Lecture 5: Acute Kidney Injury

Question 1

In a patient with AKI/ARF a hx of what serum measurement should be obtained?

Answer 1

Most recent serum creatinine baseline and preferably one 3 months before acute event

Question 2

What are 5 factors which can alter serum creatinine?

Answer 2

• Age
• Sex
• Race
• Muscle mass
• Catabolic rate

Question 3

Impaired renal autoregulation may be due to what drugs and is considered what type of cause for AKI (pre-, post- or intrinsic)?

Answer 3

• NSAIDs, ACE-I/ARBs, Cyclosporins
• Pre-renal cause

Question 4

What are 4 sources of endogenous nephrotoxins implicated in AKI?

Answer 4

• Hemolysis
• Rhabdomyolysis
• Myeloma
• Intratubular crystals

Question 5

What are 4 of the main tubulointerstitial causes of AKI?

Answer 5

• Ischemia
• Sepsis/infection
• Exogenous nephrotoxins
• Endogenous nephrotoxins

Question 6

List 5 exogenous causes of tubulointerstital AKI?

Answer 6

• Iodinated contrast
• Aminoglycosides, amphotericin B
• Cisplatin
• PPI’s
• NSAIDs

Question 7

2 major post-renal causes of AKI?

Answer 7

1. Bladder outlet obstruction
2. Bilateral pelvoureteral obstruction

Question 8

What must you be sure to ask pt about in regards to history when presenting with signs/sx’s of AKI?

Answer 8

• Be sure to ask about all meds including OTC’s and herbals/supplements
• Toxin exposures –> work/home/hobby

Question 9

What urine and serum values can be used to determine pre-, post- and intrinsic causes of AKI?

Answer 9

• Serum sodium (Na) and creatinine (Cr)
• Urine sodium (Na) and creatinine (Cr)
• Allows you to calculate fractional excretion of Na (FE_Na)

Question 10

How does the value of FE_Na differ between pre-renal and intrinsic renal causes of AKI?

Answer 10

• Pre-renal = <1 —> decreased renal perfusion w/ increased reabsorption of Na
• Intrinsic renal = >1 –> damage to tubules = salt wasting

Question 11

Key diagnostic tool for postrenal AKI?

Answer 11

Ultrasound

Question 12

Important diagnostic studies that should be done on someone with AKI?

Answer 12

• Ultrasound
• EKG

Question 13

Treatment for pre-renal cause of AKI is focused on what?

Answer 13

• Remove/treat underlying contributing factots
• Stop likely med offenders = NSAIDs, Cyclosporine, ACE-I/ARBs

Question 14

Treatment approach for post-renal causes of AKI?

Answer 14

• Drain urinary bladder –> retention cathetrs or repeat catheterization
• Eliminate obstructions –> retrieve/pass stones, reduce prostate size, ureterostomy or nephrostomy stents to avoid hydronephrosis

Question 15

The treatment for intrinsic causes of AKI is focused on improving renal perfusion, what are 3 focuses of this treatment?

Answer 15

• Optimize cardiac output
• Minimize 3rd spacing of fluids
• Give fluids (normal saline)

Question 16

For fluid resuscitation of someone with AKI, what is the first choice?

Answer 16

Normal saline