Clinical Classification: Causes and Complications

Question 1

AKI rise in creatinine

Answer 1

Acute rise (48 hours)
>26 umol/L increase from baseline or 1.5X baseline

Question 2

What is the minimal amount of urine you need to produce a day?

Answer 2

400 mL

Eating and drinking nothing - you need this to get rid of solutes

Question 3

Post renal AKI

Answer 3

Anything that impairs urinary flow
Post renal obstruction
Intraluminal (stone, tumor, abscess, clot)
Extra-luminal (vessel, lymph node, fluid, tumor, abscess)
Bladder neck (BPH, strictures/stenosis)

Question 4

Why does obstruction cause kidney dysfunction?

Answer 4

Causes back pressure to glomerulus and impairs GFR

Leads to inflammatory response in tubules and interstitium

Question 5

3 way to rule out post-obstructive AKI

Answer 5

Foley catheter (relieves any bladder neck obstruction)
Renal ultrasound
Nephrostomy tube

Question 6

Pre renal AKI

Answer 6

Anything that impairs renal perfusion
Decreased absolute ECF (fluid loss)
Decreased effective ECF (kidneys not sensing perfusion)

Question 7

Untreated pre-renal AKI eventually turns into…

Answer 7

Ischemic acute tubular necrosis

Question 8

Intrinsic renal AKI

Answer 8

Any anomaly anywhere inside the kidney

Ex: acute tubular necrosis (most common)

Question 9

Ischemic acute tubular necrosis

Answer 9

Due to any prolonged pre-renal insult (sepsis, shock, meds, relatively low BP, ischemia/reperfusion)
Can be anuric, oliguric, or non-oliguric
Can last up to 3 months

Question 10

Toxic acute tubular necrosis

Answer 10

Due to direct tubular toxin (ex: contrast dye, antimicrobials, chemo, pigments, crystals)
Usually non oliguric
Usually short lived (days)

Question 11

Complications of severe AKI

Answer 11

Severe pulmonary edema
Severe acidemia
Severe hyperkalemia
Severe uremic complications (pericarditis, encephalopathy (seizures))

Question 12

Indications for dialysis

Answer 12

If despite medical intervention your patient still has: severe fluid overload, severe acidemia, severe hyperkalemia, or uremic pericarditis or encephalopathy
OR
Toxic ingestion that can be dialyzed

Question 13

3 long term outcomes of AKI

Answer 13

Higher risk of recurrent AKI
Higher risk of CKD
Higher risk of mortality

Question 14

Clues to chronic KD

Answer 14

Electrolyte abnormalities present but not always severe
Hypocalcemia, hyperphosphatemia, hyperPTH, anemia
Uremic symptoms: pruritus, restless legs, loss of appetite, weight loss, insomnia
Small kidneys on US