GI and Liver Flashcards
What is the HABR?
Hepatic Artery Buffer Response
When portal flow decreases, hepatic arterial flow increases
and Vice Versa
What is a Phase 1 drug metabolism reaction in the liver?
Functionalization reactions, meaning the drug is exposed to or tagged with a functional group (oxidation, reduction, hydrolysis)
How are Phase 1 metabolic processes carried out?
Primarily by CYP450 enzymes
What is a Phase 2 drug metabolism reaction?
Conjugation Reactions
The functional group added to the substrate in Phase 1 gets linked to something else (glucuronic acid, sulfate, glutathione, amino acid, acetate etc)
What’s the difference between parenchymal and obstructive liver dysfunction?
Parenchymal means there’s a problem with the liver itself (the parenchyma)
Obstructive means stuff isn’t getting out of the liver, causing the liver to malfunction
Which three lab tests are used in the Child-Pugh classification system for liver failure?
Bilirubin
Albumin
PT
How do CO2 levels and pH impact hepatic circulation?
Hypercapnia and acidosis vasodilate hepatic circulation, increasing flow
Hypocapnia and alkalosis vasoconstrict hepatic circulation, decreasing flow
What fluid and electrolyte imbalances are associated with liver disease?
Low Albumin
Sodium retention, but dilutional hyponatremia
Progressive decline in renal function
decreased free water clearance
hypokalemia
Cirrhotic cardiomyopathy is characterized by:
hyperdynamic circulation
elevated baseline CO
reduced peripheral vascular resistance
decreased ventricular response to stressors
How are NMBAs impacted by hepatic dysfunction?
They all have prolonged action because there is reduced production of the cholinesterases that break them down
Acute cholelithiasis has a triad of symptoms:
Charcot’s Triad:
Fever and Chills
Jaundice
RUQ pain
What is Barrett’s esophagus?
damage to the esophageal epithelium leads to columnar cells replacing the normal squamous cells in the esophagus
Asymptomatic, but a risk factor for esophageal cancer
Gastric acid secretion is regulated by three stimuli:
acetylcholine, gastrin, and histamine
Most acute pancreatitis is caused by one of two things:
Alcohol abuse or gallstones
Are patients with acute pancreatitis usually hypo or hypervolemic?
Why?
Hypovolemic
They’re losing a lot of fluid into the peritoneum because of leaking capillary beds
They’re losing a lot fluid externally because of N/V
What is the classic diagnostic triad of chronic pancreatitis?
Steatorrhea
Pancreatic Calcification on Imaging
Diabetes
How does the diabetes produced by chronic pancreatitis differ from Type 1 diabetes?
Both the insulin producing beta cells AND glucagaon producing alpha cells are injured
This means they’re very sensitive to insulin treatment because they can’t raise their own glucose levels
Which inhaled anesthetic should be avoided in patients with inflammatory bowel disease?
Nitrous
What medication prevents carcinoid syndrome from occurring in patients with carcinoid tumors?
Octreotide, which is synthetic somatostatin
What is the hemodynamic response to insufflation?
Increased MAP, SVR, and HR
Decreased Stroke Volume
How does high pressure insufflation impact the cardiac conduction system?
It causes ventricular electrical instability, increasing the risk of arrhythmias
If there’s a sudden increase in PaCO2, EtCO2, decreased lung compliance or cardiac arrhythmias during insufflation, what should the anesthesia provider suspect?
Subcutaneous (vs. peritoneal) insufflation
It causes a much more rapid rise in CO2 levels and can cause LOTS of problems
What lung protection strategies can be used for patients undergoing laparoscopic surgery to reduce the incidence of barotrauma?
Vt 6-8 ml/kg Predicated Body Weight
6-8 cm H2O PEEP
Alveolar recruitment maneuvers every 30 min
What do most laparoscopic injuries occur?
During entry, but they’re often not found until several days later
What is the appropriate management if a gas embolism is suspected?
Stop insufflation
Turn off Nitrous
Release the pneumoperitoneum
Flood the field with NS
Place the patient in L lateral (durant maneuver)
Aspirate the gas through a CVC if in place
Support hemodynamics with meds
What is AION?
What causes it?
Anterior Ischemic Optic Neuropathy
occlusion or hypoperfusion of the anterior optic nerve
Cardia, vascular, and spine procedures
What is PION?
What causes it?
Posterior Ischemic Optic Neuropathy
Infarction of the optic nerve posterior to the lamina
elevated venous pressures, increased IOP, and interstitial edema
prone and steep trendelenberg positions
What are risk factors for POVL?
mal gender
obesity
prolonged anesthetic duration
High EBL
Low % of colloid in nonblood resuscitation
Why do liver failure patients take Rifaximin?
It eliminates ammonia producing bacteria in the gut
