Hepatic Biliary Systems Flashcards
Which vein is located in the posterior section of the liver?
Hepatic vein
What structure lies in the lateral section of the liver?
Middle hepatic vein
What does the cystic duct connect?
Gallbladder and Bile duct
What is the liver responsibe for synthesizing?
The Liver synthesizes glucose via gluconeogenesis, synthesizes cholesterol and proteins into hormones and vitamins, and also synthesizes coagulation factors (all except factors III, IV, VIII, vWF).
What does the liver do with excess glucose?
Stores it as glycogen
What does liver metabolize? Which enzymes in the liver are involved in metabolizing drugs?
Liver metabolizes fats, proteins, carbs and drugs. Liver uses CYP-450 and other enzymes to metabolize drugs.
What is a function of the liver in immune support?
Involved in the acute-phase of immune support
What does the liver do with iron?
Processes HGB and stores iron
What is the role of the liver in blood volume control?
Aids in volume control as a blood reservoir
What can liver dysfunction lead to?
Can lead to multi-organ failure
How many segments does the liver have?
8
What separates the right and left lobes of the liver?
Falciform Ligament
Where does bile drain through?
Bile drains through Hepatic duct into Gallbladder & common bile duct
Where does bile enter duodenum?
Ampulla of Vater
What are the three hepatic veins and where do they empty into?
right hepatic vein, middle hepatic vein, left hepatic vein. All of which empty into the IVC.
What percentage of cardiac output does the liver receive? How much blood flow does this represent in L/min.
25% of CO; 1.25-1.5 L/min
Where does the portal vein arise from? How much of the hepatic blood flow is derived from portal vein?
Splenic vein and superior mesenteric vein.
Provides 75% hepatic blood flow.
The Portal vein blood provides partially deoxygenated blood from what areas?
GI organs (Stomach, intestines), pancreas and spleen.
Where does the hepatic artery branch off from? What percent of Hepatic blood flow does hepatic artery provide?
hepatic artery branches off of the Aorta and provides 25% of the hepatic blood flow.
How is the oxygen delivery split between the portal vein and hepatic artery?
50% via Portal vein, 50% via Hepatic artery
What is the relationship between hepatic arterial blood flow and portal venous blood flow?
Heptic arterial blood flow and portal venous blood flow are inversely related
How Is hepatic blood flow regulated?
Hepatic blood flow is autoregulated. The hepatic artery dilates in response to low portal venous flow (portal venous flow 75% HBF), to keep the HBF consistent.
What does ↑Portal venous pressure lead to?
Blood backing up into systemic circulation
Splanchnic arterial tone and intrahepatic pressure contribute to what?
Portal venous pressure
What can high portal venous pressures lead to?
The blood backs up into the systemic circulation. If severe enough can lead to esophageal and gastric varices.
What is Hepatic Venous Pressure Gradient (HVPG) used to determine?
Determines the severity of portal hypertension
Regarding HVPG what signs and symptoms are related to the following levels: HVPG 1-5 mmHg, HVPG >10mmHg, HVPG >12 mmHg?
HVPG 1-5 mmHg: normal portal venous pressure
HVPG >10mmHg: clinically significant portal HTN, i.e., cirrhosis, esophageal varices
HVPG >12 mmHg: Variceal rupture
When will liver dysfunction symptoms be apparent?
Often asymptomatic until late stage liver disease.
Late stages may only have vague symptoms. (sleep disruption, decreased apetite)
For this reason we rely heavily on risk factors when liver dysfunction suspected.
What are risk factors for liver disease?
family hx, heavy ETOH, lifestyle, DM, Obesity, Illicit Drug use, Multiple partners, Tattoos, Transfusion (more so for transfusions in the 1980’s before blood was screened)
What are common physical examination findings in liver disease?
Pruritis, Jaundice, Ascites, Asterixis (flapping tremor), Hepatomegaly, Splenomegaly, Spider nevi (spider veins on face)
What blood tests are used to assess hepato-biliary function?
BMP, CBC, PT/INR, AST/ALT, Bilirubin, alkaline phosphatase, gamma glutamyl-transferase (GGT)
Which enzyme is most liver-specific?
Alanine aminotransferase (ALT)
present mainly in the cytosol of the liver and in low concentrations elsewhere.
Which imaging methods are commonly used to evaluate hepato-biliary issues?
Ultrasound, Doppler U/S (portal blood flow) CT, MRI
What are the 3 groups of Hepatobiliary Disease
Hepatocellular Injury
- high AST/ALT
Reduced synthetic function
- low albumin, high PT/INR (low clotting factors)
cholestasis
- high Alk phos, GGT & bilirubin
What are the characteristics of Hepatocellular injury
increased AST/ALT (hepatocyte enzymes)
- Acute Liver Failure (AST:ALT x25 elevated)
- Alcoholic liver disease (AST:ALT usually 2:1)
- Non-alcoholic fatty liver disease: (AST:ALT usually 1:1)
What is cholelithiasis also known as?
Gallstones
What are the risk factors for cholelithiasis?
Obesity, high cholesterol, diabetes, pregnancy, female gender, family history
What are the common symptoms of cholelithiasis? What percent of patients with gallstones are asymptomatic?
RUQ pain, referred to shoulders, N/V, indigestion, fever in acute obstruction.
80% are asymptomatic
What is the treatment for cholelithiasis?
IV fluids, antibiotics, pain management, Lap Cholecystectomy (surgical removal of gall bladder)
Where does the bile flow through s/p cholecystectomy?
All bile flows through the common bile duct straight into the duodenum after cholecystectomy.
What is choledocolithiasis?
A stone obstructing the common bile duct l/t biliary colic.
What is the initial presentation of choledocholithiasis?
N/V, cramping, RUQ pain
What are the symptoms of cholangitis?
Fever, rigors, jaundice
What is the treatment for choledocolithiasis?
Endoscopic stone removal via ERCP (Endoscopic Retrograde Cholangiopancreatography)
How is the stone retrieved during an ERCP?
Guidewire fed through Sphincter of Oddi into Ampulla of Vater then retrieved form pancreatic duct or common bile duct.
What is commonly used to manage Oddi Spasm during ERCP?
Glucagon 2mg IV slow
What is the preferred patient positioning during ERCP?
Patient is prone, head to patients right, tape ETT to left.
What is the function of the gallbladder?
Stores bile
What connects the gallbladder to the common bile duct?
Cystic duct
What are solid particles that form in the gallbladder called?
Gallstones
What is bilirubin? How is unconjugated bilirubin transported to the liver?
Bilirubin is the end product of heme-breakdown.
Unconjugated bilirubin is transported to the liver bound to albumin.
What happens to bilirubin in the liver?
Conjugated into its water soluble direct state then excreted into bile
What causes unconjugated (indirect) hyperbilirubinemia?
Imbalance between synthesis and conjugation (liver having issues conjugating lol)
What causes conjugated (direct) hyperbilirubinemia?
Obstruction leading to reflux of conjugated bilirubin
What are the 5 most common types of viral hepatitis?
A, B, C, D, E
Which types of viral hepatitis are chronic? Which is most chronic? How are these transmitted?
B & C are chronic. C is the most chronic (75% will develop chronic hepatitis).
B &C are both bloodborne and have long incubation periods.
Which type of viral hepatitis is most common in the US requiring liver transplant?
Hepatitis C Virus (HCV)
What is the standard 12-week treatment for Hepatitis C Virus (HCV)?
Sofosbuvir/Velpatasvir
What percentage of genotype 1A/1B clearance does Sofosbuvir/Velpatasvir provide?
98-99%
What are some common symptoms of acute and chronic hepatitis?
Fatigue, jaundice, nausea or vomiting, lack of appetite, bleeding/bruising, dark urine.
What are potential complications of chronic HCV infection?
Cirrhosis, Hepatocellular Carcinoma
What is the most common cause of cirrhosis?
Alcoholic Liver Disease (ALD)
What is the top indication for liver transplants in the US? What is the national prevalence of liver transplant for ALD?
Alcoholic Liver Disease is the top indication for liver transplants in the US. The prevalence of liver transplant for ALD is 2%.
What is the initial presentation of ALD?
Asymptomatic
What is the main focus of treatment for ALD?
Alcohol abstinence
At what platelet count does ALD management require a blood transfusion?
<50,000
Symptoms of alcoholic liver disease
Symptom of alcoholic liver disease associated with immune response
Parotid gland hypertrophy
(large the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches.)
Lab value indicating red blood cells are larger than normal in alcoholic liver disease
↑Mean (cell) corpuscular volume (MCV)
Which enzyme’s increase is a specific marker for alcoholic liver disease?
↑MCV, ALT/ALT (2:1), ɣ-glutamyl-transferase (GGT), bilirubin.
What might occur 24-72 hours after stopping alcohol in someone with alcoholic liver disease?
Symptoms of ETOH withdrawal
What is Non-Alcoholic Fatty Liver Disease?
Hepatocytes contain >5% fat
What are some risk factors for Non-Alcoholic Fatty Liver Disease?
Obesity, Insulin resistance, DM2, Metabolic syndrome
How does Non-Alcoholic Fatty Liver Disease progress?
Progresses to Non-steatohepatitis (NASH), then cirrhosis, and finally hepatocellular carcinoma
Aside from Alcoholic Liver Disease what are other leading causes of liver transplant in the US?
NAFLD & NASH
What is the gold standard in distinguishing NAFLD from other liver diseases?
Liver biopsy