Chapter 124 - AKI

Question 1

What are the two most widely accepted staging schemes for AKI?

Answer 1

• Risk Injury Failure End Stage Kidney Disease (RIFLE)

- Acute Kidney Injury Network (AKIN) or Veterinary Acute Kidney Injury staging scheme (VAKI)

Question 2

What increase in serum creatinine is associated with in-hospital mortality?

Answer 2

• Relative increase in plasma creatinine of at least 150%

- Increase of 0.3 mg/dl from baseline concentrations

Question 3

What are the 4 phases of AKI?

Answer 3

• Initiation phase (subcellular level, not biochemically evident)
• Maintenance phase (cell death and regeneration)
• Recovery phase (improvement in GFR and tubular function)
• Final phase (may last weeks to months)

Question 4

What are the different stages of the VAKI scheme?

Answer 4

• Stage 0: Creatinine increase <150% from baseline.
• Stage 1: Creatinine increase of 150% to 199% from baseline OR Creatinine increase of 0.3 mg/dl from baseline
• Stage 2: Creatinine increase of 200% to 299% from baseline
• Stage 3: Creatinine increase of ≥300% from baseline OR an absolute creatinine value of >4.0 mg/dl

Question 5

What are physical findings specific but not exclusive to uremia?

Answer 5

Halitosis, oral ulceration, tongue tip necrosis, scleral injection, bradycardia, cutaneous bruising, and peripheral edema

Question 6

Typically, what is the USG in case of intrinsic kidney failure?

Answer 6

Isosthenuric urine: 1.007 - 1.015

Question 7

In case of ethylene glycol intoxication, what can be found on urine microscopic assessment?

Answer 7

Large number of calcium oxalate crystals

Question 8

Why is ionized calcium low in case of ethylene glycol intoxication?

Answer 8

• Severe hyperphosphatemia

- Chelation of calcium by oxalate

Question 9

Usually, how is the anion gap with AKI, why?

Answer 9

The anion gap is usually high secondary to retained organic and inorganic acids that the injured kidney is unable to excrete

Question 10

What is the formula for anion gap calculation?

Answer 10

Anion gap = (Na+ + K+ )−(HCO3− + Cl− )

Question 11

How do the kidneys usually look on ultrasound (AKI)?

Answer 11

• Abdominal ultrasonography usually shows normal or
  enlarged kidneys with normal parenchymal architecture. Perirenal fluid is seen commonly
• With ethylene glycol intoxication, oxalate crystal deposition in the kidneys increases the echogenicity, making the renal cortices and, to a lesser extent, the
  medulla hyperechoic.

Question 12

Leptospirosis: For how long after the first days of illness, may titers be negative? What is the diagnostic approach if titers come back negative?

Answer 12

Titers also may be negative within the first 7 to 10 days of illness; a four-fold rise after 2 to 4 weeks is used to confirm exposure when initial titers are negative.

Question 13

In the absence of previous vaccinations, what single titer is suggestive of Leptospirosa exposure?

Answer 13

1:800 and greater

Question 14

What infectious diseases may cause AKI?

Answer 14

Leptospirosis, Rocky Mountain spotted fever (Rickettsia rickettsii), Ehrlichia canis, Lyme disease (Borrelia burgdorferi), Babesia spp., or Leishmania spp.,

Question 15

What is the Masson’s trichrome stain used for with renal biopsy?

Answer 15

Masson’s trichrome stain is used to assess the severity of fibrosis and provide insight into the potential for renal recovery (CKD?)

Question 16

Define fluid overload.

Answer 16

Fluid accumulation more than 10% of baseline body weight

Question 17

T/F: If oliguria or anuria persists despite correction of dehydration, additional fluid administration may help with glomerular filtration rate

Answer 17

F. additional fluid administration is more likely to result in fluid overload than urine production

Question 18

T/F: the use of diuretics in patients with AKI have been associated with decreased mortality

Answer 18

F: little or no clinical evidence in human or veterinary medicine, respectively, demonstrates that diuretics improve outcome in established AKI.
A recent meta-analysis of randomized controlled clinical trials o loop diuretic use in human AKI showed a statistically insignificant trend towards an association with increased mortality.

Question 19

Why is AKI often associated with metabolic acidosis?

Answer 19

When tubular unction is compromised, the ability to reabsorb bicarbonate and excrete hydrogen ions is diminished. Lactic acidosis secondary to compromised tissue perfusion (i.e., either volume deficit or excess) also may contribute.

Question 20

If you decide to administer bicarbonate, what formula would you use?

Answer 20

Bicarbonate (mE q/ L ) = 0.3× body weight (kg) × base deficit

where the base deficit = 24 mEq/L - patient bicarbonate concentration. One fourth to one third of the dose should be given intravenously as a slow bolus, and an additional one fourth over the next 4 to 6 hours.

Question 21

What is a consequence of bicarbonate therapy in case of hypoventilation?

Answer 21

Paradoxical CNS acidosis

Question 22

In case of which disease, is polyuria most commonly seen during renal recovery?

Answer 22

This phenomenon may occur with any cause of AKI, but most commonly occurs in cases of leptospirosis or obstructive disease.

Question 23

How fast should the fluid rate be decreased in case of polyuria once the patient’s azotemia and body weight are stable?

Answer 23

By 10% per day

the recovery hase may last for weeks

Question 24

What is the overall mortality rate for AKI?

For those who survive, how many will recover normal renal function?

Answer 24

Dogs:

• Mortality rate: approximately 60%
• In the dogs that survive, approximately 60% have chronic kidney disease, and only 40% recover normal renal function

Cats:

• Mortality rate: approximately 40% to 50%
• Approximately 50% of survivors left with chronic kidney disease

Question 25

What is the survival rate for dogs with AKI secondary to leptospirosis?

Answer 25

Approximately 82% to 86%