URINALYSISUrinary tract infections are the second most frequent infections (upper respiratory infections are first) that occur in children. These infections may be present and cause no symptoms, or they may cause obvious symptoms such as fever, frequent urination, and burning during urination. Some infections of the urinary tract may start as unexplained fever with no other obvious cause.
A urinalysis is a routine examination of a urine specimen in an office or laboratory that includes the study of:
The urine pH (acidity or alkalinity of the urine), which serves as a clue to urinary tract infection, urine stones, and disturbances in the body's acid-base balance.
Protein in the urine, which may be a sign of kidney disease.
Glucose (sugar) in the urine, which may be an indicator of diabetes.
Ketones in the urine, which indicate the status of body fat metabolism.
Blood in the urine, which is a sign of kidney or urinary tract disease.
Pus cells and bacteria, which may indicate urinary infection.
A colony count is a special test that checks for bacteria (germs) in urine cultured for 24 to 48 hours. Counting the number of bacteria that grow in a calculated amount of urine for a specified length of time aids the doctor in determining the presence of infection.
The colony count is more reliable than a routine urinalysis in detecting urinary tract infection. Urine that contains germs is either infected (from germs in the bladder or kidney) or contaminated from germs normally on the skin being washed along with the urine stream. If 2 or more different types of germs are found, contamination is the usual cause. Infection is usually caused by a single type of germ.
It is important to determine whether the urine is infected or merely contaminated, because prescribing medicine and referring to a urologist may be decided from the test. If the child does not have specific urinary symptoms, but the "count" is positive, your physician may wish to re-examine the urine and even catheterize the patient before labeling the problem a urinary tract infection.
Most authorities recommend X-ray studies of the urinary tract for boys after the first urinary infection is diagnosed, and for girls after the second. However, this is determined by each child's particular circumstances. Hospitalization may be necessary for some of the tests.
In addition to the urinalysis, colony counts, and X-rays, parents should observe their babies and young children for the following signs that may indicate a problem with the urinary tract.
Straining with urination. This is normal with the passage of gas and bowel movements in babies, but not with urination.
A thin, weak urinary stream or one that is interrupted (stops and starts with no reason), dribbles out, is divided, or is misdirected.
Any pain or burning during urination.
Frequent urination so the diaper or underclothes are continually wet.
Routine urinalysis screening is done annually at the regular checkup, whenever a child has fever without an apparent cause, or if there are any symptoms of a urinary tract infection.
Protein in the urine (proteinuria) may be a sign of renal (kidney) disease. The kidney acts as a sieve that allows only very small amounts of protein to pass into the urine, normally too little to show up as more than a trace on the chemical tests used for urine. Thus when protein shows up in the urine, your physician must be certain not to overlook a renal problem.
Some adolescents and older children who are growing rapidly may show protein in their urine only when they are standing, but not when they are lying down. This condition, called "orthostatic albuminuria," is not usually a renal problem, although it must be followed carefully by your physician.
To test whether orthostatic albuminuria or a renal problem is present, your child should follow these instructions:
Urinate and empty the bladder just before going to sleep at night.
Urinate upon awakening in the morning, into a jar while still lying flat in bed, if possible.
Urinate again into another jar after moving around for a few hours.
Do this for 2 days and take each urine specimen to the lab, labeled as to the time and position taken (lying flat or standing), to be tested for protein in the urine.
Children with orthostatic albuminuria should have a complete urinalysis every 6 months
to make sure no renal problem is developing. Baseline kidney tests may be ordered.
TO COLLECT A STERILE URINE SPECIMEN
Use a proper sterile container. Obtain an open-neck jar (peanut butter, jam, etc.) and wash and thoroughly rinse the jar and lid. Place the jar with the lid lying beside it in boiling water and let them boil for 15-20 minutes. Let the jar air dry. Shake the water out of the jar, but do not wipe it out, because this may introduce germs. The purity of the urine is the important part, not the exact amount. If some water droplets remain in the jar, it is not important.
Cleanse the child.
--Boys: Using a non-irritating antiseptic solution such as pHisoHex, saturate a cotton ball and thoroughly but gently cleanse the end of the penis if the child is toilet trained. If the boy is not circumcised, draw the foreskin back as much as possible, cleanse the area, and collect urine in the clean jar, with the foreskin drawn back. For an infant, cleanse the entire penis and surrounding area that fits into the urine collection bag your doctor will prescribe.
--Girls: Proper collection of a clean-catch midstream urine specimen requires that a sample be obtained after the urethra (opening to the bladder) and surrounding area have been thoroughly cleansed with a non-irritating antiseptic solution, then rinsed with sterile water and gently wiped dry with a sterile towel prior to voiding. For an infant, use the sterile urine collection bag your doctor will prescribe. Being careful not to touch the inside of the bag, peel off the adhesive, spread the child's labia (the outer lips of the genitals) after cleansing as described above, and stick the bag on the open area.
--Midstream urine: Ideally the collection of urine from a girl should be done after voiding is started and before urination stops, from the "middle of the stream." This is done by having the girl squat over the sterile container after she has begun to urinate.
--Storage: If not immediately taken to the doctor's office or laboratory, the urine should be placed in the refrigerator (not in the freezer). Urine should not stand unrefrigerated more than 2 hours before analysis.
--The first morning specimen is preferred, but urine collected at other times is also acceptable. When the specimen is brought to the office or laboratory, be sure to tell the nurse or technician that it is for a COLONY COUNT, if that is what your physician has ordered. Otherwise, only a simple, routine urinalysis will be done.