The purpose of this section is to introduce you to
global aspects associated with the clinical labora- tory and laboratory testing. As this section clearly in- dicates, laboratory testing is crucial to the diagnosis and monitoring of patient diseases and conditions, as well as to rule out any diseases and conditions. This being said, an alert medical assistant will have a comprehensive understanding of these aspects. Further, the medical assistant will use appropriate corresponding techniques and procedures to ensure proper laboratory sample collection for testing by appropriately trained and educated individuals. Our Case in Point for this section explores some of these important concepts and serves as a review of the section content.
Case in Point
As noted in this case, during the first week of your student practicum you are introduced to the clinical laboratory by your clinical instructor, Doris. Your patient, Mr. Hershey, presents to Maple Grove Clinic for evaluation. After examining Mr. Hershey, Dr. Pueblo determines that he requires laboratory testing to determine his condition. This situation gives you and Doris a wonderful opportunity to dis- cuss important concepts associated with both the clinical laboratory and laboratory testing. High- lights of this discussion follow for your review and consideration.
There are numerous ways in which laboratories are structured and organized based on a number of fac- tors, including the environment in which the laboratory exists (it may be a small rural hospital or large commer- cial reference laboratory). Each laboratory determines what tests it will run, what instrument it will use for the tests, and the values considered as normal for the typical patient population the laboratory serves. There are three phases of laboratory testing: preanalytical,
analytical, and postanalytical. Every laboratory test passes through all three phases. An error in any of the three phases may adversely affect the laboratory results generated. Most of the problems encountered in laboratory testing occur during the preanalytical testing phase because of a variety of issues, for example, collecting the sample on an individual other than the targeted patient.
Laboratory tests are categorized based in part on the difficulty of the procedure required to obtain the results. Health-care support individuals, including med- ical assistants, are allowed under government regula- tions to perform select testing under strict guidelines. Handling every sample using universal precautions is an important point to emphasize, as doing this con- tributes to the validity of the test results obtained. In ad- dition to running the laboratory tests, quality control samples must also be tested on a regular basis to ensure that the test is working properly. Laboratory test results can only be released (in laboratory jargon this is called “turned out”) to the patient’s chart if the qual- ity control samples test properly. In the event that qual- ity control results are not in range, investigation and resolution of the problem must occur before patient results can be considered valid. Individuals vary in many ways. Variations in laboratory test values (as well as quality control samples) are no exception. Because of this, laboratory test results considered as being normal fall within a range of values.
In conclusion, laboratory tests provide physicians and other primary care providers with valuable infor- mation. In fact, many sources have reported that some 70% to 80% of diagnosis and treatment deci- sions are based on laboratory results. As this section clearly suggests, there are many important aspects to laboratory structure and testing, all of which con- tribute to the bottom line: accurate laboratory tests performed in a timely manner.
118
On the Horizon
It has been widely documented that as many as 70% to 80% of all patient treatment decisions are based on laboratory test results. Similarly, there is strong evi- dence to support the fact that laboratory test results are only as good as the sample from which the test- ing occurs. Specimen collection and processing, also known as the preanalytical phase (meaning the steps before actual analysis occurs) of testing, is thus a very important factor that contributes to the reliability of the laboratory test results obtained. Results from such samples collected and/or processed improperly can- not be considered valid and thus are of no benefit to
the patient. There is widespread evidence that most laboratory testing errors occur in during the collection and processing of specimens.
Relevance for the Medical Assistant
(Health-Care Provider)
Medical assistants and other health-care support per- sonnel are often called upon to assist in the collection of, perform the collection of, instruct patients on the collection of and process samples for laboratory test- ing. To ensure the most reliable results for the patient, an in-depth understanding of specimen collection and processing is of paramount importance.
Case in Point
After a relatively smooth morning, your first patient after lunch is Wilma F., a 70-year-old woman. After reviewing Wilma’s file, you notice that she was seen and treated 3 weeks ago, on what just happened to be on your day off, for a urinary tract infection. As you help Wilma get onto the scale to weigh her and then again when you place the blood pressure cuff on her arm, you notice that she is very hot to the touch. Your suspicions are confirmed when you take her temperature and it is 101.5°F! You ask Wilma to identify all symptoms she has been experi- encing. She tells you that in addition to feeling hot all the time, she has a burning sensation and pain during urina- tion. You document these details and tell Wilma that the doctor will be in to see her shortly and you leave the examining room. After the doctor examines Wilma, he
asks you to collect her blood and assist Wilma in collect- ing urine for urinalysis and culture.
Questions for Consideration:
• What special considerations must be addressed to col- lect the blood in an appropriate manner in this case? • What special equipment do you need to collect this
blood sample?
• What type of urine sample should you assist Wilma to collect?
• How is this type of urine sample collected?
• Why are the blood and urine collection processes so important to implement in this case?
119