Urinalysis for Nurses.
Urinalysis is the technical term for “analysing urine” or “urine analysis”. It is an inexpensive way of getting objective information about a patient’s health. The procedure is both simple and cheap. Urinalysis involves testing the patient’s urine for pH value, proteins, specific gravity, leukocytes, ketones, glucose, bilirubin, blood, Nitrites and urobilinogen. All the information obtained is objective but must be assessed and related to the clinical picture of the patient.
First a clean specimen of urine is collected after obtaining consent. There are different of specimen collected for different purposes. A clean catch is sufficient for urinalysis. Five to ten ml of urine is sufficient. Do not use old specimen for testing.
Picture A: Reagent Strips of the type used for analysis.
Advantages of doing ward urinalysis.
- Dipsticks in current use are fast and cheap.
- User or tester does not require extensive training but must not be colour blind.
- No pain or discomfort to the patient.
- The tests can be performed daily as baseline measurement.
- Wide range of applications.
Disadvantages of ward urinalysis.
Inaccuracy / false positives are high. False positives cause anxiety to the patient.
Flawed urine specimen collection is the most frequent cause of false positives.
Reagent strips (Trade names: multistix, Diascreen etc.) are strips of plastic on which small squares of blotting paper impregnated with different chemicals are mounted. Look at the picture of Reagent Strips and container above. When the chemically impregnated blotting paper is dipped in a clean specimen of urine from the patient it brings about chemical changes. The chemical changes are in proportion to the substances in the urine which are being measured. Always use reagent strips which are not expired or damaged. Close the lid after obtaining one dipstick. A clean container or a test tube should be used to contain the urine. The adsorbent silica gel should always be present in the container. If not, the reagent strips will deteriorate due to excessive humidity.
Urinalysis: The Procedure.
Place a small amount of urine to be tested in a container. A test tube is the most convenient container. However, a urine container, of the type used to send urine specimen to the laboratory will do equally well. Dip the reagent strip in the urine. Let is soak the urine for a second or two. Remove it form the container and tap it on a paper to remove excess of urine. This will prevent cross migration of chemicals between the different blots. A stop watch with a second hands needle should be available as some of these tests are time sensitive. Read off the results by comparing them with the colour strips on the side of the bottle at the appropriate times. If you are unable to read off the results with the specified time then repeat the test for only the items you were not able to read off the first time. If you are unsure of the result, please check it with a colleague or repeat it. The consequences of missed results could be wrong or delayed treatment. These fairly simple tests are not substitutes laboratory tests which are usually more accurate.
There are some tests which cannot be done in the ward. So the correct type and amount of specimen must be sent to the laboratory with the correct label and requisition. Such specimen must be enclosed in appropriate biohazard labelled plastic bags.
Urine is produced by kidneys, transported to the urinary bladder via the ureters. It is accumulated in the bladder until there is sufficient stretching of the muscled of the wall of the urinary bladder. Then it is excreted to the exterior by the urethra.
Studies of normal urine have established the normal range of waste products excreted by the kidneys. Testing a sample of urine give us an accurate, objective measure of the patient’s internal biochemical processes.
Before doing formal urinalysis procedure it is usual practice to observe and document about the following.
See: Colour is influenced by a multitude of factors. These include fluid balance, diet eaten, medications consumed, and the disease affecting the patient. Concentrated urine is more dark. Pale or colourless urine is usually more dilute. If urine is more yellow than normal then the patient may have had vitamin B supplements. Blood in urine will make it more concentrated. Reddish brown urine may be due to consumption of blackberries, beets or rhubarb.
Cloudy urine: Normal urine is usually clear. Opacity or turbidity is due to bacteria, blood, sperm, crystals or mucus.
Smell, Odor. Urine usually has a slight urea smell which is not very strong. Many diseases alter this balance e.g. E. coli bacterial infections result in foul smelling urine and diabetes mellitus produce a sweet and fruity smelling urine.
The following is a list of tests / items usually tested in a hospital ward by Registered or Enrolled Nurses. The results can be used to diagnose, treat and manage pathological conditions.
