CKD (Specht)

Question 1

CKD definitions

Answer 1

• Any chronic change in kidney disease
  
  • structure
  • function
• CKD is
  
  • permanent
  • progressive

*can’t recover, but can compensate for a period of time

Question 2

CKD DX

Answer 2

• Dysfunction
  
  • GFR
  • electrolytes
  • acid base
  • hormones
  • biomarkers
• Damage / dz
  
  • appearance
  • biomarkers
  • pathology
• Secondary / compensatory change
  
  • renal: inc PTH
  • Hypertension

Question 3

Common lab values

Answer 3

• Serum biochem
  
  • BUN, Cr
  • Phos, K⁺, TCO₂, Alb
  • tCa / iCa⁺⁺, Na⁺, Cl^-
• Urinalysis
  
  • USG, Protein, Sediment
• CBC
  
  • Hct, other

Question 4

GFR estimation

Answer 4

• Creatinine, BUN, SDMA follow similar curve
  
  • normal GFR: flat curve, then steep line
• Suggest use of stricter limits on acceptable creatinine levels
• SDMA
  
  • better for animals with lack of muscle mass, or muscle wasting

Question 5

Other informations

Answer 5

• Blood pressure
• urine protein to creatinine (UPC)
• Imaging (AXR, AUS)
• Urine culture
• other
  
  • specific infectious dz
  • PTH/iCa⁺⁺
  • Aspirates/biopsies
  • Others

Question 6

Underlying dz

Answer 6

• > 50% cases are idiopathic
  
  • age-related, accumulation of injuries
• Specific causes
  
  • toxicity
  • infection
  • cancer
  • obstruction

Question 7

CKD vs Pre-renal azotemia vs AKI

Answer 7

• Pre-renal azotemia
  
  • sig dehydration/hypovolemia
  • low cardiac output
• AKI
  
  • very important to recognize
    
    • diagnostic, prognostic and therapeutic differences

Question 8

IRIS staging

Answer 8

• based on creatinine
• subcategories
  
  • proteinuria
  • blood pressure

Question 9

Why use IRIS staging

Answer 9

• Consistent records
• Client communication
  
  • ‘expert’ support for your recommendations
• Earlier recognition and response to CKD….?

Question 10

IRIS staging

Key points

Answer 10

• patient must be at a stable point in disease
  
  • > 2-3 weeks
• Helps with communication and studies
• Basis for published treatment recommendations
  
  • evidence regarding appropriate treatments
• Be careful making prognostic statements

Question 11

CKD General Management strategies

Answer 11

• no cure
• look for/treat underlying dz
• discontinue nephrotoxic meds
• pay attention to dose and frequency of medications that are eliminated by kidneys

Question 12

CKD: specific management strategies

Answer 12

• Therapy should be tailored to specific patients
• secondary problems
  
  • Hyperphosphatemia
  • Systemic hypertension
  • Proteinuria
  • hypo/hyper kalemia
  • metabolic acidosis
  • anemia
  • nausea, vomiting

Question 13

Diet/nutrition

Answer 13

• renal diets (good evidence of significant survival)
  
  • reduced phospohorus (protein)
  • omega-3 FA
  • vitamins
• Recommend for stage 2 dz or higher
• Calories are important, don’t force feed
  
  • mirtazapine: apppetite stimulant

Question 14

Fluids

Answer 14

• almost universal recommendation to maintain normal volume and hydration
  
  • support GFR and uremic toxin clearance
  • Prevent clinical signs
  • minimize progression
• For uremic crisis - IV fluids
  
  • Replacement + maintenance + losses
• For stable CRF
  
  • fresh drinking water avail
  • serial measurements of body weight
  • extra fluids PRN SQ or E-tube

*not extra but enough fluids to keep up with losses

Question 15

Control of serum phosphorus conc

Answer 15

• Minimize progression
• prevent tissue mineralization
• avoid secondary hyperparathyroidism
• variable recommendations
  
  • target value
  • method
    
    • renal diet
    • fluid support
    • phosphate binders

Question 16

Phosphate binders

Answer 16

• Aluminum based: tastes yucky
  
  • Effective, inexpensive
  • toxicity
    
    • subtle neuro to seizures
  • complexed with
    
    • hydroxide, oxide, carbonate
• Calcium based
  
  • a little more expensive
  • may help minimize secondary inc PTH
  • toxicity
    
    • hypercalcemia: inc risk of mineralization
  • complexed with
    
    • acetate, citrate, carbonate
• Others
  
  • sevelamer
  • lanthanum
  • epakatin

*may be synergistic

Question 17

Control of hypertension

Answer 17

• important to control
• difficulties
  
  • ‘white coat effect’
  • where / how to measure
• monitor and treat with hypertensive agents if
  
  • dogs repeatedly > 160-170
  • cats repeatedly > 170
  • evidence of end-organ damage

Question 18

Control hypertension dogs

stepwise

Answer 18

• Na restriction
• ACEi at standard doses
• Double dose of ACEi
• ACEi& CCB
• ACEi, CCB and hydralazine

*small inc in Cr is ok trade-off

Question 19

Control hypertension cats

stepwise

Answer 19

• Na restriction
• CCB at standard doses
• Inc CCB dosing
• CCB and ACEi

*ensuing small inc in Cr is ok trade-off

Question 20

Control of proteinuria

Answer 20

• Increasing awareness and detection of proteinuria
• Goals
  
  • minimize progression, improve survival
• strong evidence for effectiveness
• to monitor effectively requires UPC (urine protein:Cr ratio)
• Recomendations
  
  • monitor UPC
  • investigate further and treat if
    
    • UPC > 0.5-1.0
  • Typically use ACEi
    
    • Enalapril
    • benzapril

Question 21

Acid-base balance

Answer 21

• Often overlooked
• threshold values
  
  • pH < 7.25
  • HCO₃^- = 16
• target values
  
  • pH >/= 7.3
  • HCO₃^- >/= 17
• Usually use K⁺ citrate unless hyperkalemic
• IRIS stage 2+ => dogs >/= 18; cats >/= 16

Total CO₂ can approx bicarb measurement

Question 22

Serum potassium conc

Answer 22

• inc or dec potassium potentially detrimental
• recommendations
  
  • supplement when
    
    • hypokalemic (with or without clinical signs)
    • repeatedly in the low end of dose range
  • if acidotic, Specht uses K⁺ citrate
  • if not acidotic, Specht uses K⁺ gluconate

Question 23

Acid blockers

(GI issues)

Answer 23

• used to minimize gastric hyperacidity
• evidence is anecdotal
  
  • gastrin metabolized and excreted by kidneys
• recommendation
  
  • PPI (or H2 blockers)
    
    • when clinical signs, lab evidence of bleeding
    • in most cases of CRF with Creatinine > 3 mg/dL

Question 24

Hematocrit

anemia

Answer 24

• anemia
  
  • predominantly due to dec EPO sensitivity
  • GI loss, dec RBC life span, vit def, iron def
• Recommendations
  
  • try to get reticulocyte count
    
    • to prove it is non-regenerative
  • if non-regenerative with normal morph and Hct < 20%
    
    • consider darbopoeitin (1 vial is 100$ weekly admin)
      
      • • iron
      • +/- B12

* There is a human erythropoeitin that may induce a reactivity to animals own cells making them transfusion dependent

Question 25

Calcitriol

Answer 25

• Goal: normalization of PTH levels
• Good evidence for positive effect
  
  • definite reduction in PTH for both dogs and cats
• Controls secondary renal hyperparathyroidism
• Requires exceptionally close and frequent monitoring
  
  • PTH, iCa⁺⁺, Phosphorus
• potential hazards / complications
  
  • dose response variability
  • hypercalcemia
  • mineralization
    
    • phosphorus must be , 6.0 mg/dL before starting

Question 26

Azodyl

Answer 26

• Probiotic: ‘enteral dialysis’
• little evidence that reduction in BUN and some Cr affects GFR
• Specht doesn’t really use yet

Question 27

Mainstays of CKD treatment

Answer 27

1. Diet
2. Maintain hydration
3. Limit protein
4. Blood pressure control

Question 28

Conclusions

Answer 28

• Lots of treatment options, many with limited evidence regarding effectiveness
• Treatment should be individualized
• CKD is dynamic, requires intense monitoring and management