Knowing how to draw blood quickly and accurately is an important skill for doctors and healthcare professionals. As a patient, you will appreciate that a nurse is able to pick it up on the first try, without having to introduce the needle multiple times. There are some tricks to use when taking a blood draw.
Steps
Part 1 of 3: Making the Vein More Visible
Step 1. Apply the tourniquet
Using this tool hinders blood circulation, increasing the amount of blood flowing through the veins and thereby making them more noticeable. However, it shouldn't tighten so much that it blocks blood flow.
- The tourniquet should be applied to the arm approximately 10 cm above the vein.
- A sphygmomanometer (blood pressure measuring device) inflated to a pressure of 40-60mmHg will also work.
Step 2. Place a warm compress or hot water bottle on the sampling area
The heat will cause the veins to dilate and expand; this way, it will be easier to spot them.
- Place the compress or hot water bag before disinfecting the pickup area. In fact, nothing should come into contact with this area once it has been disinfected.
- Do not apply the compress or hot water bottle directly to the skin. Instead, wrap them in a thin cloth to avoid any burns. If they cause pain, it means they are too hot.
Step 3. Relax
Many people have a phobia of needles. However, nervousness causes the veins to narrow, making it difficult for the nurse to insert the needle.
- Try using some relaxation techniques to relax your nerves. You can do it at any time, even when you have to have your blood drawn. You could try meditation (How to Meditate), visualization and deep breathing (How to Deep Breath).
- If you are concerned about fainting, lie on your back. By doing this, you will increase the flow of blood to your head and will also be less at risk of falls and injuries should you pass out.
Step 4. Massage the vein
The nurse may gently rub the skin over the vein to be able to feel it by touch when it is not clearly visible. He will probably use his index finger instead of his thumb, as this finger has its own pulse that could be misleading.
- The nurse may also invite you to clench your fist to cause the veins to swell and locate them more easily.
- However, he shouldn't ask you to slap your forearm a few times, or you run the risk of bruising yourself.
Part 2 of 3: Taking the Blood from the Forearm
Step 1. Locate the vein
The inside of the elbow is generally the best place, as it is easier to see the cubital vein.
- The median cubital vein runs between the muscles and can be clearly identified as it just protrudes into the inner part of the elbow, with its typical bluish color. If you can't see it, you can usually feel it by touch. It is also easy to reach because the surrounding tissues prevent the needle from changing direction.
- The nurse will likely feel in this area using the index finger. He will not use his thumb, because this finger has its own pulse that can mislead him. If the vein is healthy, it should feel soft to the touch and return to firmness once pressed. The nurse will avoid veins that look hard or lumpy, but even those that are too fragile.
- It will also not draw blood from a place where blood vessels divide or join together, otherwise it could lead to subcutaneous bleeding.
Step 2. Disinfect the area
The most common disinfectants contain 70% alcohol. The nurse will clean an area at least 2x2 cm wide for half a minute. After a minute or two it will be dry.
- Alcohol is better than iodine, because if the latter enters the blood, it can alter the values that the laboratory will have to detect from the sample taken.
- You will notice that, after cleaning the area, the nurse will no longer touch it, even with gloves, so as not to contaminate it.
Step 3. Get your blood drawn
During this phase, many people prefer to look away to avoid the danger of fainting. If you choose to watch, you will most likely see the nurse:
- Hold the vein in place, placing your thumb under where it will insert the needle. It will do this by tapping below the previously disinfected area.
- Tilt the needle to 30 degrees or less, then hold it steady while it draws blood.
- Fill the syringe with blood.
- Loosen the tourniquet that was attached to you for a minute. It will dissolve it completely even before you remove the needle from your arm.
Step 4. Press on the hole left by the pick once the needle is removed
This way, you will promote blood clotting. You can also raise your arm to decrease any bleeding. Don't bend it, or the likelihood of causing you a bruise may increase. Meanwhile the nurse:
- You will throw the needle into a rigid container intended for medical waste disposal.
- He will carefully check the labeling on the syringe tube to make sure it is correct.
- He will throw away the gloves and wash his hands.
Part 3 of 3: Troubleshoot Any Problems
Step 1. Look for another vein if the median cubital is not visible
If the nurse cannot find the vein on the inside of both elbows, they will likely need to locate a different one. Therefore:
- He will move his forearm down in search of the basilica or cephalic vein. These veins are also identifiable through the skin. The nurse may ask you to lower your arm and clench your fist to make them more noticeable.
- The cephalic vein runs along the radial margin of the forearm, while the basilica vein runs along the ulnar margin. Usually the latter is less used than the former. In fact, it is more likely that, when inserted into the basilica vein, the needle changes direction since it is not supported by the surrounding tissues.
- If there is no access to any type of vein, the nurse may look for a blood vessel on the back of the hand. These are the veins of the metacarpus. Usually, they are quite visible and easily identifiable to the touch. However, it should not be used if the patient is of advanced age, because the elderly do not have skin so elastic and strong to support the veins in this area. In addition, blood vessels tend to become more fragile over the years.
Step 2. Pay attention to the points to avoid
It is unlikely that the nurse will proceed to draw blood from the following areas:
- Near an infection
- Near a scar;
- Near a healing burn
- On an arm that is on the same side you had a mastectomy on;
- In the vicinity of a bruise;
- Over the area where you have been given intravenous medication;
- On an arm where there is a venous catheter, fistula, or vascular graft.
Step 3. Do not move if the needle does not enter the vein
It may happen that the needle enters the skin, but the vein moves without the needle being able to enter it. In this case, it is very important to remain still. The nurse will solve the problem:
- Pulling the needle lightly without removing it from the skin.
- Changing the angle of the needle while it is still under the skin to insert it into the vein. This will probably not be easy, but it won't last long.
Step 4. Try a second time
If the nurse is unable to insert the needle into the vein on the first stroke, he may remove it and look for another place to insert it below the first one.
- If the second time fails, he will call a supervisor to get an opinion on why he can't pierce the vein or have someone more experienced try the blood draw.
- However, this operation will not be repeated more than two times.
Warnings
- The nurse should wear gloves during each step of the blood draw.
- Disposable materials, including the needle, should never be reused.
- Any material that has come into contact with blood should be disposed of in a puncture-resistant medical waste container.
