Hepatic and biliary systems Flashcards
List the functions of the liver (this card sucks)
- Synthesizes glucose via gluconeogenesis
- Stores excess glucose as glycogen
- Synthesizes cholesterol & proteins into hormones and vitamins
- Metabolizes fats, proteins, carbs to generate energy
- Metabolizes drugs via CYP-450 and other enzyme pathways
- Detoxifies blood
- Involved in the acute-phase of immune support
- Processes HGB and stores iron
- Synthesizes coagulation factors (all except factors III, IV, VIII, vWF)
- Aids in volume control as a blood reservoir
Liver dysfunction can lead to:
Multi-organ failure
How many segments does the liver have?
What is this based on?
8
- blood supply and bile drainage
What are the R & L lobes of the liver separated by?
Falciform ligament
What vessels branch into each segment of the liver?
Portal Vein
Hepatic artery
What 3 veins empty into the IVC from the liver?
Right, middle, left hepatic veins
Bile ducts travel along ______
Portal veins
Bile drains though _____ into what 2 things?
Hepatic duct
Gallbladder
Common bile duct
Bile enters the duodenum via what?
Ampulla of vater
Liver perfusion receives how much of COP?
Through what?
What is the flow rate?
25%
Via portal vein and hepatic artery
1.25-1.5 L/min
What does the portal vein arise from?
Splanchnic vein
Superior mesenteric vein
Portal vein blood is partially deoxygenated after perfusing what 3 organs?
GI organs
Pancreas
Spleen
What does the hepatic artery branch off of?
Aorta
How is O2 delivery split in the liver?
50% via portal vein (partially deoxygenated)
50% via hepatic artery
T/F
The liver receives the highest proportionate COP of all organs
True
Portal vein provides _____% of hepatic blood flow; hepatic artery provides ___% of hepatic blood flow
75%
25%
Hepatic arterial blood flow is inversely related to what?
Portal venous blood flow
Hepatic blood flow is ____
Hepatic artery ___ in response to low portal venous flow, keeping consistent HBF
Autoregulated
Dilates
Portal venous pressure reflects what 2 things?
Splanchnic arterial tone
Intrahepatic pressure
Increased portal venous pressure means what?
What does this put you at risk for?
Blood backs up into systemic circulation
- esophageal varices, gastric varices
Hepatic venous pressure gradient picture
What is this used to determine?
Severity of portal HTN
T/F
Pts develop symptoms early with liver disease
False!
Often asymptomatic until late-stage liver disease; even later stages may only have age sx (disrupted sleep, loss of appetite)
Risk factors for liver dysfunction
Family hx
Heavy ETOH
Lifestyle
DM
Obesity
Illicit Drug use
Multiple partners
Tattoos
Transfusion
Physical exam of liver dysfunction
Pruritis
Jaundice
Ascites
Asterixis (flapping tremor)
Hepatomegaly
Splenomegaly
Spider nevi
Hepato-biliary labs
- BMP, CBC
- PT/INR
- Aspartate aminotransferase (AST)
- Alanine aminotransferase (ALT)
*most liver-specific enzymes
Bilirubin - Alkaline Phosphatase
- ɣ-glutamyl-transferase (GGT)
Hepato-biliary imaging
US
Dopple US (portal blood flow)
CT
MRI
What are the 3 groups of hepatobiliary disease?
Hepatocellular injury: ↑AST/ALT (hepatocyte enzymes)
- Acute Liver Failure (ALF): may be elevated 25x
- Alcoholic Liver Dz (ALD): AST:ALT ratio usually at least 2:1
- NAFLD: ratio usually 1:1
Reduced synthetic function: ↓Albumin, ↑PT/INR
Cholestasis:↑AlkPhosphatase,↑GGT,↑bilirubin
Liver blood test and differential diagnosis of HB disorders chart
What is cholelithiasis?
What is this caused by?
Gallstones
- Hepatocytes secrete bile through bile ducts, into CHD→ GB & CBD
- GB stores bile to deliver during meals, CBD secretes bile directly into duodenum
Risk factors of cholelithiasis
Obesity, ↑cholesterol, DM, pregnancy, female, family hx
What percent of pts with cholelithiasis are asymptomatic?
80%
S/S of cholelithiasis
What’s the treatment?
RUQ pain, referred to shoulders
N/V, indigestion
fever (acute obstruction)
IVF, abx, pain management, lap chole
What is Choledocolithiasis?
Stone obstructing CBD→ biliary colic
Initial symptoms of Choledocolithiasis
N/V, cramping, RUQ pain
Cholangitis symptoms
Fever, rigors, jaundice
Treatment for choledocolithiasis
Endoscopic removal of stone via ERCP
What does ERCP stand for?
What is it?
Endoscopic Retrograde Cholangiopancreatography
- Endoscopist threads guidewire through Sphincter of Oddi, into Ampulla of Vater to retrieve stone from pancreatic duct or CBD
-GA, usually prone w/left tilt (tape ETT to left)
What med may be required during ERCP for oddi spasm?
Glucagon
Difference in conjugated and unconjugated hyperbilirubinemia chart
What is bilirubin?
end product of heme-breakdown
What is unconjugated hyperbilirubinemia?
imbalance between bilirubin synthesis & conjugation
What is conjugated hyperbilirubinemia?
caused by anobstruction, causing reflux of conjugated bilirubin into the circulation
What are the 5 most common types of viral hepatitis?
A, B, C, D, E
T/F
Viral hepatitis is on the decline
Why or why not?
True
Vaccines, new treatments
What 2 types of viral hepatitis are more chronic?
B and C
____ is most common viral hepatitis requiring _____ in US
Hep C
Liver transplant
Hep C picture
Acute and chronic hepatitis common symptoms picture
What med can you give a 12 week course of for hep C?
This provides ____% clearance of genotype ____
Sofosbuvir/Velpatasvir
98%-99% of GT 1A/1B
Characteristic features of viral hepatitis picture
What is the most common cause of cirrhosis?
Alcoholic liver disease (ALD)
What is the top indication for liver transplant in the US?
ALD
What is treatment for ALD centered around?
Abstinence
- Management sx of liver failure
- Platelet count <50,000 requires blood transfusion
- Liver transplant an option if criteria is met
Unconjugated “indirect”bilirubin is protein bound to _____, transported to ____, conjugated into to its _____, excreted into _____
Albumin
Liver
H20-soluble “direct” state
Bile
ALD symptoms
Malnutrition
Muscle wasting
Parotid gland hypertrophy
Jaundice
thrombocytopenia
Ascites
Hepatosplenomegaly
Pedal edema
*Sx of ETOH withdrawal may occur 24-72h after stopping
ALD lab values
↑Mean corpuscular volume (MCV)
↑Liver enzymes
↑ɣ-glutamyl-transferase (GGT)
↑Bilirubin
Blood ethanol (acuteintox)
How is non alcoholic fatty liver disease diagnosed?
Hepatocytes contain >5% fat
- Done by imaging and histology
Risk of Non-Alcoholic Fatty Liver Disease
Obesity, Insulin resistance, DM2, Metabolic syndrome
Treatment of hep C is based on what?
Genotype (75% of people are type 1)
HCV stage
+/- cirrhosis
What does non-alcoholic fatty liver disease progress to?
non-alcoholic steatohepatitis (NASH)
cirrhosis
hepatocellular carcinoma
____ and ____ have come additional leading causes of liver transplant in the US
NAFLD
NASH
What is the gold standard in distinguishing NAFLD from other liver dx?
Liver biopsy
Treatment of NAFLD
Diet, exercise
Liver transplant is indicated in what?
advanced fibrosis, cirrhosis, related complications
More than ___ diabetics and ___ severe obese people out of 10 have NAFLD
___ out of 4 people have NAFLD regardless of weight
6 diabetics, 9 severe obese
1
Types of fatty liver picture
Autoimmune hepatitis primarily effects who?
Women
Autoimmune hepatitis lab values
+autoantibodies & hypergammaglobulinemia
AST/ALT may be 10-20x norm in acute AIH
Treatment of autoimmune hepatitis
steroids, azathioprine (immunosuppressant)
What percent of pts with autoimmune hepatitis achieve remission?
Is relapse common?
60%-80%
Yes
When is liver transplant indicated in autoimmune hepatitis?
When treatment fails or acute liver failure ensues
Most common cause of drug induced liver injury
Is this reversible?
Acetaminophen OD
Normally reversible after drug is removed
What are the 3 specific disorders of metabolism?
What are these?
Wilsons Disease
Alpha-1 Antitrypsin Deficiency
Hemochromatosis
- Group of rare, genetically inherited disorders that lead to a defect in the enzymes that breakdown and store protein, carbohydrates &fatty acids
What is the ratio of occurrence in inborn errors of metabolism?
When is onset?
Occurs in 1:2500 births
Varies from birth to adolescence
When does the most severe form of inborn error of metabolism appear?
Neonatal period
These carry a high degree of mortality
What is Wilsons disease?
AKA hepatolenticular degeneration
- Autosomal recessive disease characterized by impaired copper metabolism
- Copper buildup leads to oxidative stress in the liver,basal ganglia, and cornea
Symptoms of Wilsons disease
range from asymptomatic to sudden-onset liver failure along with neurologic & psychiatricmanifestations
Diagnosis of Wilsons disease
Lab tests (serum ceruloplasmin,aminotransferases,urine copper level)
Possible liver biopsy for copper level
Treatment of Wilsons disease
Copper-chelation therapy & oral zinc to bind copper in the GI tract
What is Alpha-1 Antitrypsin Deficiency?
Gentetic disorder resulting in a defectiveα-1 antitrypsin protein
What does Alpha-1 Antitrypsin do?
proteins protect the liver & lungs from neutrophil elastase
- neutrophil elastase isan enzyme that disrupts tissues of the lungs and liver
- Incidence1: 16,000 to1: 35,000, although it is likely underdiagnosed
Alpha-1 Antitrypsin Deficiency is the #1 genetic cause of ______ in children
Liver transplant
Diagnosis of Alpha-1 Antitrypsin Deficiency
confirmed w/α-1 antitrypsin phenotyping
Treatment of Alpha-1 Antitrypsin Deficiency
Liver transplant is only curative treatment
- pooledα-1 antitrypsin is effective for pulmonary sx; however, it doesn’t help with liver disease
What is hemochromatosis?
Excessive intestinal absorption of iron
- Maybe genetic or caused by repetitive blood transfusions or iron infusions
- Excess iron accumulates in organs and causes damage to the tissues
What may pts with hemochromatosis present with?
cirrhosis, heart failure,diabetes, adrenal insufficiency,or polyarthropathy
What do labs look like in hemochromatosis?
elevated AST/ALT, transferrin saturation, and ferritin
How do you diagnosis hemochromatosis?
Genetic mutation testing
- echo and MRI to diagnose cardiomyopathies and liver abnormalities
What can you do to quantify iron levels in the liver and assess level of damage of hemochromatosis?
Liver biopsy
Treatment of hemochromatosis
weekly phlebotomy, iron-chelating drugs, liver transplant
What is PSC?
Primary Sclerosing Cholangitis
- Autoimmune, chronic inflammation of the larger bile ducts
- Intrahepatic and extrahepatic
- Fibrosis in biliarytree→strictures (beads on string appearance)→ cirrhosis, ESLD
Who is PSC more common in? When is the onset?
Males>females
Onset is around 40s
Symptoms of PSC?
Fatigue, itching, deficiency of fat-soluble vitamins (A,D,E,K), cirrhosis
What do labs look like in PSC?
↑alkaline phosphatase andɣ-glutamyl-transferase, +auto-antibodies
Diagnosis of PSC?
MRCP or ERCP showing biliary strictures w/ dilated bile ducts
- liver biopsy reinforces dx, but isn’t always done
Treatment of PSC?
- no drug treatment is proven effective
- liver transplant is only long term treatment
_____ is common in PSC after transplant d/t autoimmune nature
Re-occurence
What is PBC?
Primary Biliary Cholangitis
- Previously known as biliary cirrhosis
- Autoimmune, destruction of bile ducts withperiportal inflammation & cholestasis
- Can lead to liver scarring, fibrosis, cirrhosis
Who is PBC more common in? When is onset?
Females>males
Often diagnosed in Middle Ages
What is PBC thought to be caused by?
Exposure to environmental toxins in genetically susceptible individuals
Symptoms of PBC
Jaundice, fatigue, itching
Labs in PBC
↑Alk Phos,↑GGT, + Antimitochondrial antibodies
Imaging in PBC
CT,MRI, & MRCP to r/o bile duct obstructions
- Liver biopsy reveals bile duct destruction andinfiltration w/lymphocytes
Treatment of PBC
No cure, but exogenous bile acids slow progression
PSC vs PBC picture
What is acute liver failure?
- Life-threatening severe liver injury occurring within days to 6 months after insult
- Rapid increase in AST/ALT, AMS, coagulopathy
- Massive hepatocyte necrosis→ cellular swelling &mbrndisruption
What percent of acute liver failure cases are drug induced?
Which drug usually?
50%
Tylenol
Other causes of acute liver failure
Viral hepatitis, autoimmune, hypoxia, ALF of pregnancy, HELLP
Symptoms of acute liver failure
Jaundice, nausea, RUQ pain, cerebral edema, encephalopathy, multi-organ failure, death
Treatment of acute liver failure
Treat the cause, supportive care, liver transplant
What is the final stage of liver disease called?
Cirrhosis
- Normal liver parenchyma replaced with scar tissue
With cirrhosis, what do the symptoms progress to?
jaundice, ascites, varices, coagulopathy, encephalopathy, thrombocytopenia
Most common causes of cirrhosis?
ALD, NAFL, HCV, HBV
What are the elevated labs in cirrhosis?
AST/ALT, bilirubin, Alk phosphatase, PT/INR
_____ is the only cure for cirrhosis
Transplant
Cirrhosis complications include:
Portal HTN
Ascites
Bacterial peritonitis
Varicose
Hepatic encephalopathy
Hepatorenal syndrome
Hepatopulmonary syndrome
Portopulmonary HTN
What does portal HTN cause?
What is the HVPG level?
↑vascular resistance within the portal venous system
HVPV >5
What is the most common complication of cirrhosis?
Ascites
In ascites, portal HTN leads to increased _______ and __________
blood volume & peritoneal accumulation of fluid
Management of ascites
- ↓Salt diet
- albumin replacement
- Transjugular Intrahepatic Portosystemic Shunt (TIPS): Reduces P-HTN and ascites
What is the most common infection peritonitis related to cirrhosis?
What does this require?
Bacterial peritonitis
Abx
What percent of cirrhosis pts have varices?
50%
What is the most lethal complication of varices?
Hemorrhage
- Beta blockers help reduce risk
- Prophylactic endoscopic variceal banding & ligation
- Refractory bleeding → balloon tamponade
What is hepatic encephalopathy?
Buildup of nitrogenous waste d/t poor liver detoxification
What are symptoms associated with hepatic encephalopathy?
Neuropsychiatric symptoms
- cognitive impairment → coma
Treatment of Hepatic Encephalopathy
Lactulose, Rifaximin to ↓ammonia-producing bacteria in gut
What is hepatorenal syndrome?
Excess production of endogenous vasodilators (NO, PGs)→↓SVR→↓RBF
Treatment of hepatorenal syndrome?
Midodrine, octreotide, albumin
What is hepatopulmonary syndrome?
- Triad of chronic liver dz, hypoxemia, intrapulmonary vascular dilation
- Platypnea (hypoxemia when upright) d/t R to L intrapulmonary shunt
What is portopulmonary HTN?
- Pulmonary HTN accompanied by portal HTN
- Systemic vasodilation triggers production of pulmonary vasoconstrictors
What is the treatment of portopulmonary HTN?
PD-I’s, NO, prostacyclin analogs, and endothelin receptor antagonists
Transplant is only cure
What are the 2 scoring systems to determine severity and prognosis of liver disease?
Child-turcotte-pugh (CT)
- points based on bilirubin, albumin, PT, encephalopathy, ascites
Model for end stage liver disease (MELD)
- scorebased on bilirubin, INR, creatinine, sodium
CTP scoring picture
MELD scoring picture
Anesthesia in liver disease flow chart
Standard preop labs in liver disease
CBC, BMP, PT/INR
Pts with liver disease have a ____ threshold for invasive monitoring
Low
Pts with liver disease are at risk for what with anesthesia?
↑Risks aspiration, hypotension, hypoxemia
Would you use colloids or crystalloids for resuscitation in liver disease?
Colloids preferred
____ increases MAC of volatile anesthetics in liver disease pts
Alcoholism
What 2 paralytics are preferred in liver disease?
Why?
Succs and Cisatracurium
- not liver-metabolized (plasmacholinesterasemay be decreased in severe liver dz)
What does TIPS stand for?
What is this used to manage?
Transjugular Intrahepatic Portosystemic Shunt
- Portal HTN
What happens in a TIPS procedure?
- Stent or graft placed btw hepatic vein and portal vein
- Shunts portal flow to systemic circulation
- Reduces the portosystemic pressure gradient
Indications for TIPS
Refractory variceal hemorrhage
Refractory ascites
Contraindications of TIPS
Heart Failure
Tricuspid regurgitation
Severe pulmonary HTN
What is a partial hepatectomy?
- Resection to remove neoplasms, leaving adequate tissue for regeneration
- Tolerable amount of resection d/o preexisting liver disease and function
Up to what percent of liver removal is tolerated in pts with normal liver function?
75%
Anesthetic considerations for partial hepatectomy
- Invasive monitoring
- Blood products available
- Adequate vascular access for blood/pressors
______ is the definitive treatment for end stage liver disease
Transplant
What is the different considerations for living/brain dead liver donors?
Living donor: surgeries timed together, minimal ischemic time
Brain dead donors: kept HD stable to for organ perfusion
Intraop management of liver transplant
Maintain hemodynamics (Pressors/Inotropes readily available)
- A-line, CVC, PA cath, TEE
Control coagulation
Special considerations for liver transplant picture
