Liver Function Tests and Anesthesia Effect on Hepatic Fx

Question 1

tests that measure liver synthetic function include (4)

Answer 1

serum albumin
prothrombin time (PT/INR)
cholesterol
pseudocholinesterase

Question 2

can lab tests be normal in the presence of cirrhosis

Answer 2

yes because the liver has a large functional reserve

Question 3

liver abnormalities are typically divided into

Answer 3

parenchymal DO’s (hepatocellular dysfunction)

obstructive DO’s (biliary excretion)

Question 4

normal total bilirubin

Answer 4

<1.5mg/dL (includes unconjugated and conjugated)

Question 5

total bilirubin in the presence of jaundice

Answer 5

usually evident when total bilirubin >3mg/dL

Question 6

a predominantly conjugated hyperbiliruminemia (>50%) is associated with increased urobilinogen and may reflect __________, __________ and lead to _________

Answer 6

intrahepatic cholestasis or extra hepatic biliary obstruction
hepatocellular dysfunction

Question 7

a primarily unconjugated hyperbilirubinemia may be seen with

Answer 7

hemolysis orr congenital or acquired defects in bilirubin conjugation

Question 8

which type of bilirubin is toxic to cells

Answer 8

conjugated bilirubin

Question 9

transaminases

Answer 9

enzymes released into the circulation as a result of hepatocelluar injury

Question 10

two commonly measured serum aminotransferases

Answer 10

aspartate aminotansferase (AST, AKA SGOT)
alanine aminotrransferase (ALT, AKA SGPT)

Question 11

aspartate aminotransferase

Answer 11

present in many tissues in addition to liver including heart, skeletal muscle, kidneys and is therefore considered nonspecific

Question 12

alanine aminotransferase

Answer 12

present primarily in liver rand is therefore considered specific

Question 13

normal AST and ALT levels

Answer 13

<35-45IU/L

Question 14

mild elevations (<300IU/L) seen with

Answer 14

cholestasis or metastatic dx

Question 15

serum alkaline phosphatase produced by (5) and excreted into

Answer 15

liver, bone, small bowel, kidneys, and placenta and is excreted into the bile

Question 16

normal serum alk phos

Answer 16

25-85IU/L

Question 17

most of the circulating alk phos comes from

Answer 17

bone

Question 18

more alk phos is synthesized and released into the circulation in the presence of this pathology

Answer 18

biliary obstruction

Question 19

elections up to 2x normal alk phos is associated with

Answer 19

hepatocellular injury or hepatic metastatic disease

Question 20

normal serum albumin and half life

Answer 20

3.5-5.5g/dL

long half life, can be initially normal with acute liver disease

Question 21

serum albumin <2.5g/dL generally indicative of

Answer 21

chronic liver disease
acute stress
malnutrition

Question 22

two reasons hypoalbuminemia can occur that are not of liver etiology

Answer 22

nephrotic syndrome (albumin loss in urine)
enteropathy with protein loss (GI loss of albumin)

Question 23

normal whole blood NH3 (ammonia)

Answer 23

47-65mmol/L or 80-110mg/dL

Question 24

increased NH3 usually indicative of

Answer 24

hepatic urea synthesis disrruption

Question 25

marked elevations of NH3 usually reflective of

Answer 25

severe hepatocelluar damage

Question 26

normal PT and significant finding

Answer 26

11-14 seconds | >3-4 seconds from control is significant and corresponds to an INR of 1.5

Question 27

PT measures the activity of

Answer 27

fibrinogen, factor 2, V, VII, X

Question 28

factor VII

Answer 28

has short half life therefore the PT is useful in evaluating hepatic synthetic function of patients with a cute or chronic liver idsease

Question 29

what do you suspect with the PT does not correct within 24 hours of vitamin K administration

Answer 29

severe liver disease

Question 30

hepatic blood flow and anesthesia

Answer 30

usually decreased during general and regional anesthesia due to indirect and direct effects of anesthetic agents themselves, type of ventilation, surgical procedure

Question 31

``` diagnostic feature: pre hepatic (bilirubin overload) bilirubin: aminotransferase enzymes alkaline phosphatase prothrombin time albumin causes ```

Answer 31

diagnostic feature: pre hepatic (bilirubin overload) bilirubin: increased (unconjugated fraction) aminotransferase enzymes: no change alkaline phosphatase: no change prothrombin time: no change albumin: no change causes: hemolysis, hematoma reabsorption, bilirubin overload from whole blood

Question 32

``` diagnostic feature: intra hepatic (parenchymal/hepatocellular dysfunction) bilirubin: aminotransferase enzymes alkaline phosphatase prothrombin time albumin causes ```

Answer 32

bilirubin: increased (conjugated fraction) aminotransferase enzymes: markedly increased alkaline phosphatase: no change to slightly increased prothrombin time: prolonged albumin: decreased causes: viruses, drugs, sepsis, arterial hypoxemia, congestive heart failure, cirrhosis

Question 33

``` diagnostic feature: post hepatic (cholestasis) bilirubin: aminotransferase enzymes alkaline phosphatase prothrombin time albumin causes ```

Answer 33

bilirubin: increased (conjugated fraction) aminotransferase enzymes: normal to slightly increased alkaline phosphatase: markedly increased prothrombin time: no change to prolonged albumin: no change to decreased causes: stones, cancer, sepsis

Question 34

volatile agents and portal hepatic blood flow

Answer 34

all volatile agents decrease portal blood flow. greatest with halothane, least with isoflurane

Question 35

anesthetic agent and hepatic blood flow

Answer 35

all anesthetic agents indirectly decrease hepatic blood flow in proportion to any decrease in CO or MAP. decrease in CO also reduces hepatic BF by reflex SNS stimulation and vasoconstriction of arterial and venous splanchnic vasculature

Question 36

spinal and epidural anesthesia decrease hepatic BF primarily by

Answer 36

decreasing BP

Question 37

GA usually decreases hepatic BF by

Answer 37

decreasing BP, CO, and resulting SNS stimulation

Question 38

ways mechanical ventilation decrease hepatic BF

Answer 38

controlled PPV with high mean airway pressures decrease venous return and CO PEEP accentuates these effects

Question 39

spontaneous ventilation and hepatic BF

Answer 39

may be most advantageous for maintaining hepatic BF

Question 40

hypoxemia and hepatic BF

Answer 40

produces increased SNS stimulation and decreases hepatic BF

Question 41

surgical procedures on or near liver and hepatic BF

Answer 41

can reduce hepatic BF up to 60% most likely by DNS activation, local vascular reflexes, direct compression of vessels of hepatic circulation

Question 42

drugs that decrease hepatic BF

Answer 42

Beta blockers alpha agonists vasopressin

Question 43

drug that can increase hepatic BF

Answer 43

low dose dopamine

Question 44

endocrine stress response secondary to fasting and surgical stress increases levels of

Answer 44

catecholamines, glucagon, cortisol

Question 45

endocrine stress rrersponse can at least partially blunted by

Answer 45

regional anesthesia deep general pharmacological block of SNS

Question 46

CHO and protein stores are mobilized resulting in

Answer 46

hyperglycemia and negative nitrogen balance

Question 47

opioids that can cause spasm of sphincter of odd and increase biliary pressure in order of effect

Answer 47

``` fentanyl/alfentanil (short lived) morphine meperidine butorphanol nalbuphine ```

Question 48

two drugs to relieve opioid induced sphincter spasm

Answer 48

naloxone and glucagon

Question 49

most common cause of postoperative jaundice

Answer 49

over production of bilirubin due to reabsorption of large hematoma or RBC breakdown following transfusion

Question 50

hepatitis has been associated with these halogenated anesthetics

Answer 50

methoxyflurane enflurane isoflurane

Question 51

hepatitis has NOT been associated with these halogenated anesthetics

Answer 51

sevoflurane, desflurane

Question 52

risk factors associated with halothane hepatitis

Answer 52

middle aged obese female repeat exposure, particularly within 28d