HUC 113 "Rainbow" Quizlet

HUC 113 Rainbow Quizlet

This is a complete or incomplete grade assignment due by or before Jul 6th @ 8 am you need 40 points to pass.

The physician orders for a “rainbow” to be drawn. What does that mean? It means the physician wants about every colored lab tube to be drawn. What do all those colors mean and why do some tubes have additives and gel separators?  Why is the order they are to be drawn in so important? 

The blood tubes or “vacutainers” were invented by Joseph Kleiner and Becton Dickinson in 1949. Vacutainers are sterile glass or plastic tubes. They have a closure device that is evacuated to create a vacuum inside the tube and are usually used to draw a sample directly from the vein, but occasionally may be used to collect urine samples.

There is a specific order that blood must be drawn and collected in vacutainers. This is called “order of draw”. It is very important that this order is followed to ensure accurate handling and results. The needle that pierces the tubes can carry additives from one tube to the next. The draw sequence is standardized so cross-contamination of additives will not affect laboratory results.

The approved order of draw is found in the most current edition of the Clinical and Laboratory Standards Institute “Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture, H3-A6.” This document originated in 1977 and has been updated as needed. The latest edition is H3-A6, which was published in October 2007.

The first in the order of draw are blood cultures. They are always drawn first without exception, no matter how many or how few tubes are being drawn. Then the tubes with coagulation additives are drawn followed by tubes without additives. Finally tubes with other additives are drawn last.

Following are a few of the additives in the tubes:

• Anticoagulants. Sodium citrate, sodium heparin, potassium oxalate, two different types of EDTA (Ethylenediamine tetra-acetic acid), and lithium heparin are some of the anticoagulants that prevent the blood from clotting. Tubes with theses additives need to be gently inverted 3-7 times immediately after collection, depending on the test ordered. This ensures that the blood quickly comes into sufficient contact with the additive. The tubes are never to be shaken.
• Preservative. Sodium fluoride is used as a preservative. This prevents glucose in the blood from decreasing in quantity.
• Thrombin. Thrombin is a clot activator, helps the blood clot quicker.
• Gel Separator. The gel separator helps to form a barrier between red cells and serum or plasma. Serum does not contain fibrinogen, plasma does. When the tube is in the centrifuge, the separator moves up in the tube during the spinning process, allowing the blood cells to sink to the bottom and the serum or plasma rises to the top. This also allows the blood tube to be transported without the blood cells remixing with the serum.

Following is some information about the collection tubes and things the C.H.U.C. should be alert for:

1. Light Blue Top contains sodium citrate. This is used for coagulation studies such at a PT and PTT. It is imperative that the tube be completely filled. If you are sending the tube to lab and notice the tube isn’t all the way full, notify the nurse before you send the tube.
2. Red/Black Top is also called “speckled” or “tiger top” or “Corvac”. It contains both a clot activator and the gel separator. This tube may be used for chemistry and serology tests. This tube is not to be used for toxicology or drug testing.  
3. Red Top or Plain Red Top. This tube contains no gel or additives. It is used for selected chemistry like toxicology. If the nurse asks you to get them a red top tube, ask them to specify if it’s the plain red or the tube with the gel separator
4. Green Top contains sodium heparin and is used for tests requiring plasma or whole blood for specific tests such as cardiac, liver and thyroid function profiles.
5. The Green & Gray speckled tube contains both lithium heparin and the gel separator.   This tube is used for specific chemistries such as direct bilirubin and lipid profile.
6. Lavender Top contains EDTA and is used for most hematology tests such as CBC and Reticulocyte count.
7. Royal Blue Top has two different types, one contains EDTA and the other has no additives. These tubes are used for collection of whole blood or serum for trace element analysis. If you need to get one of these tubes for the nurse be sure you select the correct one.
8. Grey Top contains both an anticoagulant (potassium oxalate) and a preservative (sodium fluoride). It is used for glucose tests because the sodium preserves the glucose. It is also used for specific chemistry tests such as Uric Acid.
9. Miscellaneous Tubes (tan, white, and yellow to name a few) are used when a specific test needs a specific tube. If your nursing unit doesn’t have that specific tube, the C.H.U.C. can assist the nursing staff by calling the lab and requesting one be sent up. Also check to see about any special handing requirements, such as protecting the specimen from light or transporting the specimen on ice or keeping the specimen warm.
10. Yellow Top is drawn last. This tube contains acid-citrate-dextrose and is used for drawing whole blood for special tests like immunology and DNA studies.
11. Pink Top is similar to Lavender tube because it also contains EDTA. This tube is used for blood banking.

 It is very important that the blood specimen does not hemolyze. Hemolysis will cause the specimen to be rejected and then the blood has to be redrawn. The Center for Phlebotomy Education explains, “Hemo” means blood and “lysis” means to rupture or the destruction of cells. So hemolysis is literally the destruction of blood cells, specifically red blood cells. When red cells rupture, they spill their contents, mostly hemoglobin, into their surroundings. Hemoglobin is a respiratory pigment that has an insatiable passion for oxygen and gloms onto every molecule of it that it can hold while passing through the lungs, then dumps it off into the tissue where it’s needed for cellular functions. Hemoglobin is also what makes blood red. When red cells burst, it tinges the liquid portion of the blood. If red cells burst during specimen collection, the blood being tested is not the same as the blood circulating in the patient. Because red blood cells contain 23 times as much potassium as the liquid portion of the blood, when red cells rupture during collection, the specimen being submitted for testing is spiked with potassium.” Hemolysis occurs when the membrane surrounding red blood cells are disrupted, allowing for hemoglobin and other intracellular components to escape into the serum or plasma. The hemolyzed serum or plasma specimen varies in color from a faint pink color to bright red. Normally the serum or plasma is a pale yellow, straw color. Even slight hemolysis may alter certain test results.

The most important thing the C.H.U.C. can do for any blood tests is to ensure the accuracy of ordering them correctly, at the right time and on the correct date.

References:

http://www.phlebotomy.com/FREE/NKH_Art_of_Hmlysis.pdf 

http://clsi.org/

http://www.questdiagnostics.com/home.html

http://www.mayomedicallaboratories.com/customer-service/faq/specimen/collection-tubes

https://www.ncctinc.com/documents/phlebotomy%20order%20of%20draw.pdf

Subject: Rainbows Explained

Objective: To identify facts about the blood collection tubes and the order of the draw.