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Antecubital Fossa
The best place to start to look for a vein for blood collection is the antecubital fossa. Antecubital means “in front of the elbow.” “Fossa” means a shallow depression. The antecubital fossa is the shallow triangular depression in the arm that is anterior to (in front of) and slightly below the bend of the elbow. It is the first choice location for venipuncture because generally several major veins lie close to the surface in this area, making them relatively easy to locate and penetrate with a needle.
These major superficial veins are referred to as antecubital or AC veins. The anatomical arrangement of AC veins varies from person to person; however, two basic vein distribution arrangements, referred to as the “H-shaped” and “M-shaped” patterns are seen most often. The venous distribution patterns are so named because the major antecubital veins on the arm resemble the shape of either an “H” or an “M.”
Caution: The brachial artery and several major arm nerves pass through the AC fossa, so it is important to prioritize vein selection in either pattern to minimize risk of accidentally puncturing the artery or injuring a nerve if needle insertion is inaccurate. The greatest chance of nerve injury is associated with venipuncture in the most medial and lateral portions of the antecubital fossa.
It is important to remember that vein location differs from person to person, and you may not see the exact textbook pattern. The important thing to remember is to choose a prominent vein that is well fixed and does not overlie a pulse, which indicates the presence of an artery and the potential presence of a major nerve.
H-Shape
The H-shaped venous distribution pattern is displayed by approximately 70% of the population and includes the median cubital vein, cephalic vein, and basilic vein.
The Median cubital vein is located near the center of the antecubital area, it is the preferred, and thus first choice, vein for venipuncture in the H-shaped pattern. It is typically larger, closer to the surface, better anchored, and more stationary than the others, making it easier and the least painful to puncture as well as the least likely to bruise. However, the most medial aspect (inner side) of this vein should be avoided as it overlies the brachial artery and several major nerves.
The Cephalic Vein is located in the lateral aspect of the antecubital area, it is the second choice vein for venipuncture in the H-shaped pattern. It is often harder to palpate than the median cubital vein but is fairly well anchored and often the only vein that can palpated in obese patients. The most lateral portions of the cephalic vein and the accessory cephalic vein should be avoided to prevent injury to the lateral cutaneous nerve.
The Basilic Vein is a large vein located on the medial aspect (inner side) of the antecubital area, it is the last choice vein for venipuncture in either venous distribution pattern. It is generally easy to palpate but is not as well anchored and rolls more easily, increasing the possibility of accidental puncture of the median nerve (a major nerve). Punctures in this area tend to be more painful and bruise more easily. According to the CLSI standards, the basilic vein should not be chosen unless no other vein in either arm is suitable for venipuncture.
M-Shape
The veins that form the M-shaped venous distribution pattern include the cephalic vein, median vein, median cephalic vein, median basilic vein, and basilic vein.
Caution: Axillary lymph nodes (nodes in the armpit) are often removed as part of breast cancer surgery. Their removal can impair lymph drainage and interfere with the destruction of bacteria and foreign matter in the affected arm. This is cause for concern in phlebotomy and the reason an arm on the same side as a mastectomy is not suitable for venipuncture.
Hand Veins
According to CLSI, although the larger and fuller antecubital veins are used most frequently, veins on the back of the hand and wrist are also acceptable for venipuncture. Veins on the lateral wrist above the thumb to the mid-forearm must not be used as nerve injury could occur in this area.
Caution: Veins on the palmar surface (under-side) of the wrist are never acceptable for venipuncture.
Because of the potential for significant medical complications such as phlebitis of thrombosis, veins of the leg, ankle, and foot must not be used for venipuncture without documented permission from the patient’s physician. Puncture of the femoral vein is performed only by physicians or specially trained personnel.
Arteries are not used for routine blood collection. Arterial puncture requires special training to perform, is more painful and hazardous to the patient, and is generally limited to the collection of arterial blood gas specimens for the evaluation of respiratory function.
Venipuncture Supplies/Equipment
Venipuncture Supplies/Equipment
Before beginning a blood draw, be sure to gather all the necessary supplies for the procedure. The following list of recommended (but not limited to) supplies are needed for a blood draw.
Laboratory Requisition- This is the lab order that specifies what tests the patient needs to have drawn. Rarely can patients order tests on their own, so usually this will have a doctor's signature. Test results will be sent to the ordering doctor. Requisitions can be computer generated or hand written. They should include:
Patient's name and DOB
Ordering Physician information
Tests Requested
Special considerations or instructions
Diagnosis codes (ICD10 codes)
Be sure to read the whole order before beginning. Check for duplicate orders, discrepancies, mistakes, and missing information. If you find something questionable, verify with the physician or lab manager before proceeding.
Antiseptic- The most commonly used antiseptic are alcohol pads. They are pre packaged 70% isopropyl alcohol. Be sure to review the lab order to know if you should use something other than alcohol. For example, if you are drawing a blood alcohol level on a patient, you will want to use something else like Chloraprep solution or iodine or betadine. Blood culture draws will also require specific preparation of the draw site. As of 2017, CLSI standard requires a side to side cleaning motion for optimal sanitizing of the skin.
Tourniquet- The tourniquet should be applied 3"-4" above the draw site. The purpose of the tourniquet is to slow the venous blood flow causing the veins to bulge and be easier to find and stick. Tourniquets may be tied over skin or over clothing. Be sure to not allow the tourniquet to roll up or twist while tying it (this is more painful for the patient). Lay it flat against their arm and tie the proper amount of pressure. To prevent hemoconcentration (high concentration of blood in an area) and blood infiltration into the surrounding tissues, be sure to not leave the tourniquet on too long. Hemoconcentration can also lead to elevated glucose, potassium, and protein-based analytes' such as cholesterol. The tourniquet should not remain tied for longer than a minute. If you do not have a tourniquet available an alternative option is to use a blood pressure cuff.
Gloves- Gloves should always be worn when performing venipuncture or handling blood specimens. Use your own best judgment to determine if additional PPE is needed.
Vacutainer Tubes- Vacutainer tubes are the color-coded tubes used to collect the blood samples. They are test specific and have a set order in which they must be drawn. Some contain additives. They are called vacutainer tubes because they contain a vacuum inside. Once the needle punctures the rubber stopper at the top of the tube, the vacuum pulls the blood in. Each tube must be inverted a certain amount of times to mix the blood with the additive. We will go over each tube and its specifications in the next module. Review your requisition to be sure you have selected the correct tubes.
Vacutainer Needles- These needles are single use and disposable (in a sharps container) after use. You can use them to draw a single tube of blood or multiple tubes. The size of the needle can vary in length and gauge. Gauge refers to the thickness of a needle or the diameter. The higher the gauge number the smaller/thinner the needle is, and the lower the gauge the larger the needle is. Needles smaller than a 23 gauge are not recommended for blood draws because they can cause hemolysis (cutting or breaking or destruction of the red blood cells). The size of the needle you choose will depend on the vein size of the patient. The most common needle size used for venipuncture is the 21 gauge needle. The slanted tip of a needle is called the bevel. The needle should always enter bevel-up. On the other side (back end) of the needle there is another needle encased in a gray rubber sleeve. The hub screws on abound this encased needle.
Needle Adapters/Hubs- Hubs are the tube holders that attach to the end of the vacutainer needle. Hubs should be single-use only and disposed of after use in the sharps container. It is discouraged to unscrew the hub after the needle has been used as this puts you at risk of accidental sticks from the end of the needle that have no safety mechanism. The hub is the safety.
Winged Infusion Sets/Butterfly Needle- Butterfly needles are similar to the vacutainer needle in that they have two needle ends. There is tubing between the two, a hub still attaches to the end of the needle to hold tubes. The top of the needle has plastic "wings." These are meant to be held when inserting the needle and helping to secure the needle once the needle is in the vein. Butterfly needles are very helpful when drawing smaller or difficult veins, especially in the hands, or on elderly or pediatric patients. They are also single use and should be disposed of in the sharps containers. The most commonly used butterfly needle size is the 23 gauge (usually blue).
Sharps Container- Sharps containers are clearly marked and puncture-resistant containers for disposal of sharps and biohazards. Never recap a needle, dispose of a used needle immediately. You should engage the safety mechanism if it has it before disposal. Never reach into a sharps container or shove things down. Never fill it more than 2/3 full.
Cotton Ball and Coban- Cotton balls, gauze, brandades and/or coban should be used to stop bleeding after a blood draw. Coban should be wrapped tight enough to stay on and stop bleeding but not to cut off circulation. Patients should wear it for 20-30 minutes. Most medical supplies are made without latex now, but always double check and make sure your patient is okay with using the coban.
Venipuncture Procedure
Venipuncture Procedure
Verify the patient's information on the requisition form and confirm the tests ordered. Confirm their identity with full name and date of birth. If they are wearing an ID band, be sure the band matches the requisition form. When you meet your patient, use good bedside manners to help them feel comfortable. It is not necessary to tell them your level of experience or amount of time at a job, although this is a common question patients may ask since many are pretty nervous with needles. Introduce yourself and reassure them you will make the procedure as quick and painless as possible for them. Ask them questions to distract them. Ask them if they have a history of fainting with blood draws or if they prefer to be reclined. Explain to them the venipuncture procedure you are about to perform. Be sure you have their consent to proceed.
Ask the patient if they are fasting. Does the patient need to be fasting for this test? Are they fasting anyway? Are they fasting from food and water or just food? How long have they been fasting for? How long do they need to be fasting for? When a patient is dehydrated, which can occur with fasting from water, this can affect the blood volume and thickness. This may make a draw more challenging with some patients. Some lab tests require the fasting state for more accurate results. Blood glucose is a good example of this. When you eat, you have elevated blood glucose levels. Always be sure to read the requisition first to determine if the patient has prepared properly for their blood draw.
Wash your hands and put on gloves. Always use new gloves with each patient.
Gather your supplies and equipment and lay them out in an easily accessible manner.
Apply the tourniquet 3-4 inches above the site where you are looking for a vein.
Palpate the vein. Remember, you can look in more than one area before settling on a vein. It's best to look more than poke more. Take breaks with the tourniquet if it is taking you some time to find one. It's always a good idea to ask the patient if they have had blood drawn before and where they have had it successfully drawn from. If they give you a suggestion, you don't have to use it, but it never hurts to feel around and see if they are right. Make sure you can feel the vein "bounce back." Be cautious of tendons (those don't "bounce back!"). Adipose tissue (fat tissue) can also often feel something like a vein, so watch out for that too. The more people you draw, the easier it will be to recognize the vein. You can ask the patient to pump their fist or hold a fist. Do not let them pump vigorously as this can affect some test values, such as potassium. According to the CLSI (Clinical Laboratory Standards Institute), you should attempt to use the median vein or cephalic vein before trying other veins. The basilic vein runs close to the brachial artery and a large bundle of nerves. If this vein or any vein is not prominent, it is best to not attempt to stick it.
Once you have found the vein you would like to poke, release the tourniquet, and clean the site with your alcohol wipe. Clean in it a side to side motion. Allow it to air dry before puncturing as it can sting. Remember, if you need to feel the vein again, also clean your gloved finger with the alcohol so that you don't contaminate the site.
When you picked the vein, in your head you should have also decided which needle will be best for the draw. Assemble the needle connecting it to the hub. Reapply the tourniquet. Uncap the needle and examine it for any damage such as a blunted or barbed tip.
Anchor the vein with your hand that is not holding the needle. This means to place your thumb 1-2 inches below the antecubital area and pull the skin slightly back down towards the wrist. You can also have your patient lock their elbow if they feel they can maintain that position for the draw. This helps prevent the rolling of a vein. Your thumb should not be in the way of you being able to insert the needle properly at a 15-30 degree angle. Be sure your thumb leaves room for your other hand and the needle and hub.
Insert the needle swiftly and smoothly at the 15-30 degree angle, bevel up. Rest your knuckles against the patient's arm, maintaining a secure hold. Sometimes if you don't do this you can get shaky and move the needle while it is inside the patient. This can cause the needle to puncture through the vein or slip out and cause a hematoma (bruising). The more stable and securely you hold and needle the entire draw, the more likely you are to have less venipuncture-related injuries and problems.
Once the needle is inside the vein, push the collection tube into the hub. Make sure to use counter pressure when pushing the tube in so that you don't shove the needle farther in. To do this, set the tube in the hub but don't puncture it yet. Place your thumb against the back of the tube. Put your pointer finger and middle finger on either side of the hub where there are little "edges'' to push against. As you push the tube up with your thumb, push equally against the hub with your two fingers. Be sure to keep your hand that is holding the needle secured against the arm while you do this. If you are in the vein you will see the vacuum begin to pull blood into the tube. Wait for it to fill. If you need to collect blood in more tubes, repeat step 10. Be sure to draw the tubes in the proper Order of Draw. To remove the tube, use counter pressure again. Use your fingers to grasp the tube and pull it out while pushing on the hub with your thumb. This will be easier to understand when demonstrated, but just remember- counterpressure!
Once you are on the last tube, release the tourniquet. (The needle and last tube are still in!) If there is good blood flow the tourniquet may be removed earlier, you just don't want to leave it longer than a minute if possible.
Remove the last tube from the hub.
Grab your cotton ball or gauze and hover over the puncture site. Do not press down while the needle is still in the vein! Withdraw the needle swiftly and smoothly and then apply pressure with the cotton ball. When the needle is out, activate the safety mechanism on it. This should be able to be done one handed with most needles. Applying good pressure will help avoid a hematoma (bruise). You may ask the patient to continue to apply the pressure with their free hand if possible. Bending their elbow up to hold the cotton ball or gauze is not how to apply pressure and can lead to more bleeding and bruising.
Dispose of the needle in the sharps container right away. Do not recap your needle.
Wrap the patient's arm with coban. Be sure to not wrap it too tight as it can cause loss of circulation in the arm.
Properly label the patient's blood samples with the patient's name, DOB, time of collection and your initials.
Clean up your work area and dispose of all waste properly. Remove your gloves, wash your hands. If your patient is feeling okay (not sick or faint from the draw) then you can let them go and inform them that their ordering physician will receive the results and contact them to explain them.
When you are ready to finish the draw, remember these in this order:
Tourniquet, Tube, Needle, Cotton ball, Safety
This will eventually become muscle memory for you. But get used to repeating it in your head until that point.
In class, say it out loud to really engrain it!
Butterfly Needles
The process for using the butterfly needle is going to be the same as vacutainer needles. Here are some differences to keep in mind:
When you inter the needle you are going to hold the butterfly wings together with your thumb and pointer finger.
When you secure the hold of the needle you have two options. First, you can keep holding the wings pressed together and secure your hold by resting your other finger and side of your palm against the arm of the patient. Or you can open the wings and push down on either one or both of them to secure them against the arm.
You will know right away if you are in a vein with a butterfly needle as you will see a flash of blood. Once you put the tube on, it will pull the blood through the line into the tube.
When you remove the butterfly needle you can hold the wings or just the base of the needle.
The safety on most butterfly needles are different from the vacutainer needle. Instead of snapping over the needle, it slides up around it. Depending on the brand and style of needle, some you can activate the safety with one hand, some require two hands.
Hand Draws
Hand draws are also the same step process with a few differences to note:
The tourniquet is placed on the forearm of the patient when performing a hand draw, not above the elbow.
Butterfly needles are always to be used in hand veins.
Anchoring with the hand is a little trickier than the arm. When you pull the skin tot, it is helpful to pull it down over the knuckle so that your hand is out of the way of the needle stick. To do this, have the patient form a loose fist, or an open hand relaxed, and hold your fingers against the inside palm of their hand while your thumb anchors it in front. Depending on the angle and location of the vein it might be better to have the patient form a fist, lay their hand flat, or grip the edge of an armchair. Use your best judgment to instruct them.
Make sure that the angle of the needle when you enter the hand vein is more shallow, almost but not quite parallel with the hand itself.
Hematoma
We'll discuss this video in class. What did you notice done well? What would you have done differently?
CApillary Punctures
CApillary Punctures
The capillary blood vessels are microscopic. You can perform a capillary puncture on pediatric and adult patients. Sometimes a blood specimen from a capillary puncture requires only a drop of blood, and sometimes more is required. It will depend on the test ordered. You can collect the blood in a capillary collection tube, a slide, a pediatric collection tube or on a testing strip. The automatic lancet used to puncture the skin has a predetermined depth. For pediatrics it is 0.85mm and for adults is 3.0mm. When collecting the sample some "milking" or squeezing is helpful to get it to bleed, but excessive milking is discouraged as it can result in hemolysis (damaged red blood cells) and contamination of the blood sample with tissue fluids. Making sure the collection site is warm will help the blood flow. Use warm water or warm packs to warm the location before puncturing.
Fingerstick
Capillary fingersticks can be performed on patients ages two years old and up. There are several reasons for a fingerstick opposed to venipuncture. Always verify the test ordered can be performed off a capillary puncture collection before beginning. No tourniquets are needed for capillary punctures.
Wash your hands and apply your PPE.
Warm the patient's hands with warm water or a warm pack if necessary.
Select either the 3rd or 4th finger of the non-dominant hand.
Alcohol wipe the finger and let it dry.
You want to make the puncture on the fleshy portion of the finger, slightly to the side of the center. Place the lancet in the correct location against the skin and push the trigger button. This will make an automatic incision.
Take gauze or a cotton ball and wipe away the first drop of blood. Do this always! Don't wipe it with an alcohol wipe. The reason for wiping away the first drop of blood is because it contains thromboplastin (a clotting factor in the blood) and also skin particles and tissue fluids. These contaminants can alter the results of some tests. Wiping it away also wipes any residue of alcohol. Alcohol can cause hemolysis and make it hard for a round droplet to form.
Collect the blood specimen (in a capillary collection tube, on a slide, in a pediatric collection tube or on a testing strip). Run any test strips immediately. Dispose of the used lancet in the sharps container.
Apply a cotton ball or gauze to the puncture site and have the patient hold pressure. Apply a bandage as needed.
Heel Stick
A heel stick is to be performed on infants less than 1-2 years old. The steps are the same as the fingerstick above. A difference to note is that rather than the finger pads, the heel (not the toes) are the location for puncture. Observe the diagram here. Like the hands, warming the heel first is recommended to increase the blood flow to that area. Be sure to use an infant lancet that does not puncture deeper than 2.0mm. Do not puncture over the top of previous puncture sites as this can lead to infection. Do not use the arch of the foot or the back of the heel. And still, always wipe away the first drop of blood. Often newborn blood work requires completing a filter paper card by blotting. Instead of collecting the blood into a capillary tube or microtainer tube, you simply place the heel with a droplet of blood against the collection filter paper and fill the designated circles. A common test ordered for infants is called a PKU and it detects phenylketonuria which is a genetic disease that causes mental retardation and brain damage. This can be done with a dermal puncture or collection of urine.
Bleeding tIMe
Bleeding tIMe
Bleeding time tests are not as common but still exist. More frequently ordered is a PT/INR (Prothrombin Time Tests, International Normalized Ratio) or PTT (Partial Thromboplastin Time) test. These tests are collected via venipuncture in a light blue top tube. The bleeding time, PT/INR and PTT tests are used to test the blood's coagulation ability. We will not be doing these in class but they are important to know about. Watch this video to learn more about how they are performed.
RETURN TO THE GOOGLE CLASSROOM AND DO THE PRACTICE WORKSHEET.
For more information and references on the reading material found in Section 4: Venipuncture, click the link below. Test questions will be based on the reading in the sections and not from more information found in external references and website links.
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