Renal: AKI

Card Set Information

Author:
jcbarbery
ID:
211162
Filename:
Renal: AKI
Updated:
2013-04-03 12:07:29
Tags:
renal kidney AKI
Folders:

Description:
General presentation and treatment of acute kidney injury
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user jcbarbery on FreezingBlue Flashcards. What would you like to do?


  1. Azotemia
    • Elevation in nitrogenous waste products
    • (ex. urea and creatinine)
  2. Uremia
    • Symptoms assoc. w/ azotemic accumulations
    • fatigue, anorexia, nausea, vomiting, pruritus, mental status changes, etc.
  3. Normal Urine Output
    1-1.5 L / 24 hrs
  4. Non-oliguria
    > 500 mL/day
  5. Oliguria
    400-500 mL/day
  6. Anuria
    < 50-100 mL/day
  7. AKI
    Any sudden onset injury or impairment of the kidney
  8. Pre-renal
    • Hypoperfusion d/t:
    • Intravascular volume depletion
    • Reduced effective circulatory volume
    • Vascular occlusion
    • Drug induction
  9. Intrinsic: General
    Direct renal damage

  10. Intrinsic: Vascular
    • thrombotic thrombocytopenic purpura
    • hemolytic uremic syndrome
    • renal artery thrombosis
  11. Intrinsic: Glomerulus
    • SLE
    • glomerulonephritis
    • post-infection
  12. Intrinsic: Acute, allergic interstitial nephritis (AIN)
    • Inflammatory, immunologic reaction within the
    • renal interstitium resulting from drugs, infections or autoimmune disorders
  13. Intrinsic: Acute tubular necrosis (ATN)
    • Causes 85% of intrinsic AKI
    • Can result from extending pre-renal states or exposure to direct toxins
    • uric acid, aminoglycosides, contrast media
  14. Post-renal
    • An obstruction of the urinary collection system
    • BPH, improper catheter, cancers, fibrosis, nephrolithiasis
  15. AKI Risk Factors
    • Age (>65 y/o)
    • Pre-existing renal dysfunction
    • Volume depletion or dec. circulating volume 
    • Serious infections
    • Comorbidities  
    • Exposure to nephrotoxins
  16. KDIGO: Stage 1 SCr
    • 1.5-1.9 times baseline
    •           OR
    • ≥ 0.3 mg/dL increase
  17. KDIGO: Stage 1 UO
    < 0.5 mL/kg/h for 6-12 hours
  18. KDIGO: Stage 2 SCr
    2.0-2.9 times baseline
  19. KDIGO: Stage 2 UO
    < 0.5 mL/kg/h for ≥ 12 hours
  20. KDIGO: Stage 3 SCr
    • 3.0 times baseline
    • OR
    • Increase in SCr to ≥ 4.0
    • OR
    • Initiation of renal replacement therapy
    • OR
    • In patients < 18 years: dec. in eGFR to < 35
  21. KDIGO: Stage 3 UO
    • < 0.3 mL/kg/h for ≥ 24 hours
    •           OR
    • Anuria for ≥ 12 hours
  22. Limitations of Dx & Staging
    • Need a baseline Scr level
    • May be 1 to 2 day delay in SCr increase after injury
    • Urine output can be variable
    • Studied/validated in critically ill pop.
  23. Lab Data
    • Serial BUN, SCr, K+, BUN:SCr
    • U/A
    • Urine Na
    • FENa
  24. Fractional Excretion of Sodium Equation
    FENa =   (Urine Na x SCr / Serum Na x Urine Cr) x 100
  25. AKI Diagnostic Procedures
    • Renal ultrasound
    • Catheter
    • Kidney-ureter-bladder (KUB) X-ray
    • Cystoscopy with retrograde pyelography
    • Renal biopsy
  26. Pre-renal Parameters
    • PE: Hypotension, dry mucus membranes, dec. CO, edema, ascites, etc.
    • Urine Sediment: Normal
    • Urine Na: <20
    • FENa: <1
    • BUN/SCr ratio: ≥ 20:1
  27. Intrinsic Parameters
    • PE: Variable
    • Urine Sediment: Granular and epithelial casts; RBCs; WBCs may be present in AIN
    • Urine Na: >40
    • FENa: >2
    • BUN/SCr ratio: < 20:1
  28. Post-renal Parameters
    • PE: Prostatic enlargement, bladder distension, etc.
    • Urine Sediment: Variable; cellular debris, RBCs, or crystals possible
    • Urine Na: >40
    • FENa: Variable
    • BUN/SCr ratio: ~ 15:1
  29. Non-Pharm Prevention
    • Avoidance of nephrotoxins
    • Maintain hemodynamic stability to avoid
    • hypotension, hypovolemia, etc.
    • ID and avoid risk factors when possible
  30. Contrast Media-induced Nephrotoxicity(CIN)
    Pharm Prevention
    Sodium bicarbonate + hydration (Alkalinizing agent)

    N-Acetylcysteine (NAC) + hydration (Antioxidant effect / Neutralizes urine)
  31. Goals of AKI Tx
    • Rapid identification of cause
    • Removal or reduction of causative agents
    • Prevent further kidney injury
    • Prevent complications
    • Regain renal function
  32. AKI Supportive Care
    • Stop nephrotoxic drugs
    • Maintain adequate hemodynamic status
    • Maintain glucose control
    • Manage complications
  33. Dopamine Tx
    • vasodilation; increase U/O
    • not recommended
  34. Fenoldopam Tx
    • vasodilation; increase U/O
    • some use in crit. ill pts
  35. Loop Diuretic Tx
    • Inc. UO; Dec. renal ishemia risk
    • Contoversial: harm/ototoxicity vs. minimal benefit
  36. Ca Channel Blocker Tx
    • Dec. vasoconstriction; natriuretic
    • weak evidence for renal transplant pts
  37. N-acetylcysteine (NAC)
    • antioxidant; dec. vasoconstriction
    • weak evidence v. CIN w/hydration
  38. Ascorbic acid
    • Antioxidant
    • weak evidence in CIN
  39. Erythropoietin
    • May dec. ishemia risk
    • needs more study
  40. Natriuretic peptides
    • Inc. vasodilation and perfusion
    • may dec. need for dialysis
    • needs more study
  41. Indications for Renal Replacement Tx
    • A – Acid-base abnormalities
    • E – Electrolyte imbalance
    • I – Intoxications
    • O – Overload of fluids    
    • U – Uremia
  42. Fluid Overload
    • Minimize fluid intake
    • Loop diuretics (Furosemide; also torsemide & bumetinide)
    • Strategies to reduce diuretic resistance
  43. AKI Furosemide Dosing
    • Initiate  @ 40-100 mg x 1 --> 200-1500 mg/day
    • Cont. Infusion @ 10 mg/h dec. resistance and avoids high peaks
  44. Strategies to reduce diuretic resistance
    • Identify and eliminate/reduce potential cause
    • Increase dose or use continusous infusion
    • ADD Thiazide diuretics (Chlorothiazide 250–500 mg IV q12h)
    • ADD Thiazide-like diuretics (Metolazone 5–10 mg PO q24h)
  45. Causes of Diuretic Resistance
    • Excessive sodium intake
    • Inappropriate diuretic dose/regimen
    • Reduced bioavailability
    • Reduced renal blood flow
    • Drugs (NSAIDs, ACE inhibitors)
    • Hypotension          
    • Intravascular depletion
    • Increased sodium reabsorption
    • Nephron adaptation to chronic diuretic Tx
    • NSAIDs
    • Heart failure
    • Cirrhosis
  46. Hyperkalemia
    • Most common complication of AKI
    • Sx: Parasthesias, weakness, paralysis
    • EKG changes: peaked T waves (5.5-6.0 mEq/L); prolongation of PR and QRS intervals (6.0-7.0 mEq/L); disappearance of P wave/merger with QRS and T wave (> 7.0 mEq/L)
  47. Hypernatremia
    Treat via Na restriction
  48. Infection
    • Most common cause of death
    • Sepsis often leads to AKI
  49. CV Complications
    • HTN with intermittent hypotension
    • CHF, arrythmias, and pulmonary edema
  50. GI Complications
    • Inc. bleed risk
    • Stess ulceration
    • N/V
  51. Neurologic Complications
    • Altered mental status
    • Seizures
    • Somnolence
  52. Calcium gluconate
    (1st Line)
    • Cardioprotective; stabilizes membrane voltage
    • 10 mL 10% soln. IV push
    • 1-3 min onset; 30 min duration

    • 20-30 min infusion w/digoxin
    • incompatible w/ Ca & Bicarb
  53. Insulin (plus glucose)
    • Redistribution: inc. cellular K+ & dec. plasma K+
    • 10 U IV bolus w/50 mL D5W
    • 10-30 min onset; 2-6 hr duration

    • no D5W if BG > 250
    • monitor BG closely
  54. Β-adrenergic agonists (eg, albuterol)
    • Redistribution: inc. cellular K+ & dec. plasma K+
    • 10-20 mg neb over 10 min
    • 10-30 min onset; 2-4 hr duration

    • 25% of pts do not respond
    • tachycardia common
  55. Sodium polystyrene sulfonate
    (Kayexalate; SPS)
    • elim. K+ in gut (exchanged for Na+)
    • 15 g PO in sorbitol soln. 1-4 times/day OR
    • 30-50 g retention enema in sorbitol (retain 30-60 min)
    • 1-3 hr onset; 4-6 hr duration

    • Sorbitol minimizes constipation but may -> bowel necrosis
    • Enema has faster onset
    • 1g binds ~ 1 g K+

What would you like to do?

Home > Flashcards > Print Preview