Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
82 Cards in this Set
- Front
- Back
|
how do diuretics increase urine flow?
|
inhibiting the reabsorption of Na+ at different sites along the nephron
|
|
|
Reabsorption:
|
ion transport from urine to blood
|
|
|
secretion:
|
ion transport from blood to urine
|
|
|
What would result if you enhance the delivery of Na+K+H+ exchange site?
|
augment K+ and H+ secretion
leading to hypokalemia and metabolic alkalosis |
|
|
Why does inhibiting Na+ reabsorption at the proximal sites(where the majority of reabsorption occurs) not result in great efficacy?
|
The more distal sites will work harder to compensate for the lack of Na+ reabsorption
|
|
|
What happens if a diuretic acts on the Na/K/H exchange site in the collecting tubule?
|
it will increase the amount of Na delivered to that site
|
|
|
What is the site of action of osmotic diuretics?
|
proximal tubule
|
|
|
What is the MoA of osmotic diuretics?
|
inhibition of H20 reabsorption by osmotic aciton
|
|
|
Where is the site of action of carbonic anhydrase inhibitors?
|
proximal tubule
|
|
|
What is the MoA of carbonic anahydrase inhibitors?
|
inhibition of NaHCO3 reabsorption (which enchances Na excretion)
|
|
|
What is the MoA of Loop Diuretics?
|
inhibition of active salt transport
|
|
|
Where is the site of action of Loop Diuretics?
|
thick ascending limb of the loop of Henle
|
|
|
Where is the site of action of Thiazides?
|
Early distal tubule
|
|
|
What is the MoA of Thiazides?
|
inhibition of NaCl reabsorption
|
|
|
What is the MoA of Potassium-sparing diuretics?
|
inhibition of Na reabsorption and K secretion by competitive antagonism of aldosterone (spironolactone)
Or by direct action(triamterene or amiloride) |
|
|
Where is the site of action of potassium sparing diuretics?
|
late distal tubule and cortical collecting duct
|
|
|
Which group of diuretics are used the least?
|
osmotic diuretic
|
|
|
Are osmotic diuretics useful in treating Na retention conditions?
|
No.
They only increase the water excretion |
|
|
When are osmotic diuretics used?
|
cerebral edema
acute renal failure due to shock glaucoma (pulls H20 from tissues to blood) |
|
|
What do you need to be careful of with osmotic diuretics?
|
severe dehydration if not taken with adequate water replacement
|
|
|
Name some osmotic diuretics
|
mannitol
urea glycerol isosorbide |
|
|
Name some anhydrase inhibitors
|
Acetazolamide
Dorzolamide |
|
|
What does carbonic anhydrase do?
|
catalyzes the conversion of H2Co3 to Co2 and H20
|
|
|
What can result if Na/HCO3 are increased in the collecting tubule?
|
K+ wasting
|
|
|
Why is it useful to have Na/HCO3 retained in the lumen?
|
increases urinary pH, which will result in renal excretion of weak acids (aspirin)
|
|
|
Acetazolamide can be used to treat what?
|
high altitude sickness
|
|
|
Why can acetzolamide be used to treat high altitude sickness?
|
it decreases CSF formation which is a life-threatening complication of high altitude sickness
|
|
|
Dorzolamide is used to treat what?
|
glaucoma
|
|
|
Name some Loop Diuretics
|
Furosemide
Ethacrynic Acid Bumetanide |
|
|
Loop diuretics promote the excretion of what?
|
Ca and Mg
|
|
|
Loop diuretics can be used to treat what?
|
hypercalcemia
|
|
|
Loop diuretics usually treat what type of pt?
|
pt with impaired renal function who have pulmonary edema, CHF or hypertension
|
|
|
With loop diuretics there is a risk of what?
|
potent loss of
Na Cl K Mg Ca HCO3 H20 |
|
|
What are other adverse effects, besides loss of electrolytes, of loop diuretics?
|
ototoxicity (with reversible hearing loss)
|
|
|
Furosemdide and ethacrynic acid are what type of diuretic and the pt is at what risk with their use?
|
they are loop diuretic and can exacerbate gouty attacks
|
|
|
What are the most widely used diuretic agent?
|
thiazides
|
|
|
Name some thiazides
|
hydrocholorthiazide
chlorthalidone indapamide |
|
|
Thiazide treat what symptoms/diseases?
|
CHF
hypercalciuria diabetes insipidus (polyuria) |
|
|
How do thiazides increase NaCl excretion?
|
inhibit reabsorption in the early distal tubule by inhibition of the Na/Cl co-transporter on the luminal membrane
|
|
|
Thiazides can promote loss of what electrolyte?
What can you do to decrease this effect? |
K+
dietary supplementation |
|
|
What are some risks of thiazides?
|
pt with diabetes can become hyperglycemic
maybe because of an impaired pancreatic release of insulin deplete extracellular fluid volume unfavorable lipid profile |
|
|
Do Thiazide promote Ca retention or excretion?
|
retention!
|
|
|
Thiazide retention of Ca can help with what diseaes?
|
nephrolithiasis caused by idiopathic hypercalciuria
|
|
|
What organic compounds can block thiazides?
|
Probenecid, penicillin and salicylates
|
|
|
Name some Potassium-sparing diuretics
|
spironolactone
amiloride triamterene |
|
|
Do you use Potassium sparing diuretics alone or with other drugs?
|
use as adjuncts to loop or thiazide diuretics to prevent K depletion
|
|
|
Spironolactone competes with what hormone?
|
aldosterone
|
|
|
What role does aldosterone play in urine formation?
|
increases Na and K channels
increases activity of Na/K ATPase promotes salt and water retention decreases the amount of urine Spironolactone blocks this action |
|
|
Name some reasons for increased production of bile.
|
fetal-maternal blood group incompatibility
extravascular blood polycythemia hemoglobinopathies induction of labor |
|
|
Does breast feeding cause an increase or decrease in bile excretion
|
decrease in excretion
|
|
|
Why would an neonate have an increase in enterohepatic circulation of bile?
|
Bile is released into the small intestines, but keeps getting reabsorped
|
|
|
Hormones and drugs cause an increase or decrease in bile excretion?
|
decrease
|
|
|
What causes a decrease in bile excretion?
|
inborn errors of metabolism
prematurity hepatic hypoperfusion cholestatic syndrome obstruction hormones and drugs breast feeding increased enterohepatic circulation |
|
|
When dealing with neonatal jaundice, which type of bilirubin can be treated with phototherapy?
|
unconjugated
|
|
|
What type of bilirubin elevation is Crigler-Najar I/II?
|
unconjugated
|
|
|
Which is less severe Crigler-Najar I or II?
|
Crigler-Najar II is less severe
|
|
|
Does Crigler-Najar I response to Phenobarbital?
|
no
|
|
|
What does phenobarbital do?
|
helps enzymes conjugate bilirubin
|
|
|
What are the levels of unconjugated bilirubin in a person with Crigler-Najar I?
|
15-45mg/dL
|
|
|
When would symptoms of Gilbert's be noticible?
|
during stress
|
|
|
What is the pathological problem in Gilbert's
|
a mutation in the gene that codes for Bilirubin UDP glucuronyltransferase.
|
|
|
What does bilirubin UDP glucuronyltransferase do?
|
it binds unconjugated Bilirubin with glucuronic Acid to make it water soluble and be excreted as bile
|
|
|
What is the first question you should ask?
|
Is the bilirubin unconjugated or conjugated.
|
|
|
What could cause an increase in unconjugated bilirubin?
|
hemolysis or extravascular blood
|
|
|
What is the second question that you would ask when dealing with a jaundice neonate?
|
Is it intrahepatic or extrahepatic?
|
|
|
Why is it important to know if it is intra or extrahepatic?
|
It helps with prognosis and determining the need for surgery
|
|
|
Why can't you eat up to 4 hours before getting imaging on the gallbladder?
|
it contracts after eating.
|
|
|
How can you evaluate the biliary tree?
|
use Ultrasound
|
|
|
What does a HIDA scan (radionucleotide scan) show?
|
It shows uptake of the liver and the excretions into the small bowel
|
|
|
When taking a biopsy, what are you looking at?
|
The way cells are arranged
portal triad bile ducts fibrosis |
|
|
What is the idiopathy of intrahepatic jaundice?
|
neonatal hepatitis
or prematurity (may not ever know) |
|
|
What are some anatomical reasons for intrahepatic jaundice?
|
Congential fibrosis
Caroli's |
|
|
What is Caroli's disease/syndrome?
|
It is a congenital condition where there is multifocal, segmental dilatation of large intrahepatic bile ducts
|
|
|
What are some metabolic causes of intrahepatic jaundice?
|
AA
lipid CHO (galactosemia) a-1-antitrypsin CF Hypopit HypoT4 hemochromatosis TPN/NPO Tyrosinemia bile acid |
|
|
What are characteristics of Tyrosinemia?
|
progressive liver failure
renal tubular dysfunction hypophosphatemic rickets |
|
|
Biliary atresia is intra or extrahepatic?
|
extrahepatic
|
|
|
Pt is discovered to have choledochal cyst. How should you treat that?
|
surgery (surgical emergency)
|
|
|
Name the different causes of extrahepatic(ductular) jaundice.
|
biliary atresia
choledochal cyst spontaneous perforation mass bile duct stricture PFIC BRIC Alagille's syndrome Nonsyndromic paucity |
|
|
In a typical workup sequence, what is the first thing you would o?
|
Fractionate the bilirubin (direct vs indirect) and get a full hepatic panel
|
|
|
You order a full hepatic panel--What results will you get?
|
AST, ALT, GGT, albumin, TP (total protein)
Alkaline phosphatase |
|
|
If GGT is elevated--what does that indicate?
|
bile duct problems
|
|
|
Are pediatric's Alkaline phosphatase usually depressed or elevated compared to adults?
|
elevated
|
