
Acetaminophen
80
How is acetaminophen metabolism affected by overdose
The OD consumes the liver's supply of glutathione
| Toxic metabolite concentration increases causing hepatocellular injury
81
How is acetaminophen metabolized by the liver
The toxic metabolite N-acetyl-p-benzoquinoeimine is conjugated with glutathione increasing water solubility and a non-toxic compound
82
What is the treatment for acetaminophen OD
N-acetylcysteine within 8 hours
83
How does halothane cause hepatitis
20% is metabolized by the liver producing significant quantities of TFA
Hepatitis is an immune-mediated reaction to TFA
84
What is chronic hepatitis
Inflammation that exceeds 6 months
| Leads to destruction of hepatic parenchyma, cirrhosis, and ultimately causes failure
85
What is the most common cause of chronic hepatitis
alcoholism
86
How is chronic hepatitis diagnosed
Increased liver enzymes and bilirubin
| Histologic evidence of liver inflammation
87
What are 7 s/sx of chronic hepatitis
1. Jaundice
2. Fatigue
3. Thrombocytopenia
4. Glomerulonephritis
5. Neuropathy
6. Arthritis
7. Myocarditis
88
How does alcoholism contribute to liver disease
It impairs fatty acid metabolism causing fat accumulation in the liver and hepatomegaly
89
What are 2 primary goals of anesthesia in liver failure pts
1. Maintain hepatic BF
| 2. Avoid hepatotoxic drugs or inhibitors of CYP450
90
6 methods to maintain hepatic flow during anesthesia
1. Use iso or sevo
2. Avoid halothane
3. Avoid PEEP
4. Ensure normocapnia
5. Liberal IVF
6. regional anesthesia ok if no coag defects
91
What are 6 drugs to avoid in the liver dz pt that are hepatoxic
1. Acetaminophen
2. Halothane
3. Amiodarone
4. PCN
5. Tetracycline
6. Sulfonamides
92
Why is NMJ monitoring important with liver dz
1. Pseudocholinesterase activity may be decreased, prolonging succinylcholine
2. Decreased rocuronium excretion
3. Larger Vd
93
What are 4 anesthetic considerations for alcoholism
1. MAC is decreased in acutely intoxicated
2. MAC increased in chronic etoh abuser
3. Alcohol potentiates GABA increasing BZD effect
4. Alcohol inhibits NMDA receptors
94
Describe the aspiration risk of alcoholics
1. Pharyngeal reflexes impaired by etoh
| 2. Assume acute intoxication = full stomach
95
What are late s/sx of alcohol withdrawal
1. increased SNS activity
2. N/V
3. Insomnia
4. Confusion
5. Agitation
96
What are 3 treatments for early alcohol withdrawal
1. Alcohol
2. Beta-blockers
3. alpha-2 agonists
97
Treatment for delirium tremens
diazepam
| beta-blocker
98
What are deficiencies to consider in the alcoholic
Deficient vitamin B1 (thiamin) causing wernicke-korsakoff syndrome and loss of neurons in cerebellum
99
What is a treatment for recovering alcoholics
| Impact on liver
```
Tx = hepatotoxic
Impact = hepatotoxic
```
100
What is the pathology of cirrhosis
Cell death, where healthy hepatic tissue is replaced by nodules and fibrotic tissue reducing number of functional hepatocytes and sinusoids
101
How does cirrhosis affect hepatic bf
blood can't flow past the nodules causing increased vascular resistance
Leads to portal HTN
Pressure is then transmitted to splanchnic circulation
102
How does the body compensate for portal HTN
Increased vascular resistance is partially offset by collateral vessels that bypass the liver
Portosystemic shunts
103
What are the risks of postosystemic shunting
Blood bypasses the liver with drugs and toxins remaining in systemic circulation for longer
104
What qualifies as end-stage liver disease
when the liver cannot carry out synthetic, metabolic, and clearance functions
105
What is the MELD score
Predicts 90-day mortality in pts w/ ESLD
106
What factors are used for the MELD score
1. Bilirubin
2. INR
3. Serum Crt
107
How does MELD scoring predict mortality
Low risk = <10
Intermediate risk = 10-15
High risk = >15
108
What 5 factors are assessed with the modified child-pugh score
1. Albumin
2. PT
3. Bilirubin
4. Ascites
5. Encephalopathy
109
What are the classifications of the child-pugh scoring
Class A = 5-6 points = 10% mortality risk
Class B = 7-9 = 30% mortality risk
Class C = 10-15 = 80% mortality risk
110
What are 5 reasons cirrhotic pts hyperdynamic
1. dec SVR/BP => inc CO
2. inc RAAS activation => inc volume
3. inc peripheral BF (shunting) => inc SvO2
4. dec vasopressor response
5. Diastolic dysfunction
111
What CV pathology is associated with portal HTN
1. inc hepatic vascular resistance and backpressure
2. esophageal varicies
3. splenomegaly
112
What are 4 effects of ascites
1. dec oncotic pressure
2. dec protein binding
3. inc volume distribution
4. drainage => HoTN
113
What type of pulmonary defect is associated with cirrhosis
Restrictive
114
Why do cirrhotic pts have restrictive pulmonary defects
Ascites and pulm effusion decrease compliance
115
What acid-base imbalance is associated with cirrhosis
Respiratory alkalosis
| d/t compensation for hypoxemia with hyperventilation
116
How does hepatopulmonary syndrome affect pulmonary vasculature
Pulmonary vasodilation => intrapulmonary shunt (R to L) => hypoxemia
117
How does cirrhosis affect airway pressure
PAP>25 mmHg in setting of portal HTN
118
CNS effects of cirrhosis
Decreased hepatic clearance increase ammonia causing cerebral edema and ICP
119
Treatment for increased ammonia
lactulose, abx, dec protein intake
120
What are 3 autonomic effects of cirrhosis
1. inc SNS
2. inc RAAS
3. ANS reflex dysfunction
121
Renal effects of cirrhosis
dec GFR
122
How does cirrhosis decrease GFR
By renal hypoperfusion and hepatorenal syndrome
123
Result of decreased GFR from renal hypoperfusion
RAAS activation => Na+ and water retention
124
Result of decreased GFR from hepatorenal syndrome
Renal failure
125
How does splenomegaly affect coagulation status in cirrhosis
increases plt consumption
126
What is the TIPS procedure
transjugular intrahepatic portosystemic shunt
bypasses a portion of hepatic circulation by shunting blood from portal vein to hepatic vein
Goal = reduce portal pressure and minimize back pressure
127
What is the greatest risk with TIPS procedure
bleeding
128
What are preoperative anesthetic considerations p/t liver transplant
1. T&xmatch w/ plenty of blood
2. Coagulopathies affecting invasive line placement
3. TEE is safe w/ esophageal varices w/o transgastric views
4. Avoid anxiolytic premed w/ encephalopathy
5. Don't correct hyponatremia rapidly
129
What are the phases of transplant surgery
1. pre-anhepatic
2. anhepatic
3. neohepatic
130
What surgical objective occur during the pre-anhepatic phase
1. Surgical incision
2. mobilization of liver structures
3. mobilization of vascular structures
4. Isolation of bile duct
131
What are surgical objectives during anhepatic phase
1. removal of sick liver
| 2. implantation of donor liver
132
What are surgical objective during neohepatic phase
1. reperfusion of donor liver
2. anastomosis of hepatic artery
3. anastomosis of biliary structures
133
Anesthetic considerations for pre-anhepatic phase
1. increased risk for aspiration (RSI)
2. risk of significant blood loss, use fluid warmer
3. Anticipate CV instability (HoTN)
4. Lower CVP to reduce blood loss
134
Why is HoTN common during pre-anhepatic phase
d/t drainage of ascites and decompression of vascular structures compounded by blood loss
135
Fluid consideration during the pre-anhepatic stage
1. significant blood loss should be replaced with blood
2. Large volume of blood products leads to lactic acidosis, hyperkalemia, hypocalcemia
3. Crystalloid resus causes dilutional coagulopathy
136
Hemodynamic considerations during pre-anhepatic phase
1. Lower CVP reduces blood loss
2. Increase CVP before IVC clamping
3. HoTN is common d/t relief of ascites and pressure from vasculature
137
What are blood related lab goals during liver transplant
Hgb >7 g/dl
Plt >40,000
Fibrinogen >100 mg/dl
MA TEG >45
138
What are the differences in hepatic isolation that surgeons use
Bicaval = full IVC flow obstruction
Piggyback = Partial IVC flow obstruction
Venovenous bypass = cannulation of fem ven to ax vein
139
Considerations for bicaval clamp (complete IVC obstruction)
Preload reduction causing HoTN and tachycardia
Aggressive fluids can lead to overload when clamp released
140
Considerations with piggyback technique (partial IVC obstruction)
Less preload reduction
| Fewer blood products required
141
Considerations for venovenous bypass
Used if pt doesn't tolerate piggyback technique
Less hemodynamic instability and blood loss
Higher complication rate w/ air embolism or thromboembolism
142
How should preload reduction with IVC clamping be addressed in the liver transplant pt
Use sympathomimetics
143
Common problems during anhepatic phase
1. worsening coagulopathy
2. blood loss
3. lactic acidosis
4. hypoglycemia (no glycogen stores)
144
How is acidosis combated during liver transplant
NaHCO3
145
What is warm ischemic time
Begins when donor liver is removed from ice until it is reperfused
Should not exceed 30-60 minutes
146
How is serum K+ affected by donor liver perfusion
It will increase
147
What happens once donor liver is reperfused
D/t ischemia, restored BF washes out metabolic substances that accumulated
148
What are 10 complications associated with donor liver reperfusion
1. Hyperkalemia
2. hypocalcemia
3. cytokine release
4. Lactic acidosis
5. embolic debris
6. hypovolemia
7. HoTN
8. Pulmonary HTN
9. Hypothermia
10 Arrest
149
When is the risk of hyperkalemia highest during liver transplantation
What are first line treatments
During neohepatic phase
Tx=CaCl, NaHCO3
150
What are indications that the donor liver is functioning
Stabilization of serum glucose and acid-base status
151
What is the most important consideration during neohepatic phase and treatment
Post-perfusion syndrome
Tx=supportive including vasopressors, correcting lytes, correcting AB status
152
Type of induction for liver transplant pts and why
RSI
seldom NPO and increased pressures from ascites increase aspiration risk
153
Effects of obstruction of cystic duct
1. gallbladder distension
2. edema
3. risk of perf
4. jaundice
154
Effects of obstruction of common bile duct
1. cholecystitis
2. jaundice
3. pancreatitis
4. peritonitis
155
What are risk factors for increased incidence of gallstones
1. obesity
2. aging
3. rapid weight loss
4. pregnancy
5. women > men
156
S/Sx of cholecystitis
1. Leukocytosis
2. fever
3. RUQ pain
157
What is Murphy's sign
pain that is worse with inspiration in abd
158
Why does a prolonged NPO status increase likelihood of gallstone formation
Lack of CCK release contributes to biliary stasis
159
Treatment to relax sphincter of Oddi
1. glucagon
2. naloxone
3. NTG
4. Atropine
5. Glycopyrrolate
