How Do They Draw Blood

Phlebotomy, the practice of drawing blood from a vein, is a proficiency that all nurses should learn in their career. While not commonly taught in nursing school, programs recommend nursing students take extra courses to hone this skill.

Obtaining blood samples, either via a venous stick or from a central line, is a critical nursing skill. Phlebotomy is essential for a variety of medical diagnoses, procedures, and tests. Without proper specimens, unhelpful or even harmful medical treatment could happen. Nursing schools do not teach this skill due to legality issues. Students should study venipuncture in books and watch licensed nurses in clinical settings perform this task. In doing so, this will enable students to learn basics prior to graduation.

Even though most hospitals do have phlebotomy teams, it is still critical for nurses to learn these skills in order to provide the best patient care. In fact, the majority of intensive care units require their nurses to possess these skills. Phlebotomy teams generally only make rounds at specific times in hospital settings, therefore, if a lab test is ordered immediately it could be the responsibility of the nursing staff to draw the specimen.

Practice Makes Perfect

The practice of phlebotomy is not something that can strictly be learned from watching videos or reading a how-to guide but something that must be practiced repeatedly in a controlled environment with other trained professionals. It's important to speak to your supervisor to learn the steps in order to become certified in your hospital. Each healthcare system has their own requirements prior to nurses performing blood draws.

The World Health Organization

The World Health Organization's (WHO) best practice guidelines for blood draws include the following:

• Planning ahead
• Using an appropriate location
• Quality control

The WHO has set forth the following standards of patient care for hospitals to adhere by:

• Availability of appropriate supplies and protective equipment
• Availability of post-exposure prophylaxis (PEP)
• Avoidance of contaminated phlebotomy equipment
• Appropriate training in phlebotomy
• Cooperation on the part of patients
• Quality of laboratory sampling

Step 1: Identify The Vein.

The first step in drawing blood correctly is to identify the appropriate veins to puncture. For adult patients, the most common and first choice is the median cubital vein in the antecubital fossa. Commonly referred to as the antecubital or the AC it can be found in the crevice of the elbow between the median cephalic and the median basilic vein.

This is an extremely large vessel and if stuck properly can yield excellent blood results. Some health care settings may insert blood drawing peripheral intravenous catheters into this vessel for frequent blood draws.

For novice phlebotomists, this vein is the first choice because it is close to the skin's surface and tends not to roll when punctured. Furthermore, it has a low risk of damaging surrounding nerves, arteries, and tendons versus other veins in the hands.

Learning the anatomy of the main veins and arteries in the body is essential to becoming competent in phlebotomy. If the antecub has already been accessed there are great options for venipuncture.

Other commonly used veins include:

• basilic vein
• cephalic vein

Avoid Puncturing These Areas

While it is important to know the best veins to access it's also important to know which areas to avoid.

These areas include:

• Edematous sites (swollen sites filled with serous fluid)
• Scarred or burned areas
• Fistulas and grafts
• Hematomas
• From an IV cannula (unless permitted by your institution)
• Sites above an IV cannula in the same vessel
• Arm with PICC line
• Arm with a preexisting or current blood clot
• Arm on side of a mastectomy
• Via an open wound or area of infection
• Arm in which blood is being transfused
• Arm on the side of a surgical procedure

Step 2: Gather Supplies.

After identifying the site for the blood draw, gather the appropriate supplies needed. Some institutions have kits with all of the needed supplies while others will require the nurses to gather them individually. An important tip - take extra supplies into the patient's room in case you need to attempt a second venipuncture.

These supplies include:

• Evacuated Collection Tubes (tubes specific to labs ordered)
• Personal Protective Equipment (ie gloves)
• Appropriate blood-drawing needles
• Tourniquet
• Hand Sanitizer
• Alcohol swabs for skin disinfection
• Laboratory specimen labels
• Gauze
• Blood transfer device
• Adhesive bandage/tape
• Laboratory forms
• Bio-hazard leak-proof transportation bags
• Puncture resistant sharps container

Step 3: Venipuncture.

After assembling the appropriate equipment, follow the next steps to perform a proper venipuncture. Once again, please be aware that these are only guidelines for blood draws and nurses should consult with the appropriate hospital personnel regarding performing this procedure on patients.

Additionally, these steps only apply to the adult and pediatric population and not neonates.

• Explain the procedure and reason for the blood draw to the patient.
• Identify the patient using two patient identifiers as mandated by JCAHO.
• Confirm the ordered tests and fill out the appropriate forms and labels.
• Check for any allergies or sensitivities with the patient regarding antiseptics, adhesives, or latex. True allergies should be identified on an allergy ID band but sensitivities may not be reported at the time of patient admission.
• Position the patient and hyperextend the patient's arm.
• Perform good hand hygiene and don appropriate PPE.
• Apply a tourniquet approximately 3-4 inches above the selected site. Closely monitor the arm to ensure that is is not applied to tight or for more than 2 minutes. Reasons for concern would include numbness, tingling, change of color to blue or white, and extreme pain.
• Ask the patient to make a fist and not pump the hand. This is a common misconception - pumping the hand does not increase venous circulation.
• Prep the venipuncture site by cleansing the area with an alcohol prep pad for 30 seconds and allow to air dry for 30 seconds. Do not wave, fan, or blow on the area as this contaminates the area and leads to increased risk for infection.
• Grab the patient's lower arm (below site of puncture) firmly to draw the skin taut and anchor the vein from rolling. Insert the needle at a 15 to 30-degree angle into the vessel.

• If properly inserted blood should flash into the catheter. If this does not happen then the needle has either not punctured the vein or the needle went through the vessel.
• Attach the needed tubes or syringes to remove the proper volume of blood. Remove the tourniquet as the last amount of blood is drawn.
• Remove the needle from the patient's arm and press down on the vessel with gauze.
• Dispose of contaminated materials and needles in the designated hospital approved containers.
• Label appropriate tubes at the bedside and place into transport bags.
• Deliver blood specimens to the laboratory promptly. If the blood is not delivered in a timely manner it can cause hemolysis and skew the lab results.

Don't be discouraged if at first, you don't access the vein. Venipuncture is a skill that takes time and practice to master. Always remember to ask for help from seasoned nurses and seize opportunities to practice your skills.

How Do They Draw Blood

Source: https://nurse.org/articles/how-nurses-professionally-draw-blood/

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