Thyroid blood test

[Omadoll]

Can anyone tell me if a tourniquet should NOT be used when taking blood for a thyroid test? I was told that this should not be used but couldn't understand why not. I got bloods taken yesterday, but the phlebotomist told me she had to use it or she wouldn't take the blood.

[radd]

Omadoll,

I always have a tourniquet for all blood tests. It makes the veins below fill with blood so easier to be drawn.

Why wouldn't you want this ?

[helvella Administrator in reply to radd]

Apparently not to be used for potassium draws. Type tourniquet into the search box.

[radd in reply to helvella]

Gosh ... Interesting.

... [ ... serum potassium concentration ... It occurs most commonly with red blood cell hemolysis during the blood draw (eg, when the tourniquet is too tight or left ... ] ....

Cheers Hel.

[Hidden]

Are you saying a tourniquet shouldn't be used for just thyroid tests, or all blood tests?

[Omadoll]

A nursing sister/charge nurse told me that the doctor who took thyroid (only for thyroid) would not use a tourniquet when taking the blood as it interfered with the many readings needed for thyroid. I wanted to know if this was the case? Thanks for the replies.

[LtAngua52]

The hospital I go to for all my blood tests never use one. I don't know if that is good or bad.

[Omadoll]

It would be good to find out why they do this, if possible. Thanks.

[juniperex]

See under ..."Special requirements in addition to basic instructions...

BMP or CMP - Get blood drawn without a tourniquet

Note: A tourniquet can cause blood cells to break and release their potassium, causing a falsely high result.

If the phlebotomist absolutely refuses, ask for a blood pressure cuff to be used rather than a rubber band."

rt3-adrenals.org/doing_bloo...

[BMP = Basic Metabolic Panel. e.g Glucose; Calcium; Electrolytes; Sodium; Potassium; CO2 (carbon dioxide, bicarbonate); Chloride. Kidney Tests - BUN (blood urea nitrogen); Creatinine

CMP = Comprehensive Metabolic Panel = BMP and Proteins Albumin; Total Protein and Liver Tests].

and

Tourniquets

The tourniquet should be applied approximately three to four inches above the venipuncture site.

The tourniquet must be tight enough to increase the pressure in the veins, making them more accessible, but no so tight to result in hemoconcentration.

The tourniquet should not be left on the arm longer than one minute.

1) A good rule of thumb to determine the one-minute tourniquet time is to remove the tourniquet when blood starts to flow into the first tube of blood being drawn.

2) Prolonged tourniquet application can cause hemoconcentration of blood at the puncture site, which can lead to a false increase in various chemistry analytes, including serum protein, potassium, total protein, iron, cholesterol, aspartate aminotrans ferase (AST), total lipids, and lactic acid.

austincc.edu/mlt/phb/Consid...

[elsewhere also includes sex hormones]

juniperex

[Omadoll in reply to juniperex]

thank you