LAB TEST
Clinical analysis and study of a body substance to obtain objective data for the diagnosis, treatment and management of a patient’s condition
Homeostasis
state in which body systems are functioning normally and the internal environment is in equilibrium
Body substances
fluids, secretions and excretions
specimen
small sample taken from the body. ex : blood urine, stool. sputum…
clinical diagnosis
tentative diagnosis of a patient’s condition through the evaluation of the health history and the physical exam without the lab tests or diagnostic procedures .
final diagnosis
Called the diagnosis . . it refers to the scientific method of determining and identifying a patient’s condition through evaluation of the health history, physical examination, lab tests and diagnostic procedures
example of condition that does not require lab test
otitis media : dx can be made by the patient s symptoms and looking at the ear with an otoscope
lab test in hematology
involves the examination of the blood for detection of abnormalities including blood cell counts, cellular morphology, clotting ability of the blood , identification of cell types. Ex: RBC count, WBC count, Hgb, Hct, platelet count…
Lab test in Clinical Chemistry
determines the amount of chemical substances present in the blood, body fluids, excreta and tissues . Ex: albumin, bilirubin, blood alcohol,CO2, Cholesterol, creatinine, glucose, potassium .sodium, uric acid, cortisol…
Lab test in serology (immunology ) and blood banking
involves studying antigen -antibody reactions to assess the presence of a substance or to determine the presence of a disease . Exs: HIV test, TB test, Helicobacter pylori test, PSA test, Covid -19 test… It also detects the blood type, Rh type
Urinalysis
it is the physical ,chemical and microscopic analysis of the urine to detect deviations from normal.
lab test in microbiology
involves identification of pathogens present in specimens taken from the body. Ex: throat culture, urine culture, stool culture, blood culture… ,
lab test in parasitology
involves detection of the presence of disease-producing human parasites or eggs in specimens taken from the body ( stool, vagina, blood)Human disease caused by parasites includes : scabies, tapeworms, trichomoniasis ,malaria,amebiasis
lab test in cytology
deals with detection of the presence of abnormal cells. ex: chromosome studies, pap test
lab test in histology
involves the detection of diseased tissues. Ex : biopsy tissue ,tissue analysis .
what is the most frequent purpose or use of lab test?
to assist in the diagnosis of a pathologic condition .It can confirm a clinical diagnosis , assists in differential diagnosis and obtain info regarding patient’s condition that is vague and need more evidence .
why do we use lab tests? 5 purposes
1.assist in the Dx of pathologic conditions
2.evaluate the progress and regulate treatment
3. to establish a baseline level of the patient against which future results can be compared
4. to prevent or reduce the severity of a disease ( screening tests / routine tests
5. requirements by state law. Statutes of most States require gonorrhea and syphilis tests to be performed on pregnant women
routine test
test performed on a routine basis on apparently healthy patients to assist in the early detection of disease.
what are the 2 types of clinical labs ?
1.POL: PHYSICIAN’S OFFICE LAB
2. OUTSIDE LABS : includes hospital lab, private lab
Pols and lab tests
POL performed usually CLIA-waived tests and tests that are commonly required
CLIA
Clinical laboratory improvement Amendments. which consists of regulations developed by the federal government to improve the quality of the lab testing in the USA. Regulations are developed by the department of HHS and impleMented by the CMS (Centers for Medicare and Medicaid Services ).
CLIA WAIVED TEST
lab test that has been determined by CLIA to be a simple procedure that is easy to perform and has a low risk of erroneous test results.POL must apply for certificate of waiver from CMS and it must be renewed every 2 years .CLIA WAIVED TESTS exempt POL from many CLIA requirements but POL must still adhere to good lab practices.
CLIA NON WAIVED TESTS
are test that are subjects to CLIA regulations . They require complex testing method and are usually performed in an outside lab.
Lab tests directory
it serves a reference source for proper collection and handling of specimens.
content of a lab test directory (12)
Name and CPT code ,reference range ,type and amount of specimen required ,supplies necessary for collection of specimen, techniques to use for collection of specimen, special instructions, patient instructions, proper handling and storage of specimen, uses and limitations of test, methodology used to perform test.
Lab request form
it serves as a means of communication between the medical office and the outside lab .to designate the test ordered by the provider
reference range
defined as a certain established and acceptable range within which the lab test results of a healthy individual are expected to fall .
when is a lab request form required ?
required in 2 scenarios
when a specimen is collected at the office and sent to an outside lab for testing
when a specimen is collected and tested at an outside lab
purpose of a lab request
provides lab for accurate testing, for reporting results and for billing
components of the lab request
physician name /address
Patient name /address
Patient age /gender
Date /Time of collection of specimen
lab tests desired (CPT code)
Profiles
Source of specimen
Physician clinical DX in ICD- 10 format
Meds
STAT
panel= profile
A combination of lab tests that have been determined to be the most sensitive and specific means of identifying a disease state and evaluating a particular organ or organ system
specific profile
all tests relate to a specific organ or particular disease state ex: hepatic function panel or rheumatoid arthritis panel
it is used when the Dr has a good idea of what organ is involved in the patient ‘s condition .
general metabolic profile
contains numerous routine lab tests .It is used for a routine health screens or when patient ‘s symptoms are vague .
why do reference range varies slightly from one lab to another ?
due to test method used ,equipment used and reagents used
Factors that alter certain tests
food, meds, activity and time of the day
how long do u usually need to fast for certain lab test ?
usually 12-14h
for urine collection and for blood collection , how long do u need to stop meds ?
28-72h before for urine collection
4-24h before blood collection
OSHA BBPS
OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION BLOODBORNE PATHOGENS STANDARDS assists employers in providing a safe and healthy environment and it is required to follow standards to reduce risk of exposure to infectious disease
for collection of a specimen , where do u look for the requirements and info ?which manual ?
if the specimen is sent to an outside lab, look in the lab test directory
if the specimen is tested in the medical office , look in the manufacturer ‘s instruction of the specimen tested
moderate complexity tests
nonwaived tests subject to CLIA regulations.
accounts for 75% of the 7 to 10 billion of lab tests in the USA . most of these tests are done in hospital and independent labs . some Medical offices perform moderate complexity tests but it is done by the provider (PPM) . other moderate complexity tests are urine and throat culture and hematology and blood chemistry tests .
PPM : what is it ?
Provider performed microscopy procedures
Involves examination of a specimen under the microscope and it is considered moderate complexity test
high complexity test
nonwaived test subject to CLIA 1988 Regulations which includes cytogenetics, histopathology ,cytology (ex : pap test )
those tests are not performed in the medical office.
requirements for moderate /high complexity tests
must meet CLIA regulations and is
subject to unannounced inspections every 2 years by CMS .
Components of the CLIA 1988 regulations
Patient test management
quality control
quality assessment
proficiency testing
personnel requirement
Patient test management
to make sure the sample comes from the right patient . system to maintain optimal integrity and identification of specimens
system to ensure accurate reporting of results
quality control
is to ensure accurate and reliable test results . each lab must establish and follow written procedures that monitor an evaluate the quality of each testing process
quality assessment
must establish and follow written policies and procedures to monitor and evaluate overall quality of total testing process
proficiency testing
form of external quality control. It is used to verify accuracy and reliability of lab testing .
unknown specimens are shipped to POL and POL tests specimens and reports results to a proficiency testing agency for evaluation.PT agency grades results and sends POL a score .
personnel requirements
CLIA specifies education training qualifications and responsibilities for lab directors ,clinical consultants , technical consultants and testing personnel.
analyte
substance that is being identified or measured in a lab test ex: glucose, cholesterol
CLIA WAIVED TESTS most frequently done in the Medical Office
blood glucose determination
dipstick urinalysis
Fecal occult blood testing
Urine pregnancy tests with visual color comparisons
Group A rapid streptococcus testing
HEMOGLOBIN TESTING
Cholesterol testing
Triglyceride testing
Prothrombin time testing ( test for measuring how long it takes to coagulate )
Spun microhematocrit
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purpose of Quality Control
ensure that tests results are reliable and valid
detects and eliminate errors that may interfere with obtaining accurate results ..
test system
a setup that includes all of the test components required to perform a lab test such as testing devices, controls and test reagents.
how to handle refrigerated controls and testing reagents in a testing process ?
allow refrigerated controls and testing reagents to reach room temperature before use . it usually takes 15-30 min
calibration
mechanism to check the precision and accuracy of a test system. ex: automated analyzer)it is performed using a calibration standard or calibration device . it may come in the form of a calibration strip or cassette that is inserted into the analyzer and calibration results are displayed on screen or printed out
control
a solution used to monitor a test system to ensure the reliability and accuracy of test results .
internal control
built-in to some test systems .it evaluates whether certain aspects of the testing procedure are working properly. it is performed at the same time as the testing procedure .
if test result is invalid with internal control build in the test , what do u check for ?
if a sufficient amount of specimen was added
if a sufficient amount of testing reagents was added
if the testing reagents migrated through the test device properly
external control
used to determine if testing reagents are performing properly or if you detect any error in the technique.
2 levels of controls here must be performed on a test system :
low level control: produces results that fall below the reference range for the test
high-level control produces result that fall above the reference range of the test
control procedure is done the same way we will do the test procedure but instead of adding patient specimen we add control .
factors that can cause abnormal control results in an external control ?
outdated controls or testing reagents
improper storage of testing components
error in the technique used to perform the procedure
qualitative test results
indicates if a substance is present in he specimen being tested . .It provides an approximate indication of the amount of the substance present. results are recorded in
terms of 1+, 2+, 3+
trace ,small ,moderate or large
negative or positive
reactive or nonreactive
quantitative results
indicate the exact amount of the substance present in the sample
express with its respective unity of measure .