Ch. 28 Renal, Liver, and Biliary Tract Disease Flashcards
What does AKI stand for?
Acute Kidney Injury
The kidneys account for about ___% of total body weight and account for about ___% of cardiac output.
0.5%; 20%
(autoregulation) Renal blood flow and GFR remain relatively constant at renal arterial pressures of ___-___mmHg.
80-180mmHg
When might the renal autoregulation range be different?
chronic HTN
Any decrease in renal blood flow will initiate the release of _____.
renin
Roughly what percent of fluid that flows through glomeruli is reabsorbed?
~90%
What is normal GFR?
125cc/min
Renin may be released in response to any of three conditions - name them
SNS stimulation, decreased renal perfusion pressure, decreased sodium delivery to distal convoluted tubule
Prostaglandins may be released in response to any of three conditions - name them
sympathetic stimulation, HoTN, increased levels of angiotensin II
What is arginine vasopressin (AVP)?
ADH
Where does AVP bind?
V2 receptors in collecting duct
AVP has what effect on serum and urine osmolality?
decreases serum osmolality; increases urine osmolality
Which are more efficiently filtered at the glomerulus - drugs that are highly protein-bound drugs or those that are not?
drugs that are not highly protein-bound
What kind of drugs undergo passive reabsorption in the proximal and distal tubules?
un-ionized acidic drugs and basic drugs
What are the flaws in using serum Cr concentration as a measure of GFR?
concentration is dependent upon muscle mass
What are the flaws in using BUN as a measure of GFR?
influenced by protein metabolism and flow through renal tubules
Formula for determining GFR from serum Cr?
GFR = (140 - age) x kg wt/serum Cr x 72
Which method for determining GFR requires urinalysis and blood gas analysis?
creatinine clearance testing
Can proteins travel through the glomerulus?
yes, small ones can
What is proteinurea?
high levels of protein in the urine
Proteinurea is caused by what?
abnormally high filtration of protein, exercise, fever, or CHF
Which diuretics cause hypokalemic, hypochloremic metabolic alkalosis?
thiazides and loop diuretics
Which diuretics cause hyperglycemia?
loop diuretics (somewhat) and thiazides
What are side effects associated with diuretic-induced hypokalemia?
skeletal muscle weakness, risk of digitalis toxicity, enhancement of non-depolarizing NMBD
What is the most commonly administered osmotic diuretic?
mannitol (a six-carbon sugar)
Fluid overload secondary to cirrhosis is often treated with what diuretic?
spironolactone
What is the predominant cause of death in patients with ESRD?
cardiovascular disease
What are two of the most common reasons for systemic HTN in ESRD pts?
hypervolemia and excess activation of the renin-angiotensin-aldosterone system
Patients with prerenal oliguria have decreased/increased levels of Na+ in the urine? Why?
decreased. Low kidney perfusion due to hypovolemia or poor cardiac output - kidneys trying to conserve volume.
Patients with intrinsic renal disease have decreased/increased levels of Na+ in the urine? Why?
increased. Tubules ineffective at reabsorbing Na+.
The liver receives what percent of CO?
~25%
Most of the blood to the liver comes via the _____ with the rest supplied by the ______.
portal vein; hepatic artery
How is hepatic blood flow determined?
MAP or (portal vein P - hepatic vein pressure) and splanchnic vascular resistance
What is the main organ for the storage and release of glucose?
liver
In what form is glucose stored? What hormone releases glucose from its stored form back into the bloodstream? What is the process called?
glycogen; glucagon; gluconeogenesis
Hepatocytes are responsible for the synthesis of the majority of procoagulent proteins as well as regulators except for which factor?
factor VIII
Hepatic metabolism of drugs is characterized by the conversion of _____-soluble drugs to _____-soluble drugs.
lipid; water
What are the three phases of hepatic metabolism of drugs?
polarization, conjugation, excretion
What percentage of erythrocyte production occurs in the liver (in adults)?
~20%
Heme degradation results in what end product?
bilirubin
In the liver, bilirubin is turned into what?
bile
Does the liver store dietary fat as triglycerides, cholesterol and phospholipids?
yes it does!
What is hepatic encephalopathy?
worsening brain function when the liver is no longer able to get rid of toxic substances (i.e. ammonia)
What is physiologic shunting?
passage of blood from the arterial to venous side of circulation without effectively traversing a capillary bed (i.e. spider veins)
Gastric varices can develop as a result of what?
high resistance of blood flow through liver (characteristic of ESLD)
What drug has been shown to decrease symptoms of hepatic encephalopathy?
flumazenil
With severe liver disease, highly protein bound drugs are more likely to be found in the _____ form.
unbound
What is ascites?
buildup of fluid between lining of abdomen and abdominal organs
Inhaled anesthetics and regional anesthesia both _____ hepatic bloodflow __-__% in the absence of surgical stimulation.
decrease; 20-30%
What is a pre-operative test the can be used to assess liver function?
a liver function test
The Child-Pugh score is used to assess what?
severity of liver dysfunction
The MELD score is used to assess what?
severity of liver dysfunction
Why might liver disease be exposed during surgery?
The liver has large reserves, so when part of it is damaged, it won’t necessarily show up on a liver function test. The decrease in liver function during anesthesia exposes it.
Patients with what condition may bleed when a TEE probe is placed?
esophageal varices
IV anesthetics have what effect on hepatic blood flow?
minimal
Sympathetic stimulation has what effect on hepatic blood flow?
decreases
Which volatile anesthetic can cause hepatotoxicity?
halothane
Alcohol has what effect on gastric emptying?
slows
What is the treatment for alcohol withdrawal?
benzos
How common are gallstones in men and women between ages of 55-65?
men ~10%, women ~20%
What are the reasons for using an OG or NG tube during laparoscopic surgery?
decompression of stomach decreases risk for visceral puncture at time of needle insertion; also improves visualization
