1. Quality Assurance
Urinalysis

2. Introduction Urinalysis seems to be an ideal test
The sample is easy to collect;
the test procedures are simple and uncomplicated
Unfortunately the development of a quality assurance program for urinalysis has lagged behind other areas of the laboratory
Because of its simplicity and low regard in the laboratory it is not unusual to find that the least experienced and trained technologist and technicians are assigned to this workstation
These individuals more often than not do not understand the importance of adhering to test procedures and fail to recognize or correctly count the formed elements in the urine sediment

3. Introduction
The macroscopic and microscopic examination of urine can reveal important insights to a patient's physical condition and state of health
Until recently little effort has been spent on the standardization of this widely practiced procedure
The quality of the laboratory result can be improved and maintained with a small amount of effort placed in assuring:
sample integrity
standardization of procedures
and correct interpretation and reporting of the urine sample

4. Major Errors In Urine Testing
Failure to test a fresh specimen
Inadequate communication between the laboratory and the patient or nursing staff for collecting a urine specimen properly
Use of unclean collection containers, tubes, and slides
Inadequate care of specimen
Improper recording of information and test results
Poor or inconsistent technique in using the reagent dipstick
Inadequate understanding of interfering substances
Failure to mix urine specimen (blood, bacteria, casts) before pouring---a-portion for the microscopic analysis
Incomplete training of personnel to perform properly the technical aspects of the urinalysis or to identify elements in the sediment

5. Specimen Collection
Most routine urinalysis is performed on a freshly collected random urine
Regardless of when the sample is to be obtained, clear and concise written instructions are necessary for both patients and nursing personnel
The validity of a test result is no better than the quality of the specimen
Once the urine specimen has been collected it should be processed immediately to prevent deterioration
If samples can not be processed within 1-2 h of collection, they should be refrigerated or preserved

6. Specimen Collection Types of Urine Specimens
Random specimen:
A urine specimen collected at any time by either clean catch, catheterization, or suprapubic aspiration
Random specimens are collected most often for routine urinalysis
First morning specimen:
A urine specimen collected upon rising from sleep in the morning
First morning specimens are also used for routine urinalysis
Postprandial specimen:
A urine specimen collected at a specific interval after eating
This type of sample is used to evaluate a diabetic condition, either as part of a glucose tolerance test, or for the control of a diabetic state
Specially timed specimen (2-hour and 24-hour specimen):
Involve the collection of all urine in the specified time period
used in various renal function tests such as creatinine clearance

7. Specimen Collection Preservation of Urine Specimens
It is important to recognize which preservative is necessary for which test
Type of preservative should me marked on the container to ensure safety
Some of the more common methods of preservation include:
Freezing
Destroys cells and some components
Refrigeration
Preferable method, sample should come to RT before analysis
Commercial preparation tablets
For routine urinalysis in absence of refrigeration
Formalin, Toluene, Chloroform, Phenol & other chemicals
used mostly for 24-hour specimens

8. The Decomposition Of Urine
Urine undergoes these changes after collection if proper steps are not taken to preserve it
pH: May increase
Color: Darkens
Odor: Becomes smelly
Turbidity: Develops
Protein: May appear or disappear
Bilirubin: Decreases and disappears
Urobilinogen: Decreases and disappears
Ketone bodies: Decrease and disappear
Ascorbic acid: Decreases and may disappear
Ammonia: Increases
Glucose: Decreases and disappears
Bacteria: increase
Nitrite: Appears
Casts: Disappear
Red blood cells: Hemolyze
Occult Blood: Reactivity appears or increases

9. Procedure Manual
Should pay special attention to the collection procedure
Should specify which preservatives are appropriate for which tests and should detail the proper labeling of these sample containers
Definition of the various formed elements in the sediment should be clear and methods of reporting should be well defined
Arbitrary terms such as small, moderate, and large should be avoided and semiquantitative terms such as trace, 1+ , and 2+ should be defined to help reduce reporting inconsistencies between individuals
Instructions for the preparation of control samples should be included in the urine procedure
The control tolerance limits should be clearly displayed and specific actions to be taken when limits are exceeded

10. Standardization Of The Urinalysis Procedure
The routine urinalysis is divided into two parts:
the chemical urinalysis
and the microscopic urinalysis
Until recently the chemical urinalysis was performed manually with:
Reagent strips
The determination of the final color of the strip pad is a subjective one and two persons may interpret the same test in different ways
The timing between immersion and reading the strip is another source of variation between one individual and another
The longer the reaction is allowed to proceed before reading, the darker the color development
Consistent timing is important for precision and accuracy
Or reagent tablets
The reagent tablets are also colorimetric reactions that require timing and interpretation by technologists
Positive
Negative

11. Standardization Of The Urinalysis Procedure
The manual performance of the chemical portion of the urinalysis is subject to imprecision and inaccuracy due to shortcuts and inconsistent performance
The introduction of automated readers has improved the precision and accuracy of the chemical portion
Light is directed to the pad and the intensity of the reflected light is measured

12. Standardization Of The Urinalysis Procedure
The introduction of standardized systems for performing the microscopic examination reduces another variable in the urine procedure
These systems standardize:
the volume of urine used to collect the sediment
the force of centrifugation
the volume of urine in which the sediment is resuspended
and the volume of sediment examined for cells and casts

13. Quality Control
Commercially prepared controls for the chemical portion of the routine urinalysis are available for the reagent strips and tablets
Lyophilized urine samples or reagent sticks with impregnated chemicals that dissolve in measured amount of water
Positive and negative controls are available to check the sensitivity of the reagent system
Both positive and negative controls should be run daily and when opening a new bottle of reagent sticks or tablets

14. Reagent And Instrumentation Quality Assurance
Reagent sticks and tablets should be stored under conditions specified by the manufacturer to prevent the absorption of moisture and prevent exposure to light that may degrade some of the chemicals in the reagent pads
Written maintenance procedures and schedules for all instrumentation in the urinalysis laboratory should be kept current and reviewed for compliance by the laboratory director or his designee