Exam 3 - Hepatic/Biliary Systems Flashcards
Functions of the liver?
- Glucose synthesis (gluconeogenesis)
- Storage of glucose as glycogen
- Synthesis of hormones and vitamins from cholesterol
- Metabolism to create energy and drug metabolism (CYP450)
- Iron storage
- Makes coag factors (except III, IV, VIII, and vWF)
- Blood reservoir
How many segments are there in the liver? What creates them?
What seperates the 2 lobes?
- 8 segments (each has a branch of the portal vein and hepatic artery)
- Falciform ligament
What veins return blood from the liver to the IVC?
Right, middle, and left hepatic veins
How does bile travel through and out of the liver?
Via bile ducts that travel along portal veins
Drains through hepatic duct into CBD and GB
Enters duodenum via Ampulla of Vater
The liver recieves how much of the CO?
25% or 1.25-1.5 L/min, highest portion of CO of all organs
The portal vein provides ____ of hepatic blood flow and is partially ____
75%, deoxygenated
The hepatic artery branches off the ____ and provides ____ of the hepatic blood flow
aorta, 25%
The liver obtains ____ of oxygen from both portal vein and hepatic artery
50%
How is hepatic blood flow regulated?
What can happen when this fails?
Hepatic blood flow is autoregulated; Hepatic artery dilates when portal blood flow is low
When portal venous pressure increases blood backs up in the systemic circulation and can cause varices
What is a normal HPVG?
1-5 mmHg
What HVPG correlates with cirrohsis and esophageal varices?
HVPG > 10 mmHg
What can happen at an HVPG >12 mmHg?
Variceal rupture
What risk factors may lead to liver disease?
- Family hx
- EtOH abuse
- DM
- Obesity
- Illicit drug use
- Multiple partners
Someone with liver failure may have what physical findings?
- Pruritis (bilirubin excess)
- Jaundice
- Ascites
- Asterixis (flapping tremor)
- Hepatomegaly
- Spleenomegaly
- Spider nevi
What are the 3 groups of hepatobiliary disorders?
- Bilirubin overload
- Hepatocellular injury
- Cholestasis
What abnormal lab findings are found with bilirubin overload?
- Unconjugated bilirubin predominants
- BUN may be slightly increased
What abnormal lab findings are found with hepatocellular injury?
- Incrased aminotrasferases (AST/ALT)
- Decreased albumin
- Prolonged PT
- Retention of dye
What abnormal lab findings are found with cholestasis?
- Increased alkaline phosphatase
- Increased Ɣ-Glutamyl transpeptidase
Risk factors, S/S, and treatments for cholelithiasis
Risk factors: Obesity, ↑cholesterol, DM, preganancy, female, family hx
S/S: RUQ pain referred to shoulders, N/V, indegestion, fever
Tx: IVF, abx, lap cholecystectomy
What is choledocolithiasis?
Stone obstructs the CBD causing retrograde flow of bile
Sx of choledocolithiasis?
N/V, cramping, RUQ pain
Can progress to cholangitis → fever, rigors, jaundice
Treatment for choledocolithiasis?
ERCP - Endoscopic Retrograde Cholangiopancreatography
Guidewire threaded through Sphincter of Oddi into Ampulla of Vater to retrieve stone
Anesthesia concerns for ERCP?
- Pt is under GA
- Usually prone with left tilt (tape ETT to the left)
- Glucagon may be needed if sphincter of oddi spasm
What is bilirubin and the different forms?
Bilirubin - end product of heme breakdown
Unconjugated (indirect) bilirubin - protein bound to albumin; conjugated in the liver to “direct” state and excreted into bile (now water soluble)
What causes unconjugated hyperbilirubinema?
Imbalance between bilirubin synthesis and conjugation: drug induced, sepsis, sickle cell
What causes conjugated hyperbilirubinemia?
Caused by obstruction, causing reflux of bilirubin into circulation: intrahepatic cholelithiasis, hepatitis, drugs, cirrhosis
What type of hepatitis usually requires a liver transplant?
What treatments reduce HCV?
- Hepatitis C
- HCV genotyping and staging has improved
- Sofosbuvir/Velpatasvir clear 99% of 1A/1B genotypes
How are the different viral hepatitis’ spread?
A, E: fecal-oral, contaminated water
B,C: Transfusion, percutaneous, sexual
D: Percutaneous
Which viral hepatitis has the longest incubation period?
Type B: 60-110 days
What viral hepatitis’ progress to chronic liver disease?
B: in 1-5% of adults and 80-90% of children
C: up to 75% of patients
What is the most common cause of cirrhosis and liver transplants?
Alcholic liver disease
S/S of Alcoholic LD?
- Jaundice
- Thrombocytopenia
- Acites
- Hepatosplenomegaly
- EtOH withdrawl
Abnormal lab values found in ALD?
- ↑Mean corpuscular volume (MCV)
- ↑Liver enzymes
- ↑ɣ-glutamyl-transferase (GGT)
- ↑Bilirubin
- Blood ethanol (acuteintox)
Diagnosis and causes of NAFLD?
Dx: hepatocytes contain >5% fat - requires liver biopsy
Causes: Obesity, insulin resistance, DM2, metabolic syndrome
Treatments for NAFLD?
Diet, exercise, liver transplant for advanced fibrosis/cirrhosis
Describe autoimmune hepatitis?
Treatments?
- Predominantly effects women
- Have autoantibodies and hypergammaglobulinemia
- AST/ALT may be 10-20x normal in acute phase
- Steroids and azathioprine (immunosuppressant)
- Liver transplant for acute liver failure
Most common cause of drug induced liver injury?
Acetaminophen OD
What are the 3 cogenital hepatic disorders?
- Wilsons disease
- ⍺-1 Antitrypsin deficiency
- Hemochromatosis
Describe Wilsons Disease (hepatoenticular degneration)?
- Autosomal recessive disease causing impaired copper metabolism (excess Cu buildup)
- Leads to oxidative stress on liver, basal ganglia, and cornea
S/S and treatmets for Wilsons disease?
- Asymptomatic
- Sudden onset liver failure
- Neurologic and psychiatric manifestations
- Tx: copper-chelation therapy and oral zinc to bind Cu in GI traact
Describe ⍺-1 antitrypsin deficiency?
- Defective ⍺-1 antitrypsin protein
- Normally ⍺-1 antitrypsin protects the lung and liver from neutrophil elastase (enzyme disruptes tissues)
- Leading genetic cause of liver transplants in children
Treatments for ⍺-1 antitrypsin deficiency?
- Pooled ⍺-1 antitrypsin for pulmonary symptoms
- Liver transplant is the only curative treatment
What is hemochromatosis?
- Excessive GI absorption of iron → accumulates in organs and causes tissue damage
- May be genetic or from blood/iron transfusion
S/S and treatments for hemochromatosis?
- Cirrhosis, heart failure, DM, adrenal insufficiency or polyarthropathy
- ↑AST/ALT, transferrin saturation, and ferritin
- Tx: weekly phlebotomy, iron-chelation, liver transplant
What is Primary Sclerosing Cholangitis (PSC)?
- Autoimmune inflammation of the large bile ducts
- Leads to fibrosis in biliary tree causing a “beads on string” appearance
- Can cause cirrhosis and ESLD
Intra and extrahepatic
S/S of PSC?
- Fatigue
- Itching
- Fat soluble vitamin deficiency (A,D,E,K)
- Cirrhosis
- ↑Alk phos, ɣ-glutamyl-transferase, +auto-antibodies
- Males > females
How is PSC diagnosed and treated?
MRCP/ERCP showing biliary strictures
Liver transplant is only long term treatment (re-occurence common)
Describe Primary Biliary Cholangitis (PBC)?
- Autoimmune destruction of bile ducts causing periportal inflammation and cholestasis
- Can lead to fibrosis, scarring, and cirrhosis
- Thought to be caused by enviornmental toxin exposure in genetically susceptible individuals
intrahepatic only
S/S of PBC?
- Jaundice
- Fatigue
- Itching
- ↑Alk Phos,↑GGT, + Antimitochondrial antibodies
- Bile duct destruction and infiltration w/ lymphocytes on biopsy
Treatment for PBC?
No cure, bile acids slow progression (can damage stomach lining)
Patho of acute liver failure?
S/S?
Treatment?
- Massive hepatocyte necrosis leads to cellular swelling and membrane disruption
- Sx: Jaundice, nausea, RUQ pain, cerebral edema, encephalopathy, MODS
- Tx: fix underlying cause, suppoprtive care, liver transplant
What is the final stage of liver disease?
Cirrhosis - normal liver parenchyma replaced with scar tissue
What is the most common complication of cirrhosis and treatments?
Ascites - due to increase abdominal blood volume and peritoneal accumulation of fluid
Tx: ↓Salt diet, albumin replacement, Transjugular Intrahepatic Portosystemic Shunt (TIPS)
Most common infection r/t cirrhosis?
Bacterial Peritonitis
Cirrhotic varcies treatments?
- BB reduce risk
- Prophylactic banding and ligation
- Balloon tamponade for refractory bleeding
Causes, symptoms, and treatments for hepatic encephalopathy?
- Buildup of nitrogenous waste d/t poor liver detoxification
- Neuropsychiatric symptoms (cognitive impairment → coma)
- Tx: Lactulose, Rifaximin to ↓ammonia-producing bacteria in gut
What is hepatorenal syndrome?
Treatments?
- Excess production of endogenous vasodilators (NO, PGs)→↓SVR→↓RBF
- Tx: Midodrine, Octreotide, Albumin
What is hepatopulmonary syndrome?
Symptom?
- Triad of chronic liver dz, hypoxemia, intrapulmonary vascular dilation
- Platypnea (hypoxemia when upright) d/t R to L intrapulmonary shunt
What is portopulmonary HTN?
Treatments?
- Pulmonary HTN accompanied by portal HTN
- Systemic vasodilation triggers production of pulmonary vasoconstrictors
- Tx: PD-I’s, NO, prostacyclin analogs, and endothelin receptor antagonists
- Transplant is only cure
What is the Child-Turcotte-Pugh score and what is it based on?
Awards points based on bilirubin, albumin, PT, ascites, and encephalopathy
What is the Model for End Stage Liver Disease score and what is it based on?
Score based on bilirubin, INR, creatinine, and sodium
How does the MELD and CTP score influence preoperative decision making?
Intraoperative anesthetic considerations for liver disease?
- Invasive monitoring
- Colloids preferred to crystalloids
- Chronic alcholism increases MAC
- Drugs may have prolonged DOA/slower onset
- Incerased risk for bleeding
What NMB is preferred for liver disease patients?
Sucinylcholine and cisatricurium (not liver metabolized)
Although plasma cholinesterases may also be decreased
What is a TIPS procedure?
- Stent or graft placed btw hepatic vein and portal vein
- Shunts portal flow to systemic circulation
- Reduces the portosystemic pressure gradient
TIPS indications and contraindications?
Indications: Refractory variceal hemorrhage and ascities
CI: HF, Tricuspid regurgitation, severe pulmonary HTN.
Indications for partial hepatectomy?
Anesthetic considerations?
- Removal of neoplasms
- Up to 75% can be removed (tissue can regenerate)
- Need invasive monitoring, blood products, adequate IV access, maintain low CVP to reduce blood loss.
Liver transplant anesthetic concerns?
