1) RECOMMENDATIONS
a) General Approach
i) Generally speaking, we are referring to symptomatic patients with a
significant liver dysfunction
(1) Higher risk is associated with low albumin, elevated bilirubin,
elevated coag tests
(2) A clinically normal patient with elevated ALT and/or ALP who has
normal hepatic function does not necessarily require a unique
perianesthetic approach
ii) Generally, use lower doses of everything
iii) Avoid agents that require extensive liver metabolism for clearance
iv) Regardless of agents used, expect a more prolonged anesthetic
recovery
b) Pre-anesthetic Medications
i) Reversible agents are advantageous
ii) Benzodiazepines and opioids are generally good choices
(1) Use lower doses, titrating to effect
(2) Morphine may be the most attractive opioid as it is the least
protein bound opioid
(a) Morphine’s route of metabolism is the best preserved in liver
failure (glucuronidation)
c) Induction
i) Propofol
ii) Etomidate is an attractive agent for severe liver disease cases but
caution must be extended to the proplylene glycol containing preparations
(1) The lipuro version (similar to propofol) is preferred over the
propylene glycol containing preparation
d) Maintenance
i) Isoflurane or
Sevoflurane
e) Support
i) Epidural analgesia and regional analgesia help reduce systemic
doses of opioids
ii) IV fluids highly recommended
iii) May need glucose support
(1) Monitor blood glucose
(2) Consider 5% dextrose containing fluids if needed to maintain blood
glucose
2) PRECAUTIONS
a) Pre-anesthetic Medications
i) Avoid acepromazine
ii) Avoid alpha-2 agonists (xylazine & medetomidine)
iii) Avoid high doses of opioids and benzodiazepines
b) Induction
(1) Avoid barbiturates, especially if hypoalbuminemic
c) Maintenance
i) Avoid halothane
ii) Avoid methoxyflurane
d) Support
i) Avoid hyperventilation and positive pressure ventilation
(1) Both can decrease hepatic blood flow
(2) Maintain PaCO2 at or slightly above 40 helps preserve hepatic blood
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