Renal (general) Flashcards
What does isosthenuria indicate?
Urine that has the same specific gravity as the plasma. The kidney is unable to concentrate or dilute urine. USG is between 1.008-1.012.
Seen with renal azotemia.
What does hyposthenuria indicate?
The kidney is able to dilute urine (solute absorbed in excess to water).
USG < 1.008.
What USG indicates adequate renal concentrating ability in dogs?
> 1.030
What USG indicates adequate renal concentrating ability in cats?
> 1.040
What USG indicates adequate renal concentrating ability in cattle and horses?
> 1.025
True or False: AKD and CDK can be differentiated based on bloodwork alone
False. This requires more information such as clinical findings, history, duration of signs, etc.
When do we see increased BUN levels?
We see increased BUN with kidney disease. Urea should always be filtered out in the urine, therefore if it is seen in the blood it indicates decreased GFR.
When do we see decreased BUN levels?
We see decreased BUN with liver disease because the liver produces urea, so a liver with decreased ability would make less urea.
What are two other causes of increased BUN?
- Intestinal hemorrhage
- Increased protein catabolism (this generates more NH4 +, therefore increased BUN production by hepatocytes)
Change is typically mild and creatinine is concurrently normal.
What is creatinine?
A compound produced in the skeletal muscle at a constant rate (result of normal muscle metabolism). Should be excreted 100% and never reabsorbed.
What is the difference between azotemia and uremia?
Uremia refers to the clinical signs associated with azotemia.
What is an example of pre-renal azotemia? What is the USG?
Decreased blood flow or perfusion to kidney. USG still remains above 1.030 (cats and dogs) or above 1.025 (large animals).
What is an example of renal azotemia? What is the USG?
Damage to renal parenchyma or intrinsic renal disease. USG is 1.008-1.012.
What is an example of post-renal azotemia?
Damage distal to nephron, such as a urinary tract obstruction.
Renal failure occurs when ______% functional renal mass is lost
66-75%
What is SDMA?
A more reliable indicator of kidney function than creatinine, allowing earlier detection of acute kidney injury and chronic kidney disease (SDMA increases at 40% loss versus creatinine which increases at 75% loss).
True or False: Creatinine is not affected by age or muscle mass
False. Creatinine decreases with age in cats. It is SDMA that is not affected by age or muscle mass, therefore it’s a better indicator of kidney disease.
True or False: The presence of protein in dilute urine is never normal
True
What is pre-renal proteinemia?
When increased amounts of small proteins in blood are filtered through glomerulus and seen in urine (ex. hemoglobin or myoglobin).
What is renal proteinemia?
Glomerular: When damage occurs to glomerulus, there is decreased selective permeability allowing passage of larger proteins (ex. albumin). Tubular: When damage to tubules, smaller proteins that are normally resorbed in proximal tubule remain in urine.
What is post-renal proteinemia?
When there is hemorrhage or inflammation in lower urinary tract (ex. UTI), causing increased protein in urine.
Hypo____________ in blood is most often associated with renal proteinuria
Hypoalbuminemia
What is UPCR?
Urine protein:creatinine ratio.
A laboratory test that evaluates loss of protein relative to loss of creatinine. You get this by dividing the protein value by the creatinine value (creatinine should be lower). Ex. Creatinine (1)/protein (2) = 0.5 (normal). Basically it tests how much protein is being lost through the kidneys, and if this loss poses a major health risk.
When should a UPCR be performed?
If protein filtration is increased relative to creatinine filtration. This is to prove if there is renal proteinemia present.
