Term
| Define: Acute Kidney Injury |
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Definition
1) abrupt decline in the glomerular filtration rate manifested by an acute rise in the serum creatinine (S_Cr)
2) variable definitions used: rise in serum creatinine by >0.5mg/dl in 24 hrs |
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Term
| What are the three types of acute kidney injury? |
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Definition
1) anuric AKI
2) oliguric AKI
3) Non-Oliguric AKI |
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Term
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Definition
| 1) indicated less than 50cc of urin output in 24 hrs |
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Term
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Definition
| - indicates less than 500cc of urine output in 24hrs |
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Term
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Definition
| 1) normal urine output despite inadequate clearance. |
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Term
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Definition
1) P_UF = (P_gc - P_t) - (Pi_gc - Pi_t)
2) Pi_t =~= 0 |
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Term
| What is a normal value for GFR? |
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Definition
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Term
| What are characteristics of an appropriate marker to measure GFR? Example? Why is creatinine not a great tool? What is the relationship of the effective GFR by creatinine and the true GFR? |
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Definition
1) marker that is freely filtered by the glomerulus but neither secreted nor reabsorbed by the tubules
2) inulin
3) creatinine is freely filtered and not reabsorbed, but variable secreted by the tubules
4) clearance of creatinine tends to overestimate GFR |
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Term
| What are normal serum ranges for creatinine? |
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Definition
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Term
| What are the three major classes of AKI |
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Definition
1) perfusion-related AKI
2) Obstructive AKI
3) Intrinsic AKI |
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Term
| Describe perfusion-related AKI |
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Definition
1) due to a reduction in blood flow to the kidneys (compromised P_gc)
2) accounts for 50% of AKI
3) readily reversible |
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Term
What are perfusion-related causes of Acute Kidney Injury related to:
hypovolemia? |
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Definition
- diuretics
- trauma
- burns
- sugery
- hemorrhage
- hypoalbuminemia |
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Term
What are perfusion-related causes of Acute Kidney Injury related to:
decreased ECV? |
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Definition
- nephrotic syndrome
- hepatic failure
- heart failure
- sepsis |
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Term
What are perfusion-related causes of Acute Kidney Injury related to:
decreased cardiac output |
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Definition
- cardiogenic shock
- CHF
- acute massive PE |
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Term
What are perfusion-related causes of Acute Kidney Injury related to:
renovascular obstruction |
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Definition
- atherosclerosis
- thrombosis
- embolism
- vasculitis |
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Term
What are perfusion-related causes of Acute Kidney Injury related to:
interference with glomerular autoregulation |
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Definition
- prostaglandin inhibitors
- ACE-inhibitors |
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Term
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Definition
- results from obstruction of the flow of urine
- commonly at urethra or bladder outlet
- <10% AKI
- readily reversible |
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Term
What are obstructive-related causes of Acute Kidney Injury related to:
bladder outflow obstruction? |
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Definition
- urethral obstruction
- prostatic hypertrophy
- carcinoma |
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Term
What are obstructive-related causes of Acute Kidney Injury related to:
ureteral obstruction (bilateral or single kidney) |
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Definition
- stones
- crystals
- blood clots
- tumors
- papillary necrosis
- surgical ligation |
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Term
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Definition
1) involves blood vessels glomeruli, tubules, or interstitium of the kidney
2) pathophys depends on specific d/o
3) NOT ALWAYS REVERSIBLE
4) =~=40% AKI
5) acute tubular necrosis = most common |
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Term
What are intrinsic-related causes of Acute Kidney Injury related to:
glomerular and small vessel diseases |
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Definition
- rapidly progressive glomerulonephritis
- endocarditis
- post-streptococcal glomerulonephritis
- scleroderma |
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Term
What are intrinsic-related causes of Acute Kidney Injury related to:
interstitial nephritis |
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Definition
- infection-related
- drug induced
- infiltrative (sarcoid) |
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Term
What are intrinsic-related causes of Acute Kidney Injury related to:
tubular lesions |
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Definition
- post ischemia
- nephrotoxic damage
- pigment nephropathy |
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Term
| Define: acute tubular necrosis (ATN) |
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Definition
| - pathologic description of damage to the tubules cause by prolonged ischemia or exposure to nephrotoxins |
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Term
| What are the major factors involved in the reduction in GFR with acute tubular necrosis? |
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Definition
1) intratubular obstruction (casts and debris)
2) backleak: filtered toxins return to blood
3) reduction in kidney blood flow: not yet elucidated
4) adherence of neutrophils to vascular endothelium: release of damaging enzymes
5) release of phospholipases: ischemic cellular injury
6) reduced Kf: decreases GFR directly |
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Term
| What are the major diagnostic approaches to Acute Kidney Injury |
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Definition
1) Consider time of Onset
2) careful review of Hx and Exam
3) Urinalysis
4) Urine indices in AKI
5) rule out Obstruction
6) Kidney biopsy (reserved) |
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Term
| What patient population is the time of onset of AKI especially important? |
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Definition
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Term
| What key factors should be identified in careful review of Hx and Exam of patients with AKI |
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Definition
1) volume status
2) skin lesions
3) flank/abdominal signs |
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Term
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Definition
*ruling in or out an intrinsic cause of AKI*
1) clean catch w/ dipstick measurement
2) findings: muddy brown casts/granular casts (ATN), WBCs or WBC casts (interstitial kidney disease), proteinuria/dysmorphic RBCs/RBC casts (glomerulonephritis), negative dip/positive sulfasalicyclic acid (multiple myeloma, urine concentration, isoosmotic w/ isosthenurin w/ no casts (obstructive uropathy), crystal deposition (obstruction), broad waxy casts (chronic kidney disease) |
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Term
Describe the following lab values typically seen for the Perfuion-related AKI:
U_na
U_cr/P_cr
FeNa
U_osm
BUN/P_cr |
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Definition
U_na < 20*
U_cr/P_cr >40
FeNa <1*
U_osm >500
BUN/P_cr >20:1 |
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Term
Describe the following lab values typically seen for the ATN-related AKI:
U_na
U_cr/P_cr
FeNa
U_osm
BUN/P_cr |
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Definition
Describe the following lab values typically seen for the ATN-related AKI:
U_na > 40*
U_cr/P_cr <20
FeNa >1*
U_osm = 300-350
BUN/P_cr = 10:1 |
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Term
| What are metabolic complications of AKI? |
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Definition
1) hyperkalemia - arrhythmias
2) metabolic acidosis
3) hypocalcemia |
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Term
| What are volume complications of AKI? |
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Definition
| 1) volume expansion (in oliguric AKI) |
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Term
| What are Uremic complications seen with AKI? |
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Definition
1) platelet dysfunction
2) pericarditis
3) catabolism
4) CNS complications - lethargy, coma, seizures
5) anemia (decreased erythropoietin production |
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Term
| What are key Tx and management techniques used for patients with AKI? |
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Definition
1) ID/Tx of life-threateninc complications and underlying cause
2) discontinue all non-essential nephrotoxic medications
3) maintain kidney perfusion
4) manage volume status |
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Term
| What is the prognosis with AKI? |
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Definition
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