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Questions and Answers
What effect does decreased hepatic blood flow have on the metabolism of anesthetic drugs with high hepatic extraction ratios?
What effect does decreased hepatic blood flow have on the metabolism of anesthetic drugs with high hepatic extraction ratios?
Which of the following anesthetic agents is primarily metabolized in the liver and exhibits decreased clearance and prolonged half-life?
Which of the following anesthetic agents is primarily metabolized in the liver and exhibits decreased clearance and prolonged half-life?
What is a significant concern when administering midazolam in patients with liver disease?
What is a significant concern when administering midazolam in patients with liver disease?
In the context of peripheral nerve blockade, what factor can affect the duration of action of local anesthetics?
In the context of peripheral nerve blockade, what factor can affect the duration of action of local anesthetics?
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What consideration should be taken into account when using nitrous oxide in patients with impaired hepatic oxygenation?
What consideration should be taken into account when using nitrous oxide in patients with impaired hepatic oxygenation?
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What factor is most critical for the clearance of drugs with high extraction ratios?
What factor is most critical for the clearance of drugs with high extraction ratios?
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Which anesthetic consideration is crucial in patients with advanced liver disease?
Which anesthetic consideration is crucial in patients with advanced liver disease?
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What is a contraindication for performing a percutaneous liver biopsy?
What is a contraindication for performing a percutaneous liver biopsy?
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How should hypotension be managed during neuraxial anesthesia to maintain hepatic perfusion?
How should hypotension be managed during neuraxial anesthesia to maintain hepatic perfusion?
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Which type of local anesthetics are primarily metabolized by the liver?
Which type of local anesthetics are primarily metabolized by the liver?
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What procedure utilizes a shunt between the hepatic vein and portal vein to treat bleeding varices?
What procedure utilizes a shunt between the hepatic vein and portal vein to treat bleeding varices?
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What effect does a high neuraxial block (T-5) have on liver function?
What effect does a high neuraxial block (T-5) have on liver function?
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Which of the following is true regarding peripheral nerve blockade and liver function?
Which of the following is true regarding peripheral nerve blockade and liver function?
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Which statement is true about the metabolism of ester local anesthetics?
Which statement is true about the metabolism of ester local anesthetics?
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In the context of hepatic perfusion, what is a critical factor to avoid during anesthesia?
In the context of hepatic perfusion, what is a critical factor to avoid during anesthesia?
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What is the primary goal of managing hepatic blood flow in patients with liver disease during surgery?
What is the primary goal of managing hepatic blood flow in patients with liver disease during surgery?
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How does altered protein binding affect drug metabolism in patients with liver disease?
How does altered protein binding affect drug metabolism in patients with liver disease?
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What adjustment should be made to anesthetic drugs for patients with reduced hepatic function?
What adjustment should be made to anesthetic drugs for patients with reduced hepatic function?
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What is a significant concern when inducing general anesthesia in patients with liver disease?
What is a significant concern when inducing general anesthesia in patients with liver disease?
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What is the impact of ascites on drug volume distribution in patients with liver disease?
What is the impact of ascites on drug volume distribution in patients with liver disease?
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What effect does impaired hepatic metabolism have on anticoagulant therapy in patients with liver disease?
What effect does impaired hepatic metabolism have on anticoagulant therapy in patients with liver disease?
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What should be monitored during perioperative management in patients with liver disease?
What should be monitored during perioperative management in patients with liver disease?
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What is the explanation for lower anesthetic doses required for patients with liver impairment?
What is the explanation for lower anesthetic doses required for patients with liver impairment?
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What is the primary purpose of placing a shunt in patients with ascites and esophageal varices?
What is the primary purpose of placing a shunt in patients with ascites and esophageal varices?
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Which complication is commonly associated with major hepatectomy?
Which complication is commonly associated with major hepatectomy?
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What change occurs in the minimum alveolar concentration (MAC) during acute alcohol intoxication?
What change occurs in the minimum alveolar concentration (MAC) during acute alcohol intoxication?
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In chronic alcoholics undergoing anesthesia, what is a common effect on anesthetic drug metabolism?
In chronic alcoholics undergoing anesthesia, what is a common effect on anesthetic drug metabolism?
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Which symptom is associated with severe alcohol withdrawal syndrome?
Which symptom is associated with severe alcohol withdrawal syndrome?
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What condition results from a genetic deficiency in one of the enzymes needed for heme production?
What condition results from a genetic deficiency in one of the enzymes needed for heme production?
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Which testing parameter is essential for assessing synthetic liver function in chronic alcoholics?
Which testing parameter is essential for assessing synthetic liver function in chronic alcoholics?
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Which of the following can act as a trigger for Acute Intermittent Porphyria?
Which of the following can act as a trigger for Acute Intermittent Porphyria?
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What is a primary concern when managing a patient with splenic or hepatic disease requiring general anesthesia?
What is a primary concern when managing a patient with splenic or hepatic disease requiring general anesthesia?
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What common postoperative complication is associated with hepatic resection?
What common postoperative complication is associated with hepatic resection?
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Study Notes
Liver Disease and Anesthesia
- Patients with liver disease have altered pharmacokinetics and are more susceptible to CNS-depressant effects
- Monitor coagulation, electrolytes, and albumin levels
- Treat ascites and encephalopathy
- Maintain cardiac output to support hepatic blood flow
- Be vigilant for alcohol withdrawal
Perioperative Management
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Altered Pharmacokinetic Considerations
- Reduced albumin levels and drug-binding proteins
- Increased Total Body Water (TBW) due to ascites
- Reduced drug metabolism
- Potentiation of anticoagulants due to decreased clotting factor production
- Altered drug elimination, including altered enzymatic activity, altered hepatic extraction, and low albumin
- Impaired oxidative metabolism
- Conjugation relatively unaffected
- Biliary excretion depends on intrahepatic shunting
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Overall:
- Systemic medications should be decreased by 50%
- Patients with liver disease have an increased Volume of Distribution, requiring an increase in the initial dose
- Smaller doses are subsequently administered at longer intervals
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General
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Induction of General Anesthesia
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Monitoring
- Arterial line (AL), Pulmonary Artery Catheter (PAC), Transesophageal Echocardiogram (TEE), Thromboelastography (TEG)
- Increased aspiration risk and rapid desaturation
- Preoxygenate and use Rapid Sequence Intubation (RSI)
- Propofol, Etomidate, and Midazolam minimally affect hepatic artery perfusion during short procedures
- Expect increased susceptibility to CNS depressant effects
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Monitoring
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Transjugular Intrahepatic Portosystemic Shunt (TIPS)
- Used to treat ascites and esophageal varices
- Shunt placed between portal vein and hepatic vein, bypassing the liver
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Induction of General Anesthesia
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Hepatic Resection
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Major Hepatectomy
- Resection of 3 or more liver segments
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Complications
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Bleeding
- Vasopressors can decrease blood loss by reducing splanchnic pressure
- Portal Triad Clamping of afferent vessels
- Total vascular occlusion (Portal Triad plus IVC)
- Ischemic preconditioning (occlusion, reperfusion, clamping)
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Air Embolism
- Increased risk if tumor is near vena cava or involves portal vessels
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Bleeding
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Postoperative
- Pleural effusions, biliary leakage, wound dehiscence, ascites, abdominal abscess
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Major Hepatectomy
Alcoholism and Anesthesia
- Malnutrition and dehydration
- Decreased infection resistance and delayed wound healing
- Liver damage: Monitor labs and use scoring systems
- Pulmonary complications due to smoking, COPD, or HPS
- Cardiomyopathy: Arrhythmias are common
- Renal disease: Glomerulonephritis or Hepatorenal Syndrome (HRS)
- Neurological disease: Neuropathy, Delirium Tremens (DTs), or acute intoxication
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Cross Tolerance to medications:
- Benzodiazepines and other sedatives stimulate the same receptors as many anesthetics
- Patients with End-Stage Liver Disease (ESLD) are more sensitive to medications if the liver cannot metabolize them
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Chronic Alcoholics
- May have cardiomyopathy and dysrhythmias
- Predisposed to aspiration and may have diminished pulmonary function
- May have impaired synthetic liver function: Monitor albumin and prothrombin time
- Alcohol withdrawal may cause seizures
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Acute ETOH Intoxication
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Acutely Intoxicated:
- Decreased Minimum Alveolar Concentration (MAC)
- Aspiration risk due to decreased gastric emptying and lower esophageal sphincter tone
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Alcoholic (Not acutely intoxicated):
- Increased MAC
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Alcohol Withdrawal Syndrome:
- Tachycardia, agitation, increased Sympathetic Nervous System (SNS) tone 48-72 hours after last alcohol intake
- Tremulousness, hallucinations, hyperpyrexia, cardiac dysrhythmias, and grand mal seizures
- Severe withdrawal (Delirium Tremens) is a medical emergency
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Acutely Intoxicated:
Porphyrias
- Rare genetic aberrations in heme production
- Accumulation of porphyrins in tissues
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Acute Intermittent Porphyria:
- Most common type (1:10,1000)
- Recurrent serious neurologic reactions, abdominal pain, dark urine, hypertension
- Can be life-threatening
- Triggers: Barbiturates, sex hormones, glucocorticoids, cigarettes, other meds (ketorolac, phenytoin, birth control pills, sulfonamides, benzodiazepines, ketamine)
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Cutaneous Porphyria:
- Porphyrins build up in skin
- Symptoms occur when skin is exposed to sunlight
Anesthesia Considerations for Liver Disease
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General Anesthesia
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Hepatic Blood Flow
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High Extraction Ratio Medications
- Propofol, Fentanyl, Morphine, Labetalol, Propranolol
- Clearance is highly dependent on hepatic blood flow
- Reduce dose but not frequency
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High Extraction Ratio Medications
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Neuraxial
- May be contraindicated due to coagulopathy and/or thrombocytopenia
- Reduced doses in advanced liver disease
- Epidural anesthesia can be used for lower abdominal and limb surgeries
- Avoid hypotension to maintain hepatic perfusion
- Avoid high neuraxial block (T-5) due to decreased hepatic blood flow
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Peripheral Nerve Blockade
- No negative effects on hepatic blood flow or liver function
- Remember some local anesthetics are metabolized by the liver
- Esters: Hydrolysis by pseudocholinesterase in plasma
- Amides: Biotransformation in the liver
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Hepatic Blood Flow
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Procedural Considerations
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Liver Biopsy
- Method of choice to determine liver damage
- Contraindicated in coagulopathy or thrombocytopenia
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TIPS Procedure
- Interventional encephalopathy procedure
- Access hepatic vein via internal jugular vein and place shunt between hepatic vein and portal vein
- Treats bleeding esophageal varices and refractory ascites
- Risks: Hemoperitoneum, unintentional shunt formation between hepatic artery or bile ducts and portal vein, worsening encephalopathy
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Liver Biopsy
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Induction Agents
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Propofol, Ketamine, Etomidate
- Highly lipid-soluble and high hepatic extraction ratios
- Expect decreased clearance in liver disease
- Clearance mostly unaltered with cirrhosis
- Increased Volume of Distribution may prolong elimination
- Recovery time after propofol infusion may be prolonged in cirrhotic patients
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Dexmedetomidine
- Liver metabolism primarily with little renal clearance
- Decreased clearance and prolonged half-life
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Midazolam
- Reduced clearance prolongs elimination half-life
- Infusion is a bad choice due to prolonged elimination
- Benzodiazepines: Metabolized in the liver, use with caution in the elderly
- Lorazepam undergoes phase II glucuronidation, normal metabolism in liver disease
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Succinylcholine:
- Avoid in hyperkalemic patients
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Propofol, Ketamine, Etomidate
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Maintenance of General Anesthesia
- Monitor and IV access based on preexisting disease and surgical procedure
- Maintain cardiac output and hepatic blood flow
- Avoid hypocapnia
- Hematologic considerations - perioperative bleeding
- Meticulous fluid management (albumin!)
- Avoid hypothermia
- Increased susceptibility to CNS-depressant effects
- Nitrous oxide: Appears to be safe if not used in the setting of impaired hepatic oxygenation
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Description
This quiz covers the essential considerations for managing patients with liver disease undergoing anesthesia. It highlights the altered pharmacokinetics and the necessary monitoring for complications associated with liver dysfunction. Understanding these key elements is crucial for ensuring patient safety in perioperative settings.
