Liver- Periop management Flashcards
1
Q
Pre-operative H&P:
If history of jaundice or abnormal lab results, what should you ask about?
A
- 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
Q
What are some pre-operative indications that you should do further liver workup?
A
- 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
Q
If has known liver disease, how can you quantify it?
A
- 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
Q
What can be done pre-operatively to optimize the pt?
A
- 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
Q
IV anesthetics can be unpredictable in the liver pt, what might you expect with:
benzos
dexmedetomidine
propofol
TPL, etomidate, ketamine
A
- 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
Q
How does liver disease affect:
morphine
meperidine
fentanyl
sufentanil
alfentanil
remi
A
- **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
Q
How will liver disease affect NMB?
A
- 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
Q
How will liver disease affect catecholamines?
A
- 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
Q
What kind of monitors/access do you need intraoperatively for a pt with liver disease?
A
- 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
Q
What kind of anesthetic technique for a pt with liver disease?
What type of fluid is preferred?
A
- 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
Q
What do you want to avoid during the maintenance phase?
A
- 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
Q
What is seen with post-operative liver dysfunction?
A
- 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
Q
What is a TIPS procedure?
A
- 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
Q
What kind of anesthetic should be done for a TIPS procedure?
What should you be prepared to do?
A
- 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
Q
What are some problems that can be encountered during a TIPS procedure?
A
- 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
