Drug-Induced Kidney Disease- Intrinsic Renal; ATN

Question 1

Number 1 cause of hospital AKI

Answer 1

ATN

Question 2

Clinical presentation of ATN

Answer 2

Acutely progressive increase in SCr and BUN, with decrease in GFR and urinary output

Metabolic acidosis

Hyperkalemia (depending on the site of injury)

FeNa >1%

Mg-wasting with cisplatin

Question 3

Clinical presentation of ATN: urinalysis

Answer 3

Proteinuria
Cellular debris, muddy brown color, granular casts (“muddy brown casts”)

Question 4

Drugs that can cause ATN

Answer 4

Aminoglycosides
Amphotericin B
Contrast media
Antineoplastic agents

Question 5

Mechanisms that can cause ATN

Answer 5

Direct cellular toxicity
Prolonged ischemia

Question 6

AGs: ATN risk is highest when aminoglycosides are used with what drugs?

Answer 6

Concomitant nephrotoxic drugs like vanco, amphotericin, contrast media, NSAIDs, etc.

Question 7

AG nephrotoxicity is related to what?

Answer 7

trough concentrations

Question 8

Goal trough concentration of gentamicin and tobramycin

Answer 8

<2mg/L

Question 9

Goal trough concentration of amikacin

Answer 9

<8mg/L

Question 10

What type of AG dosing interval may reduce risk of nephrotoxicity?

Answer 10

Extended-interval dosing

Question 11

Goal trough concentrations of AGs in EID

Answer 11

Undetectable at 24 hours!!

Question 12

ATN is more likely to occur in what formulation of Amphotericin B?

Answer 12

Conventional (compared to liposomal)

Question 13

IV contrast media-induced ATN (CIN) pathology

Answer 13

combo of pre-renal and intrinsic renal injury, maybe post-renal

Question 14

CIN risk factors

Answer 14

CKD
GFR <60ml/min/1.73m2
Low effective circulatory volume
Concomitant nephrotoxic agents

LARGE DOSE (volume) IODINATED CONTRAST
HIGH OSMOLAL CONTRAST
IONIC CONTRAST
SHORT TIME INTERVAL BETWEEN 2 CONTRAST ADMINISTRATIONS

Question 15

CIN prevention: what is the gold standard of treatment?

Answer 15

SALINE HYDRATION

NS 1-1,5ml/kg/hr 12 hours prior to and after procedure

Question 16

CIN prevention: thoughts on sodium bicarb

Answer 16

Should only give if patient has metabolic acidosis (low bicarb and low pH)

150mEq/L in D5W at 1-1.5ml/kg/hr 12 hours before and after procedure

Question 17

CIN prevention: thoughts on NAC

Answer 17

Use it as an add-on to hydration (saline hydration)

1200mg PO BID x4 doses (2 doses before and 2 after procedure or 150mg/kg IV x1 prior to procedure, then 50mg/kg IV over 4 hours after procedure

Question 18

CIN prevention: what kind of contrast agents should you use to prevent CIN?

Answer 18

Low or iso-osmolal nonionic agents

Question 19

ATN management

Answer 19

Supportive care

D/C offending agent and other nephrotoxic drugs

Maintain hydration and euvolemia

Electrolyte management

Kidney replacement therapy (hemodialysis, CKRT) if severe ATN (anuria, uremia, edema, K+ >7mEq/L)