Kidney Disease (Final Exam) Flashcards
what are the basic functions of the kidney
- cleansing of the extracellular fluid (ECF)
- maintenance of ECF
- acid-base balance
- excretion of metabolic wastes and foreign substances
- eyrthropoiesis (making RBCs)
what are some ways the RAAS is activated to result in increased cardiac pumping and O2 demand
decreased blood volume, decreased BP, decreased renal perfusion, beta1 stimulation
renin release -> angiotensin I -> angiotensin II -> aldosterone (increases sodium and water retention and increases potassium excretion -> vasoconstriction
this is a syndrome characterized by rapid deterioration of renal function; it is reversible
acute kidney injury (AKI)
a ___________ (decrease/increase) in serum creatinine (SCr) concentration often associated with a reduction in urine volume in AKI
increase
true or false: BUN rapidly rises in AKI
true
true or false: oliguria (decreased urine output) is always present in AKI
false - not always present
what are some causes of AKI
- aging
- comorbidities
- trauma to kidney
this is the most common form of AKI. it is retention of metabolic wastes, and is monitored by BUN.It is the designation for a rise in SCr or BUN concentration due to inadequate renal plasma flow and intraglomerular hydrostatic pressure to support normal glomerular filtration. can produce widespread systemic affects.
pre renal azotemia
what are some causes of pre-renal AKI that cause an absolute decrease in circulating blood volume
- dehydration
- burns
- hemorrhage
what are some causes of pre-renal AKI that cause a relative decrease in circulating blood volume
- distributive shock (sepsis, anaphylactic)
- heart failure, MI
- decrease cardiac output
- third-spacing and edema
what are some primary renal hemodynamic abnormalities that cause pre-renal AKI
- occlusion or stenosis of renal artery
- drug induced impairment of renal auto-regulation in susceptive persons
what are some causes of intra renal AKI
- prolonged pre renal failure
- sepsis
- transfusion reactions
- rhabdomylosis
- antimicrobials
- cytotoxic chemotherapy agents
- snake and insect venom
- acute glomerulonephritis
what are some causes of acute post-renal AKI
- benign prostatic hyperplasia
- kinked or obstructed catheters
- intra-abdominal tumors
- calculi (kidney stones)
this is one of the theories related to the pathogenesis of AKI. accumulation of cellular debris. occlusion of tubules leads to decreased GFR
tubular theory
this is one of the theories related to the pathogenesis of AKI. afferent arterioles obstruction combined with efferent arteriole dilation (sepsis) leads to decreased GFR
vascular theory
true or false: under a normal situation, are arteriolar resistances the same or different in afferent and efferent arterioles
same!!
what happens intranrenally if there is decreased perfusion pressure in order to maintain a normal GFR
less resistance in afferent, more resistance in efferent to maintain a normal GFR
explain what happens intrarenally if someone is taking NSAIDs
afferent resistance increases because there are less vasodilatory prostaglandins (because NSAIDs inhibit these) therefore we get a low GFR
explain what happens intrarenally if someone is taking an ACE-I or an ARB
efferent resistance is reduced therefore more being filtered out than coming in which leads to low GFR
how may inflammation/injury lead to oliguria in AKI
inflammation/injury -> tubular obstruction -> increased tubular intraluminal pressure -> decreased GFR -> oliguria
what are some clinical manifestations of AKI
- fatigue/malaise
- dyspnea, orthopnea, rales, third hard sounds
- peripheral edema
- altered mental status
- elevated BUN
very vague
this is characterized by low GFR, oliguria, high urine specific gravity and osmolality and low urine sodium. S/S of fluid overload are present. if this is prolonged, it can lead to intra-renal injury
pre-renal AKI
this is caused by primary dysfunction of the nephrons. most often a problem within the renal tubules resulting in acute tubular necrosis.
intra-renal AKI
this is caused by obstruction within the urinary collecting system distal to the kidney; elevated pressure in the Bowman’s capsule; impedes glomerular filtration. if this is prolonged, can lead to intra-renal AKI
post-renal AKI
