LA acute & chronic kidney dz (Reuss) Flashcards Preview

Urology > LA acute & chronic kidney dz (Reuss) > Flashcards

Flashcards in LA acute & chronic kidney dz (Reuss) Deck (32):
1

Pre-Renal Azotemia

  • Inadequate renal perfusion
    • hypovolemia
    • dehydration
      • GI fluid loss
    • hypotension
      • acute blood loss
    • dec CO
  • USG > 1.025
  • FCNa < 1%
  • >/= 50% reduction in azotemia w/in 24 hours of fluid therapy

*may be a back door determination

2

After starting IV fluids a patient should urinate in

8-12 hours

3

Renal azotemia

  • Acute kidney injury: abrupt  decrease in GFR
    • Most common cause: Acute tubular necrosis (ATN)
      • vasomotor nephropathy (ischemia)
      • aminoglycoside toxicity
      • NSAIDS
      • Pigment nephropathy
      • lepto

4

Ischemia

'vasomotor nephropathy'

  • Continuum of pre-renal azotemia
  • prolonged marked hypotension 
    • endotoxemia (toxic line on MM)
  • Blood loss

5

Aminoglycoside toxicity

  • Bind to brush border of proximal tubule
    • pinocytosis
    • accumulate in renal cortex
    • inhibit phospholipase activity
    • impair organelle function
    • proximal tubular epithelial cell damange
  • Renal vasoconstriction
  • Toxicity Neomycin > Kanamycin > gentamicin > amikacin > streptomycin
  • Precipitated by concurrent dehydration
  • Binding saturable: once daily dosing preferred

6

Other nephrotoxic antimicrobials

  • Oxytetracycline
    • given to foals with tendon contracture
  • Polymyxin B
    • endotoxemia
  • Amphotericin B

7

NSAIDS

  • Medularry crest necrosis
    • medulla receives 10-20% Renal blood flow
  • COX inhibitors
    • dec prostaglandin formation
  • PGE2 and PGI2
    • renal vasodilators, especially when decreased RBF
  • Enhanced by dehydration

8

Pigment nephropathy

  • Myoglobinuria
    • rhabdomyolysis
    • crush injury
    • heat stroke
    • inc CK, AST
    • serum clear
  • Hemoglobinuria
    • intravascular hemolysis
    • serum pink

9

Pigment actions causing tubular necrosis

  • Pigment
    • vasoconstriction
    • ischemia
  • Tubular obstsruction by protein casts
  • Hydroxyl radicals

 

  • Cortex most susceptible d/t inc blood flow

10

Leptospira interrogans

Hosts

Exposure

Syndromes

  • Zoonotic
  • cause acute kidney injury
  • horses
    • incidental host (except bratislava)
    • maintenance hosts: rat, cow, skunk, opossum
  • Exposure
    • urine
    • aborted fetus
  • Clinical syndromes
    • AKI, tubulointerstitial nephritis
    • Uveitis
    • Abortion, stillbirths, neonatal death

11

Lepto

Diagnostics

TX

  • Diagnostics (organism or antibody)
    • Serum microscopic agglutination test (MAT) for antibody
      • rise in titer
    • Urine PCR
      • organism in urine
      • sheds more after furosemide
    • Dark field microscopy
    • Culture
      • takes months: clinically useless
    • Immunofluorescence on tissue sample
  • Treatment
    • doxycycline, ampicillin, penicillin, amoxicillin, ceftiofur

*Don't use oxytetracycline ***nephrotoxic

12

Acute Glomerulonephritis

  • Rare in horses
    • usually sequela to other diseases
  • Marked proteinuria, red cell casts
  • Inciting antigens
    • Streptococcus
    • EIA
  • Immune complex deposition
    • complement activation
    • tissue damage

13

Post-Renal azotemia

  • Rare in adult horses
  • more common in neonatal colts
  • Dysuria, colic
  • Signs
    • neonatal uroabdomen
      • don't rule out even if peeing thru normal hole
    • obstructive urolithiasis
    • bladder necrosis

14

Clinical Eval of AKI

  • Clinical signs non-specific
  • Rule out pre-renal and post-renal azotemia
  • Frequently oliguric
    • no urine within 6-12 hours of initiation of fluid therapy
  • Rectal palpation
    • kidney enlarged, painful
  • Ultrasound
    • perirenal edema
    • hypoechogenicity
    • loss of corticomedullary distinction
    • dilation of renal pelvis

15

Clin path AKI

  • Chem
    • inc BUN and Cr ( < 10:1 ratio)
    • dec Na, Cl, Ca
    • inc K, P
  • Urinalysis
    • hematuria, proteinuria, casts, glucosuria
    • inc UGGT
    • in FCNa, P

16

Treatment of AKI

  • d/c nephrotoxic drugs
  • treat concurrent dz
  • correct volume def and establish diuresis
    • balanced electrolyte solution
    • deficit = % dehydration x BW
    • maintenance = 40-60 ml/kg/day
  • monitor closely for urination or development of edema

17

TX of hyperkalemia in AKI

  • 0.9% NaCl fluids
  • 5% dextrose
  • Calcium gluconate
  • Sodium bicarbonate
  • Insulin

18

Other treatments AKI

establishing diuresis

  • Furosemide
    • loop diuretic: blocks Na/K/2Cl co-transporter
    • depends on GFR
  • Mannitol - NOT REALLY USED
  • Dopamine - NOT REALLY USED
  • Peritoneal dialysis
  • Hemodialysis: brutus the tiny cow

19

Prognosis for AKI

  • Varies with underlying cause
  • if oliguria persists > 72 hours, prognosis guarded
  • secondary complications: laminitis
  • polyuria
    • transient
    • permanent

20

Chronic kidney disease

  • irreversible
  • variable rate of decline
  • 'end stage kidney dz'

21

Causes CKD

  • Acquired
    • glomerular dz
      • glomerulonephritis
      • amyloidosis => more common in cattle
    • tubulointerstitial dz
      • chronic interstitial nephritis
        • incomplete recovery from ATN
        • pyelonephritis
        • obstructive dz
  • Congenital (dx with rectal, ultrasound, bx)
    • suspect if < 5 yo with CKD
      • renal agenesis
      • hypoplasia
      • dysplasia
      • PKD

 

22

Clinical signs of CKD

  • Uremia: clinical manifestation of azotemia
  • Chronic weight loss
    • uremic toxins: appetite supp, oral and GI ulcers
    • Gastrin half-life prolonged
    • inc catabolic state
  • Rough hair coat
  • Poor athletic performance
    • anemia: dec EPO; dec RBC survival time
  • PU/PD
    • degree not correlated
    • collecting tubule can't compensate for excess glom filtrate
  • Ventral edema
  • Uremic halitosis
  • urea exretion in sweat
  • dental tartar, gingivitis, oral ulcers

23

Uremia

  • Uremia: clinical manifestation of azotemia
    • effects of uremic toxins on cell metabolism and function
      • BUN, other nitrogenous compounds 
      • Cr and other guanidino compounds
      • products of intestinal bacterial metabolism
      • middle molecules
      • abnormal metabolism of hormones and trace minerals

*correlation btwn magnitude of azotemia and degree of uremic syndrome is poor

24

Ventral edema

  • dec oncotic pressure
    • PLE
    • glomerular protein loss
  • inc vascular permeability
    • uremic toxins
  • inc hydrostatic pressure
    • renin release

25

four mechanisms of edema

  1. dec oncotic pressure
  2. inc vascular permeability
  3. inc hydrostatic pressure
  4. dec lymphatic return

26

Clinical evaluation of CKD

  • Azotemia
    • BUN: Cr > 10:1
      • > 15:1 = excessive protein intake
      • BUN actually helpful here
  • Electrolytes
    • hyperCa, hypoP
    • HypoNa, Cl
    • +/- K
    • metabolic alkalosis or neutral until terminal
      • metabolic acidosis late
  • hypoalbuminemia
  • hyperlipidemia
  • hematology
    • non-regenerative anemia
  • Urinalysis
    • isosthenuria (1.008-1.014)
      • develops before azotemia
    • enzymuria, proteinuria, glucosuria
    • pyuria, bacteruria
    • FCNa > 1 %
  • Rectal: small firm kidney
  • U/S: small, hyperechoic
  • BX: end stage kidney dz, congenital dz, immunfluor, EM

27

CKD prognosis

  • Grave
    • 75% renal function loss if azotemic
  • doubling of Cr = 50% decline in GFR
  • Cr < 5 mg/dl => may manage for months - years
  • Cr > 10-12 mg/dl => marked compromise
  • Cr > 15 mg/dl => grave

28

CKD prognosis

GFR measuring

  • Measure GFR
    • endogenous creatinine clearance
      • Requires timed collections
      • tubular creatinine secretion possible
    • plasma dissapearance of
      • exogenous creatinine sulfanilate
      • technicium 99 tag

*not done clinically

29

acute exacerbation tx

  • treat like AKI
    • judicious fluid therapy
  • antimicrobials if pyelonephritis
  • discontinue nephrotoxic drugs

30

CKD management

  • d/c alfalfa, legumes
    • use good grass instead
  • maintain normal protein intake (about 10%, not higher, deficiency can inc morbidity/mortality)
    • maintain BUN:Cr 10:1 - 15:1
  • maintain BCS
  • Only if necessary
    • NaCl
    • NaHCO3
  • omega-3 fatty acids
    • flaxseed oil

31

AKI vs CKD

AKI signs

  1. Good BCS
  2. normal hematocrit
  3. kidney consistency normal to soft
  4. recent association with disease, drugs
  5. US: normal echogenicity or hypoechoic with loss of renal architecture
  6. BUN:Cr < 10:1
  7. HypoCa, hyperPh

32

AKI vs CKD

CKD signs

  1. Poor BCS, weight loss
  2. Anemia
  3. Kidney size normal to decreased
  4. Kidney consistency normal to firm
  5. No recent history of other dz
  6. US: hyperechoic
  7. BUN:Cr > 10:1
  8. HyperCa, HypoPh