Venous sampling

5.1.1 Conditions:

The conditions vary depending on the test to be done. They will be described for each test.

All useful information collected during the sampling will be noted in the patient’s electronic file or on the sampling sheet (current treatment, date of last menstrual period, etc.)

5.1.2 Technique:

The sample is usually taken from the veins inside the bend of the elbow, the back of the hand or the femoral vein (baby or adult in certain circumstances). The attached table of recommendations serves as a guide for the choice of sample collection tubes according to the prescribed tests.

– Wash hands.

– Apply the tourniquet without tightening too much.

– Locate the vein; clean the skin with 70% rubbing alcohol.

– Prick the vein with the needle, and then perforate the tube cap to collect the blood.

– Once the blood begins to flow into the first tube, release the tourniquet so that certain parameters, such as potassium, will not be altered.

– Invert the tube 2 or 10 times to mix the blood with the anticoagulant or to activate the coagulation. Never shake the tubes vigorously in order to avoid hemolysis.

– Discard the needle in a hard sharps container.

– Firmly compress the vein at the puncture site and apply a dressing.

– Label the tubes.

– If the sample was taken at the laboratory, enter into the Laboratory Information System (LIS) the code of the person taking the sample, the time and, if indicated, the tubes sampled.

– If a sample cannot be collected, note it in the LIS.

– Apply the dressing and escort the patient.


NB: In newborns and infants, depending on the quantity of blood needed, the sample is taken from the heel, femoral veins, forearm vein or exceptionally the fontanel.

Introduction Sample manuel

List of laboratory tests

Consent forms


Urines sample collection procedures

Urgent sample

Skin and appendage samples

Subcontracted tests

Manegement of sempling incident

Manegemtn of blood exposure

Medical Monitoring form Medical

Sample sheet

Sample transport

Waste disposal

Additional tests

Sample storage