Minimizing Pre-Examination Variability During Venipuncture, Urine Sample Collection, and Sample Processing
Continuing Education Credits
Clinicians make patient care decisions based on the results of laboratory testing. Pre-analytical errors can have a significant negative impact that prevents the delivery of quality patient care. These negative outcomes can range from unnecessary redraws and delayed results, to improper treatment, misdiagnosis, and even death. This course is intended to emphasize the pre-analytical variables that must be controlled during venipuncture and urine collection procedures in order to ensure the quality reporting of laboratory test results.
Objectives
- Categorize the phases of clinical laboratory testing as pre-examination, examination, and post-examination.
- Identify several of the pre-examination variables associated with patient preparation.
- Explain the phlebotomist’s role in minimizing pre-examination variability associated with venipuncture and urine sample collection.
- Specify the most frequently encountered sources of hemolysis.
- Recognize potential sources of pre-examination variability associated with sample handling and transportation.
- Determine the common pre-examination causes of unanticipated laboratory results.
Course Outline
- Phases of Clinical Laboratory Testing
- The Testing Process
- The Pre-examination Phase and Importance of Minimizing Variability
- Patient Identification
- Proper Patient Identification is Crucial
- Variables Related to Patient Preparation
- Patient Preparation: Fasting
- Patient Preparation: Medications and Supplements
- Patient Preparation: Hydration and Dehydration
- Patient Preparation: Sleep
- Patient Preparation: Stress
- Stress affects the production of many hormones and neurotransmitters and may impact some laboratory test values. Which of the following methods will help to minimize stress prior to blood collection?
- Variables Related to Blood Sample Collection
- The Blood Collection Process
- Blood Collection: Patient Position
- Site Cleansing/Disinfecting
- Blood Collection: Needle Gauge
- Blood Collection: Tourniquet
- Tube Mixing
- Blood Collection: Tube Type and Collection Volume
- Order of Draw
- Blood Collection: Traumatic Draw
- Blood Collection: Intravenous Solutions
- Which of the following blood collection variables may falsely increase the plasma potassium level if the potassium sample is collected using a green-top tube?
- Variables Related to Urine Sample Collection
- Urine Collection: Preservatives
- Urine Collection: Timed Urine Specimens
- Urine Collection: Incomplete Urine Collection
- Urine Collection: Dilutional Effect on Urinary Markers
- Urine Collection: Contamination of Urine Samples
- True or False: A 24-hour urine collection should include the first morning void on day one of the collection and the first morning void on day two of the collection.
- Variables Related to Sample Transport
- Sample Transport Time
- Sample Transport Temperature
- Sample Mechanical Transport
- True or False: When the transport time may be prolonged for circumstances beyond the control of the laboratory, the integrity of the sample may be preserved by keeping the sample chilled during transit.
- Variables Related to Sample Handling
- Time Between Sample Collection and Centrifugation
- Incomplete Gel Barriers in a Sample
- Variables Related to Sample Preparation
- Sample Centrifugation Speed
- Sample Centrifugation Temperature
- Variables Related to Sample Storage
- Sample Storage Time
- Sample Storage Temperature
- Sample Light-Sensitivity
- Sample Freeze-Thaw Cycling
- Which analyte may be falsely decreased due to a delay in transport time to the laboratory?
- The Matrix Interferents
- The Matrix Interferents
- Hemolysis
- Lipemia
- Icterus
- Viscosity
- Which blood matrix interferent is considered to be the most preventable when precautions are taken during sample collection and handling?
- Investigating Unanticipated Analysis Findings
- Investigating Unanticipated Analysis Findings
- Case Study: Highly-Elevated Serum Potassium
- Investigation: Highly-Elevated Serum Potassium
- Case Study: Severely Decreased Serum Calcium
- Investigation: Severely Decreased Serum Calcium
- Case Study: Critically Low Serum Glucose
- Investigation: Critically Low Serum Glucose
- References
- References
Additional Information
Level of instruction: Basic
Intended Audience: This course is intended for phlebotomists, phlebotomy supervisors, patient care coordinators, medical laboratory technicians, medical laboratory scientists, laboratory supervisors, managers and directors. This course is also appropriate for medical laboratory science students and pathology residents.
Author Information: Jack A. Maggiore, PhD, MLS(ASCP) serves as the Assistant Laboratory Director of Chemistry and is Head of Research and Development at Doctor's Data, Inc. in Saint Charles, Illinois. Dr. Maggiore is a medical technologist, certified by the ASCP, with a Master of Science in Clinical Chemistry and Doctorate in Pathology from the University of Illinois. His expertise includes clinical instrumentation, method development and validation, quality assurance, medical device clinical trials, and scientific regulatory affairs. His clinical research interests include the development of novel biomarkers for chronic diseases using blood spots and other non-conventional samples. Dr. Maggiore holds several medical device patents, has authored more than fifty peer-reviewed and invited publications and textbook chapters, and has presented his research findings at international scientific society meetings. Dr. Maggiore's mission is to work with healthcare professionals to empower consumers to take a more active role in their health maintenance.
The author has no conflict of interest to disclose.
Reviewer information: Lisa Dewey, MLS(ASCP) is the Quality Manager at Doctor's Data, Inc. and has been a medical technologist since 1990. She obtained a BS in Clinical Laboratory Science from the University of Illinois at Chicago. Lisa has experience working in various specialties in hospital and clinic laboratories, research & development, laboratory management, and a commercial laboratory specializing in dried blood spot testing.
Reviewer information: Carol Becker, MS, MLS(ASCP)CM is a retired Program Director for the Clinical Laboratory Science program and Histology program at OSF St. Francis Medical Center located in Peoria, Illinois. Carol received her Master's degree at the University of St. Francis in Joliet, Illinois and her Bachelor's degree in Medical Laboratory Science from the University of Illinois.