Primary Renal Profile Flashcards
(26 cards)
Primary Renal Panel
BUN
Creatinine
Urinalysis (esp. urine SG)
Secondary Renal Panel
Electrolytes: Ca, P, Mg, Na, K, Cl
Acid base: TCO2, anion gap, electrolytes (Na, Cl, K), urine pH
Cholesterol
What are the sources of creatinine (2)?
Endogenous production related to muscle mass (byproduct of muscle metabolism)
Note: Conditioning in horses and rhabdomyolysis may increased values.
Dietary intake (muscle/meat)–>minor role, unlikely to cause values out of the reference range
How is creatinine produced?
Creatine formed in liver–>transported to muscle–>
phosphorylated to form creatine phosphate (energy source for muscle contraction–>creatinine is a degradation product of creatine
Creatinine freely diffuses out of muscle cells. T/F
How long does it take for creatinine to equilibrate throughout body fluids? BUN?
True
Creatinine–> 4 hours
BUN–> 1.5 hours
How is creatinine excreted (2)?
Renal
Freely filtered, no reabsorption
GI, sweat (minor, clinically insignificant)
Is creatinine secreted by the tubules? Be specific related to species.
Female dogs, cats, ponies–>NONE
Male dogs, humans–>Mild
Goats–>Considerable
This is really only important if doing creatinine clearance rate assay for glomerular function.
Increased creatinine?
Decreased creatinine?
Increased–>decreased GF
Decreased–>increased GF
Extra renal considerations for creatinine?
Muscle mass and diet
Decreased values are present in cachexia
Sources of BUN (2)
Protein catabolism (ammonia–>urea)
- Tissue (normal turnover, corticosteroids, fever…)
- Dietary proteins (MAIN SOURCE)
What is your first thought for changes in BUN?
Changes in glomerular filtration
Name 4 clinically significant increases in BUN that are non-renal.
Enteric hemorrhage (moderate) High protein diet (minimal) Terminal starvation (rare, mild) Severe burns (rare)
Name 3 clinically significant decreases in BUN that are non renal.
Anorexia (mild) with prolonged fasting (lose normal protein breakdown in the GI tract)
Low protein diet (Hill’s K/D)
Decreased liver function (decreased fxn mass, shunt)
How is BUN excreted (2)?
Renal
Freely filtered
Tubular reabsportion occurs
GI (very mild influence on serum values bc no fecal urea)
Why does BUN stay lower than creatinine in ruminants with azotemia?
BUN diffuses from the blood into the rumen where it is broken down by microbes.
How much tubular reabsorption occurs with BUN?
Where does reabsorption of BUN occur?
40-60% depending on flow rate (passive reabsorption)
In the collecting ducts
Explain the beneficial effect of BUN reabsorption in dehydration.
Dehydration decreases flow rate–>increases reabsorption–>increases osmotic gradient–>increases concentration of urine and reabsorption of water
Urea is a MAJOR osmotically active molecule. T/F
True
BUN is more specific for GF than creatinine. T/F
False
What clinical signs are associated with uremia and renal failure?
Vomiting (gastritis), diarrhea (+/-), tachypnea (acidosis), lethary (anemia, toxemia, etc.), anorexia, petechiation, soft tissue mineralization
Define adequate urine concentration. Red Flag!
The minimum urine specific gravity that is consistently attained in healthy animals when faced with a need for water conservation.
What are the mechanisms for pre-renal azotemia (2)? Name 2 examples of each.
All extra renal changes!
- Decreased blood flow to the kidneys
a. Decreased blood volume
b. Altered blood flow - Increased production of nitrogenous wastes
What 3 components make up the acid-base primary profile?
TCO2
Anion Gap
Chloride
What 3 components make up the acid-base secondary profile?
Potassium
Urine pH
