Hepatic Flashcards
how much blood does the liver store
1 L
highly vascular
How much does the liver weight
median weight of 1.8 kg in men and 1.4 kg in women.
Liver location
RUQ under rib cage = somewhat protected
hard to get exposure = steep trendelenberg
How much bile is produced by the gallbladder?
500 ml daily
problems with no gallbladder
don’t digest as well and problems in post bariatric sx and pregnant women
Gal bladder sythesizes ….
Fat
Cholesterol
Lipoproteins
what divides the liver?
falciform ligament
liver lobes
the right, left, caudate, and quadrate lobes
purpose of gal bladder
concentrate and storage for bile
blood supply for the gal bladder
cystic artery- ligated when taken out and if miss = large source of bleeding = put extra clips. X ray; kub or chest x ray will see 3-4 clips on the cycstic artery
cholecystitis and tx
inflammation of the gall bladder
tx; cholecystectomy
cholelithiasis and tx
Gallstones
tx cholecystectomy
choledocholithiasis and tx
stones in the common bile duct
- may be the result of inflammation of the pacreatic head w/ obstruct the common bile duct
tx; ERCP
Pain worsening with inspiration
murphys sign = gal bladder issues
Where does the majority of blood for the liver come from?
Portal vein
What percent of CO goes to the liver
20-30%
Average blood flow between 100-150- ml / min and. Half consumed in the liver
Venous drainage of liver
hepatic sinusoids -> central vein -> interlobar and sub lobular veins -> 3 hepatic veins -> IVC
Budd-Chiari syndrome
thrombosis of the major hepatic veins occurs
colateral blood flow through caudate veins
Portal htn
Portal vein receive blood that has already pass through the splachnic circulation
increase SVR = increase portal vein pressure
> 20-30 mmhg
normal portal vein pressure
7-10 mmhg
Hepatic artery perfusion pressure formula
Hepatic Artery Perfusion Pressure=MAP-Hepatic Vein Pressure
Vitamin K dependent factors
(2,7,9,10)
2= prothrombin
factors that increase hepatic blood flow
feeding
glucagon- dilates common bile duct
beta agonists
recumbent position
hepatocellular enzyme induction
hepatitis
hypercapnia
factors that decrease hepatic blood flow
anesthetic agents
surgical trauma
alpha agonists and beta blockers
PEEP, PPV
vasopressin - avoid boluses
hepatic cirrhosis
hypocapnia
Where does bilirubin come from
Degradation product of Hgb
Inc bilirubin = dec hb;
causes of hb to degrade; tissue, surgery, meds = inc bili
Where is unconjugated bilirubin stored?
Conjugated and stored in liver
Water soluble…..elimination
Normal billirubin levels and levels for dz processess
Normal <1mg/dL
3mg/dL ->scleral icterus
>4mg/dL ->jaundice
normal also; 0-11 units/L
Where are Aminotransferases involved?
Involved in gluconeogenesis
What is AST/ALT used for
Can signify hepatic injury
If AST/ALT BOTH elevated……
Ratio of <1: non-alcoholic liver disease; MASH
Ratio of 2-4: alcoholic liver disease;
Ratio of > 4: Wilson’s disease (hereditary)
Alkaline Phosphatase facts
Lack specificity
Serum ½ life 1 week
Increases…bile salt-induced damage of hepatocyte membranes
normal alkaline phosphate levels
30 to 100IU/L(liver and bone contributes more than 80 percent of the total value).
or 45-115 units/L
Normal total bilirubin value
is < 1mg/dl. Out of these, up to 0.3mg is conjugated bilirubin
Alanine transaminase
facts
Relatively liver specific
Cytosol
Zone 1>3
N.value O – 45 IU/L
Half life is 18hrs (beneficial for acute)
Aspartate transaminase
facts
Non specific
Cytosol and mitochondria
Zone 3>1
N.Value 0 – 35IU/L
Half life is 36hrs
International Normalized Ratio increases means….
Strong correlation with declining hepatic function
Impaired synthetic function of coag factors
Where is albumin synthesized
Synthesized by hepatocytes
Impaired liver = don’t produce
Albumin normal value
3.5 to 5.5gm/dl.
half life : 18-20 days
Paracentesis replacement
1;1 fluid to albmumin replaces or 1/3 of fluid removed
PT normal values
12-14 seconds
sensitive to acute injury,
prolonged by vitamin K deficiency
ERCP
Ampula of Vater
Site of biliary obstruction
Balloon dilation, sphincterotomy, stenting
Multiple times -> stent = stone too big to fit through -> obstruct again
Encephalopathy grades
- Changes in behavior; minimal change in LOC
- disorientation, drowsiness, inappropriate behavior
- marked confusion, incoherent speech, sleeping most of time
- comatose, unresponsive to pain, decorticate/decerebrate
Encephalopathy exaggerated by….
infection, GI bleeding, TIPS
treatment for encephalopathy
decrease ammonia; lactulose
and neomycin
Coagulopathy labs and tx
INR > 1.5- w/ no other means
Tx; Vit K administration
Guided replacement
FFP
Cryo
Platelets
Calcium ( with blood products as well)
what happens to the VOD with liver diseases
Increased volume of distribution
Decreased plasma protein binding
Decreased clearance of drugs
Treatment of cerebral edema
Head up 30 degrees
- Head/neck neutral
- Muscle relaxants when intubated; sedatives and muscle relaxants because difficult to actual get to sleep
- Mannitol/hypertonic saline
- Hyperventilation
- Barbiturates coma till ICP resolves.
- Treat; Lactulose
what is Acute Hepatitis and what causes it
Inflammation of the liver parenchyma
causes by virus , hepatotoxins, autoimmune response
Symptom free till late to disease…..malaise/jaundice
Most common cause of liver cancer and most common indication for hepatic transplant
Hepatitis
contraindication to elective surgery associated w/ liver
acute hepatitis
Hepatitis A
vaccine
Common in countries without modern sanitation
Lasts few weeks to months
tx pooled gamma globulin
leading cause of liver ca an tx
Hepatitis B- Blood, sexual
tx; : Hepatitis B immunoglobulin
Leading cause of liver transplantation
Hepatitis C (non A, non B)
50% unaware
3 out 4 1945-1965
No vaccine
Parenteral drug use
Treatment; interferon with ribavirin (less effective)
Cure for Hepatitis C
Sofosbuvir (Sovladi, Soforal)—–
Inhibits HCV RNA synthesis
In combo with ribavirin
12 weeks
Hepatitis D
Occurs in conjunction with HBV; Coinfection or superinfection
Hepatitis E
Oral/fecal route
Transplants on immunosuppressives (for chemo or transpants)
Treatment; unknown, supportive therapy leading to transplant
Most common cause of acute liver failure in the US
acetaminophen Overdose >4g/day
Halothane and hepatitis
VAA metabolized in the liver to Inorganic Fluoride and Trifluoroacetic Acid (TFA)- sticks around. Halothane produces 20%.
Alcoholics and elective procedures
Chronic alcoholic patient should be abstinent from alcohol for at least 6 mon to undergo elective procedure.
Meld score
Model of end stage liver diseases
creatinine, bilirubin, INR
Meld score > 40
71.3% mortality
MELD score 10-19
6.0% mortality
Meld < 10
safely undergo elective surgery.
Meld 10 -15
may undergo elective surgery after
optimization with caution.
Meld > 15
contraindication for elective surgery.
Treatment for cirrhosis
TIPS?
Renal Replacement Therapy to transplantation
Diuresis- get fluid out of lungs, or drainage
O2 administration
Ammonia comes from…. and what causes it
Byproduct of nitrogen not processed out
causes; Neurotoxins, GABA, oxidative stress, inflammatory mediators, hyponatremia
Treatment for ascites
Salt restriction
Diuretics
Paracentesis- replace with albumin
Albumin replacement … if >5L
Antibiotics- high risk sepsis/ infection
Most common complications leading to hospitalization
ascites
TIPS
Trans-jugular Intrahepatic Portosystemic Shunt
bypasses a portion of the hepatic circulation by shunting blood from the portal vein to the hepatic vein
This reduces portal pressure and minimizes the back pressure on the splanchnic organs thus reducing the volume of ascites and risk of varices. May also be a temporizing measure for hepatorenal syndrome
what kinds of drugs are more markedly affected by changes to HBF
HIGH EXTRACTION RATIO= stick around for longer
Propofol
Fentanyl, Morphine, Meperidine
Lignocaine
Verapamil
Labetalol
Propanolol
what are the metabolic functions of the liver
fat metabolism
carbohydrate metabolism
protein metabolism
rocuronium metabolism
what part of the liver cleans the blood as it passes through
Kupffer cells
The liver performs what tasks?
gluconeogenesis
forms many compounds from carbohydrate intermediaries
conversion of galactose and fructose to glucose
storage of large amount of glycogen
most common cause of cirrhosis
etoh
Cirrhosis results in ….
splenomegaly, esophageal varies, LHF
cirrhotic patients should be rescucitated with….
colloids
vitamin K is used to treat elevated PT which measures the ____pathway
extrinsic
WEPT
warfarin, extrinsic pathway, measured w/ PT
Plat count less than ____ requires preoperative replacement
75 K = plat before OR
Chronic alcoholism increases MAC for _____and this is probably due to cross tolerance
isoflurane
Anesthetic drugs may cause postoperative liver dysfunction to be_____
exaggerated
plasma cholinesterase may be _____ in severe liver disease
decreased
manifestation of alcohol w/d occur in ____ hours after receiving no alcohol intake
24-72 hrs
hepatitis A is most commonly transmitted by_____
fecal contamination
drugs that cause hepatitis include
analgesics
VAA
Anticonvulsants
Tranquilizers
What surgical procedure is associated with the highest mortality?
Laparotomy
normal INR
n healthy people an INR of 1.1 or below is considered normal. An INR range of 2.0 to 3.0 is generally an effective therapeutic range for people taking warfarin for certain disorders.
