13-14 Flashcards
Prerenal or functional renal failure is caused by a reduction in ___
Glomerular perfusion
Most prerenal ARF is caused by a decrease in ___
Effective intra-arterial volume
RBF remains remarkably constant through autoregulation despite wide variations in ____
BP and renal perfusion pressure from 70-150 mmHg
Maintenance of GFR is by combined ___
Afferent arteriolar vasodilation and efferent arteriolar vasoconstriction, which increases FF contributing to Na ad H2O retention
___ constructs the efferent arteriole and is the predominant influence in maintaining GFR
Ang II
BUN:Cr in acute renal failure (ARF)
>20:1 = prerenal failure <5-10:1 = liver disease
Muddy brown, dirty brown casts, DARK, think ___
But no blood or protein
Acute tubular necrosis
With prerenal azotemia and ATN what will you find with US?
Normal kidneys
What segments in the kidney are most susceptible to ischemia and nephrotoxins
PT
Thick a limb
3 phases of ATN
- Initial: ischemia or toxin exposure
- Maintenance: injury is established. GFR stabilizes at 5-10 urine output is lowest at this point
- Recovery: gradual rise in urine output and decrease in Cr caused by diuresis from salt and water accumulation
Tx of acute kidney injury:
Intravascular volume depletion:
___ is the replacement fluid of choice until stabilized.
NaCl - 0.9% - normal saline
Crystalloids
Tx of acute kidney injury:
Decreased Effective Volume:
Bacterial sepsis causes excessive ___ and ____. Treatment includes ____ and _____
Vasodilation and intrarenal vasoconstriction
Tx: NaCl and vasopressors
Tx of acute kidney injury:
Decreased Effective Volume:
Cirrhosis tx:
Lasix
Spironolactone
I’m treatment of impaired renal compensatory responses, stop use of ____
NSAIDs and ACEI
Pharmacological therapy for ATN:
What not to use/do
Dopamine Loop diuretics ANP Fenoldopan Acetylcysteine Protein restriction
therapy for ATN:
Keep blood sugar between ____
110-149 mg/dL
Profound renal vasoconstriction in the setting o histologically normal kidneys
Hepatorenal syndrome
Hepatorenal syndrome resembles prerenal azotemia. The defining feature is ___
Lack of improvement with volume expansion. Improves with liver transplant
Hepatorenal syndrome pathogenesis:
*primary mechanism is decrease in ____ which leads to hyperdynamic circulation and activation of vasoconstrictor systems
Impaired Na and H2O handling leads to fluid retention causing ascites and edema.
*splanchnic and systemic vascular resistance
Pathophys of HRS:
- a reduction in ____ due to ____ in the splanchnic circulation, triggered by ____. Caused by increased production or activity of ____, such as ____
- SVR
- Primary arterial vasodilation
- Portal HTN
- Vasodilator factors
- NO, Carbon monoxide, endogenous cannabinoids
HRS has a ___ survival rate
Very low
HRS
Stage 1
Stage 2
- Portal HTN is moderate, increased Cardiac output increases to compensate for decreased vascular resistance
- Severe portal HTN, cardiac output cannot compensate, vasoconstrictors are activated.
HRS
Causes ____ retention which leads to ascites and edema. This leads to renal failure by causing ____
Na and H2O
Cortical vasoconstriction and hypoperfusion
Renal failure rarely occurs in cirrhosis without ___
Ascites
