Procedures and principles of urinalysis in hospital lab
Purpose of random or spot urinalysis?
What is benign orthostatic proteinuria?
A phenomenon in teenage boys when, upon standing, after lying down and protein dumps into their urine showing elevated protein in the urine. No protein shows when urine sample taken after period of lying down.
Define second morning void and purpose.
A fasting sample, last meal from "night before" is cleared out of system. It is the second pass of urine upon waking.
Define 2-hr postprandial urine sample.
For those who are starting to develop type II diabetes stays elevated for several hours rather than spiking and being absorbed w/in 2 hrs.
Used for diabetic monitoring.
For urine and serum.
Glucose tolerance test?
An eval. of gestational diabetes. Pt takes a measured about of glucose in a beverage called glucola. Then, every 15 min thereafter, insulin is measured in blood to dtermine insulin tolerance. Urine is assessed every hr to see if there is glucose spill-over in the urine.
Define 24-hr urine test.
Collect total urine output for 24 hrs.
Assesses creatinin, protein excretion over 24 hrs. Can see if pt has consistent eleveated protein levels and not just transient protein levels from a meal.
Each kidney contains how many nephrons?
Approx 1 million.
Purpose of urine sample from catheter?
Assesses for bacterial culture-more of a nosocomial context. Taken from catheter tip, not urine bag urine.
What is midstream clean catch?
Start flow of urine to wash away normal flow or urine, etc. For men it is distal 2mm; for women distal 7mm. Clears specimen of normal flora, epithelial cells, etc.
Define suprapubic aspiration of urine.
Using a syringe you can bypass urethra to aspirate urine to determine if infection has reached bladder. Can also be performed for cytologic purposes.
What is functional unit of Kidney?
What is 3-glass collection?
To determine if prostate is infected. B/c prostate drains into urethra, pt's prostate can be massaged to express some prostatic fluids.
First collection is a wash. Stop flow.
Massage prostate-collect second urine flow.
Stop massage and continue urinating into 3rd glass. 3rd glass will show if UTI or if legit prostate infection.
The glomerulus is a __________ filter.
Substances with a molecular weight of less than ___________ daltons can/cannot pass into the filtrate.
Why can't albumin be filtered by glomerulus?
B/c of negative charge.
Difference btwn absorption and reabsorption.
What is the renal threshold?
When plasma level of a substance reaches a concentration that leads to excretion in the urine.
Above renal threshold active transport cannot reabsorb all of the substance from the filtrate.
Name 3 type of urine examination.
Physical, chemical, microscopic.
What should normal urine's appearance be?
pale yellow or straw to very dark yellow or amber. Variations in yellow color reflect hydration status.
Dark amber urine or beer brown urine is result of?
Presence of conjugated bilirubin.
Pink or red urine contains?
Red blood cells. Intact RBCs can give urine a cloudy appearance.
(Cloudy urine always has something in it.)
Pink or red and clear is result of presence of Hb or Myoglobin.
Brown or black urine is result of:
Upon standing, Hemoglobin iron in acidic urine will be oxidized to methmoglobin, which turns urine brown.
Melanin (result of metastatic malignant melanoma)
Dark orange urine is result of:
Pyridium (phenazopyridine) a urinary tract analgesic commonly prescribed for bladder infections (cystitis).
Normal urine is clear or hazy? T/F
Normal haziness in urine may be due to:
Amorphous crystals, squamous epithelial cells (lab will tell what type of cells-helpful to know iot determine where along process cells were sloughed off), seminal fluid, fecal contamination, mucus.
Cloudy or turbid urine is normal? T/F
Is a result of:
Renal epithelial cells
Does the Lab report urine odor?
Describe source of urine's odor when:
pungent odor of volatile aromatic acids.
odor of ammonia develops due to breakdown of urea.
Unusual urine odor may be due to?
-Bacterial infections: noxious, fetid.
-Elevated Ketones: sweet, fruity
-Maple Syrup Urine Disease: maple syrup or burnt sugar.