O this is a powerful compensatory mechanism but it

o This is a powerful compensatory mechanism, but it cannot typically
compensate for systolic blood pressures below 70 mm Hg. Pressures at
or below that level result in a decreased GFR
 Cannot filter blood if systolic BP is below 70
 The hormones antidiuretic hormone (ADH) and aldosterone
o control the permeability of the DCT membrane. Antidiuretic hormone,
also known as vasopressin, is discussed in detail later regarding the
kidneys’ role in the regulation of water balance
 ANTIdiuretic to retain urine
o Aldosterone is a hormone secreted from the adrenal cortex
that increases the reabsorption of sodium in the DCT. Because
water follows sodium, the reabsorption of water is also increased
o A serum glucose over 220 mg/dL results in incomplete reabsorption
and resulting glycosuria.

Hormonal Function
 Renin
o Renin aids in blood pressure regulation within the body. It is
produced and released when receptors in the kidneys sense a
decrease in blood flow, volume, or pressure
o Renin interacts with angiotensinogen released from the liver
to produce angiotensin I, which, with the aid of angiotensin-
converting enzyme (ACE) secreted from the lungs, results in
the formation of angiotensin II . Angiotensin II constricts blood
vessels, resulting in increased blood pressure
 Erythropoietin
o Erythropoietin is a hormone produced exclusively by the kidneys
in response to decreased renal blood flow and hypoxia
o Erythropoietin stimulates the bone marrow to produce RBCs
 Potential Nephrotoxic Substances
o Vancomycin (Vancocin)
o Nonsteroidal anti-inflammatory drugs (NSAIDs, e.g., aspirin, ibuprofen)
o Salicylates
o ACE inhibitors
o Benzodiazepines
o Lithium (Lithobid)
o Contrast media
 Anuria
o is a total urine output of less than 100 mL in 24 hours
 Oliguria
o decreased amount of urine output, 100 to 400 mL in 24 hours
 Polyuria
o describes excess quantities of urine output
Renal and Urinary System Assessment Abnormalities
 Anuria
o Less than 100-mL urine output/24 hr
 End-stage renal disease, acute renal failure, urinary tract
obstruction
 Dysuria
o Difficulty or pain with urination
 Urinary tract infection, cystitis (bladder infection)
 Hematuria
o Presence of blood in the urine
 Cystitis or other inflammation in the urinary tract, calculi,
cancers of the urinary tract, renal disease, bleeding disorders,
medications such as anticoagulants

 Oliguria
o Decreased urine output; less than 400-mL urine output/24 hr
 Shock, end-stage renal disease, acute kidney injury, severe
dehydration, blood transfusion reaction
 Percussion
o patient reports pain or tenderness, it is suggestive of kidney
inflammation or infection
 Blood Test
o The most utilized blood tests include serum creatinine, BUN, and
BUN/creatinine ratio
o Electrolyte values including sodium, potassium, phosphorus, and
calcium are also monitored as a reflection of kidney function.