Phlebotomy - Order of Draw Stories — Part 3 - “The Final Tubes”

Characters

• Kayla — phlebotomy student

• Mr. Jordan — patient in the emergency department

Kayla:
Good evening. My name is Kayla, and I’ll be drawing your blood today.

Mr. Jordan:
Busy night?

Kayla:
Very busy.

Mr. Jordan:
Emergency room?

Kayla:
Yep. Lots of bloodwork tonight.

(Kayla prepares the supplies.)

Mr. Jordan:
You still studying those tube colors?

Kayla:
Always.

Mr. Jordan:
What colors are left?

Kayla:
Tonight:

• green,

• lavender,

• and gray.

Mr. Jordan:
What’s special about the green tube?

Kayla:
The green tube contains an additive called heparin.

Mr. Jordan:
What does heparin do?

Kayla:
It prevents blood from clotting.

Mr. Jordan:
Didn’t another tube already do that?

Kayla:
Yes, but different additives work in different ways and are used for different tests.

Mr. Jordan:
So why use heparin?

Kayla:
Heparin helps produce plasma quickly, which is useful in emergency situations when doctors need fast laboratory results.

Mr. Jordan:
What kinds of tests use green tubes?

Kayla:
Commonly:

• electrolyte tests,

• chemistry panels,

• and cardiac testing.

Mr. Jordan:
Electrolytes like sodium and potassium?

Kayla:
Exactly.

Mr. Jordan:
Those affect the heart, right?

Kayla:
Yes. Electrolytes help control:

• muscles,

• nerves,

• hydration,

• and heart rhythm.

(Kayla places the tourniquet.)

Kayla:
This will feel tight for a moment.

Mr. Jordan:
No problem.

(Kayla palpates the vein.)

Mr. Jordan:
You seem much more confident now.

Kayla:
Understanding the purpose behind the tubes helps a lot.

Mr. Jordan:
Probably easier than memorizing random colors.

Kayla:
Definitely.

(Kayla cleans the site.)

Kayla:
Cold alcohol wipe.

Mr. Jordan:
Always cold.

(Kayla performs the venipuncture.)

Kayla:
Small pinch.

(Blood begins flowing into the green tube.)

Mr. Jordan:
So what comes after green?

Kayla:
The lavender tube.

(Kayla changes tubes.)

Mr. Jordan:
What’s inside the lavender one?

Kayla:
An additive called EDTA.

Mr. Jordan:
What does EDTA do?

Kayla:
It preserves blood cells and prevents clotting.

Mr. Jordan:
Why preserve the blood cells?

Kayla:
Because some laboratory tests need to examine the blood cells themselves while they’re still intact.

Mr. Jordan:
What tests?

Kayla:
A very common one is called a CBC.

Mr. Jordan:
What does CBC mean?

Kayla:
Complete Blood Count.

Mr. Jordan:
And what does that test measure?

Kayla:
It measures:

• red blood cells,

• white blood cells,

• hemoglobin,

• hematocrit,

• and platelets.

Mr. Jordan:
That sounds like a lot from one tube.

Kayla:
Blood contains a huge amount of information.

Mr. Jordan:
What do those blood cells actually do?

Kayla:
Red blood cells carry oxygen through the body.
White blood cells help fight infection.
Platelets help blood clot after injuries.

Mr. Jordan:
So CBCs help doctors look for problems?

Kayla:
Exactly. CBC results can help show:

• infection,

• anemia,

• inflammation,

• bleeding disorders,

• and many other conditions.

(Kayla gently inverts the lavender tube.)

Mr. Jordan:
And you still have to mix the additive carefully?

Kayla:
Right. Proper mixing helps preserve accurate results.

Mr. Jordan:
So what’s the last tube?

Kayla:
The gray tube.

(Kayla changes tubes again.)

Mr. Jordan:
What’s inside the gray tube?

Kayla:
Usually sodium fluoride and potassium oxalate.

Mr. Jordan:
That sounds less friendly.

Kayla:
Definitely less friendly sounding.

(Both laugh.)

Mr. Jordan:
What do those additives do?

Kayla:
They help preserve glucose levels in the blood sample.

Mr. Jordan:
Why is that important?

Kayla:
Because blood cells naturally continue using glucose after collection. If the glucose changes too much before testing, the laboratory result may become inaccurate.

Mr. Jordan:
So the tube basically helps “freeze” the glucose level?

Kayla:
That’s actually a pretty good way to think about it.

Mr. Jordan:
What tests use gray tubes?

Kayla:
Commonly:

• glucose testing,

• diabetes testing,

• glucose tolerance tests,

• and lactic acid testing.

Mr. Jordan:
There’s way more science behind blood draws than I realized.

Kayla:
That’s something patients say almost every day.

(Kayla fills the final tube.)

Kayla:
Alright, I’m releasing the tourniquet now.

(She removes the needle and places gauze on the site.)

Kayla:
Please hold pressure here.

Mr. Jordan:
Got it.

(Kayla activates the safety device and disposes of the needle safely.)

Mr. Jordan:
So now you’ve learned all the major order-of-draw tubes?

Kayla:
The major ones, yes.

Mr. Jordan:
And you finally survived all the colors?

Kayla:
Barely.

Mr. Jordan:
Which tube was hardest to learn?

Kayla:
Honestly? The tubes became easier once I understood what the blood was actually being used for.

Mr. Jordan:
That makes sense.

Kayla:
Memorizing colors is hard.
Understanding patients is easier.

(Mr. Jordan smiles.)

Mr. Jordan:
That sounds like the beginning of becoming a good healthcare worker.

(Kayla smiles back.)

Kayla:
I hope so.