Vascular Anesthesia Pt.2 (Exam II) Flashcards
How much of CO (at rest) goes to the liver?
25%
What major vessels supply oxygenated blood to the liver? What percentage is provided by each?
Hepatic Artery: 30%
Portal Vein: 70%
What type of cells make up 75 - 80% of the liver’s cellular volume?
Hepatocytes
What is the functional unit of the liver?
Hepatic Lobule
What three structures make up the portal triad?
- Portal vein
- Hepatic artery
- Bile Duct
In what zone does aerobic metabolism take place in the hepatic lobules?
- Zone 1 — Periportal (outermost)
What zone of the liver is the major site of aerobic metabolism?
Zone 1
What vascular structure is hepatic zone 3 located next to?
Hepatic Vein
What hepatic zone is the site of glycolysis/glucuronidation?
Zone 3
What hepatic zone is most susceptible to ischemia?
Zone 3
What type of hepatic cells are characterized by their dormancy and only responding to cytokines during inflammatory periods?
Hepatic Stellate Cells
8 - 10 % of liver cells.
How would compensated cirrhosis compare to uncompensated cirrhosis?
Compensated:
- No portal HTN
- No GI Varices
- No Liver dysfunction
Uncompensated:
- Ascites
- Portal HTN
- Varices & hemorrhage
- Hepatic Encephalopathy
How does the body attempt to compensate for portal hypertension? What is the end result?
Release of NO & angiogenic factors → Vasodilation & new vessels → esophageal varices.
Which two veins receive much increase venous flow due to portal hypertension?
- Azygos vein
- Hemiazygos vein
Contribute to esophageal varices.
Where are the azygos & hemiazygos veins located? What areas do they receive venous flow from?
- Located on either side of vertebral column
- Drain & thoracic & abdominal walls
How can esophageal varices bleeds be prevented?
- non-selective β blocker
- Endoscopic band ligation
How is active bleeding of esophageal varices managed?
- Endoscopic banding
- Sclerotherapy
- Octreotide (Somatostatin)
How does Somatostatin treat variceal bleeding?
- Vasoconstriction
- ↓ portal HTN
- Inhibits glucagon release
What does glucagon do to abdominal vessels?
Glucagon = Splachnic dilation
What is a TIPS?
Transjugular Intrahepatic Portosystemic Shunt
What two vessels are connected via TIPS to control portal HTN?
Hepatic Vein & Portal Vein