Liver Flashcards by Maggie McDonell

How might liver dysfuntion typically present?

What are some labs that are essential to determine the cause and severity?

typically presents as flu-like symptoms followed by jaundice
Labs
- bilirubin
- aminotransferases (ALT, AST)
- alkaline phosphatase
- INR
- albumin
- serologic and genetic testing

How well did you know this?

Not at all

Perfectly

What is bilirubin?

What is its “pathway?”

Bilirubin is the pruduct of broken down hemoglobin and myoglobin
Unconjugated bilirubin is formed in the periphery, it is transported to the liver bound to albumin
- In the liver it is conjugated, making it water soluble so it can be excreted

How well did you know this?

Not at all

Perfectly

What increases unconjugated bilirubin?

What increases conjugated bilirubin?

Unconjugated
- increased bilirubin production
- decreased hepatic uptake
- decreased conjugation
Conjugated
- decreased canalicular transport of bilirubin
- acute/chronic hepatocellular dysfunction
- obstruction of bile ducts

How well did you know this?

Not at all

Perfectly

What is the difference between AST and ALT?

What can the ratio of AST to ALT tell us?

AST represents Liver AND extrahepatic tissues
ALT is highly specific to the liver
Ratio of AST:ALT
- 2:1 is seen in patients with Alcoholic liver disease (ALD)
- <1 is seen in patients with non-alcoholic steatohepatitis (NASH)

How well did you know this?

Not at all

Perfectly

What can an elevated alkaline phosphatase tell us?

Increases in serum Alk phos levels lack specificity because it is found in cell membranes throughout entire body
In Cholestatic disorders, increased levels may indicate that bile salts are damaging hepatocyte membranes

How well did you know this?

Not at all

Perfectly

What can the INR tell us regarding liver disease?

INR is a good test of the liver’s ability to synthesize things
- if clotting time is prolonged, the liver may not be making adequate clotting factors
INR depends a lot on factor VII, which is produced in the liver and relies on Vit K
- other vitamin K clotting factors are II, IX, X, proteins C and S
INR is part of MELD score because it is a reliable independent risk factor for mortality

How well did you know this?

Not at all

Perfectly

What is another scoring tool used to determine mortality with ESLD?

Child-Pugh score

How well did you know this?

Not at all

Perfectly

How is albumin used to assess liver function?

What else can cause decreased albumin levels?

Albumin is the most abundant plasma protein and is synthesized exclusively by hepatocytes
decreased albumin levels also seen in:
- protein malnutrition
- protein-losing disease (nephrotic syndrome)
- severe reduction in synthetic capacity of liver

How well did you know this?

Not at all

Perfectly

What lab differences would you see between prehepatic, intrahepatic, and posthepatic dysfunction? (chart)

Bili

AST/ALT

Alk phos

causes of changes

How well did you know this?

Not at all

Perfectly

What are the different types of liver disease?

Biliary disease (acute cholecystitis)
acute hepatitis
chronic hepatitis
cirrhosis
acute liver failure
porphyria

How well did you know this?

Not at all

Perfectly

What are the functions of the liver?

Glucose homeostasis
coagulation
metabolism of:
- drug/toxin
- heme
- cholesterol/lipid
- protein
production of thrombopoietin
**impaired liver function affects nearly every organ system in the body

How well did you know this?

Not at all

Perfectly

What is cholecystitis?

Who is at greatest risk?

symptoms

How is it treated?

gallbladder or biliary tract stone
Fat, fair, female, forty, fertile
symptoms:
- N/V
- fever
- abdominal pain
- RUQ tenderness radiating to back
- dark urine
- scleral icterus
Surgery when condition has stabled
- laparoscopic–>5% convert to open
- ERCP (endoscopic retrograde cholangiopancreatography)

How well did you know this?

Not at all

Perfectly

What are some considerations for all laparoscopic procedures?

insufflation will increase intraabdominal pressure
- risk for inadequate ventilation- decrease TV, increase RR
- decreased venous return leading to decreased CO and increased MAP and SVR
- bradycardia due to peritoneal stretching
Risk for vascular injury and acute blood loss
CO2 embolism

How well did you know this?

Not at all

Perfectly

General considerations for Liver patients

Consider volume and electrolyte replacement before procedure
Consider how pt will be positioned
- trendelenburg- increases venous return and CO
- reverse trendelenberg- aids surgical access and may improve ventilation but decreases venous return and CO
support HR and BP
Ventilation-watch PIP and MV
- adjust accordingling: decrease TV, increase RR
NG/OG tube
avoid N2O
careful use of opioids- risk of sphincter of oddi spasm

How well did you know this?

Not at all

Perfectly

How do inhaled agents affect blood flow to the liver?

Halothane: vasoconstriction of hepatic arterial bed, decreased O2 delivery to liver
- also a concern for halothane hepatitis
- NO Halothane, isoflurane, or sevoflurane
Isoflurane- increased flow velocity in hepatic sinusoids
Sevoflurane- equal or superior to Isoflurane in maintaining Hepatic artery blood flow (HABF)

How well did you know this?

Not at all

Perfectly

What is the Hepatic artery buffer response (HABR)?

Autoregulatory
matches a drop in portal bloodflow (PBF) with an increase in hepatic artery blood flow (HABF)

How well did you know this?

Not at all

Perfectly

What are the different types of hepatitis?

acute vs chronic?

Inflammation of the liver parenchyma
viral
autoimmune
drug induced
Acute- usually self limiting
- most often viral
- can be caused by drugs/toxins
Chronic- hepatic inflammation >6 months
- cirrhosis, hepatocellular carcinoma or liver failure
Symptoms can range from minimal (malaise/jaundice) to severe with multiple organ compromise

How well did you know this?

Not at all

Perfectly

What is autoimmune hepatitis?

How is it diagnosed?

How is it cured?

Treatment goals?

cellular immune response against self-antigens in the liver
diagnosis is confirmed with clinical findings, lab testing, and histologic evaluation
no curative intervention
Goal is to induce remission with corticosteroids and immunosuppressive drugs or liver transplantation

How well did you know this?

Not at all

Perfectly

What are some drugs that induce hepatitis?

What is APAP? How does it cause problems?

Study These Flashcards

Drugs that can induce hepatitis: (NOT a complete list)
- analgesics
- anticonvulsants
- antibiotics
- antihypertensives
APAP is acetaminophen
- uses up all the glutathione stores leading to inability to conjugate substances (free radicals??)
- Administer N-acetylcysteine within 8 hours (it provides cystein to make more glutathione)
Drug induced hepatitis resembles viral hepatitis so prompt diagnosis is important
remove offending agent

What is Halothane Hepatitis?

Study These Flashcards

An immune mediated hepatitis caused by all inhaled agents except sevoflurane
- Trifluoroacetyl halide metabolites covalently bond with microsomal proteins on hepatocytes, changing them from “self” to “non-self”
IgG antibody mediated
Halothane is the most common culprit d/t high degree of liver metabolism
Sensitized ppl may show cross-reactivity with other volatile anesthetics (except sevo)
- use TIVA or Sevo

What is cirrhosis?

What are some signs and symptoms?

Study These Flashcards

Chronic, progressive parenchymal damage leads to scarring and nodular formation
Signs/symptoms
- fatigue/malaise
- jaundice
- anorexia, weakness, N/V
- spider angiomata
- hypoalbuminemia
- ascites/hepatomegaly
- coagulation disorders
- endocrine disorders
- hepatic encephalopathy
- gastoresophageal varices
- hyperdynamic circulation
- hepatorenal syndrome

What labs would you expect to see elevated in a pt with cirrhosis?

decreased?

Study These Flashcards

elevated:
- bilirubin
- aminotransferase (AST/ALT)
- alk phos
- INR
decreased
- serum albumin
- platelets
- blood sugar

What is the Child-Pugh score?

Study These Flashcards

People with severe liver disease have a decreased ability to respond to stress
Child-Pugh score is used to predict surgical mortality with cirrhosis based on extent of liver damage and type of surgery
- total bili, serum albumin, INR, ascites, and hepatic encephalopathy
Class A- 10% mortality rate with intrabdominal surg
Class B- 30% mortality
Class C- 80% mortality
Class A&B ok for surgery if optimized, Class C avoid or delay elective surgery

How can the liver pt be optimized prior to surgery?

Study These Flashcards

improve diet with protein and caloric intake
blood glucsoe control pre/intra/post op
aldosterone antagonist
- cirrhosis is associated with increased aldosterone secretion
electrolyte and fluid status

What should you consider if your patient has hepatic encephalopathy? Ascites?

* encephalopathy * RSI! * Use sedatives and induction agents judiciously (or not at all) * Ascites * RSI * mechanical ventilation * pulmonary artery pressures * fluid status

What should you consider if your patient has esophageal varices?

* NO esophageal temp probe or NG/OG * If bleeding, RSI * octreotide 50 mcg/hr or vasopressin 20 units over 5 minutes

How can you prepare for the coagulopathy common in liver patients?

* type and cross * vitamin K non-emergently * FFP, cryo, platelets * the only factors NOT produced in the liver are factors III, IV, and XII * PRBCs * impaired ability to handle citrate loads * monitor ionized Ca * may need to administer Ca-- especially if they are not responding to pressors

How could liver disease affect pharmacokinetics of some drugs?

* low albumin will cause decreased protein binding and increased volume distribution * decreased clearance * Ex. larger initial dose of NDMR to compromise for the increased VD bt decreased subsequent dosing due to decreased clearance * use caution with drugs dependend on liver for clearance

What muscle relaxants are good choices?

* Cisatracurium * atracurium * mivacurium

What is importing regarding hepatic blood flow and anesthetics?

* Need to maintain liver blood flow * Hepatic artery is 25% of blood flow and 50% of O2 delivery * Portal vein is 75% of blood flow and 50% O2 delivery * IV anesthetics maintain hepatic blood flow if **arterial pressure is maintained** * All inhalational agents maintain hepatic blood flow except **halothane** * avoid SNS stimulation

What are some post-op concerns for patients with cirrhosis?

* Post-op morbidity is increased * liver dysfunction/failure (#1 problem) * pneumonia * bleeding * sepsis * poor wound healing * DTs * electrolyte disturbances * renal failure * **frequent aspiration**

What is the difference in anesthetic needs between acute and chronic ETOH use?

* Chronic ETOH causes enzyme induction = **increased** anesthetic needs * Acute ETOH **decreases** anesthetic needs due to additive effects * RSI

What are the symptoms of alcohol withdrawal syndrome?

* increased SNS/catecholamine release * agitation * tachycardia * delirium tremors- 48-72 hours post ETOH; this is a medical emergency * hallucinations * diaphoresis * cardiac dysrhythmias * hemodynamic instability * grand mal seizures and hypoglycemia

How is alcohol withdrawal syndrome treated?

* benzos * beta blockers (propranolol or esmolol) * airway protection * correct fluid/electrolyte and metabolic disturbances * DTs mortality rate is 10% d/t hemodynamic instability, cardiac dysrhythmias and seizures

What is porphyria?

* A metabolic disorder that results from deficiency of specific enzyme in the heme synthetic pathway * results in overproduction of porphyrins * accumulation of intermediate forms of porphyrin at the site of blocked enzyme

What are porphyrins essential for? How is heme production regulated?

* oxygen transport and storage * Heme is the most important porphyrin * heme is bound to proteins to form hemoproteins (including hemoglobin and CYP450 isoenzymes) * Heme production is regulated by aminolevulinic acid (ALA) synthase, which is in mitochondria * formation of ALA is controlled by endogenous concentrations of Heme in a feedback loop * \*\* In porphyria, an increase in heme requirements results in accumulation of pathway intermediates

What can induce ALA synthetase? What will that cause in a pt with porphyria?

* Any metabolism that relies on CYP450 will induce ALA synthetase * this will result in increased intermediates in a pt with porphyria

What is the most serious porphyria?

* Acute intermittent porphyria * affects central and peripheral nervous system * systemic HTN and renal dysfunction * this is life threatening!

What are some porphyria triggers?

* Enzyme inducing drugs * allyl group on barbiturates * steroid structure * avoid pentathol, thiamylal, methohexital, etomidate * hormonal fluctuations * menstruation/menopause/ pregnancy * fasting (pre-op) * dehydration * stress * infection

What are signs and symptoms of porphyria?

* Severe abdominal pain, N/V, due to autonomic neuropathy * ANS instability * electrolyte imbalances (Na, K, Mg) * skeletal muscle weakness- respiratory failure * cardiovascular instability resulting in hypertension and tachycardia (hypotension less likely) * seizures

How is porphyria treated?

* remove triggering agents * hydration * carbohydrates * treat pain, N/V * BB for HTN and tachycardia * benzos for sz * fluid and electrolyte balance * 10% glucose saline infusion * Hematin 3-4 mg/kg IV * Somatostatin * plasmapharesis

Anesthetic management of porphyria

* Pre-op prep: identify and avoid triggers * assess skeletal and CN function * assess cardiac- HTN, tachycardia * minimize multiple drug exposure * fluid/electrolyte management * anticipate post-op ventilation * minimize stress of pre-op fasting: glucose-saline infusion * preop meds: * anxiolytics, aspiration porphylaxis

What drug inhibits ALA synthetase activity and decreases heme consumption?

Cimetidine

GA in a pt with porphyria:

* Use short acting agents * moniors! * induction with propofol or ketamine * maintenance with N2O, IA, opioids or NDMR * cardiopulmonary bypass is a stressor

Is regional contraindicated in a pt with porphyria?

* Same contraindications and risks as other pts * Avoid regional in acute exacerbation of porphyria

What are the unsafe drugs for patients with porphyria?

* barbs * etomidate * sulfa antibiotics * ETOH * diazepam * Nifedipine * ketorolac * phenacetin

Liver Flashcards

(46 cards)