Kidney Flashcards
What is the kidney responsible for?
- synthesis of renin
- acid-base balance
- reabsorption of electrolytes
- regulation of extracellular fluids
Where is angiotensin released?
the liver
how much do kidneys make up of total body mass
0.5%
how much of the resting cardiac output do the kidneys receive?
20-25%
what are risk factors for acute kidney injury?
- dehydration
- advanced age
- cirrhosis
List some nephrotoxic NSAIDs (i think all of them are?)
- ibuprofen
- celecoxib
- aspirin
- naproxen
how much does the kidney reabsorb?
bulk reabsorption: up to 80% of solute and water
controls urine concentration, up to 25% of water & solute are reabsorbed
What are some functions of the kidney?
- Excretion of wastes in the form of urine
- Regulation of extracellular fluid volume, electrolyte composition, acid/base balance
- Synthesis and release of hormones
What hormones are synthesized and released from the kidneys?
- 1,25 dihydroxyvitamin D
- renin
- EPO (erythropoietin) - stimulates production of RBC
What does the 20-25% of CO mean?
so 20-25% of any drug in the blood stream ends up in the kidneys, so that’s why kidneys are so susceptible to drug toxicity due to high exposure
Where are concentrate toxicants ?
in tubular fluid
Why are the kidneys susceptible to toxicity?
- 20-25% of CO, 0.5% of body mass
- concentrate toxicants in tubular fluid
- kidneys are responsible for metabolism of xenobiotics
- glomeruli and insterstitium are susceptible to attack by the immune system
Describe what will happen in an AKI (acute kidney injury)
Abrupt decline in GFR
-SCr increase >0.3mg/dL within 48 hours
OR
-SCr to > 1.5 times baseline within 7 days
OR
-urine volume < 0.5 mL/kg/hr for 6 hours
AKI is ___% secondary to medications
30
Describe a pre-renal AKI
- will cause impaired renal perfusion
- 55-60% of AKI’s are pre-renal
_____ can cause pre-renal AKI
NSAIDs
what causes volume depletion
diuretics, cathartics (purgative drug?), emetics
what causes bleeding
anticoagulants
what drugs cause cardiac dysfunction
B blockers, cardio toxins (such as doxorubicin)
what drugs cause vasoconstriction
NSAIDs calcineurin inhibitors (cyclosporin)
describe a renal AKI
- intrinsic damage to the kidney (glomerulus or vascular damage)
- 35-40% of AKI patients
what drugs cause vascular damage (thrombotic thrombocytopenia purpura)
cyclosporine, tacrolimus, quinine, clopidogrel