Hepatobiliary

Question 1

Why is it important for anesthesiologists to have a firm grasp of the anatomy, physiology, and pathophysiology of the liver?

Answer 1

It is important because hepatic dysfunction has profound effects on all organ systems and introduces significant challenges to anesthetic management.

Question 2

What percentage of cardiac output does the liver receive, and what are the contributions of the hepatic artery and portal vein to the liver’s blood supply?

Answer 2

The liver receives approximately 25% of the resting cardiac output. The hepatic artery contributes 25% to 30% of the blood supply, while the portal vein accounts for 70% to 75%.

Question 3

What is the basic structural unit of the liver parenchyma and what does it consist of?

Answer 3

The basic structural unit of the liver parenchyma is the liver lobule, consisting of a portal canal at each corner and a central vein at the center.

Question 4

What is the role of the portal triad within the liver lobule?

Answer 4

The portal triad consists of a bile ductule, hepatic arteriole, and portal venule, playing a key role in the liver’s blood and nutrient flow.

Question 5

How do hepatocytes contribute to liver function, and what zones are they divided into based on their proximity to the portal triad?

Answer 5

Hepatocytes make up 75% to 80% of the liver’s cellular volume, are responsible for various metabolic functions, and are divided into three zones based on their proximity to the portal triad.

Question 6

What is the significance of hepatic stellate cells (HSCs) in liver pathology?

Answer 6

Hepatic stellate cells (HSCs) play a significant role in liver fibrosis and inflammation, particularly in response to liver injury.

Question 7

What role do myeloid cells, specifically Kupffer cells, play in liver immunity?

Answer 7

Kupffer cells are resident macrophages in the liver that play crucial roles in innate and adaptive immunity, detoxifying pathogens, and regulating hepatic inflammation.

Question 8

How do hepatic myeloid-derived suppressor cells (H-MDSCs) affect the immune response in the liver?

Answer 8

Hepatic myeloid-derived suppressor cells (H-MDSCs) suppress the immune response in the liver, helping to reduce inflammation and limit tissue injury.

Question 9

How do lymphocytes in the liver contribute to maintaining hepatic homeostasis and responding to foreign substances?

Answer 9

Lymphocytes in the liver, including NK cells and T cells, contribute to hepatic homeostasis by promoting tolerance to foreign substances and expanding the clearance of foreign substances.

Question 10

What is the primary source of oxygenated blood to the liver?

Answer 10

The portal vein.

Question 11

What percentage of the liver’s resting cardiac output does the hepatic artery supply?

Answer 11

Approximately 25% of the resting cardiac output.

Question 12

What percentage of the liver’s blood supply does the portal vein provide?

Answer 12

70% to 75%.

Question 13

What percentage of the liver’s total cellular volume do hepatocytes make up?

Answer 13

75% to 80%.

Question 14

What are the primary responsibilities of hepatocytes?

Answer 14

Drug, protein, carbohydrate, lipid, and heme metabolism.

Question 15

How are hepatocytes polarized and divided into different zones?

Answer 15

Based on their proximity to the portal triad.

Question 16

What cells suppress the immune response in the liver?

Answer 16

Hepatic myeloid-derived suppressor cells.

Question 17

What do these cells reduce in acute hepatitis?

Answer 17

Inflammation and limit tissue injury.

Question 18

What may happen when these cells are associated with certain pathologic conditions?

Answer 18

They may promote viral persistence.

Question 19

What is the main function of the liver in protein metabolism?

Answer 19

Synthesis and catabolism of proteins, amino acids, and peptides.

Question 20

What percentage of circulating proteins does the liver synthesize?

Answer 20

80% to 90%.

Question 21

What is the predominant protein produced by the liver?

Answer 21

Albumin.

Question 22

What is GST and why is it a useful marker?

Answer 22

GST is a sensitive test for liver injury, with a half-life of 60-90 minutes. It helps monitor for disease recovery in early stages of liver injury.

Question 23

How is alkaline phosphatase (AP) related to cholestatic diseases?

Answer 23

Elevated AP from a hepatobiliary source is most commonly due to cholestatic diseases and typically manifests as an increase to 2 to 4 times the upper limit of normal.

Question 24

What is the significance of elevated LDH in liver injury?

Answer 24

Extremely elevated LDH signifies massive hepatocyte damage, usually from drug-induced hepatotoxicity.

Question 25

What does serum bilirubin measure and differentiate?

Answer 25

Serum bilirubin measures the water-soluble form of bilirubin and helps differentiate the clinical cause of hyperbilirubinemia, indicating whether it is conjugated or unconjugated.

Question 26

How is the serum albumin concentration used in liver disease evaluation?

Answer 26

The serum albumin concentration is used to evaluate chronic liver disease and hepatocellular function.

Question 27

How does severe liver dysfunction affect prothrombin time (PT) and INR?

Answer 27

Severe liver dysfunction prolongs PT and increases INR, reflecting a decreased ability of the liver to synthesize clotting factors.

Question 28

What is the role of AFP in diagnosing liver diseases?

Answer 28

AFP is a glycoprotein used to monitor HCC disease progression and response to treatment.

Question 29

What is the purpose of noninvasive serum testing for fibrosis?

Answer 29

Noninvasive serum testing for fibrosis uses combinations of standard tests such as aminotransferases, platelet count, and INR to assess the severity of fibrosis.

Question 30

What is the significance of ICG in liver function tests?

Answer 30

ICG is used in liver function tests to estimate hepatic blood flow and predict outcomes after partial liver resection or transplantation.

Question 31

What are clearance techniques based on and what do they measure?

Answer 31

Clearance techniques are based on the Fick principle and measure the hepatic blood flow by the rate of disappearance of substances cleared by the liver.

Question 32

What is the main function of indicator dilution techniques?

Answer 32

Indicator dilution techniques measure hepatic blood flow even in the setting of liver dysfunction by creating an indicator dilution curve with a radiolabeled indicator.

Question 33

How can radiologic methods assist in diagnosing liver diseases?

Answer 33

Radiologic methods like ultrasound, CT, and MRI help diagnose signs of cirrhosis, portal hypertension, and assess the severity of liver lesions.

Question 34

What are the implications of chronic cholestasis for the anesthesiologist?

Answer 34

Chronic cholestasis leads to increased serum levels of AP and GGT, fatigue, pruritus, and dark urine.

Question 35

What is the most common presenting symptom of primary biliary cirrhosis (PBC)?

Answer 35

Fatigue and pruritus.

Question 36

What percentage of patients with primary sclerosing cholangitis (PSC) are asymptomatic at diagnosis?

Answer 36

Approximately half of the patients.

Question 37

What are the key risk factors associated with cirrhosis?

Answer 37

Alcoholic liver disease, hepatitis C, and nonalcoholic steatohepatitis.

Question 38

What complications can arise from portal hypertension?

Answer 38

Ascites, spontaneous bacterial peritonitis, and variceal hemorrhage.

Question 39

What are the management strategies for patients with compensated cirrhosis?

Answer 39

Monitoring portal hypertension, preventing variceal bleeding, and managing ascites.

Question 40

What is the significance of an HVPG greater than 10 mm Hg in cirrhotic patients?

Answer 40

HVPG greater than 10 mm Hg indicates a higher risk of variceal bleeding and hepatic decompensation.

Question 41

What is the first-line treatment for variceal hemorrhage in patients with cirrhosis?

Answer 41

Nonselective beta-blockers or endoscopic variceal ligation.

Question 42

What is the primary cause of renal failure in patients with end-stage liver disease (ESLD)?

Answer 42

Acute kidney injury, often precipitated by hypovolemia or infections.

Question 43

What are the grades of hepatic encephalopathy (HE) according to the West Haven criteria?

Answer 43

I - Trivial lack of awareness; II - Lethargy; III - Somnolence; IV - Coma.

Question 44

What is the primary treatment for portopulmonary hypertension (PoPH)?

Answer 44

Phosphodiesterase-5 inhibitors and endothelin receptor antagonists.

Question 45

What is the most common primary liver malignancy?

Answer 45

Hepatocellular carcinoma (HCC).

Question 46

How do volatile anesthetics affect hepatic blood flow?

Answer 46

They reduce hepatic arterial blood flow, affecting total hepatic blood flow.

Question 47

What is the role of xenon in anesthesia for patients with liver dysfunction?

Answer 47

Xenon is an inert gas with favorable anesthetic properties and minimal hepatic metabolism.

Question 48

How should patients with cirrhosis be evaluated preoperatively?

Answer 48

Assess severity of liver disease, presence of comorbid conditions, and evaluate for anemia, thrombocytopenia, and coagulopathy.

Question 49

What is the purpose of the Transjugular Intrahepatic Portosystemic Shunt (TIPS) procedure?

Answer 49

To create a shunt between the portal and hepatic venous systems to reduce portal hypertension.

Question 50

What are the major complications of TIPS?

Answer 50

Intra-abdominal hemorrhage, hepatic encephalopathy, and TIPS failure.

Question 51

What should the preoperative assessment for TIPS include?

Answer 51

Assessment of liver dysfunction, associated morbidity, and patient's ability to tolerate the procedure.

Question 52

What are the most common indications for hepatic resection?

Answer 52

Treatment of secondary metastases and primary hepatic malignancies.

Question 53

What are the factors impacting morbidity and mortality in hepatic resection?

Answer 53

Extent of the resection, patient history, and comorbidities.

Question 54

What is the impact of laparoscopic hepatic resection compared to open liver resection?

Answer 54

Laparoscopic resection is associated with lower rates of complications and faster recovery.

Question 55

What should be focused on during the preoperative evaluation of liver disease?

Answer 55

Severity of liver disease and presence of comorbid conditions.

Question 56

What is the purpose of portal vein embolization (PVE)?

Answer 56

To induce atrophy and hypertrophy of liver lobes to ensure adequate liver mass post-resection.

Question 57

What are the strategies for minimizing blood loss during liver resection?

Answer 57

Use of techniques like low CVP, normovolemic hemodilution, and intraoperative autologous blood salvage.

Question 58

How is low central venous pressure (CVP) related to blood loss management?

Answer 58

CVP less than 5 mm Hg is associated with reduced blood loss and need for transfusion.

Question 59

What is the benefit of clamping the infrahepatic IVC?

Answer 59

It minimizes hemorrhage in patients with elevated CVP during hepatic surgery.

Question 60

What is the role of tranexamic acid (TXA) in blood loss management?

Answer 60

TXA reduces blood loss and the need for transfusions.

Question 61

What should be considered in anesthetic management for liver resection?

Answer 61

Consideration of comorbidities, surgical approach, and need for vascular occlusive maneuvers.

Question 62

How is rapid sequence induction beneficial in patients with significant ascites?

Answer 62

It maintains general anesthesia, considering the increased risk of aspiration.

Question 63

What is the significance of stroke volume variation (SVV) in volume management?

Answer 63

SVV can be used to predict blood loss and guide fluid management.

Question 64

How does hepatic resection impact coagulation?

Answer 64

Hepatic resection can lead to significant hemorrhage and development of coagulopathy.