Final Flashcards
What are the functions of a normal kidney?
Fluid and electrolyte balance
Excretion of nitrogenous wastes
Erythropoietin
Renin
Vitamin D activation
Filtration (glomerulus)
Reabsorption and secretion (tubular)
What is azotemia? What is uremia?
Azotemia: accumulation of nitrogenous wastes BUN and/or creatinine)
Uremia: clinical signs associated with renal failure
What is the difference between pollakiuria and polyuria?
Polakiuria: increased frequency, small amounts
Polyuria: large amounts
What are systemic clinical signs of renal failure?
Fever
Body condition
Oral ulcers
Pale MM
Which tests evaluate the upper vs lower urinary tract?
UA: both upper and lower
Serum chemistry: upper
Renal function tests: upper
Imaging: upper and lower
What produces creatinine? How is it excreted? Is it secreted or reabsorbed?
Produced by muscle
Excreted by filtration
Neither secreted or absorbed
What produces BUN? How is it excreted? Is it secreted or reabsorbed?
Produced by liver
Excreted by filtration
Also secreted and reabsorbed
When should you evaluate a urine sample?
Within 1 hour of collection
Reagent urinalysis strips are reliable for assessing which parameters?
WBCs,
Nitrites
Urobilinogen
SG
What factors affect the accuracy of reagent urinalysis strips?
Moisture
Alkaline urine
Discolored urine
What ketone does chemical urinalysis accurately test for?
Actoacetate
How do you tell the difference from blood, hemoglobin, and myoglobin in urine?
Spin down urine -> pellet on bottom with clear supernate = blood, no pellet = myoglobin or hemoglobin
To differentiate between myoglobin and hemoglobin, need to spin down blood -> pellet with clear supernate = myoglobin, red supernate = hemoglobin
What are differentials for bilirubin in urine?
Hemolysis
Liver disease
Bile duct obstruction
What is important to keep in mind when evaluating casts?
They will dissolve is urine is allowed to sit before analysis
What type of cast is indicative of on-going renal disease?
Cellular
Does absence of casts rule out renal damage?
NO
Fat is common in the sediment of what species?
Cats
T/F: crystalluria is not always pathogenic?
True
Can you tell which urine is more concentrated by comparing color?
No
What are the defining parameters for AKI?
Increase in creatinine by > 0.3 mg/dL in 48 hours
Increase in creatinine > 1.5 x baseline
Urine production < 0.5 mL/kg/hr (6 hours)
What is the principle biomarker of AKI?
Creatinine
What defines normal urine output, oliguria, and anuria?
Normal: 20-50 ml/kg/day or 1-2 ml/kg/hr
Oliguria: < 1 ml/kg/hr
Anuria < 0.1 ml/kg/hr
What is the RIFLE staging system of AKI?
Risk: inc. Cr 50-100% or UO < 0.5 ml/kg/hr > 6 hrs
Injury: inc. Cr 100-200% or UO < 0l.5 ml/kg/hr >12 hrs
Failure: inc. Cr >200% or > 4mg/dL or UO < 0.3 ml/kg/hr for > 24 hrs or anuria >12 hrs
Loss of function: need dialysis for > 4 wks
End-stage renal disease: need dialysis for > 3 mo
What is the IRIS staging system of AKI?
Used in vet med
Grades 1-5 based on rises in serum Cr
What are the main clinical signs that differentiate AKI from CKD?
AKI: acut onset of clinical signs, normal BCS
CDK: chronic, decreased body condition
What are causes of renal tubular injury?
Toxins (ethylene glycol, lillies, grapes/raisins)
Nephrotoxic drugs (abx, NSAIDs, radiocontrast agents)
Metabolic dz (hypercalcemia)
Endogenous substances (myoglobin, hemoglobin)
What causes interstitial nephritis?
Pyelonephritis
Leptospirosis
Granulomatous disease
Neoplasia
What causes glomerular disease?
Immune-mediated complex deposition causing inflammation of the glomerulus (glomerulonepehritis)
What is the most common cause of AKI in cats?
Urinary obstruction
What is the most common cause of AKI in dogs?
Unknown
Elevated anion gap, ionized hypocalcemia, and calcium oxalate monohydrate crystals may be observed following what cause of AKI?
Ethylene glycol toxicity
What changes in hematocrit are seen with AKI?
Normal or elevated
A positive urine culture raises concern for what cause of AKI?
Pyelonephritis
What types of fluid should be avoided in the treatment of AKI?
Chloride-rich solutions
Synthetic colloids
What is the definition of fluid overload?
More than 10% increase in BW from baseline
What are the main goals of nutritional support in treatment of AKI?
- Preserve lean body mass
- Avoid further metabolic complications
- Support immune system
- Improve GI tract function
Give a phosphate binder with each meal!
What should you avoid force feeding renal diets?
Creates aversion
What are the indications for dialysis?
Severe hyperkalemia
Severe fluid overload
Severe acid-base disturbance
Sever or progressive azotemia
Oliguria/anuria
Pre-surgical conditioning
What is the cause and treatment or uremic gastritis?
Cause: decreased Gastrin elimination
Tx with antiemetics and reduce acid production
Antiemetics: cerenia, ondansetron, metoclopramide
Decreased acid production: H2-blockers, proton pump inhibitors, sucralfate
What is true about using furosemide?
No evidence supports the use of loop diuretics, used as a rescue protocol
What is fenoldopam?
Dopamine-1 receptor antagonist used to increase GFR but ultimately there is no change in renal funtion
What vasopressor is recommended for use in AKI to restore blood pressure and urine output?
Norepinephrine
What are the types of renal replacement therapies?
Therapeutic Plasma Exchange (TPE)
Hemoperfusion
Intracorporeal: Peritoneal dialysis
Extracorporeal: Intermittent Hemodialysis (IHD), Continuous Renal Replacement Therapy (CRRT)
What is the difference between Intermittent Hemodialysis and Continuous Renal Replacement Therapy?
IHD: 3-6 hours, most efficient, “saw tooth” excursions with greater risk of complications, water purification systems, non-portable
CRRT: Long >24hr sessions, less efficient, replacement fluid before or post filter, Sterile dialysate, portable, more expensive
What is the prognosis of AKI with hemodialysis?
~50%
What do beta receptors control?
Bladder relaxation
What do alpha receptors control?
Bladder contraction, increase tone of internal urethral sphincter
Which nerves control bladder filling?
Hypogastric n. and pudendal n.
Which nerves control the voiding phase?
Distention -> pelvic n.
Pain/over-distention -> hypogastric n.
What does acetylcholine control?
Contraction of bladder
What are the characteristics of storage disorders?
Voluntary urination is normal
Involuntary leakage
Normal residual volume
stranguira is uncommon
What are the characteristics of voiding disorders?
Voluntary urination is abnormal -> stranguria, pollakiuria, diminished urine stream, usually postures
Increased residual volume
What are examples of storage disorders?
Urethral incompetence
Detrusor relaxation
Ectopic ureter
What is the most common storage disorder?
Urethral sphincter mechanism incompetence (USMI)
Spayed female dogs, incontinence at rest
What is the cause of urethral sphincter mechanism incompetence and what is the treatment?
Cause: decreased estrogen-> inc collagen and dec muscle
Tx: phenylpropanolamine (alpha adrenergic agonist), estrogen
What disorders are considered urethral incompetence?
Urethral sphincter mechanism incompetence
Pelvic bladder
How do you diagnose pelvic bladder and what is the treatment?
Dx: clinical signs and rads
Treatment: similar to USMI (PPA) +/- surgery
What is a bladder relaxation disorders?
Detrusor spasticity
What are the clinical signs of detrusor spasticity, what are possibly causes, how do you diagnose it, and what is the treatment?
CS: sudden voiding with small bladder
Cause: usually secondary to inflammation (infection, cystoliths, neoplasia, idiopathic)
Dx: presumptive, cystometrography
Tx: Treat underlying disease!/enhance bladder relaxation with anticholinergics
What are the clinical signs of ectopic ureters, how do you diagnose it, and what is the treatment?
Cs: constant dribbling of urine
Dx: cystoscopy, contrast radiography or CT,
Tx: Laser ablation (intramural), surgery, manage like USMI
What are examples of voiding disorders?
Detrusor contraction (atony or LMN disease)
Urethral relaxation
physical obstruction
What are the clinical signs of detrusor atony?
Large, soft bladder,
Stranguira with minimal/weak stream
Large residual volume
May see “overflow” incontinence
What are the clinical signs of LMN disease?
Distended, flaccid bladder
Decreased anal tone and perineal reflex
+/- paraparesis/paralysis
What is the treatment for detrusor atony?
Neurogenic: fix underlying problem
Non-neurogenic: relieve physical obstruction or address functional obstruction
Re-establish tight junctions, keep bladder small, stimulate detrusor contraction -> bethanecol
Do not do this if urethral obstruction present!
Which class of drug would you use to relax the internal urethral sphincter?
Alpha- adrenergic antagonist
What are the clinical signs of urethrospasm?
Relatively common post-catheterization, especially cats
Stranguria, pollakiuria,
Large, firm bladder
Initial normal stream then stops
What is the treatment for urethrospasm?
Internal sphincter: a-antagonist (phenoxybenamine, prazosin, tamsulosin– dogs only)
External sphncter: diazepam, alprazolam, midazolam, ace
What do upper motor neuron lesions result in?
Loss of voluntary bladder function
Tetra or para-paresis
Hyperreflexia
CP deficits