Exam 4

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Exam 4
2012-04-17 22:37:14

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  1. What causes more deaths and disabilities than any other illness in the world?
    Ischemic Heart Disease (IHD)
  2. What type of acute renal failure results from injury to nephrons and renal tissue?
    Intrarenal (Intrinsic)
  3. What would cause (etiology) Pre-Renal acute renal failure?
    • hypovolemia
    • hemorrhage
    • inadequate cardiac output (CHF)
    • shock
    • hypotension
    • renal vasoconstriction
    • **anything that causes a significant decrease in renal blood flow
  4. Which type of acute renal failure is reversible?
  5. Is intrarenal failure reversible?
    maybe, but not rapidly
  6. What are the causes of intrarenal acute failure?
    • vascular disease (malignant hypertension, disseminated intravascular coagulation)
    • acute glomerulonephritis (SLE, graft rejection, Goodpastures, post Streptoc, autoimmune)
    • interstitial disease (drug allergy)
    • acute tubular necrosis (ATN) ****MOST common cause
  7. What is the most common cause of intrarenal acute renal failure?
    Acute tubular necrosis (ATN): post ischemic and nephrotoxic
  8. What are the 3 types of ARF?
    • pre-renal
    • intrarenal (intrinsic)
    • post-renal (rare)
  9. What would you see in the urine if there is glomerular injury/damage?
    • albumin
    • casts
    • dysmorphic RBCs
  10. What are the 2 main causes of glomerulonephritis?
    • antigens/antibodies
    • cell-mediated
  11. What type of cells have a role in the progression of glomerulonephritis?
    T cells
  12. Which is a better measure of GFR, BUN or serum creatinine?
  13. What is azotemia?
    an excess of urea or other nitrogenous bodies in the blood
  14. What is oliguria?
    scant production of urine in relation to fluid intake
  15. What does a specific gravity test that is high tell us?
    • urine is concentrated
    • patient could be dehydrated
  16. What does a specific gravity test that is low tell us?
    the kidney is not concentrating the urine
  17. When are people most at risk for ATN (acute tubular necrosis)?
    • post surgery (40-50%)
    • sepsis
    • obstetric complications
    • severe burns
    • trauma
    • hypotension +/- hypovolemia, followed by reperfusion injury
  18. What type of antibiotics could cause intrarenal ARF nephrotoxicity?
    aminoglycosides (gentamicin, tobramycin)
  19. What are some contributing factors to intrarenal ARF nephrotoxicity?
    • Type 1 or 2 DM
    • age
    • dehydration
    • concurrent renal insufficiency
  20. What type of injury is more "patchy" within the nephron?
    ischemic injury
  21. What type of injury is caused by certain drugs accumulating in the cortex and is usually concentrated in one specific area of the nephron?
    toxic injury
  22. What are some causes of intrarenal ARF nephrotoxicity?
    • aminoglycosides
    • radiographic contrast media
    • heavy metals
    • heme pigments (bilirubin, myoglobin)
    • bacterial toxins
    • other factors: age, dehydration, diabetes, renal insuff
  23. What are the typical normal levels of BUN?
    10-20 mg/dl
  24. What is the normal range of SCr?
    0.7-1.2 ml/dl
  25. Which is easier to test, BUN or SCr?
    BUN b/c it is a blood test and SCr is a GFR timed urine test
  26. What are the four clinical stages of ATN?
    • onset
    • oliguria
    • diuresis
    • recovery
  27. What does the course of ARF depend on?
    • magnitude of the insult
    • length of time that hemodynamics are altered
  28. What is the most critical stage of ATN?
    Oliguric Stage
  29. What is the normal level of urine output per day?
    1-2 Liters
  30. How much urine is produced in 24 hours in anuria?
    less than 50 ml in 24 hours
  31. What will happen to a patient that has ARF fro 2-3 days?
    they will become anemic
  32. What can oliguria cause?
    • hyperkalemia
    • fatal cardiac dysrhthmias
    • metabolic acidosis
    • azotemia
  33. What are the 2 possible complications of diuresis?
    • dehydration
    • hypokalemia
  34. How long does the recovery period of ATN take?
    3-12 months
  35. What is the most common cause of death in ARF patients?
    infection as toxins render WBCs dysfunctional
  36. What are the causes of chronic renal failure?
    • immunologic (SLE)
    • infectious (pyelonephritis)
    • obstructive (neoplasms)
    • metabolic (diabetes)
    • vascular (hypertension, infarction)
    • nephrotoxins (heavy metals, solvents)
    • congenital (renal hypoplasia)
    • physical (radiation)
  37. When do we establish chronic renal failure?
    when ARF becomes irreversible
  38. what are the most important functions of the kidney?
    • water balance (via ADH/vasopressin)
    • electrolyte balance (via aldosterone)
    • acid-base balance
    • secretion of waste products (urea, creatinine)
    • blood pressure regulation (RAA system)
    • erthropoiesis
    • Vitamin D activation (via PTH)
    • responds to ANP
  39. Where does renal disease rank on the list of US mortality?
    • 9 in 2003
    • 8 in 2010
  40. In relation to acid-base balance, what ion does the kidney excrete and what does it reabsorb?
    • secretes H+
    • reabsorbs HCO3-
  41. What are the 3 main (broad) functions of the kidney?
    • filtration
    • reabsorption
    • excretion
  42. What 2 substances could you give to test GFR?
    • inulin
    • PAH
  43. What endogenous substance helps us measure GFR?
  44. What is AKI?
    acute kidney injury: sudden decline in kidney fxn and azotemia
  45. What is renal insufficiency?
    • typically renal fxn is 25% of normal
    • GFR is 25-30 ml/min
  46. What do we call a significant loss of renal fxn?
    renal failure
  47. What do we call it when we have less than 10% of renal fxn?
    end stage renal failure (ESRF)
  48. increased serum urea and/or creatinine = ?
  49. What is uremia?
    azotemia + signs and symptoms: fatigue, anorexia, N/V, pruritis, neuro disorders due to toxic waste buildup, electrolyte disorders, deficiencies
  50. What would we have to do to measure the TRUE GFR, but seldom do?
    inulin test
  51. What are the units for GFR?
  52. What does GFR reflect?
    the # of mls of blood filtered by the glomeruli in 1 minute
  53. What is typically measured in mg/dl?
    serum creatinine
  54. What is typically measured in mls/min and is a rate?
    creatinine clearance
  55. What are two other tests that are used to estimate GFR?
    • FeNA: fraction of excreted sodium (reflects kidney's ablility to reabsorb sodium)
    • MDRD: calculates estimated GFR
  56. What does MDRD stand for?
    modification of diet in renal disease
  57. Will there be more or less creatinine in the blood with a decrease in kidney function?
    more SCr
  58. What is the Cockcroft-Gault Formula for males?
    • CCR = (140-age) x weight(kg)
    • 72 x SCR
  59. What is the Cockcroft-Gault Formula for females?
    • CCR = (140-age) x weight(kg) x 0.85
    • 72 x SCR
  60. Who tends to have slightly higher Scr levels, males or females?
    males: aroung 1.3 mg/dl
  61. What is GFR useful for monitoring, chronic or acute renal disease?
  62. What is creatinine?
    • metabolite of muscle
    • produced at a constant rate
  63. What will trauma or muscle breakdown do to Scr?
    increase it
  64. If creatinine clearance goes up, is that a good thing or a bad thing?
  65. If serum creatinine goes up, is that a good thing or a bad thing?
  66. What is the normal range for creatinine clearance?
    90-140 ml/min
  67. If there is an increase in GFR, is that good or bad?
  68. If there is a decrease in GFR, is that good or bad?
  69. What is the cutoff for high IBW when calculating creatinine clearance (what % increase do we have to adjust the equations?)
    130% +
  70. T/f: both weight in kg and IBW can be used in the Cockcroft-Gault formula.
  71. What is BUN a reflection of?
    GFR and urine concentrating capacity
  72. Between Creatinine clearance and BUN, which one tends to overestimate GFR and which one tends to underestimate GFR?
    • BUN: under (b/c of reabsorption)
    • CCr: over
  73. What is the normal BUN: creatinine ratio?
  74. What are some conditions that increase BUN?
    • dehydration: allows increased reabsorption of urea
    • slowed flow of urea being reabsorbed= more reabsorption
    • Catabolism: GI bleed, cell lysis, steroid use
    • Increased protein in diet
    • Decreased renal perfusion: CHF, renal artery stenosis)
  75. What are some conditions that decrease BUN?
    • good or hyperhydration: decreased urea reabsorption
    • liver disease
    • SIADH (inappropriate ADH secretion)
  76. Why does creatinine clearance overestimate GFR?
    b/c a small amount is secreted by the renal tubules, which increases w/ decreasing GFR
  77. During severe renal failure, what can end up degrading creatinine?
    gut flora
  78. What is another term for BUN?
    urea clearance
  79. Why does BUN(urea clearance) under-estimate GFR?
    b/c although it is freely filtered by the glomerulus, 30-70% is reabsorbed in the nephron
  80. What are 3 tests that are done for a full urinalysis?
    • Urine pH
    • Specific gravity
    • urine sediment
  81. If a specific gravits is too high, what does that mean?
    • urine is too concentrated
    • patient is dehydrated
  82. If a specific gravity is too low, what does that mean?
    kidney can't concentrate the urine
  83. What is found in a urine sediment?
    • RBC (hematuria)
    • WBCs (pyuria)
    • crystals (as urine cools, these form)
    • casts (RBC, WBC, or epithelial tubular)
  84. What is the RIFLE criteria?
    • Risk
    • Injury
    • Failure
    • Loss
    • ESKD
  85. Which two stages of RIFLE don't have any urine output?
    • Loss
    • ESKD
  86. What is the GFR criteria for the Risk stage of RIFLE?
    increased creatinine x 1.5 OR decreased GFR >25%
  87. What is the GFR criteria for the Injury stage of RIFLE?
    increased creatinine x 2 OR decreased GFR > 50%
  88. What is the GFR criteria for the Failure stage of RIFLE?
    increased creatinine x 3 OR decreased GFR >75%
  89. What is the GFR criteria for the Loss stage of RIFLE?
    persistent ARF= complete loss of kidney fxn for > than 4 weeks
  90. What is the GFR criteria for the ESKD stage of RIFLE?
    end stage for > than 3 months
  91. What is the most common cause of acute renal failure?
    pre-renal (any condition that significantly decreases renal blood flow)
  92. What causes post-renal ARF?
    • anything that obstructs urinary excretion
    • kidney stones
    • prostatic hyperplasia
    • neoplasms (tumors)
  93. Can albumin be filtered by the glomerulus?
    no, not unless there is injury
  94. What are the 3 main results of glomerular damage?
    • damage to the filter = leakage
    • damage causing swelling= less filtration
    • damage causing scarring = less filtration = buildup of metabolites
  95. What antibody do we see deposited in the kidney and skin of a patient with SLE/lupus (Which Ig?)
  96. What will the RBCs in the urine of a renal transplant patient look like?
    dysmorphic and abnormal
  97. Where in the kidney do the aminoglycoside antibiotics tend to accumulate?
    renal cortex
  98. What is a cause of oliguria?
    acute tubular necrosis (and back leak)
  99. When does the oliguric stage begin and how long can it last?
    starts within 1 day and last up to 3 weeks
  100. What happens to the renal blood flow and GFR during the oliguric stage of ATN?
    • blood flow = 1/3 of normal
    • GFR = 1% of normal
  101. What are the 3 proposed mechanisms of oliguria during ATN?
    • back leakage
    • tubular destruction
    • altered renal blood flow
  102. What is the main complication causing post-renal kidney injury?
    renal vasoconstriction
  103. In the oliguric stage of ATN, what is the cause of potential anemia?
    • suppressed EPO production
    • RBC life expectancy is reduced due to hemolysis in azotemic blood
  104. Hyperkalemia and metabolic acidosis during oliguria of ATN are caused by an inability to excrete what two ions?
    • K+ : hyperkalemia
    • H+ : met. acidosis
  105. Does in increase (up to 6 liters) that occurs during diuresis indicate a renal function returning to normal?
  106. Who are the 3 high-risk patients of acute renal failure?
    • elderly
    • trauma patients
    • post-op patients
  107. What stage of ARF has the highest mortality rate? (pre-renal, post-renal, or intrarenal)
    intra-renal (87%)
  108. What are some clinical manifestations of ADVANCED chronic renal failure?
    • hypernatremia (due to decr. GFR)
    • Hyperkalemia (from oliguria)
    • Metabolic acidosis
    • magnesium imbalance (can cause cardiac arrest)
    • Calcium imbalance = hypocalcemia
    • Anemia
    • purpura and epistaxis (due to incr. nitrogen waste which causes a decr. in plateley fxn)
  109. What 3 things should we do treat the hypocalcemia associated with advanced chronic renal failure?
    • increase calcium intake
    • decrease dietary phosphate
    • supplement large amounts of vitamin D
  110. ____ is directly related to the # of functional nephrons remaining during chronic renal failure, and often the nephrons hypertrophy to carry a bigger load?