Flashcards in Patient Test Management Deck (69):
Define a Chain of Custody.
Chain of custody refers to the chronological documentation, and/or paper trail, showing the procurement, custody, control, transfer, analysis, and disposition of the specimen.
What is the purpose of a chain of custody?
a chain of custody form is required for any specimen used as legal evidence in court.
Computerized Provider Order Entry (CPOE)
Computerized Provider Order Entry (CPOE)
CPOE is a computerized process for health care providers to electronically enter and order medical procedures and laboratory tests based on a predetermined algorithm.
Current Procedural Terminology
What is the purpose of Current Procedural Terminology (CPT) codes?
The purpose of CPT is to provide a uniform language accurately describing medical, surgical, and diagnostic services.
Name two reason that a CPT code might have a modifier.
1. a service or procedure has both a technical and professional component2. a service or procedure was performed by more than one physician and/or in more than one location
What does a -26 CPT code modifier stand for?
26 - Professional Component
What does a -59 CPT code modifier stand for?
59 - Distinct Procedural Service
What does a -91 CPT code modifier stand for?
91 - Repeat Clinical Diagnostic Laboratory Test
Define a reference range.
A reference range is a collection of normal values for a constituent of clinical interest.
Code of Federal Regulations
How much blood is present in the average adult male?
What is the composition of blood in an average adult male?
5 quarts of blood; 3 quarts of plasma and 2 quarts of cells
What are blood cells suspended in in the human body?
What are red blood cells?
erythrocytes; delicate, round, biconcave bodies that contain hemoglobin that is used to transport oxygen to the tissue and carbon dioxide to the lungs.
Name 5 ways that hemolysis can occur.
1. improper handling of a blood specimen;2. dilution;3. exposure to contaminants;4. extremes in temperature; 5. pathological conditions
How does hemolysis occur?
when the thin protective membrane of red blood cells is ruptured and hemoglobin is released into the plasma.
What type of cell in the blood is responsible for hemolysis?
red blood cell or erythrocte
What is the primary purpose of white blood cells?
Leukocytes fight infection
How would one obtain serum?
Serum is obtained from clotted blood that has not been mixed with an anticoagulant. The clotted blood is then centrifuged, yeilding serum.
a chemical that prevents the clotting of blood
What two types of proteins does serum contain?
albumin and globulin
What type(s) of tubes can be used to collect serum?
marbled red/gray, red-stopper tubes, and/or gold top tubes
How would one collect plasma?
Plasma is obtained from blood that has been mixed with an anticoagulant in the collection tube and is therefore not clotted. This tube is then centrifuged to yield plasma.
What three types of proteins are contained in plasma?
Albumin, globulin, and fibrinogen
What is the main difference between plasma and serum?
Plasma retains fibrinogen
What is similar between plasma and serum?
They both contain albumin and globulin
What are the four steps involved in obtaining a good quality specimen for diagnostic testing?
1. preparation of the patient;2. collection;3. processing;4. storing and transport
What is the most common type of error when comparing the preanalytical phase to the analytical phase?
Specimen collection, preparation, and submission
List the four most comon errors affecting all types of specimens.
1. mislabeled specimen or failure to provide all pertinant information on the requisition form;2. insufficient quantity of specimen;3. failure to use the correcct container/tube;4. failure to tighten specimen container lids
Describe the process for drawing whole blood.
Whole blood is drawn into tubes containing an anticoagulant. Once filled the tube must be inverted 8-10 times to ensure adequate mixing and prevent clotting.
Is it recommended to split whole blood specimens?
What is the consequence of not allowing complete clotting of a serum preparation to happen prior to centrifugation?
Failure to allow clotting may result in fibrin clots that interfere with accurate laboratory results.
What are the consequences of leaving a serum sample to clot for an extended period of time?
1. increase in enzyme levels;2. increase in potassium;3. decrease in glucose
What three pathologic conditions can adversely impact lab results using serum preparations?
1. hemolysis;2. lipemia (lipemic)3. icteric
What type of blood-related specimen collection requires no coagulate in the collection tube?
What two blood-related specimen collection does require anticoagulants in the collection tube?
whole blood and plasma
What are the most common erros affecting tests utilizing serum?
1. Failure to tighten specimen container lids (leakage, contaimination); 2. Failure to allow specimens to clot before centrifugation;3. hemolysis;4. lipemia (cloudy or milky serum)
What affect does lipemia have on a patient's serum and why?
Lipemia causes cloudy or milky serum sometimes due to the patient's diet.
How is plasma obtained?
Plasma is obtained by drawing a whole blood specimen and then processing with subsequent centrifugation to separate the plasma. Remember the tube must be inverted 8-10 times to ensure adequate mixing and prevent coagulation.
Why is it important to distinguish between serum and plasma?
plasma contains clotting factors
What are the seven most common errors in the collection and preparation of plasma?
1. failure to collect specimen in the correct additive;2. failure to mix the specimen with additive immediately after collection;3. hemolysis4. incomplete filling of the tube;5. failure to separate plasma from cells within 30-45 minutes of venipuncture for those specimens requiring this step;6. failure to label transport tubes as plasma;7. failure to indicate type of anticoagulant (EDTA or citrate)
What color is hemolyzed serum or plasma?
Pinkish red, rather than the normal clear straw or pale yellow color
What types of analytes are adversely affected by hemolysis and/or prolonged exposure to a clot?
glucose, potassium, lactate dehydrogenase (LDH), cholesterol, creatinine, iron, phosphorous, calcium, and most enzymes.
Hemolyzed specimens are not suitable for what two specialized types of testing?
hematology and coagulation
What is one of the most common and expensive errors in specimen collection?
submission of an insufficient vollume of specimen for testing
Name one instance of patient preparedness that could lead to lipemia.
Patients who consume lipid rich foods, such as meats, butter, cream, and cheese, within a 12-16 hour period immediately preceding collection of a blood specimen may have temporarily elevated lipid levels. These may manifest ass cloudy or lipemic serum.
What sort of tests can be falsely elevated by lipemia?
liver enzyme results (ALT and AST) and CBCs. That is why fasting is important before these sorts of tests are performed.
Hematology specimens must be tested within what timeframe from collection?
What type of additive tube is used for plasma determinations in chemistry and are good for STAT procedures because they eliminate the need to wait for a clot to form?
What type of additive is used for whole blood hematology determinations, immunohematology testing and blood bank testing?
K2 EDTA and K3 EDTA
Can whole blood collections be frozen?
No, freezing will cause red blood cells to hemolyze
According to the NCCLS and the International Council for Standardization in Hematology (ISCH), what is the coagulant of choice in specimen collection and blood cell counting?
Name the three reasons why K2 EDTA was choosen over K3 EDTA as the anticoagulant of choice in specimen collection and blood cell counting.
1. K3 EDTA results in greater RBC shrinkage;2. K3 EDTA produces a larger increase in cell volume on standing;3. K3 EDTA is a liquid additive and will result in the dilution of the specimen
What type of additive is used for routine coagulation studies?
What is the typical concentration of citrate used in a citrate additive collection tube?
3.2% buffered sodium citrate
What type of additive is used for glucose determination on plasma?
Describe a red-stopper tube.
contains no anticoagulant or preservative
What collection tube color is used for serum or clotted whole blood?
How soon after venipuncture must serum be separated from cells?
45 - 60 minutes
What does a blue-stopper tube contain?
What color stopper does a sodium citrate additive tube have?
What color tube contains sodium fluoride?
What color stopper for a collection tube contains sodium heparin or lithium heparin?
What color stopper indicates the additive acid citrate dextrose (ACD)?
What color stopper indicates the additive EDTA for trace metal studies?
royal blue-stopper tube
List the major patient identifiers of which you must have two on a requisition form.
2. DOB or age