Lecture 6.2 highlights Flashcards
True or false: both BUN and creatinine can build up when GFR is low
True
There are 3 forms of acute kidney injury; list and describe them
1) Prerenal = lack of blood flow to the kidney
2) Postrenal = obstruction of urine outflow
3) Intrarenal = intrinsic kidney disease
1) In step 1 of prerenal AKI, there’s low blood flow to the kidneys; what is the effect of this?
2) What is not impacted?
1) Filtration is impaired
2) Resorption in the tubules is intact
In step 2 of prerenal AKI, what 2 things are not adequately filtered out?
1) Blood Urea Nitrogen
2) Creatinine
In step 3 of prerenal AKI:
1) Some ______ is resorbed
2) Therefore, both values (BUN and Cr) go up, but BUN goes up _________
3) This occurs at a ratio of about _______ and is a clinically significant laboratory finding
1) BUN
2) higher
3) 20:1
Prerenal AKI: Because filtration is down, _______ is down
GFR
Prerenal AKI:
________ > ang I > ang II > Aldo/ADH
Renin
What urine osmolality level is a marker of increased resorption secondary to the effect of ADH?
Elevated osmolality (high solute)
In prerenal AKI, urine has ________ sodium
This is evidence of the action of aldosterone
low
Post Renal AKI:
1) In step 1, there is a(n) _____________ of the urine outflow.
2) After urine volume grows, the normal direction of ______________ force which favors filtration is met with a significant _______________.
3) What is the end result of this on filtration and resorption?
1) obstruction
2) hydrostatic; “backwards pressure”
3) Filtration is impaired; resorption remains intact
Kidney damage can occur in what 4 places?
Tubules, interstitium, blood vessels, glomeruli
What are the 2 types of ATN (acute tubular necrosis/ injury)? What are the effects of each?
1) Ischemic ATI: reduced blood to kidneys following MI, cardiac arrest, ischemia (hypotensive shock) → damages tubules
2) Nephrotoxic ATI: Poisons, antibiotics (gent), and IV contrast → damage tubules
Toxic type ATN:
1) A blood borne toxin is delivered to the _____________ where is it filtered out
2) This toxin is then dumped directly into where?
1) glomerulus
2) Proximal convoluted tubule
1) In toxic type acute tubular necrosis, do the cells undergo necrosis or apoptosis?
2) Is there local inflammation? Why/ why not?
1) Apoptosis
2) Cells are unable to be resorbed; local inflammation still ensues
In ischemic type of ATN, what is the main issue? What is not being supplied with blood?
Impaired renal blood flow; peritubular capillaries
The peritubular capillaries have what two jobs?
1) Resorb
2) Perfuse
Are the cells of the renal tubules resilient to ischemia?
No; very susceptible to ischemia
1) In an ATN pt, collection of apoptotic mass in the renal tubules leads to formation of “__________” casts that show up on UA
2) What is obstructed in this stage?
1) waxy brown
2) Flow of urine
1) What type of flow is occurring when a pt with ATN becomes oliguric?
2) What does this flow cause to be impaired?
3) What does this impairment cause?
1) Retrograde
2) Filtration
3) Oliguric (for a second reason), potassium buildup
What does BUN:Cr look like in an ATN pt?
BUN:Cr is not drastically different (appx 10:1)
What can happen as the epithelium regenerates in an ATN pt? (2 things)
Pt becomes:
1) Polyuric
2) Volume depleted
What 3 distinct conditions fall under the category of Acute Interstitial Nephritis (AIN)?
1) Pyelonephritis
2) Allergic Nephritis
3) NSAID Nephropathy
Ascending infection following UTI is usually the cause of what?
Acute pyelonephritis
E. coli is a common cause of what kidney conditions?
Acute pyelonephritis
Pyelonephritis Pathology: Infxn __________ the tubules, then spreads to the ____________
ascends; interstitium
What two phagocytes occur with polynephritis?
Neutrophils > macrophages
Pyelonephritis Pathology:
1) When neutrophils are done causing local damage, they die, forming _____________ in the tubules
2) What is an enzyme produced by WBC that is also detectable in urine?
1) “WBC casts”
2) Leukocyte esterase
Allergic Interstitial Nephritis:
1) List the drug rxns that can cause this
2) What mediates it? When does it start?
3) What are45 Sx?
4) True or false: Withdrawal of drug usually leads to recovery
1) Sulfa, antibiotics (Betalactams), diuretics
2) Immune mediated (mixed); ~15 days after drug exposure.
3) Fever, eosinophilia, rash, hematuria
4) True
Allergic Nephritis: what infiltrates the interstitial space?
Leukocytes (eosinophils)
List some characteristics of the typical allergic nephritis patient
1) AKI
2) Fever, eosinophilia, rash
3) New medicine
1) Afferent tubule is less sensitive to the effect of angiotensin II; one reason is bc it can __________ the effect of angiotensin II with ______________ that allow it to remain dilated.
2) What do NSAIDs allow for?
3) What does this do to the kidney and why?
1) block; prostaglandins
2) Blocking prostaglandins; both the afferent and efferent tubules to become constricted at once
3) Reduces blood flow through the glomerulus which injures the kidney
Define CKD
Broad term; describes the final common pathway of progressive nephron loss resulting from any type of kidney injury.
High hydrostatic pressure occurs in Bowman’s capsule; what are 2 things that move [into Bowman’s space and then to renal tubules] to ultimately get resorbed?
1) Water
2) Ions
Capillaries in Bowman’s capsule are meant to be a filter; therefore, the endothelial cells are ______________
fenestrated
Glomerular filtration:
1) Just past the endothelial cells lies the ______________
2) Past this, are the podocytes (“foot cell” etymology) that wrap their appendages around the _____________
1) basement membrane
2) fenestrations
Glomerular filtration:
1) The ______________ are what regulate what gets through.
2) Nephrin molecules make “____________” between foot processes by being _________ and by having a __(+/-)__ charge.
1) podocytes
2) “nephrin bridges”; small; positive (+)
In glomerular filtration, what are the sizes of:
1) Fenestrations
2) Space between podocyte pedicles
3) Albumen (not supposed to get through)
1) 75 nm
2) 35 nm
3) 15 nm
Glomerular filtration:
The ____________ are what regulate what gets through and they have ______________ with small spaces between them.
podocytes; pedicles
Nephrotic Syndrome causes damage to what?
Podocyte
Nephrotic Syndrome: This results from damage to the basement membrane in the glomeruli with loss of _______________ “podocyte effacement
filtration slits
1) How big are leukocytes that would normally be much too large to pass through the glomerulus, but can during nephrotic syndrome bc of the inflammation?
2) In nephrotic syndrome, RBCs that are only ____________nm will have no problem getting through and coming to reside in the lumen of the renal tubules where they turn to ____________.
1) 25,000nm
2) 6,000nm; RBC casts
Nephrotic syndrome:
1) RBCs that are only 6,000nm come to reside in the lumen of the renal tubules where they turn to ____________
2) Both ________ and ___________ are markers that can be identified on urinalysis
3) True or false: some albumin can also get through
1) RBC casts
2) RBC casts and leukocytes
3) True
1) What mediates Acute Post-Infectious Glomerulonephritis?
2) What does it usually occur 1-4 weeks after?
3) What is a hallmark Sx?
1) Immune complex
2) Group A Strep infection
3) Tea colored urine
1) Most common primary glomerulonephritis worldwide is what?
2) What is the hallmark?
3) When does it occur?
1) IgA nephropathy
2) Deposition of IgA in Mesangium
3) Occurs 1-2 days after upper respiratory tract as gross hematuria
Autosomal Dominant (ADULT) Polycystic Kidney Disease:
1) What is the pathogenesis?
2) What do the kidneys look like?
1) Mutations in the gene encoding polycystin 1 & polycystin 2
2) May be very large and contain many cysts.
Autosomal Recessive (CHILDHOOD) Polycystic Kidney Disease
1) What is the inheritance pattern?
2) What do the kidneys contain w this condition?
3) What else is seen w this disease?
1) Autosomal recessive inheritance
2) Kidneys contain small numerous cysts.
3) Oligohydramnios
Name something that can increase your chances of renal cell cancer
Smoking
Hematuria, flank pain, palpable mass are a classic triad for what?
Renal cell cancer
Most common solid (non-hematologic) cancer in children <10
Wilm’s Tumor
