Acute kidney

Question 1

Stage 1 AKI

Answer 1

SrCr 26 increase or 1.5-1.9 fold
<0.5ml/kg/hr for 6-12hS

Question 2

Stage 2 AKI

Answer 2

SrCr >2-2.9 fold increase
<0.5/ml/kg/hr for >12h

Question 3

Stage 3 AKI

Answer 3

SrCr >3 fold or 354 mmol/L increase
<0.3/ml/kg/hr >24 or anuria for >12h

Question 4

AKI risk factors

Answer 4

CKD (less renal buffer)
Volume depletion
Nephrotoxic agents
Obstruction of urinary tract (BPH)

Question 5

AKI Sx

Answer 5

Urinary habit change, sudden weight gain, flack paint, foamy urine, orthostatic hypotension
- Check ACR, SrCr, BUN, Urine volume

Question 6

Prerenal AKI causes

Answer 6

• Blood volume loss (hemorrhage, renal loss, GI loss, sepsis, hepatorenal syndrome)
• Low cardiac output
• severe burns

Question 7

hepatorenal syndrome

Answer 7

Vasodilators made in liver cause systemic decrease in BP leading to hypo perfusion of kidney

Question 8

Prerenal AKI Sx

Answer 8

Thirst
Orthostatic hypotension
Dehydration (tachycardia, decreased skin turgor, dry mucous membranes)

Question 9

Lab picture of pre renal AKI

Answer 9

• Hyaline casts
• Fena <1%
• Una <20mmol/L
• SG >1.020

Question 10

Post renal causes

Answer 10

Bilateral kidney stones, prostate hypertrophy
Crystallizable drugs (sulphonamide, methotrexate, acyclovir)

Question 11

Post renal Sx

Answer 11

Pain
Anuria
Pyuria

Question 12

Lab picture of post renal AKI

Answer 12

cellular debris
hematuria (variable)
Una >40mmol/L
Fena >2%
none to moderate urea increase

Question 13

Lab picture of infrarenal AKI

Answer 13

Casts and cellular debris
hematuria (for sure)
pyuria
Una >40mmol/L
Fena >2%
None to moderate urea increase

Question 14

AKI treatment

Answer 14

• Hydrate >200ml Normal saline/hr
• D/C drug
• Diuretics if volume overload
• Dialysis for serious electrolyte imbalance or volume overload

Question 15

AEIOU

Answer 15

When to start dialysis
- Acid- base abnormalities
- electrolyte imbalance
- intoxications
- fluid overload
- uremia (declining mental status)

Question 16

ACE or ARB

Answer 16

Cause Pre-renal by preventing efferent arteriole constriction
They are a sick day skip to help kidneys adapt to low fluids

Question 17

NSAIDS

Answer 17

Cause pre-renal by preventing PG from dilating afferent arteriole

Question 18

Intrarenal acute tubular necrosis

Answer 18

Cell death in two phases (Oliguric, within 24h lasting 1-3 weeks) (Diuretic phase, slow return). High chance on CKD with incomplete recovery
- Aminoglycosides
- Amphotericin B

Question 19

Aminoglycosides

Answer 19

Gentamicin, tobramycin
Causes cation charge damage to proximal tubular cells blocking filtration causing Intrarenal acute tubular necrosis
- When giving AG make sure to hydrate like crazy

Question 20

Intrarenal acute tubular necrosis lab picture

Answer 20

Epithelial cell casts and free cells
High urine sodium >40
FeNa >3%

Question 21

Amphotericin B

Answer 21

Toxic build up in distal tubule causing infrarenal acute tubular necrosis, can be helped if given by liposomal formulations

Question 22

Intrarenal acute interstitial nephritis

Answer 22

Delayed hypersensitivity that occurs ~14 days after exposure, causes lymphocytic infiltration of the intersitium and inflamm response causes damage
- Penicillins and lithium
- can be treated with prednisone for 4 weeks

Question 23

Intrarenal acute interstitial nephritis Sx

Answer 23

Fever, rash, Blood and WBC in urine, metabolic acidosis, hyperkalemia, salt wasting

Question 24

Intrarenal acute interstitial nephritis lab picture

Answer 24

WBC and WBC casts
hematuria
FeNa >1%
Urine sodium >40mmol/L

Question 25

Obstructive nephropathy

Answer 25

post renal AKI
From crystallizable drugs or myoglobin from rhabdomyolysis
- Aggressive hydration and diuretics to blast through block
- Urine alkalization to reduce crystals

Question 26

Extrarenal urinary tract obstruction

Answer 26

BPH and anticholinergic drug together