How it's done
The blood needed for a diagnostic test is usually fairly easy to obtain. It requires a procedure called venipuncture (a term which quite simply means "puncturing the vein"). The person performing this procedure may be your doctor, a nurse, or someone specially trained in collecting blood samples called a phlebotomist.
Phlebotomists who work in hospitals, cancer clinics, and outpatient settings perform many venipunctures each day. Their experience makes them good at handling difficult situations and distressed individuals. The phlebotomist knows how to put patients at ease, and how to help someone who is feeling lightheaded, dizzy or faint.
Knowing that the person collecting the sample has received thorough training and demonstrated a high level of competency, can help a patient relax no matter how nervous they are.
What will happen? During venipuncture, the phlebotomist inserts a needle through your skin and into a vein. Most often, the phlebotomist is able to identify a vein in the crook of your elbow that is easily accessible and applies a tourniquet around the upper arm to make the vein more obvious, (the elbow area does not have many nerves so this is a good site; the wrist, hand and foot are other sites that can be used). Clenching your fist, when you are asked to, helps make the vein more prominent. The procedure usually takes less than 3 minutes. Afterward, the patient, or carer, is usually asked to apply gentle pressure, over a clean dressing, to help the blood clot and prevent swelling and bruising.
The amount of blood needed for the test is taken out through the needle into a syringe; blood may be put into a special tube or tubes. The tubes are sent to a laboratory where the blood is analysed as your doctor has requested on the referral form. After taking the blood, a clean dressing is put over the skin puncture and the patient, or a carer, is usually asked to apply gentle pressure with the fingers. This is to help the blood clot and prevent swelling and bruising.
Will it hurt? When the needle is inserted under the skin you might feel a slight sting, and there may be additional discomfort when it is withdrawn. If you are accompanying a child or someone who is anxious, it helps to explain that he or she will feel momentary pain or discomfort. Don’t say, "This won't hurt a bit", because the person will then have reason to mistrust the people and situation involved when it does sting. Be honest, create a reasonable expectation, and you will really help the patient.
Not flowing well? Drinking 8 to 10 glasses of liquid a day helps blood flow better and makes the veins more likely to stick up and be found easily, so drink plenty of fluids for a day or two before your test. But, also, remember to follow your doctor’s instructions - some tests require that you do not drink certain liquids prior to the test. You may also want to take a walk while waiting, or on your way to the test, to increase blood flow and keep the veins pumped up (routinely doing hand and arm exercises also helps those requiring frequent testing). Even eating well the day before, if fasting is not required, improves blood flow.
Dry Skin? Applying a moisturizer at least 4 times a day, from the hand to the elbow (or wherever you expect the skin will be punctured) can make the puncture less painful. Lotions work best when applied just after the skin has just been wet, for example after bathing, showering, swimming, or washing dishes.
Cold hands? Being warm increases your blood circulation, which makes it easier for the phlebotomist to find a vein. While you are waiting, you may want to leave your coat or sweater on and let your arm dangle down to increase the blood pressure in the veins. If you have difficulty with blood being taken, lying down and warming your hands under a heating pad and blanket usually provide good results.
Getting anxious? Talk about or recall something pleasant while you wait. This takes your mind off your anxiety; you can also bring interesting reading, music, or even relaxation tapes to listen to on a portable CD or tape player.
Feeling faint? If you are nervous or have a tendency to feel dizzy or faint, tell the phlebotomist before you begin. Your blood can be taken while you are lying down, which will help avoid fainting and causing injury. If, at any time, you feel faint or lightheaded, tell the phlebotomist or someone nearby. Putting your head between your knees or lying down should soonmake you feel better. It may be best that avoid driving home
Can't find the vein? If the phlebotomist does not succeed in reaching the vein, another phlebotomist may step in to complete the procedure. This keeps both the patient and the phlebotomist from becoming flustered and should be seen as a reassuring step.
What helps afterwards? If you experience swelling, bruising, or pain then follow general first-aid procedures, including putting ice on the site, using the affected arm as little as possible, and taking a pain killer if that is an allowable medication for you. Other complications related to venipuncture are rare.
