PMLS L6

• Areas to be avoided - Due to the possibility of decreased blood flow, infection, hemolysis, or sample contamination
• Sample contamination affects the integrity of the specimen causing invalid test results. 
• Incorrect blood collection techniques that cause contamination include blood collected from edematous areas, blood collected from veins with hematomas, blood collected from arms containing an IV, sites contaminated with alcohol or iodine, or anticoagulant carryover between tubes
• damaged veins - Veins that contain thrombi or have been subjected to numerous venipunctures often feel hard (sclerosed)
• damaged veins - Should be avoided as they may be blocked (occluded) and have impaired circulation.
• Chemotherapy patients, chronically ill patients, and illegal IV drug users may have hardened veins.
• The presence of a hematoma indicates that blood has accumulated in the tissue surrounding a vein during or following venipuncture. 
• Puncturing into a hematoma is not only painful for the patient but will result in the collection of old, hemolyzed blood.
• Blood should be collected below the hematoma to ensure sampling of free-flowing blood.
• Drawing from areas containing excess tissue fluid (edema) also is not recommended
• edema - Sample will be contaminated with tissue fluid and yield inaccurate test results.
• Extensively burned, scarred, and tattoos areas are more susceptible to infection.
• burns, scars, and tattoos - Have decreased circulation and can yield inaccurate test results.
• burns, scars, and tattoos - Veins in these areas are difficult to palpate and penetrate.
• • Applying a tourniquet to or drawing blood from an arm located on the same side of the body as a recent mastectomy can be harmful to the patient and produce erroneous test results. 
• mastectomy - Patients are in danger of developing lymphedema in the affected area, and this could be increased by application of a tourniquet.
• For these reasons, blood should be drawn from the other arm. In the case of a double mastectomy, the physician should be consulted as to an appropriate site, such as the hand.
• Veins on obese patients are often deep and difficult to palpate. 
• obese patients - Often, the cephalic vein is more prominent and easier to palpate. 
• • It is important to not probe to find the vein as that can be painful to the obese patient and cause hemolysis by destroying red blood cells that can alter test results. 
  • Using a syringe with a 1 1⁄2 inch needle may offer more control
• patient in IV therapy - Blood should then be drawn from the other arm because the sample maybe contaminated with IV fluid. 
• • If an arm containing an IV must be used for sample collection, the site selected must be below the IV insertion point and preferably in a different vein. 
• • CLSI recommends having the nurse turn off the IV infusion for 2 minutes, the phlebotomist then may apply the tourniquet between the IV and the venipuncture site and perform the venipuncture. 
• If blood is collected from the IV line, the nurse should turn off the IV drip for at least 2 minutes. 
• The first 5 mL of blood drawn must be discarded, because it may be contaminated with IV fluid. A new syringe is then used for the sample collection. 
• If a coagulation test is ordered, an additional 5 mL (total of 10 mL) of blood should be drawn before collecting the coagulation test sample because IV lines are frequently flushed with heparin.
• Heparin or saline locks are winged infusion sets connected to a stopcock or cap with a diaphragm that can be left in a vein for up to 48 hours to provide a means for administering frequently required medications and for obtaining blood samples.
• patient with heaprin or saline lock - The first 5 mL of blood drawn must be discarded from either device. It is not recommended to collect blood through these devices for coagulation testing because residual heparin can affect test results. 
• Venipuncture in children under the age of 2 should be limited to superficial veins and not deep, hard-to-find veins.
• Normally, the most accessible veins of infants and toddlers are the veins of the AC fossa and forearm. 
• Other potential pediatric venipuncture sites include:

  1. Medial back side of the wrist
  2. Dorsum of the foot
  3. Scalp
  4. Medial ankle
• • Capillary collection is normally recommended for pediatric patients, especially newborns and infants up to 12 months, because their veins are small and not well developed, creating a considerable risk of permanent damage. 
• Other potential pediatric venipuncture sites include:

  1. Medial back side of the wrist
  2. Dorsum of the foot
  3. Scalp
  4. Medial ankle
• Other potential pediatric venipuncture sites include:

  1. Medial back side of the wrist
  2. Dorsum of the foot
  3. Scalp
  4. Medial ankle
• Other potential pediatric venipuncture sites include:

  1. Medial back side of the wrist
  2. Dorsum of the foot
  3. Scalp
  4. Medial ankle
• removing more than 10% of an infant’s blood volume at one time can lead to shock and cardiac arrest
• Cumulative blood losses from repetitive draws may lead to an iatrogenic anemia
• iatrogenic anemias - This is characterized by dropping hemoglobin and hematocrit levels, which are accompanied by a normal mean corpuscular volume (MCV). 
• Often diagnosed as a hypochromic, normocytic anemia, iatrogenic anemias can be quite insidious (subtle) and perplexing to the healthcare team
• • If parents or guardians are present, it is important for the phlebotomist to earn their trust before attempting venipuncture. 
  • Behave in a warm and friendly manner and display a calm, confident, and caring attitude