Top 10 Laboratory Tests and Tips

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Top 10 Things Nurses and Doctors Can Learn From Lab Techs

1. Drawing Blood for Laboratory Testing

Once upon a time, it was a lab tech's job to go up to the patient and draw the correct tubes of blood using the correct techniques. Today's nursing world has decided that nurses should be the ones to draw 'the labs'.

This would be great for everyone concerned - the patient, the nurses, the doctors and the laboratory, except for one thing. Nurses, doctors and aides traditionally do not have the education they need for phlebotomy. Laboratory Technicians and phlebotomists have spent long hours learning how to do this right.

There are thousands of laboratory tests these days. Most of the tests have strict requirements on their collections for the results to be valid. If a CBC is drawn in a RED top tube, for instance, it will have to be rejected as the CBC requires unclotted blood from an EDTA (purple) additive tube or from a BLUE top tube (Sodium Citrate)

Some tests that doctors order are so complicated, that a fully qualified Medical Laboratory Scientist or trained Phlebotomist must be sent up to draw the blood anyway.

Just remember this: The lab results are only as good as the samples being tested.

2. Questions Nurses Ask - A Lot!

"Can't I just come down and label it? I'm pretty sure I know whose blood/urine/sample it is."

Blood Tests by L.A. Cargill
So many specimens! Which one belongs to YOUR patient?

For years, I have had to stress over and over how important it is to label each and every lab specimen sent to the lab. No, you cannot look at a tube of blood and tell me who it belongs to unless you are truly psychic. Patient specimens must be labeled immediately at the patient's bedside!

A nurse was called with QNS (quantity not sufficient) CBC. Her response, "No way, I drew plenty of blood. Just take some out of the blood culture bottle . what is wrong with you people in the lab?"

This goes back to my opening paragraphs - All lab tests have specific requirements and blood drawn in one tube cannot be switched to another tube.

"What do you draw a 'fasting' in?"

Fasting is a patient condition (no food or drink for a prescribed period). It is not a lab test. Doctor's writing is so bad sometimes, their orders get confused. The doctor probably meant to write an order for a 'fasting blood sugar'. But who knows?

"Can you make the bacteria grow faster?"

Can you make your child grow faster? No, we can't make bacteria grow faster. Some bacteria take weeks to grow. Some grow only in certain conditions. Some funguses can take months to grow.

"Hurry and do these lab tests because I don't want them to hemolyze."

Of all the problems we have with blood specimens, this is probably the most common. Even trained phlebotomists will occasionally get a hemolyzed draw. There are certain things that can be done to reduce hemolysis, but this is what I mean by getting the education you need to do safe and productive phlebotomy.

There are hundreds more questions like this that we, in the lab, get every day. It takes time to answer each one, which is time we could better spend actually running the lab tests and reporting the results. Hopefully, this hub will help.

3. Start Phlebotomy Out Correctly

There are several things that a trained phlebotomist needs to do before ever sticking a needle into a vein. These need to be memorized!

  1. Correctly identify your patient!
  2. Read through the orders, making sure to arrange your needed tubes into the correct order of draw. A correct order of blood collection tubes chart is usually available from the lab, just ask.
  3. Inspect the patient's arms, hands or other places to draw blood from.
  4. Assemble the equipment needed.
  5. Gently tie a tourniquet above the venipuncture site. The purpose of the tourniquet is to DISTEND the vein, NOT cut off the flow of blood. Tie the tourniquet only as tightly as necessary in order to distend the vein.
  6. Swab the vein with disinfectant and GENTLY perform the venipuncture.
  7. Mix all tubes gently and completely immediately after collecting them to avoid clotting, non-clotting and hemolysis. Some tubes will clot, and some tubes have anticoagulants in them and will not clot if mixed properly. Do this while still drawing other tubes. Use both of your hands!
  8. Release the tourniquet as soon as possible. Some phlebotomists do not use a tourniquet at all if the patient's veins are big enough.
  9. Remove the needle and apply pressure to the venipuncture.
  10. Observe the patient while labeling the specimens. Don't forget to label all specimens in front of the patient!
  11. Thank the patient for their cooperation.

All of these steps should be done in this order every single time a phlebotomy is done. Remember - ALL of these steps are important!

As a patient, myself, I have refused phlebotomy from people that skip any or all of the above. It is the patient's right to have a qualified and trained phlebotomist whenever a blood test is needed.

Labeling Your Specimens

What a proper label looks like:

  • Mary Jane Smith - (Full Name)
  • 1/1/1954 999-999-999 (Date of Birth and Required ID Numbers)
  • 12/26/2013 14:40 LAC (Date / Time / Initials of Phlebotomist)

4. Patient Identification!

Nurses should not speak patient's names out loud now to avoid being overheard. This causes a HIPPAA violation. Hospitals are not even allowed to report the patient's names to friends who call to ask about them. It's for the patient's safety as well as so they can get the rest they need.

But this does not apply to the lab/nurse interaction. It is vital for us to know all of the patient identifiers!

First off, we must know the patient's full name. Mary Smith is just not enough. There may be two or more Mary Smiths in the hospital. We do NOT need to know the patient's room number as patients are always being moved frequently, and the lab is not in that loop! We have no idea what room a patient is in.

Secondly, the patient's birthday can be used for patient identification. Although, once I did have blood from two different patient's that had the same name and the same birthday. So even this is not enough.

Thirdly, we need the patient's encounter number (sometimes called account number). This is tied to the patient's medical record number, which is a permanent medical record. We do not usually need the medical record number as this number may be several years old. Some blood banks do use the medical record number, so check with your facility and lab draw requirements. Sometimes the patient's social security number is used, but this is kind of a no-no.

Fourth, we need the date/time/initials of the person who drew the blood. This is required by several regulatory agencies for a very good reason. If an error occurs, we have to trace it back to the exact tube of blood or specimen! This has medical and legal consequences.

You can draw the finest specimen in the world, but if we cannot trace that specimen in a chain of custody manner, the results are worthless.

Common Laboratory Departments:

Lab Department

Usual Tests Performed

Usual Color of Tubes


CBC, Platelet Count, H&H, Sed Rate, Peripheral Smear, HCT, HGB, WBC, RBC

Purple, Lavender, Light Blue


PT, PTT, APTT, Fibrinogen, Clotting Factors, Platelet Count, Bleeding Time

Light Blue (Sodium Citrate)


Literally thousands of tests, BMP, CMP, Liver function, Kidney function, Pancreatic function, HgbA1C, Electrolytes, therapeutic drug levels

Generally, Red or Tiger Top, Green, Purple, Special Tubes


Urinalysis, Serology tests like pregnancy tests, HIV tests, RPR, Urine drug tests

Usually a urine sample or a Tiger Top, Purple, Other

Blood Bank or Transfusion Services

Crossmatches, Blood Typing, Compatibility Testing, FFP, Platelet transfusion, blood transfusion, Cryoprecipitate, Fetal Bleed Screens

Pink or Purple, Plain Red


Blood Cultures, Wound Cultures, Surgical Cultures, Gram Stains, Culture and Sensitivity

Blood Culture tubes, or swabs from wounds

5. How Much Longer For The Results?

We know the doctor probably puts you up to calling the lab for results. Otherwise, we are going to have to accept that you do not know how to use your station's computer.

Test results take as long as they take! We cannot speed up the laws of physics. We have to process the specimens, deliver them to the proper testing department, prepare the specimen for whatever the testing requirements are, physically place the specimen on the machine, then wait for the results. After that, we can verify the results and release the results into the computer.

The computer almost always has the results faster than we do. In the time it takes you to call the lab and ask for the results, and the tech has to access those results on the same computer that you have on your desk, you could have already read the results without having to call.

Hint: Instead of picking up the phone, you should use the computer first!

If the results are not in the computer, then the results are not ready yet. It is rare to lose a specimen, but it does happen. If the results are not ready in a reasonable length of time, then start tracking the specimen down.

6. Why Nurses and Doctors Should Listen to Medical Laboratory Scientists

Nurse returning a unit of O-negative packed cells because "the patient is O-positive, and I'll kill her if I give O-negative."

If a nurse or even a doctor doesn't work with accurate information, it is possible to do serious harm to a patient. Sometimes information gets garbled. Sometimes, an old nurse is set in his or her ways and believes things that just aren't true because, "that's the way I've always done it". Sometimes the care giver learned it wrong in the first place.

Medical Laboratory Scientists must go through four years of college, plus one year of internship. They must have a Bachelor's level degree. Then they must pass a certifying test to get a license. Sometimes they have to pass a state test also.

Every year now, everyone that works in a lab must pass educational courses to be re-certified. They have to keep up with complicated testing parameters, legal issues and safety requirements.

Nurses do too, but both care givers have different areas of specialization. I am an expert in laboratory stuff, and nurses are experts in nursing stuff. We can learn from each other!

Laboratory Personnel and Their Titles:

What We're Called

Our Credentials

Chain of Command

Medical Technologist, Medical Laboratoy Scientists, Med Techs

M.T.; MLS; (ASCP - credentialing agency), Bachelor's Degree, Master's Degree

Supervisory, Legal Authority (may testify in court), Decision Makers

Medical Laboratory Technician (MLT), Lab Techs

MLT, Lab Technician, (credentialing agency)

Works under the supervision of the MLS or MT


Phlebotomy school and certification

The 'face' of the laboratory. These are the people nurses usually interact with

Lab assistants

May or may not have lab credentials

The helpers of the laboratory

7. Specialty Areas of the Laboratory

Nurse, given FFP, claims that's not what she's there to pick up, she wants fresh frozen plasma. Tech tells her that's what she was given. Nurse exclaims "but it's all warm and squishy!" Tech had to explain that you have to thaw it in order to infuse it.

All of the departments of the lab have their specialties, but the Blood Bank or Transfusion Services is probably the most misunderstood area of the entire hospital.

Blood Bank Technologists are a unique breed of Laboratory Technologists. The Blood Bank is probably the only area in which we, as techs, may actually kill a patient. We also have to constantly prevent nurses and doctors from killing patients too.

Doctors receive very little training in transfusion therapies. An oncologist or a hematologist M.D. will probably know more and keep up with changes, but on average, doctors and nurses are woefully uneducated in this area.

I could and have written several articles about Blood Banking as a Blood Bank specialist for over 30 years. But suffice it to say that it is one difficult area to work in. In fact, most lab techs refuse to work in this department because it is so complicated.

Technologists in transfusion services must be 100% accurate, 100% of the time. There is no margin for error. We must also educate the health care team continuously as changes to therapy are frequent.

8. Following the Doctor's Orders

Order says: "Perform susceptibilities even if no growth."

I really don't know how a doctor can write an order like this, but they do. Sometimes their orders are just impossible to follow. Seriously? How could the lab perform drug susceptibilities on nothing? If there is 'no growth', there is nothing to do further testing on.

So, when a laboratory says they cannot perform miracles, do not ask them to do so. Educate the doctor that wrote a nonsense order.

9. Get it Right the First Time!

RN: "I mislabeled the vaginal pack that was just sent down. Can you send it back?" Me: "Sorry. Once it's in the lab it can't be sent back or re-labeled." RN: "So are you telling me I have to tell the doctor this patient has to be redone?" Me: "Yep, and the patient. She'll be just as happy as you are!"

Sometimes it seems like you just have one of those days and nothing goes according to plan. Mistakes happen. Face up to them.

It really does take less time to do things right the first time than to have to repeat everything. It's also less stress for you, the nurse. The same is true for any job worth doing. It's worth doing correctly.

10. Impossible Questions!

I worked in a reference lab, and we received samples from multiple locations and several were areas where the demographics of the population were such that there was a larger number of alcohol abusers in that area. We received multiple blood alcohol samples that would be in the very critical range and when we would call the facility the nurse taking the call would always ask, "What is the therapeutic range?"

This is probably the second biggest reason for calls to the laboratory. The test result 'ranges' are always stated these days on the report alongside the result.

But, there are continuous questions like the one above that defy common sense. Just in case you are wondering, there are no 'therapeutic' ranges for drunks.

Even though you are busy, and we know you are, take a few seconds to think about the question you are going to ask someone. There are no dumb questions? Sure there are!

Source Quotes

All the quotes on this page are from Jon Harol's (Lighthouse Recruiting for Health Care) page on Lab Chuckles. They are from his article in the Advance For Laboratory Technologists magazine.

Jon has collected these wonderful quotes over the years. I have heard each and every one of them and maybe a few others.

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