Phlebotomy ch 39

Methods used to process lab tests

- specimen obtained and performed within physician's office laboratory (POL)
- specimen packaged to transport to outside lab
- patient is referred to a separate lab for collection and testing of specimen

purposes of lab testing

- to record an individual's stat of health
- to satisfy employment, insurance, or legal requirements
- to gain statistics for research and clinical trials
- to detect asymptomatic conditions or diseases
- to confirm a clinical diagnosis
- to differentiate

tests done to record an individual's state of health

Blood tests may be performed periodically to be assured of healthy normal ranges (reference values)

reference values


baseline values


tests done to satisfy employment, insurance, or legal requirements

- Blood may be tested for presence of drugs/alcohol. this can indicate if pt is guilty/innocent of a crime
- Places of employment or life insurance may require drug tests to be assured that their employers/clients be free of illegal drugs

tests done to gain statistics for research and clinical trials

- Lab tests may be gathered for research for clinical trial information.
- This information is used for medical research.
- Clinical trials address efficacy of medications.

tests done to detect asymptomatic conditions or diseases

- Asymptomatic condition: pt exhibits no symptoms that may be associated with a disease process
- Discovered during routine screening

tests done to confirm a clinical diagnosis

Physician may be able to diagnose pt without lab tests (clinical diagnosis). Physician orders lab test to confirm clinical diagnosis.

tests done to differentiate between 2 or more diseases

- Patient presents with symptoms that can be related to multiple diseases/conditions
- Provider chooses simple and least invasive lab tests to rule out a particular disease/condition (differential diagnosis)

tests done to diagnose

- Pt presents with vague symptoms making diagnosis difficult. series of lab tests done.
- Group of related tests (panel) performed to help narrow the field for diagnosis

tests done to determine effectiveness of treatments

- Blood test used to check level of medication in patient's system to determine if level is within therapeutic range (therapeutic drug monitoring)
- Peak: measure highest level of medication 1/2 hour after pt takes medicine.
- Trough: measure the lowest l

tests done to prevent disease/disorders

- protects public, families, and coworkers
- helps people become aware of their condition so they can take preventative measures from spreading their disease/condition to others (if transferable)

tests done to prevent exacerbation of disease

blood test done, results determine if it is necessary for pt to adjust their diet or medication