Laboratory Methods Flashcards
What are the different types of specimens that can be collected for laboratory testing?
Blood Body fluid Urine Microscopic Stool
What are the different types of medical labs?
Hospital lab
Reference lab = sample gets sent outside of place it is taken
STAT lab = more expensive
Point of Care Testing = bedside
What is lab standardization?
Provides accurate and reproducible results
Ensures credible and comparable data across laboratories
What organization is in charge of lab standardization?
National Accrediting Agency for Clinical Lab Sciences (NAACLS)
What is considered CLinical Pathology?
Hematology Chemistry Immunology Serology Immunohematology Microbiology Support Services
What is considered Anatomic Pathology?
Histology
Cytology
Autopsy
Who sets the regulations for medical labs?
Center for Medicare and Medicaid Services (CMS)
These people aren’t medical workers
Who do laboratories work under for regulations?
Clinical Laboratory Improvement Act (CLIA)
What do we currently use to code and classify disease?
ICD-10
What are the two main purposes of HIPAA?
1) Provide continuous health insurance coverage for workers who lose or change their job
2) Reduce administrative burdens/cost of healthcare by standardizing the electronic transmission of administrative and financial transactions = this is where the privacy piece comes in
What is lab quality control?
Gives confidence that results are accurate and Reliable
What does internal lab control evaluate?
Test is working as it should
Enough sample is added
Sample is moving correctly
Electronic functions of instrument working correctly
What does external lab control evaluate?
Entire testing process is performed correctly
Control results are in expected ranges or values as found in manufacturer’s instructions
What is the reference range of a test?
Upper and lower limits generally given as range in healthy people
Normal values vary from person to person
What are therapeutic ranges for lab tests?
Upper and lower limits to measure medication efficacy
MIC
What is Diagnostic cutoff or threshold?
Presence of disease associated with value above a certain threshold
A compromise between sensitivity and specificity
It wants to minimize false negatives and false positives
What is Sensitivity?
Capacity to identify all individuals with disease
What is specificity?
Statistical term indicating effectiveness of test to correctly identify those without disease
What is a positive predicative value?
Likelihood that positive test identifies with disease
What is the negative predictive value?
Likelihood that negative test results identifies someone without disease
What test is an example where the threshold is selected to maximize sensitivity?
HIV screening
What is accuracy?
The ability of a test to actually measure what it claims to measure
Proportion of all test results (both positive and negative) that are correct
What is precision?
Ability of a test to reprocess the same results when reacted on the same patient or sample
What is the pretext probability effect?
Probability you have disease
What are the indications for ordering a lab test?
1) Screening
2) Establish diagnosis
3) Monitor disease
4) Monitor Therapy or medical management of disease
5) Testing related to specific event like a needle stick of sexual assault
What is the process for lab testing?
1) Order test
2) Patient prep for testing
3) Collect sample
4) Transport sample to lab
5) Lab receives sample
6) Lab prepares sample for testing
7) Lab reports results
What are preanalytical values for ordering lab studies?
1) Patient Age
2) Patient Gender
3) Body Mass
4) Preparation of the patient for testing
5) Differences in results with sample type
What are the standard precautions for lab studies?
Sharps Box
Gloves
Eyewear
What are blood studies ordered for?
1) Assess quantities of RBCs and WBCs
2) Levels of enzymes, lipids, clotting factors, and hormones
3) To establish a diagnosis = Elevate BUN and creatinine levels indicate renal failure
4) Rule out clinical problem = Normal K level rules out hyperkalemia
5) Monitor Therapy = PTT values to regulate heparin therapy
6) Establish prognosis = Declining CD4 counts reflect a poor clinical prognosis for the AIDS patient
7) Screen for disease = PSA levels to detect prostate cancer
8) Determine effective drug dosage and to prevent toxicity = peak and trough levels
What is the primary type of blood collected for blood studies and where is it collected from?
Venous blood
From antecubital fossa of the arm where basilic, cephalon, and median cubical superficial veins can be found
If you can’t use the upper extremities to obtain a blood sample, where is the next best place to obtain a venous blood sample from?
Femoral V.
What type of blood study is the first sample to be drawn?
Blood Cultures
What is serum?
Lacks clotting factor
Clotted blood sample
Clear
What is plasma?
Clotting factors present
Anticoagulated blood sample
Slightly more cloudy
What is the order of recommended blood draw?
1) Blood Cultures tubes
2) Nonadditive tubes
3) Coagulation tubes
4) Heparin tubes
5) EDTA-K3 tubes
6) Oxalate-fluoride tubes