Renal function test

levels of waste

A urine renal panel measures the _____________ in the urine filtered by the kidneys.

levels of filtered substances

A serum or plasma renal panel measures the ______________ in the blood.

liver

Ammonia is converted to urea by the

levels of urea excretion

A BUN measures the

high

In patient with an acute kidney injury what would their BUN look like?

dietary intake, kidney excretion

BUN amount is determined by

dehydration, CHF, kidney disease, liver disease, antibiotics, steroids, high protein diet, trauma

Examples of things that cause a high BUN (more common than low)

liver disease, malnutrition, low protein diet, pregnancy

Examples of things that cause a LOW BUN

Creatinine

A waste product from muscle tissue and dietary protein metabolism that is filtered out of the blood by the kidneys and excreted (not reabsorbed)

High (creatinine has a direct relation to muscle mass)

For a swole patient, how is their normal creatinine going to look

constant

Formation of creatinine is

Creatinine

What is a more reliable kidney function test, creatinine or BUN

urinary tract obstruction, kidney disease, meds

High levels of creatinine are associated with

liver disease, decreased muscle mass

Low levels of creatinine are associated with

Glomerular filtration rate (GFR)

What lab test calculates an estimated value that reflects filtration (specifically creatinine clearance) and is the primary way to measure kidney function?

urinary tract obstruction, kidney disease, dehydration, medications

A low GFR is associated with

pregnancy, hyperfiltration syndrome

A high GFR is associated with

serum and urine creatinine, height, weight, 24 hour urine output, a well hydrated patient

To calculate an accurate GFR what do we need

big body, big GFR (normalizing for body surface area aims to remove this affect)

How does body size affect GFR?

general kidney disease, dehydration, trauma

What can cause uremia?

high BUN

How will uremia show up on a BMP?

azotemia

High level of nitrogen

High BUN, high Creatinine

How will azotemia show up on a BMP?

dehydration, CHF, liver failure, Addison’s, high protein catabolism

What can cause prerenal azotemia?

Intrinsic renovascular disease, glomerular disease, Tubulointerstitial diseasse

What can cause intrarenal azotemia?

ureteral obstruction, neurogenic bladder, UTI, medications, BPH

What can cause post renal azotemia?

kidney function test, 24 hour urine, kidney ultrasound

How do you diagnose azotemia?

loop diuretics/positive inotropic meds, hemodialysis, peritoneal dialysis

Treatment options for azotemia?

greater than 20

A BUN/Creatinine ratio ________________ is characteristic of prerenal azotemia

Renal azotemia

If the BUN/Creatinine ratio is normal both but both creatinine and BUN are high, what are we dealing with

Cystacin C

What lab test measures the amount of a low molecular weight protease inhibitor produced by all nucleated cells that filtered freely by the glomerulus and not reabsorbed?

inversely proportional

How are cystatin C levels related to GFR

when race cannot be specified, people with impaired muscle mass (age, amputee)

When may cystatin C be useful

uric acid

A lab test that measures the final breakdown product of purine metabolism in the liver that is excreted in the urine

urate crystals may deposit in tissues

What happens if uric acid is over 6.4 mg/dL

increased production/dietary intake/cell breakdown hyperuticemia

Gout is characterized by

decreased excretion hyperuricema

Toxiema of pregnancy, type I glycogen storage disease, lesh-nyhan syndrome, and renal disease are associated with