Gastrointestinal / Hepatic Systems / Nutrition Flashcards
What are the respiratory quotients for lipogenesis, gluconeogenesis, and ketogenesis?
lipogenesis (from glucose): 1.0
gluconeogenesis (from alanine): 0.8
ketogenesis (from fat): 0.7
What vessels provide blood flow to the liver?
portal vein: 75% of flow, 50% of O2
hepatic artery: 25% of flow, 50% of O2
How do NSAIDs promote stomach ulceration?
decreased prostaglandin synthesis
- > decreased mucus secretion
- > increased corosive effects of HCl and pepsin
What does an ABG look like in a patient with acute, unremitting diarrhea?
a non-gap metabolic acidosis w/ hyperchloremia and hypokalemia
Which type of anesthetic is associated with quicker return of bowel function post-op?
thoracic epidural
Which classes of medications reduce LES tone?
anti-cholinergics
opioids
thiopental
volatiles
What are the ASA NPO guidelies?
clear liquids: 2 hours
breast milk: 4 hours
light meal, formula, non-human milk: 6 hours
heavy meal: 8 hours
How does propranolol decrease portal pressure?
blockade of ß2 receptor in the hepatic artery causing vasoconstriction
How is portal hypertension defined?
pressure gradient between the portal vein and IVC
>5: portal hypertension
>12: symptomatic
What should be used for volume resuscitation after large volume paracentesis?
5g of albumin per 1L of ascites removed
What are the components of the Child-Pugh score?
INR
bilirubin
albumin
ascites
encephalopathy
What are the components of the MELD score?
INR
bilirubin
creatinine
Is hepatorenal syndrome a pre-, post-, or intrinsic renal condition?
pre-renal that doesn’t respond to treatment
(likely vasoconstriction of renal arteries and vasodilatation of the splanchnic circulation)
How should muscle relaxants (except cisatracurium) be dosed in patients with hepatic failure?
Increased initial dose (larger volume of distribution)
Decreased maintenance dose (decreased metabolism)
How is hepatic blood flow affected by general anesthesia? Neuraxial anesthesia?
decreased for both
Why is hypocalcemia associated with increased morbidity and mortality in acute pancreatitis?
it’s a sign of calcium precipitating with fats degraded by the pancreatic enzymes
Which is associated with less morbidity and mortality, enteral nutrition or TPN?
there is no difference
Which is associated with a better immune response, enteral nutrition or TPN?
enteral nutrition
What are the transmission rates for HIV, HCV, and HBV following needle stick (roughly)?
HBV ~ 20%
HCV ~ 2%
HIV ~ 0.2%
After HCV infection, how many patient go on to develop chronic infection? Cirrhosis?
85% develop chronic infection
of those, 20% develop cirrhosis
How does propofol lead to pancreatitis?
It elevated triglycerides, which are broken down by pancreatic lipase to free fatty acids, which cause a proinflammatory state, leading to pancreatits (usually takes about a week)
Which opioid has causes the least sphincter of Oddi contraction?
meperidine
What drug counteracts the sphincter of Oddi contraction caused by opioids?
glucagon
How many ATPs are made per molecule of glucose via aerobic metabolism?
38
Why do cirrhotic patients often have an elevated SvO2?
high cardiac output and peripheral A-V shunting
Which electrolyte deficiency associated with TPN is most likely to cause respiratory failure?
hypophosphatemia
What are the risk factors for acalculous cholecystitis? Why is it a surgical emergency?
- trauma, surgery, and TPN
- rupture can occur within 48h
