Medical Lab Flashcards
What are the two types of pathology labs?
Clinical and Anatomic
Hematology, Chemistry, Immunohematology, and Microbiology are examples of what kind of lab?
Clinical Pathology
What are the three types of Anatomic Pathology labs?
Autopsy, Cytology, Histology
The Clinical Lab of Hematology looks at what?
Looks at cellular components of the blood
The Clinical Pathology lab of Chemistry looks at what?
Any chemical reaction or make up of blood. Electrolytes, liver functions, etc
The Clinical Pathology lab of Immunohematology is also called what?
Blood bank
The Clinical Pathology lab of Microbiology checks for what?
Bacteria
Anything used to test humans must be cleared by what two things?
CLIA and FDA
A hospital lab gets results in ___ hours?
Within 24
What is a Reference Laboratory and what is the wait time?
A warehouse lab where special tests are performed. Turn-around can be lengthy.
What is a STAT laboratory?
Tests that can be done in an urgent setting for very quick results
What is a Point of care Test (POCT)? What is “waived” about them?
Device used at patient that gives immediate result. EX glucometer, coumadin levels. “CLIA-waved”.
What type of testing is CLIA waved for?
Point of care Testing (POCT)
What is Quality Control?
Gives confidence that results are accurate and reliable
What are two types of controls in Quality Control?
Internal Control, External Control
What does Internal Control check?
Test is working as it should, enough sample added, sample is moving correctly, electronics of device are working
What does External Control check?
Entire testing process is performed correctly and control results are within expected range
What are three types of ranges?
Reference range, Desirable range, Therapeutic range
Define Reference Range
Ranges of values considered normal for that test. Made from healthy, unmedicated individuals in 95% of people.
What is a Desirable Range?
Establishes a range where people want to be in order to have a healthy outcome. EX: cholesterol below a certain number
Define Therapeutic Range
Range while treating someone, shows if PT is adaquetly medicated. ex INR while on coumadin
Define “Sensitivity”
If catching positives, including false positives. EX: HIV test is very sensitive and will catch everyone with HIV but also people who don’t have HIV (False Positive)
Define “Specificity”
If positive from sensitivity then certain that is it. Can exclude false positives. EX: Specific HIV testing rules out those who falsely tested positive via sensitivity
Define “Prevalence”
A lot of people having something means more people will test positive
What are the two types of Predictive Values?
Positive Predictive Value and Negative Predictive Value
Define Positive Predictive Value
Likelihood that positive test identifies someone with the disease
Define Negative Predictive Value
Likelihood that negative test result identifies someone without disease
Threshold is when what two things are minimized?
Minimize false negatives and false positives
Threshold is a compromise between what two things?
Sensitivity and Specificity
Define Accuracy
If you hit the target, aka “is it correct”?
Define Precision
How reproducable a test result is
A clinical lab is one of the few ways to get _____ data
Objective
What are the 5 indications to order a lab test?
Screening, establish a diagnosis, monitor disease, monitor therapy/management, testing related to specific events
What is screening?
An indication to order a lab test. When check population for disease ex >50y/o for colon cancer. No symptoms required. ex newborn screenings.
Are symptoms requires for ordering a lab test based on “screening”?
No symptoms requires. Are routine tests like cholesterol or new baby testing
What is the reason behind the lab test reason of “Establish Diagnosis”?
When you’re not completely sure what the diagnosis is and need test to help confirm suspicion
What is the reason behind using “Monitor Disease” to order a lab test?
To see how the disease is progressing over time. EX HbA1C which gives a 3 month glucose evaluation
What is the reason behind using “Monitor Therapy” to order a lab test?
EX: INR. Need to know if the treatment is having the desired result in order to avoid issues
What is the reason behind using “testing related to specific event” to order a lab test?
When there are specific signs or symptoms. ex car accident, sexual assault
What/where are the three types of blood?
Venous, arterial, capillary
What is a very common type of patient preparation before a lab test?
Fasting
What are the two most common types of urine tests?
Clean Catch, Random Urine
What is a “clean catch”?
Urine test that gets rid of external contaminants better than peeing and catching midstream
What is a Random Urine test?
Collecting urine sample without cleaning ahead of time
What will Formalin do to a culture?
Kills the culture and everything else
What does a tourniquet allow when doing a venipuncture?
Prevents venous return allowing swelling of vein and easier collection of veinous blood
What is special about vacutainer holder?
Has suction, negative pressure environment to draw out blood
Should you load the vacutainer onto the needle before insertion into a vein?
NO!
What are the three most common veins to draw blood from?
Cephalic Vein, Median Cubital Vein, Basilic Vein
What does the gauge number represent with regards to a needle diameter?
The small the number the larger the diameter.
What are the most common gauge sizes for veinpuncture?
21, 22, 23
What can small needles do to blood during a venipuncture?
Lyse the RBCs making the test no good
Which way should the lumen be pointed during a venipuncture?
UP!
What is in a “light blue top” and what test is it for?
Citrate for coag studies.
What is in a red top and what is it for?
No additives. The blood clots and is serum. For chemistry studies, some blood bank, drug monitoring
What is in and what does a red/black stripe top do?
SST. Stimulates blood to clot, serum/cell separator.
What is in and what does a Green Top do?
Heparin for anticoag. Checks coagulation and sometimes for cardiac enzymes.
What is in and what does a Lavender/Purple top do?
EDTA anticoagulant. For CBC, hematology studies.
Why do some samples need light protection?
UV can break down some things like bilirubin
What should be on a label for a specimen?
PT name, dob, initials of specimen takee, date time taken, what specimen is, and where taken on body
How can hemolysis screw up a sample?
Red blood cells open up then screws up serum levels as the cells spill their intracellular contents into the serum and screw up test results
What does centrifuging to do a blood sample?
Separates serum from cellular components
Define lipemic
Very high triglyceride levels
What does Serum lack that Plasma has?
Serum lacks clotting factors
Plasma has ____ while serum doesn’t.
Plasma has clotting factors
In centrifuge where do the non-cellular components end up?
Rise to the top
Which tops for serum?
SST and Red Top
Which tops for Plasma?
Blue, purple, or green.
What does Serum look like vs Plasma?
Serum is clear, Plasma is slightly cloudy
If test results don’t make sense what should you do?
Redraw and retest
At what phase of blood testing do most errors occur?
Most errors in pre-analytical. During PT preparation until specimen gets to lab.
Hemolysis can mess up what type of electrolyte count?
Potassium spilling from inside RBC due to hemolysis
Icteric is another name for what?
Jaundice
Jaundice aka
Icteric
Describe jaundice/icteric specimines
jaundice. icteric=high bilirubin and brownish color change. tests done through spectometry and if specimen is discolored then can’t get accurate result
What is the first steps before taking a blood sample?
Identifying PT with two forms of ID (name and birthdate) and checking for any pre-draw instructions (fasting)
What time do you remove the tourniquet?
1 minute
Arteries are more ____ to the touch and have thicker or thinner feeling walls?
More elastic to the touch; thicker feeling walls
What is the motion for the alcohol prep pad? How do you dry it?
Fluid, circular motion from center to periphery. Let air dry to prevent contamination.
Where do you place your thumb when doing a venipuncture?
2 inches below the intended puncture side and pull skin taught to keep vein anchored in place
What is the angle when inserting a needle into a vein?
30 degrees
Once blood starts flowing into the vacutube what do you do with the tourniquet and PT’s hand?
Remove tourniquet and relax hand
How many times do you mix by inversion after drawing blood into tube?
Gently 8 times to ensure additives are mixed into the sample
Apply pressure at needle puncture site immediately after withdrawing needle enables what to happen and prevents what?
Prevents a hematoma, allows hemostasis
Serious complications most happen at which vein? How?
Basilic vein due to close proximity to nerves and brachial artery which can be niched
What gauge is a Butterfly Needle?
23-25 gauge
What can happen do the RBCs when using a Butterly Need or similar sized bore?
RBCs can lyse due to too small bore which screws up results
What is a hematoma?
Bleeding from vein into surrounding space under skin. Bruised in appearance and painful to touch.
When can a hematoma form?
When you don’t put immediate pressure on a venipuncture side
To prevent release of shut off valve on tube what do you do?
Keep a constant and slight forward pressure on end of tube
As soon as blood begins to flow into the tube what do you do?
Tell PT to relax hand and remove turniquet
What is the color order for filling tubes?
Light blue, red, gold, green, lavender, grey
Normal number of RBCs?
3.5-5.5 million
Normal number of WBCs?
4.5-11 thousand
Normal number of thrombocytes (platelets)?
150-400 thousand
Where is the problem in Pancytopenia?
Bone marrow problem
Define Pancytopenia
Decrease of all cell lines (RBCs, WBCs, platelets)
Define Anemia
Reduced number of RBCs
Define Polycythemia
Increased number of RBCs
Define Thrombocytopenia
Decreased platelets
Define Thrombocytosis
Increased platelets
Define Leukocytosis
Increased WBCs
Define Leukopenia
Decreased WBCs
Define Neutopenia
Decreased neutophils
What sort of precaution does neutropenia require?
Reversed precautions. Protecting PT against the world.
Define Leukemoid Reaction
Benign and temporary WBC increase (leukocytosis) in response to normal illness
Define Hematopoiesis
Production of blood cells
Define Erythropoiesis
production of RBCs
Define Thrombopoiesis
Production of platelets
Define Leukopoiesis
Production of WBCs
Define Lymphopoiesis
Production of lymphocytes
Define Medullary Myeloid Hematopoiesis
Production of myeloid blood cells in bone marrow
Define Extramedullary Hematopoiesis
Production of blood cells outside bone marrow (in liver or spleen). Usually indicates a malignancy.
What is the only blood cell that is not from the myeloid line?
Lymphocytes
What is “Peripheral Flow”
Blood flow outside of bone marrow and out in the system
Where do T-cells mature?
T cells mature in thymus.
Where to B-cells mature?
B cells mature in bone marrow.
Where do NK cells mature?
Bone marrow
B cells are involved in what type of immunity?
Humoral immunity involved in production of antibodies.
What are B cells involved in production of?
Antibodies