Hepatic and Biliary Systems Flashcards
Which coagulation factors does the liver NOT synthesize?
3, 4, 8, vWF
How many segments is the liver split into?
8 segments
What seprates the R and L lobes of the liver? Which lobe is bigger?
Falciform Ligament; Right lobe is bigger
Which vein and artery branch into each segment to perfuse the liver?
Portal Vein
Hepatic Artery
What are the names of the 3 hepatic veins and where do they empty into that perfuse the liver?
Right, Middle, Left Hepatic Veins
Empty into the IVC
What vessel do the bile ducts travel among?
Portal Veins
Bile drains through the _______ into the _____ and ______
Bile drains through the hepatic duct into the gallbladder and common bile duct
Through what structure does bile enter the duodenum?
Ampulla of Vater
How much % of the CO does the liver receive?
25% of CO
**Highest proportionate **CO of all the organs
How much of the hepatic blood flow does the Portal vein provide?
75% of Hepatic blood flow
What 2 veins does the portal vein arise from?
Splanchnic Vein & Superior mesenteric vein
Is the Portal vein oxygenated or deoxygenated?
**Partially deoxygenated **after perfusing GI, Pancreas and spleen
How much of the hepatic blood flow does the Hepatic Artery provide?
25% of HBF (Branches off aorta)
Does the portal vein or hepatic artery provide more O2 delivery to the liver?
The portal vein and hepatic artery each supply 50% of the oxygenation
The portal vein is partially deoxygenated
Hepatic artery and portal vein blood flow are _____ related
Inversely
Hepatic blood flow is….
Autoregulate
What would the hepatic artery do if portal venous blood flow was low?
Hepatic artery would dilate
What does the portal venous pressure most closely reflect?
Splanchnic Arterial Tone & Intra-hepatic pressure
What is the consequence of increased portal venous presure?
Esophageal Varicies & Gastric Varicies
Blood backs up into the systemic circulation
What is the Hepatic venous pressure gradient used for and what is a normal value?
Severity of portal hypertension
Normal gradient: 1-5
What does a HVPG of >10 indicate?
Significant Portal HTN (Cirrhosis, esoph. varicies)
What does a HVPG of >12 indicate?
Variceal Rupture
Do risk factors or symptoms offer a greater degree of suspicion for liver function?
Risk Factors
What would you see on physical exam for someone with liver disease?
- Pruritis (Bilirubin build up)
- Jaundice
- Ascites
- Asterixis (Flapping tremor)
- Hepatomegaly
- Splenomegaly
- Spider Nevi (Spider vessels s/e of venous congestion)
What are the 2 major liver-specific Hepato-biliary function tests?
Aspartate Aminotransferase (AST)
Alanine Aminotransferase (ALT)
What are the AST/ALT Labs for Acute liver failure?
AST/ALT elevated 25x for ALF (not chronically trending up)
What are the AST/ALT Labs for alcoholic liver disease?
AST:ALT ratio 2:1 (AST is usually higher)
What are the AST/ALT Labs for Non-Alcoholic Fatty liver disease?
AST:ALT ratio 1:1
What will the labs look like for hepatocellular injury?
Increased AST/ALT
Decreased Albumin
Increased PTT
Increased Conjugated Bilirubin
What is cholestasis?
Sluggish/lack of bile flow from the liver
What will the labs look like for cholestasis?
Normal AST/ALT
Increased Alkaline Phosphate
Increased GGT
Increased Conjugated bilirubin
What are gallstones called?
Cholelithiasis
What is the function of the gallbladder?
Gallbladder stores bile to deliver it during meals (in boluses)
What is the function of the CBD?
CBD secretes bile directly into the duodenum
What is the function of bile?
Breakdown fatty acids for absorption
Risk Factors for gallstones?
- Obesity
- Inc. Cholesterol (Stones might be made out of cholesterol)
- DM
- Pregnancy
- Female
- Family Hx
What percent of gallstones are asymptomatic?
80%
If you have gallstones, where will you experience pain?
RUQ pain referred to shoulders
What type of GI symptoms will gallstones produce?
Nausea, Vomiting, Fever, Indigestion (can’t break down fatty acids therefore no moving food forward)
What is the treatment for gallstones?
Conservative Tx
-IVF to restore flow
-ABX
-Pain Management
What is Choledocolithiasis?
When a stone is obstructing the CBD causing biliary colic. The bile refluxes back and can’t move forward
What are the initial s/s of choledocolithiasis?
N/V, Cramp, RUQ pain, Cholingitis (Fever, rigors, jaundice)
What is the treatment for choledocolithiasis?
Endoscopic removal of the stone via ERCP
What path does a surgeon take during an ERCP (Endoscopic Retrograde Cholangiopancreatography)?
Sphincter of oddi –> Ampula of Vater –> to retrieve stone from pancreatic duct or CBD
What position is someone in for a ERCP?
Gen. Anesthesia:
Prone
Head to patient’s Right
ETT taped to the patient’s left
What medication can you give for a oddi spasm?
1 mg Glucagon
What is bilirubin?
End product of hemaglobin Breakdown
Unconjugated bilirubin or “indirect” bilirubin is protein bound to ____, transported to the ____, conjugated into its ______ _______ state, and excreted in the ______
Albumin, Liver, Water soluble, bile
What is Unconjugated (Indirect) Hyperbilirubinemia?
Imbalance between bilirubin synthesis and conjugation
What is Conjugated (Direct) Hyperbilirubinemia?
Caused by an obstruction resulting in reflux of conjugated bilirubin into the circulation
Which Viral hepatitis (ABCDE) is more chronic?
B & C
Which type of hepatitis is the most common, requiring liver transplant in the US
HCV
HCV treatment is based on
Genotype (75% is type 1)
Stage
+/- cirrhosis (irreversible when cirrhosis is in the picture)
Most HCV can be cured by what drug?
Sofosbuvir/Velpatasvir
Symptoms of HCV
- Fatigue
- Jaundice
- N/V
- Lack of appetite
- Bleeding/Bruising
- Dark urine
Which hepatitis is bloodborne?
B & C
Is Hep. B or C more likely to be chronic in adults?
C is more chronic (75%)
What is the incubation period of Hep. B and C?
B: 4 months
C: 1-2 months
What is mortality for Hep B and C?
B: Low mortality
C: Unknown mortality
Alcoholic liver disease is the most common cause of what?
Cirrhosis
ALD is also top indicator of liver transplants in the US
What platelet count requires blood transfusion for ALD patient?
PLT < 50,000
When do alcohol withdrawal symptoms show up?
24-72 hrs after stopping
Symptoms of ALD?
- Malnutrition
- Muscle wasting
- Parotid gland hypertrophy
- Jaundice
- Thrombocytopenia
- Ascites
- Hepatosplenomegaly
- Pedal Edema
- ETOH withdrawal
What are the lab values in ALD?
Increased: MCV, Liver enzymes, GGT, Bilirubin
When is NAFLD diagnosed?
Hepatocytes > 5% fat
Risk Factors for NAFLD?
- Obesity
- Insulin Resistance
- DM2
- Metabolic Syndrome
What is the gold standard for distinguishing NAFLD from other liver diseases?
Liver biopsy
Tx for NAFLD?
Fat Reduction (Diet and Exercise)
What are the main differences between NAFLD and AFLD?
NAFLD can progress for a long time, AFLD advances to cirrhosis very fast
What % of people have NAFLD, regardless of weight?
25%
Who is affected by autoimmune hepatitis and what do the labs look like? What is the treatment?
- Women are more affected
- Lab: + autoantibodies and Increased Gammaglobinemia
AST/ALT 10-20x normal - Treatment: Steroids, Azathioprine
60-80% achieve remission, relapse common then liver transplant
What is the most common cause of drug induced liver injury?
Acetaminophen OD
What is Wilson’s Disease?
Autosomal Recessive Dx - Impaired copper metabolism
Copper buildup leads to oxidative stress in the liver, basal ganglia and cornea
Symptoms of wilson’s dx?
Asymptomatic to sudden onset liver failure with Neuro and psychiatric manifestations
Treatment of Wilson’s Dx?
Copper chelation therapy and oral zinc to bind the copper in GI tract
What is a-1 antitrypsin protein’s function?
Protects the liver and lungs from neutrophil elastase which is an enzyme that disrupts lung & liver tissue
A-1 antitrypsin deficiency is a ____ disorder
1 genetic cause of liver transplant in children
Rare resulting in a-1 AT deficiency and decreased protection from neutrophil elastase
Treatment for a1AT deficiency?
Pooled a-1 AT is good for pulmonary effects, but does not help with liver disease
What is the only curative Tx for liver disease in a-1 AT deficiency?
Liver Transplant
What is hemochromatosis?
Excessive intestinal absorption of iron (from blood/iron transfusions) resulting in iron accumulation in organs and damage to tissues
What is presenting s/s of hemochromatosis?
- Cirrhosis
- HF
- DM
- Adrenal insufficiency
- Polyarthropathy
Labs in hemochromatosis?
Increased AST/ALT
Increased Transferrin Saturation
Increased Ferritin
What is primary sclerosing cholangitis?
Autoimmune, chronic inflammation of the larger bile ducts
Male > Female onset in the 40’s
Fibrosis in the biliary tree leads to strictures and cirrhosis
What are s/s of primary sclerosing cholangitis?
Itching & deficiency of fat-soluble vitamins (ADEK)
Dx and Tx for PSC?
Dx: ERCP that shows the strictures with dilated bile ducts
Tx: No drugs, liver transplant but recurrence is common after transplant due to autoimmune nature
What is primary Biliary Cholangitis?
Destruction of bile ducts with portal inflammation and cholestasis leading to liver scarring, fibrosis and cirrhosis
Females > males dx in middle ages
Caused by exposure to env. toxins
Only treatment for primary biliary cholangitis?
Bile acids slow progression but are invasive to stomach lining
How can you tell the difference between PSC and PBC?
Primary sclerosing is intrahepatic and extrahepatic while primary biliary is intrahepatic only
What characterizes acute liver failure?
Massive hepatocyte necrosis leading to cellular swelling and membrane disruption
RUQ pain, cerebral edema, encephalopathy, jaundice
What characterizes cirrhosis?
Final stage of liver disease (replacement of normal tissue with scar tissue)
-Elevated Labs, Thrombocytopenia
-Asymptomatic in early stages
-Normal liver parenchyma with scar tissue
What is the most common complication of cirrhosis?
Ascites
What is ascites?
Portal HTN leads to increased blood volume and peritoneal fluid accumulation
Tx: Low salt and albumin
What can “Put a bandaid on things for ascites and cirrhosis?”
TIPS Procedure (transjugular intrahepatic portosystemic shunt)
-Reduces Portal HTN and ascites
what is the most common infection r/t cirrhosis?
Bacterial peritonitis from ascites
Varicies are present in ___ % of cirrhosis patients with _____ being the most lethal complication
50%; Hemorrhage
What can you give to reduce risk of variceal hemorrhage?
Beta blockers
What is hepatic encephalopathy?
Buildup of nitrogenous waste products due to poor liver detoxification leading to cognitive impairment –> coma
What is the tx for hepatic encephalopathy
Lactulose
Rifaximin (ABX to remain in the gut)
What is hepatorenal syndrome?
Excess production of endogenous vasodilators (NO, PGDs) resulting in Decreased. SVR and decreased RBF
Tx for hepatorenal syndrome?
Midodrine, Octreotide, Albumin
What is hepatopulmonary syndrome?
Triad of Liver dx, Hypoxemia, Intrapulmonary vascular dilation
-Platypnea: Hypoxemia when upright due to R-L intrapulmonary shunt
What is portopuolmonary HTN
Pulmonary HTN accompanied by portal HTN because systemic vasodilation triggers production of pulmonary vasoconstrictors
Treatment for portopulmonary HTN
Prostaglandin Inhibitors (PD-I), NO, Prostacyclin analogs, endothelin receptor antagonists
Child-turcotte-Pugh scoring system assigns points based on:
- bilirubin
- Albumin
- +/- encephalopathy
- Ascites
Model for end stage liver disease (MELD) scores based on:
- Bilirubin
- INR
- Cr
- Sodium
MELD or CCA < 10 means what?
Proceed to OR
MELD 10-15 or Child Class B with portal HTN should go or not go to the OR?
Consider TIPS placement, optimize patient before OR
MELD 10-15 or Child Class B without portal HTN should go or not go to the OR?
Proceed to OR with careful monitoring
Are colloids or crystalloids preferred for liver patients?
colloids
What does chronic ETOH use do to MAC levels?
Chronic ETOH needs increased MAC of Volatiles
Late stage: Lower tolerance and Inc. sensitivity to volatiles
What are the best drugs for liver patients that are not liver metabolized?
Succs and cisatracurium
What might be decreased in severe liver disease?
Plasma cholinesterase
What is a surgeon doing during TIPS procedure?
Stent or graph placed between hepatic and portal veins to shunt the portal flow to the systemic circulation
-Decreases the portosystemic pressure gradient
Indications for TIPS procedure?
- Refractory variceal hemorrhage
- Refractory Ascites
Contraindications for TIPS?
- HF
- Tricuspid Regurgitation
- Severe pulmonary HTN
What is a partial hepatectomy used for?
Resection to remove neoplasms (up to 75%), leaving adequate tissue for regeneration
Anesthetic considerations for hepatectomy?
- Invasive monitoring
- Blood products
- Adequate vascular access for pressors
What is standard practice in an partial hepatectomy?
Fluid restrict to maintain low CVP prior to resection to reduce blood loss
-Pt. require post-op PCA
What is a common post-op complication of liver resection?
Coagulation disturbances
