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Flashcards in Liver- Periop management Deck (18)
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1

Pre-operative H&P:

If history of jaundice or abnormal lab results, what should you ask about?

  • Prior surgical or anesthetic technique
  • blood transfusions 
  • ETOH or recreational drug use
  • current medications and herbal meds
  • family hx of jaundice/liver dx
  • travel history

2

What are some pre-operative indications that you should do further liver workup?

  • easy bruising
  • anorexia or weight changes
  •  N/V or pain w/fatty meals
  • pruritis or fatigue
  • abdominal distention/ascites
  • GI bleeding
  • scleral icterus
  • hepatomegaly or splenomegaly
  • palmer erythema
  • gynecomastia
  • asterixis (hand tremor)

3

If has known liver disease, how can you quantify it?

  • MELD score: Cr, bilirubin, INR, (Na?)
    • if pt is getting dialyzed 2x per week, Cr score is set to 4 for the equation
  • Modified Child-Pugh score: albumin, PT, INR, bilirubin, ascites, and encephalopathy
    • elective surgery contraindicated for Class C

4

What can be done pre-operatively to optimize the pt?

  • Optimization- correction of ETOH dependency, coagulopathy, pH, electrolyte abnormalities (esp K+), malnutrition, anemia, esophageal varices and hepatic encephalopathy
  • PT or INR
    • parental vitamin K
    • recombinant factor VII
    • FFP in emergency
  • Consider plt tx if <100,000
  • Assume full stomach
  • Sedation premedication- altered pharmacodynamics, titrate to effect

5

IV anesthetics can be unpredictable in the liver pt, what might you expect with:

benzos

dexmedetomidine

propofol

TPL, etomidate, ketamine

  • Benzos- increased cerebral uptake, decreased clearance, prolonged E1/2 life
  • Dexmed- decreased clearance and prolonged 1/2 life
  • propofol- single dose similar response as normal pts, recover times may be longer after infusions
    • drug of choice with encephalopathy
  • TPL, etomidate, ketamine- E1/2 unchanged in most studies

6

How does liver disease affect:

morphine

meperidine

fentanyl

sufentanil

alfentanil

remi

  • **In general: longer E1/2 life, careful with infusions and repeat dosing
  • morphine
    • prolonged E1/2 life
    • increased bioavailability of oral form
    • decreased plasma protein binding
    • exaggerated sedative and resp dep effects
  • meperidine
    • 50% reduction in clearance and a doubling of the half life
    • may experience neurotoxicity form accumulation of normeperidine
  • Fentanyl
    • decreased plasma clearance
    • exaggerated and pronounced effects with infusion or repeat dosing
  • Sufentanil
    • pharmacokinetics are not significantly altered
    • some differences seen in e1/2
      • infusions or multiple doses could have prolonged effect
  • alfentanil
    • E1/2 life almost doubled
    • higher free fractions of the drug
    • prolonged duration and enhanced effects
  • Remi- elimination unaltered

7

How will liver disease affect NMB?

  • Increased Vd may require a higher initial dose
  • cirrhosis/advanced liver disease reduces elimination of vecuronium roc, panc, mivac = increased DOA, especially after repeated doses
  • Atracurium and cisatracurium are not dependent on hepatic elimination 
    • no need to modify dosing
  • Succ effect will be prolonged d/t decreased plasma cholinesterase levels
  • Increased Vd may require a higher initial dose
  • sugammadex- excreted unchanged in the urine

8

How will liver disease affect catecholamines?

  • Decreased response b/d of circulating vasodilators such as bile acids and glucagon
  • impaired ability to translocate blood from pulmonary and splanchnic blood reservoirs to systemic circulation
  • consider incrased doses or addition of on adrenergic vasoconstrictor (vasopressin)
  • pts with biliary obstruction are particularly intolerant of blood loss

9

What kind of monitors/access do you need intraoperatively for a pt with liver disease?

  • Decisions based on severity of disease and type of surgery
  • Loarge bore IVs- for all but the most minor procedures, blood loss is unpredictable
  • A-line- for BP and labs
  • +/- CVP or PA (if pulm HTN)
  • TEE risky

10

What kind of anesthetic technique for a pt with liver disease?

What type of fluid is preferred?

  • if using local/MAC- adequate sedation is essential to minimize SNS stimulation and resultant decreases in hepatic blood flow and O2 delivery
  • Regional is nice ONLY IF NO COAGULOPATHIES
  • If GA: RSI or awake intubation
    • sevo and iso are agents of choice
    • N2O ok
  • Fluids: no proof colloids are better than crystalloids

11

What do you want to avoid during the maintenance phase?

  • Avoid hepatic hypoxia
    • FiO2- right to left shunting, VQ mismatch
    • anemia
    • hypotension, decreased CO hypovolemia
    • release of endogenous vasoconstrictors
      • RAAS
      • catecholamines
      • ADH
    • Vasodilation (hypotension) and low CO increases O2 upatake in pre-portal areas and decreases the O2 content of portal blood
      • ESLD can nolonger autoregulate hepatic arterial flow causing hepatic hypoxia!

12

What is seen with post-operative liver dysfunction?

  • Jaundice appears in many pts following major surgery
    • overproduction or underexcretion of bilirubin
    • direct hepatocellular injury
    • extrahepatic obstruction
    • other causes:
      • hemolytic anemia
      • resorption of lg surgical hematomas
      • transfusions of RBCs 
      • hepatocellular drugs
      • ischemia
      • viral hepatitis
      • Cholestasis
  • If encephalopathy occurs within 2-8 weeks of symptoms it is defined as fulminant hepatic failure

13

What is a TIPS procedure?

  • Transjugular intrahepatic portal-systemic shunt procedure
    • a percutaneously created intrahepatic connection of the portal and systemic circulations
    • Used in pts with ESLD to decrease portal pressure and attenuate the complications related to portal HTN (variceal bleeding or refractory ascites)
    • Diversion of PBF into the hepatic vein is achieved by placement of an expandable intraparenchymal tract

14

What kind of anesthetic should be done for a TIPS procedure?

What should you be prepared to do?

  • Can be done under MAC, use GA depending on length of procedure, comorbidities
  • Resuscitation with fluid and blood products in pts with variceal bleeding
  • Pts w/severe coagulopathy require preprocedural correction

15

What are some problems that can be encountered during a TIPS procedure?

  • PTX or neck vesel injury can occur during vesse puncture--reduced with US
  • Cardiac dysrhythmias can be mechanically induced during intracardiac catheter passage
  • Acute, life-threatening hemorrhage can be caused by hepatic artery puncture, a hepatic capsular tear, or extrahepatic portal venous puncture
  • increased risk of pulmonary edema and CHF in patients with borderline cardiac reserve

16

What are some pre-op considerations for pts undergoing liver resections?

  • Risk assessment similar to all other major abd procedures
  • Anemia and coaguopathy should be corrected preop
  • Choice/dosing of anesthetic drugs
    • consider baseline hepatic parenchymal dysfunction and potential postop dysfunction resulting from resection of a major portion of the liver parenchyma

17

What are some intr-op considerations for a pt undergoing a liver resection?

  • Risk of significant intra-op blood losse
    • have appropriate monitoring and access for rapid tx
    • overall fluid management is controversial in resection
      • give blood and fluids to buffer loss
      • keep CVP low to minimize loss
  • Modest degree of t-berg = reduction of intrahepatic venous pressure
    • also maintains or increases cardiac preload and CO
    • and reduces risk of VAE

18

What are some post-op considerations for a pt undergoing a liver resection?

  • Similar to those of other major abd procedures
  • IV fluids should include phosphates which are needed to facilitate liver regeneration and avoid severe hypophosphatemia
  • Decreased clearance of hepatically metabolized drugs
    • careful when selecting and titrating for post-op analgesia