AKI, CKD, and Dialysis

Question 1

How is AKI defined?

Answer 1

ACUTE reduction in function (GFR, UOP) and accumulation of nitrogenous wastes (BUN, creatinine)

Question 2

According to the RIFLE criteria, changes in labs need to be within how many days to be classified as AKI?

Answer 2

7 days

Question 3

What are the three distinct types of AKI?

Answer 3

Pre-renal (most common)
Intra-renal
Post-renal

Question 4

What is the cause of pre-renal AKI?

Answer 4

Hypoperfusion due to: low volume, bad pump, vasodilation, or intra-renal vasoconstriction

Question 5

What are the causes behind intra-renal AKI?

Answer 5

• 85% due to ATN (Ischemic or nephrotoxic)
• Glomerulonephritis

Question 6

What is the cause of post-renal AKI?

Answer 6

Obstruction

Question 7

What drug classes are considered to be nephrotoxic?

Answer 7

A LOT! Just to name a few…

ACE
ARBs
Antibiotics (aminoglycocides in particular)
Diuretics
Vancomycin
Contrast
Methotrexate

Question 8

What is the number one cause of intra-renal AKI?

Answer 8

Acute tubular necrosis (ATN)

Question 9

What are the typical causes of ATN?

Answer 9

• Ischemia
• Infection (sepsis)
• Nephrotoxins (direct cellular injury)

Question 10

What are the response expectations in the three distinct types of AKI to fluids?

Answer 10

• Pre-renal: improve with fluids
• Intra-renal: no change with fluids
• Post-renal: no response to fluids

Question 11

What type of AKI will have symptoms of volume depletion, CHF, and cirrhosis?

Answer 11

Pre-renal

Question 12

What type of AKI will appear euvolemic?

Answer 12

Intra-renal and Post-renal

Question 13

Because intra-renal and post-renal AKI will present similarly, what test should be ordered to differentiate the type of AKI?

Answer 13

Fractional excretion of sodium (FENa)

Question 14

What does fractional excretion of sodium (FENa) help differentiate?

Answer 14

Helps differentiate between pre-renal and intra-renal AKI

Normal 1-2%
< 1% = pre-renal
> 2% = intra-renal

Question 15

What type of AKI will there be abnormal casts?

Answer 15

Intra-renal

Question 16

What type of AKI will there be no casts?

Answer 16

Post-renal

Question 17

What type of AKI will have increased urine osmolality?

Answer 17

Pre-renal

Question 18

What is the treatment for AKI?

Answer 18

Supportive
- Avoid additional injury: discontinue offending agents
- Maintain perfusion/volume (fluids)
- +/- renal replacement therapy

Question 19

The rise in what element is used to define AKI?

Answer 19

Creatinine

*AKI is defined as an absolute increase in serum creatinine by 0.3 mg/dL or more over 48 hours, or a relative increase of 1.5 times baseline or more that is known or presumed to have occurred within 7 days.

Question 20

Can there be neurologic changes with AKI?

Answer 20

Yes, prolonged bleeding time due to platelet dysfunction may occur with uremia. Progressive uremia may also cause neurologic signs such as asterixis, encephalopathy, and seizures

Most commonly associated with pre-renal AKI

Question 21

What are the risk factors associated with chronic kidney disease?

Answer 21

• Hypertension
• DM
• Small birth weight
• Childhood obesity
• Increasing age
• Black race
• • FH

Question 22

How is the decline in kidney function measured in CKD?

Answer 22

GFR

Question 23

A GRF greater than ______ is considered severe CKD

Answer 23

30

Question 24

What is the presentation of stage 1 or 2 of (mild) CKD?

Answer 24

Asymptomatic, typically caught on routine labs

Question 25

What symptoms are associated with moderate (stage 3 and 4) CKD?

Answer 25

- Hypertension - Anemia - Fatigue - Decreased appetite - Malnutrition - Electrolyte and mineral abnormalities

Question 26

What labs should be ordered in the work-up for CKD?

Answer 26

BMP/CMP *Persistant reduced GFR (>3 months) is diagnostic of CKD

Question 27

What is the mainstay of treatment for ESRD?

Answer 27

Renal replacement therapy

Question 28

What is the definitive treatment of CKD?

Answer 28

Renal transplant

Question 29

What is likely the complication leading to mortality in CKD?

Answer 29

CVD *80% will die of CVD before reaching ESRD

Question 30

What GFR value qualifies a patient for dialysis (RRT)?

Answer 30

GRF < 10 if no DM; GFR < 15 in DM

Question 31

In pre-renal AKI there is decreased GFR, what are the downstream effects?

Answer 31

- Elevated creatinine, urea (BUN) - Decreased Na+ in distal convoluted tubule which activates RAAS

Question 32

Why does intrarenal AKI more associated with surgery, trauma or burns?

Answer 32

Due to the fluid shifts and third spacing --> kidney's become dry from decreased blood flow

Question 33

What is the pathophysiology of intrarenal AKI?

Answer 33

Decreased blood flow --> ischemia --> necrosis --> dead, sad nephrons

Question 34

How do you differentiate prerenal vs. intrarenal AKI?

Answer 34

Fluid response

Question 35

True or False: Typically, Post-renal AKI requires bilateral obstruction to occur

Answer 35

True

Question 36

What type of casts will be present with kidney tubule injury?

Answer 36

Brown casts

Question 37

What are the two most common causes of chronic kidney disease?

Answer 37

DM and HTN

Question 38

What is Azotemia?

Answer 38

Increased urea, creatinine, nitrogenous compounds Elevated BUN and creatinine in labs

Question 39

What is uremia?

Answer 39

Azotemia with symptoms or signs of renal failure (uremic syndrome)

Question 40

What systemic changes will be seen in CKD?

Answer 40

Hyperkalemia Hypocalcemia Hyper/onatremia Hypoalbuminemia

Question 41

What is a simple cyst?

Answer 41

Acquired, thin walled cyst (serous fluid) within the surface of the kidney

Question 42

What type of genetic inheritance is polycystic kidney disease?

Answer 42

Autosomal dominant

Question 43

What is the pathophysiology of polycystic kidney disease?

Answer 43

Ciliary defects will decrease the signaling between cells Decreased intracellular signaling --> increased cellular division, increased apoptosis, decreased resorptive function