Blodvärden

Question 1

Urea (UN)

Answer 1

This is produced in the liver from ammonium and bicarbonate, and is excreted from the body via glomerular filtration through the kidneys. Approximately half of the UN
excreted into the tubules is reabsorbed passively in the
proximal tubule and actively by the cells of the collecting
ducts. Urea is held in the medullary interstitium.

Question 2

Kreatinin (Ct

Answer 2

This is a breakdown product of muscle creatine and creatine phosphate that is excreted via glomerular filtration in the kidneys. Serum or plasma Ct concentration ([Ct]) is not increased until approximately 75% of nephons are not filtering adequately.

Question 3

Azotemi

Answer 3

This is the most commonly used laboratory indicator of renal dysfunction and occurs when the serum concentration of urea nitrogen and/or creatinine concentrations are increased.
Serum or plasma UN or Ct concentration are not increased
until approximately 75% of nephrons are not filtering adequately.
Azotemia can be caused by prerenal, renal (glomerular,
tubular, interstitial, pelvis), or postrenal problems.
Patietns may be azotemic but are not yet uremic.

Question 4

Uremi

Answer 4

This is the term used when clinical signs are attributed to
azotemia. With progression of renal disease, a clinical state known as “uremia” can develop. Among other things,
uremia results in anorexia, weight loss, depression, stupor, vomiting, electrolyte and fluid imbalances, and hormone
deficits and or increases. This is caused by accumulation of nitrogenous waste products and uremic toxins in blood.

Question 5

Prerenal azotemi

Answer 5

This is recognized when azotemia is noted in blood and
urine specific gravity (USG) is concentrated. To be considered concentrated, USG should be greater than 1.030 in dogs, 1.035 in cats. Causes of prerenal azotemia include any state that results in a decreased renal plasma flow: hypovolemia due to dehydration, shock, and cardiac insufficiency. Prerenal conditions are a common cause of azotemia, and if these conditions persist, they can lead to kidney damage and renal azotemia.

Question 6

Renal azotemi

Answer 6

This is recognized when azotemia is coupled with inability
to concentrate urine, especially isosthenuric urine, as indicated by a USG between 1.007 and 1.013. Isosthenuria
implies that the kidneys are damaged to such an extent that they are no longer able to concentrate nor dilute urine.
Renal azotemia can be due to acute or chronic renal failure.
The defect in renal function may arise from one of several
diseases of the glomeruli, tubules, interstitium, renal pelvis,
and, least likely, from within renal blood vessels.

Question 7

Postrenal azotemi

Answer 7

This is associated with any obstruction to the outflow of
urine or rupture of urinary bladder. Oliguria or anuria will
be observed, and any urine specific gravity is possible.