Finding a Vein For Blood Draw

A day in a life of phlebotomists can go without a hitch. But there are times when challenges come their way by way of difficult draws, patients that would require all their training and skills just to collect blood. Some of them may have small and almost invisible veins, will faint at the sight of blood or has a predisposition towards blood collection.

To ensure a quick and smooth process, proper vein selection is a must. How does a phlebotomist go about finding a vein?

How fast you can spot a puncture site may depend on a patient. Male veins are larger and more prominent, as opposed to most women whose veins are usually covered with subcutaneous fat. Unless a woman does cardio or is physically active, finding a puncture site may be challenging. Difficulties may also be experienced in elderly, children, infants or patients that are really sick and dehydrated. But following the best practices in phlebotomy (http://www.ncbi.nlm.nih.gov/books/NBK138665/#ch2.s30) will definitely help.

Feel rather than look for a vein

Finding a vein is easier when it is already prominent on the outset. If this is not the case, a phlebotomist must use the sense of touch. With the use of an index finger, palpate and trace the path of veins. Arteries can be identified if it pulsates, have a thick wall and feels very elastic. A thrombosed vein, on the other hand, feels cord-like, rolls easily and lacks resilience. If it feels bouncy as you press on a vein, you have found a good site to work on.

Massage into prominence

Massage the arm, from wrist to elbow, to force blood into the vein. Then, using the index and second finger, tap the puncture site. It would also help to lower the arm so the blood will fill the veins, or apply a warm washcloth for 5 minutes over the site.

Use a tourniquet

Binding a tourniquet 3 to 4 inches above the puncture site will help a phlebotomist locate a vein. It must be tied lightly at first, and should only be tightened if the first attempt fails. Applying a warm damp cloth on the site will help increase circulation, causing the veins to pop. When using a tourniquet, it is crucial to never tap the site to avoid hemolysis, premature destruction of red blood cells that results in shorter life span. This will render a blood sample unusable.

Also, the tourniquet must not be left on for more than a minute to prevent hemoconcentration, a decrease of fluid in the blood content resulting in loss of plasma. The same condition will happen if a patient pumps his or her fist, while the tourniquet is on.

Find another puncture site

Difficult draws will make finding a vein a real challenge. If a phlebotomy technician has tried everything else and still failed to locate a decent site, it is high time to find other options, such as the top or side of the hands, on the wrist, or veins in the thumb. These sites should be considered as a last resort, especially if a considerable volume of blood must be collected.

Order of venipuncture site

1. Median antecubital vein

The first choice for venipuncture is the median antecubital vein that is located in the area of the arm in front of the elbow or the antecubital fossa. If the vein is well anchored, it usually becomes larger and more prominent. Using this puncture site has very few problems and offers the most painless puncture for both the phlebotomist and the patient.

2. Cephalic vein

Located in the upper or shoulder side of the arm is the cephalic vein. This should only be considered as the second choice, as the site increases the risk of spurting or blood forming a drop if a needle is incorrectly inserted.

3. Basilic vein

The third choice is the basilic vein in the underside of the arm. The downside with this particular vein is that it is not well-anchored and is bound to roll. This not only leads to a difficult draw, but also possible formation of hematoma or blood pooling. When collecting blood from a basilic vein, using a syringe is highly recommended.

4. Dorsal hand veins

If finding a vein is difficult on the antecubital area, the dorsal hand veins provide a good alternative. But this should only be used if all efforts have been exhausted or that the median antecubital vein is not usable. The right phlebotomy equipment for hand veins must be used for this type of draw.

5. Foot veins

Foot veins must be used with utmost care and only under special circumstances. A lot of complications come with a foot draw, which is why it is rarely requested. It can pose a problem if the patient is prone to clot formation or have diabetes, where wounds would take time to heal or will result to infections.

Special cases

There are instances when the use of median cubital and cephalic veins is not possible, and other venipuncture site must be selected.

• When there is extensive scarring due to burns or surgery. Obtaining a specimen would be difficult when a phlebotomist has to puncture through scar tissues.
• When a patient has previous mastectomy, the upper extremity must be avoided because lymphedema (http://www.breastcancer.org/treatment/lymphedema) may affect test results.
• When possible hematoma is expected, resulting in erroneous test results.
• When previous blood transfusion or intravenous therapy has been done to a prospective site. A phlebotomist must find a vein someplace else, like the opposite arm.
• When an arm has fistula/cannula/herapin lock.
• When there is an accumulation of tissue fluid.

Now days there are devices that allow you to see veins in the arm for blood draw. These devices are called vein finders and are available across the web.

It all starts with finding a vein. A phlebotomy would not be successful if the right puncture site is not selected. There are rules that a technician must follow in this vital process to avoid problems, as specified on the order of venipuncture site. If a basilica vein is used when both the median antecubital vein and cephalic vein are usable can put a phlebotomist’s career in jeopardy and endanger the life of a patient. This can lead to legal action that is not only expensive, but can also ruin a health care provider’s reputation.