Case 33 - Major hepatic Resection Flashcards
What is liver cirrhosis?
Can be due to cholestatic diseae and hepatocellular disease.
Cholestatic Disease
- primary biliary cirrhosis
- primary sclerosing cholangitis
Hepatocellular Disease
- infectious (Hep C)
- autoimmune
- steatohepatitis
- alcoholic
what does liver cirrhosis do to the CNS system?
Hepatic Encephalopathy
- variable manifestations
- confusion, personality changes, coma
- can be preciptated by anesthesia or sx if hepatic perfusion is impaired (hypotension, hypoxemia)
what does liver cirrhosis do to the Cardiovascular system?
Hemodynamic State
- decrease SVR due to nitric oxide effects (not metabolized due to poor functioning liver)
- increase CO
- normal to low BP
Cardiomyopathy
- s/sx of CHF
Altered Blood Flow
- incrase splachnic blood flow with central hypovolemia
- AV collateralization –> increase MVO2
what does liver cirrhosis do to the portal system?
Portal HTN
- results in collateral flow around liver –> portosystemic collateral development
- caput medusa, esophageal varices, spinger angiomas
what does liver cirrhosis do to the pulmonary system?
**Atelectasis **
- ascities
- pleural effusion
pulmonary shunting
- impaired hypoxic pulmonary vasoconstriction
Hepatopulmonary syndrome
- Intrapulmonary vascular dilation and shunting
- Dyspnea and hypoxemia are worse in the upright position (which is calledplatypnea and orthodeoxia, respectively).
Portopulmonary HTN
- pulmonary vascular remodeling due to imbalance between vasoconstrictor and vasodilator mediators
What is hepatorenal syndrome?
- HRS is prerenal failure from advanced chirrhosis
- due to lack of blood flow to the renal artery due to imbalance between vasoconstrictor and vasodilator mediators. Flow increased in splachnaic circulation, but decreased to renal arteries.
Describe edema and ascities in liver cirrhotic pts
Edema and ascities
- ascities due to portal HTN, backflow of blood
- central hypovolemia due to edema/third spacing/ascites causes activation of RAA which leads to sodium and water retention
- pts on diuretic and salt restricted diet
- albumin is mainstay of tx
- infection of ascitic fluid = spontaneous bacterial peritonitis –> renal failure and sepsis
what does liver cirrhosis do to the coagulation system?
- clotting and fibrinolysis is impaired
- PT/INR, PTT elevated
How does liver cirrhosis casue thrombocytopenia?
portal HTN causes increase flow to collateral circulation, one of which is to the spleen
- portal HTN induces splenomegaly
- splenomegaly sequesters PLT (decrease circulation of PLT)
- bone marrow suppresion also decrease PLT
What is esophageal varicies
- long term portal HTN will cause collateral flow to the lower esophagus
- superficial veins lining the esophageal mucosa, drain into the left gastric vein (coronary vein), which in turn drains directly into theportal vein. These superficial veins (normally only approximately 1 mm in diameter) become distended up to 1–2 cm in diameter in association with portal hypertension.
how is MELD score different from Child-Pugh Score?
MELD Score (CBP)
- creatinine
- bilirubin
- PT/INR
- more useful in transplant selection; no subjective data
Child- Pugh Score (A&E ABP)
- ascites (subjective)
- encephalopathy (subjective)
- Albumin
- Bilriubin
- PT/INR
- straifying risk in cirrhotic patients for non-transplant procedures
Would you consider an LMA for a cirrhotic patient undergoing surgery?
NO!
- decrease dose or avoid premeds (BZD) in setting of even mild encephalopathy
- full stomach due to ascities and decreased GI motility
- ET intubation to secure airway (avoid facemasks and LMAs)
Do you have any concern with the pharmacokinetics when giving anestheia meds to a cirrhotic patient?
YES!
- cirrhosis is associated with abnormalities in protein binding, protein concentration, volume status, volume of distribution, metabolism from hepatocyte derangment
- all meds given to these patients should be titrated to effect
What happens to cirrhotic patients using inhaled anesthetics? Do you need a change in dose?
No change in dose necessary
- encephalopathic pts may require less inhaled anes
- high dose inhaled anes can cause hypotension, exacerbate disease state through hypoperfusion
- sev, des, iso presever hepatic blood flow well
what happens to cirrhotic patients using induction agents like prop, etom, ket?
no change in dose necessary
- modest impact on hepatic blood flow and post op liver function when arterial blood pressure is maintained