Renal Laboratory Tests

both — are used to evaluate renal function

urine and blood tests

a urinalysis for renal function includes, but is not limited to, an evaluation of urine for

bacteria (bacteriuria), pus (pyuria), blood (hematuria), and protein (proteinuria)

blood tests may be used to analyze levels of

blood urea nitrogen (BUN), creatinine, glomerular filtration rate (GFR), and lactate dehydrogenase (LDH)

BUN measures the

amount of urea nitrogen, a byproduct of protein metabolism that occurs within the liver and is excreted by the kidneys

creatinine, also secreted by the kidneys, measures the

amount of creatinine phosphate found in the skeletal muscles.

an elevation in either BUN or creatinine indicates

renal disease

the GFR utilizes

creatinine, age, body size, and gender

GFR can be used to evaluate the

overall function of the kidneys

LDH is an additional enzyme found within the blood that may be used to

monitor renal function and other abnormalities, including some forms of cancer

LDH elevates as a result of

cell death

LDH is NOT a

specific indicator for renal disease

urinalysis results: bacteriuria

• acute pyelonephritis

• UTI

urinalysis results: pyuria

• UTI

• usually accompanied by bacteria

urinalysis results: hematuria

• acute and chronic pyelonephritis

• hypernephroma (renal cell carcinoma)

• renal infection

• trauma

• urinary calculi

urinalysis results: proteinuria

• benign and malignant masses

• glomerulonephritis

• infection

• nephrotic syndrome

• acute or chronic pyelonephritis

• urinary calculi

urinalysis results: urine pH (abnormal)

urinary calculi (used to determine composition of stones

urinalysis results: specific gravity

• low: renal failure and pyelonephritis

• high: dehydration

urinalysis results: elevated WBC (in urine)

• UTI

elevated BUN

• renal failure

• parenchymal disease

• renal obstruction

• dehydration

• diabetes mellitus

• hemorrhage

reduction in BUN

• liver disease and failure

• malnutrition

• overhydration

• smoking

• pregnancy

elevated creatinine

• renal failure

• chronic nephritis

• renal obstruction

• diabetes mellitus

• reduced renal blood flow

reduced glomerular filtration rate

• renal insufficiency

• chronic renal disease

elevated lactate dehydrogenase

• renal infarction

• chronic renal disease

elevated total WBC count

• infection

• inflammation

reduced total WBC count

• chemotherapy

• radiation therapy

• toxic reaction

reduced hematocrit

acute hemorrhage