Obtain and Label Blood Specimens
Venipuncture is the technique that permits access to a vein so that a needle or catheter can be inserted, usually to withdraw a blood specimen or initiate an intravenous infusion. Venipuncture is a sterile procedure since the integrity of the skin is broken.
Terms and definitions
(1) Venipuncture - the transcutaneous puncture of a vein to withdraw a specimen of blood, start an IV or instill a medication
(2) Palpate - to feel or to examine by hand
(3) Antecubital fossa - hollow or depressed area at the bend of the elbow
(4) Anticoagulant - substance that prevents or delays clotting of the blood
(5) Hematoma - swelling or mass of blood confined to an organ, tissue, or space and caused by a break in a blood vessel
Veins used for drawing blood
(1) Median cubital vein - first choice, well supported, least apt to roll
(2) Cephalic vein - second choice
(3) Basilic vein - third choice, often the most prominent vein, but it tends to roll easily and makes venipuncture difficult
CAUTION: Universal precautions for this task will include hand washing and gloves.
CAUTION: Strict adherence to the sharps policy and the use of sharps containers will be utilized during this hands on exercise.
Verify the request to obtain a blood specimen. Check the physician's orders
Select the proper blood specimen tube for the test to be performed. Check local laboratory SOP
(1) The type of blood tube needed will depend on the specific test to be performed
(2) For some tests, an anticoagulant or other additives are present in the tube
(3) Rubber stoppers of the tubes are color-coded for different tests
(1) Stamp label with patient's addressograph plate. If there is no plate, write name, organization, social security number, prefix code, ward or clinic, facility, and date.
(2) Apply to specimen tube
Perform a patient care hand wash/don gloves
(1) Constricting band
(2) Vacutainer sleeve/holder
(3) Sterile disposable double-ended needle
(a) Single specimen vacutainer needle
(b) Multiple samples - a rubber sheath covers the shaft of the needle. It is pushed up when the blood tube is inserted onto the needle then slips back over the needle holder while tubes are being changed to prevent blood from dripping into holder
(4) Betadine or alcohol wipe or sponge
CAUTION: Always ask the patient if he/she has an allergy to iodine or Betadine before applying.
(5) Protective pad (chux)
(6) Sterile 2 x 2-inch gauze sponge(s)
Assemble vacutainer and needle
(1) Put short end of needle into threaded hole in vacutainer
(2) Screw tightly using clockwise motion
Insert rubber stoppered end of the specimen tube into vacutainer holder and advance the tube until it is even with the guideline
CAUTION: If the tube is pushed beyond the guideline, the vacuum may released and blood will not be pulled into the tube.
Explain the procedure and purpose for collecting the blood specimen to the patient
CAUTION: Ask patient about allergies (i.e., iodine or alcohol).
Position the patient - sitting or lying
CAUTION: Never attempt to draw blood from a standing patient.
Position protective pad under patient's extended elbow and forearm
NOTE: Demonstrate steps (12-22 below) on another instructor or student assistant, as appropriate.
Expose area for venipuncture
(1) Roll garment above the elbow
(2) Extend patient's arm with palm up
Select vein for venipuncture - Palpate and select one of the most prominent veins in antecubital fossa
CAUTION: You may need to apply the constricting band at this point for venipuncture site selection.
Prepare sponges for use
(1) Open the betadine or alcohol and 2 x 2 gauze sponge packages
(2) Place them within easy reach (still in the packages)
Apply constricting band with enough pressure to stop venous return without stopping the arterial flow. A radial pulse should be felt
(1) Wrap latex tubing around limb about 2 inches above venipuncture site
(2) Stretch tubing slightly and hold with one end longer than the other
(3) Loop longer end and draw under shorter end so tails are away from site
(4) If a commercial band is used, wrap it around limb as in step 14a and secure by overlapping Velcro ends.
(5) Instruct patient to clench and unclench his fist several times and then hold clenched fist to trap blood in veins and distend them.
CAUTION: Avoid veins that are infected, injured, irritated, or have an IV running distally.
Palpate selected vein
(1) Palpate along length of vein with index finger up and down 1 or 2 inches from selected site in both directions so size and direction of vein can be determined.
(2) Vein should feel like a spongy tube
Clean the skin - moving alcohol/betadine wipe in a circular motion away from selected venipuncture site.
CAUTION: Do not repalpate the vein after cleansing the skin.
Prepare to puncture vein
(1) Remove protective cover from needle
(2) Position needle in line with vein and grasp patient's arm below entry point with free hand
(3) Place thumb of free hand 1 inch below entry site and pull skin taut toward hand
(1) Align needle, bevel up, with the vein and pierce skin at 15 to 30 degree angle
(2) Decrease angle until almost parallel to skin surface, then pierce vein wall
(a) A faint "give" will be felt when the vein is entered, and blood will appear in the needle
(b) If venipuncture is unsuccessful, pull needle back slightly (not above the skin surface), and redirect needle toward vein and try again
CAUTION: If needle is withdrawn above skin surface, do not attempt venipuncture again with the same needle.
(c) If still unsuccessful
(i) Release the constricting band
(ii) Place 2 x 2 gauze sponge over site
(iii) Quickly withdraw the needle and instruct the patient to elevate arm slightly and keeping the arm fully extended apply pressure to the site for 2 to 3 minutes.
(iv) Notify supervisor before attempting another venipuncture
Collect the specimen
(1) Single specimen
(a) Hold vacutainer unit and needle steady with dominant hand. Collection tube is positioned against, but not through, the needle
(b) Place index and middle fingers of other hand behind flange of vacutainer
(c) Push the tube as far forward as possible with thumb of nondominant hand without causing excessive movement
(d) Instruct patient to relax and unclench fist after blood has started flowing
(e) Release the constricting band by pulling on long end of looped tubing or releasing velcro fastener with the non dominant hand
(f) When tube is about two-thirds full of blood or blood stops, grasp tube firmly and remove tubes
(g) Prepare to withdraw needle
(2) Multiple specimens
(a) Follow same steps for collecting single specimen
(b) Remove first tube from vacutainer sleeve without dislodging needle position
(c) Insert second tube into vacutainer sleeve. Push tube as far forward as possible without causing excessive movement.
(d) Repeat these procedures until the desired number of tubes are filled or blood stops flowing
(e) Release the constricting band by pulling on long end of looped tubing or releasing velcro fastener with the non dominant hand.
CAUTION: DO NOT withdraw the needle before the constricting band is released because of potential for heavy blood loss and/or hematoma formation.
(f) After the last tube is about two-thirds full of blood or blood stops, grasp tube firmly and remove tubes
(g) Place 2 x 2-inch sponge lightly over venipuncture site
(h) Withdraw the needle smoothly and quickly. Immediately apply pressure to the site with the 2 x 2-inch sponge, keeping patient's arm fully extended.
(i) Instruct the patient to elevate arm slightly and keeping the arm fully extended, apply firm manual pressure for 2 to 3 minutes. If the patient is unable to do this for himself, you must do it for him.
If specimen tube contains an anticoagulant or other additive, gently invert tube several times to mix with blood
Apply a bandaid to the venipuncture site after the bleeding has stopped
CAUTION: Dispose of needle into sharps container as soon as possible or IAW local protocol. DO NOT unscrew needle from sleeve with hands. DO NOT recap needle.
Provide for patient's comfort and safety
(1) Remove protective pad
(2) Roll down patient's sleeve
(3) Reposition patient and raise side rails if patient is in a bed
Dispose of equipment
(1) Remove all the equipment from area
(2) Dispose of used supplies
(3) Store reusable equipment and dispose of needle IAW local SOP
(4) Remove gloves and wash hands
(1) Check and complete laboratory form IAW local SOP
(2) Apply prepared label(s) to specimen tube(s)
(3) Document procedure IAW local SOP
If venipuncture is done smoothly and properly, there should be little pain for the patient and little risk to the medical personnel. The procedural steps are designed to ensure a properly drawn specimen. With practice, obtaining a blood specimen can become a smooth routine.