PMLS LAB LECTURE 2

• Blood Sampling Systems


  • Open systems
  • Closed systems
• Open systems


  Include hypodermic needle and syringes, as well as winged steel needles attached to a syringe
• Closed systems


  Preferable for blood sampling because they have proven to be safer than open systems
• Vacuum extraction systems/Evacuated Tube System

  The use of vacuum extraction tube systems as closed systems for blood collecting reduces the risk of direct exposure to blood and has made it easier to take multiple samples from a single venipuncture
• Vacuum extraction systems are widely available in most well-resourced countries and are recommended, but users should check their own country's recommendations
• Although vacuum extraction systems are safe, training and skill is required for their use
• Multisample Needles


  ETS needles that allow multiple tubes of blood to be collected during a single venipuncture
• Needle and syringe system

  Remove the syringe from the packaging and insert the nozzle of the syringe firmly into the exposed hub of the capped hypodermic needle
• Vacuum extraction system


  The barrel holds the sample collection tube in place and protects the phlebotomist from direct contact with blood. Do not push the laboratory tube onto the needle inside the barrel until the needle is in the blood vessel, or the vacuum will be lost
• Winged butterfly system (vacuum extraction)

  A vacuum system combined with a winged butterfly needle. Do not push the laboratory tube onto the needle inside the barrel until the winged needle is inside the blood vessel or the vacuum will be lost

  
• Winged butterfly system (syringe)


  A syringe combined with a winged butterfly needle
• If it is felt by the phlebotomist that this procedure would cause vein collapse, then there is no need for early release of tourniquet, but tourniquet must not be tied for more than 2mins
• Conventional Devices for Drawing Blood

  • Hypodermic single-use needle and syringe
  • Vacuum-tube system
  • Winged Steel Needles (butterfly)

  
• Hypodermic single-use needle and syringe

  • Widely available, least expensive, comes in wide range of needle lengths and gauges, does not require special training, can be used for blood drawing in paediatric population, for patient with small or difficult veins, blood drawing can be easier than an evacuated tube system, if heparinized, can be used for arterial blood drawing
• Hypodermic single-use needle and syringe

  • Requires blood transfer, creating additional risk for needle-stick injuries or blood splashing, difficult to draw large or multiple blood samples, a smaller syringe and paediatric laboratory tube should be used for paediatric patients
• Vacuum-tube system


  • Safer than using hypodermic needle and syringe, eliminates blood transfer, allows numerous blood samples to be collected through single venepuncture
• Vacuum-tube system


  • Requires user to be skilled in its use, reuse of needle holder (tube holder) creates risk for needle-stick injuries during disassembly, mixing components from different manufactures can create a problem during use, a smaller tube with a reduced vacuum should be used for paediatric patients
• Winged Steel Needles (butterfly)


  • Good for blood drawing from paediatric population or patient with small or difficult veins, allows better precision than hypodermic needle or evacuated tube needle
• Winged Steel Needles (butterfly)

  • Because of the air in the tubing, first tube must be collected without additive or discarded, difference in winged steel needles for evacuated system tubes and winged infusion set can create confusion, higher cost
• Vascular Access Devices (VADs)


  Tubing and other devices that are specifically designed to allow entry to veins or arteries, often used for patients who require frequent venous or arterial access, most commonly used for administration of medications, fluids, blood products, and sometimes blood collection
• As a general rule, venipuncture should not be performed on an extremity with a VAD. Follow facility policy.
• Intravenous Line (IV)


  A quick way to deliver fluids, medications, blood transfusion products, and other substances to patients, consists of a catheter inserted in a peripheral vein
• It is preferred that blood specimens not be drawn from an arm with an IV, as the specimens can be contaminated or diluted with the IV fluid, causing erroneous test results
• Purpose: To obtain a blood specimen by venipuncture below an IV

  1. Ask the patient's nurse to turn off the IV for at least two minutes prior to collection

  2. Apply the tourniquet distal to the IV

  3. Select a venipuncture site distal to the and the tourniquet

  4. Perform the venipuncture in a different vein than the one with the IV, if possible

  5. Ask the nurse to restart the IV after the specimen has been collected

  6. Document that the specimen was collected below an IV, indicate the type of fluid in the IV, and identify which arm was used

  
• A phlebotomist is not qualified to make IV adjustments. Turning off the IV for two minutes allows IV fluids to dissipate from the area.
• Avoids disturbing the IV.
• IV Venous blood flows up the arm toward the heart. Drawing below an IV affords the best chance of obtaining blood that is free of IV fluid contamination.
• IV fluids can be present below an IV because of backflow and may still be there after the IV is shut off because of poor venous circulation.
• IV flow rates must be precise, and starting or adjusting them is not part of a phlebotomist's scope of practice.
• This aids laboratory personnel and the patient's physician if test results are questioned.
• IV Catheter Lock

  Heparin readily adheres to surfaces; therefore, it is difficult to remove all traces of it. Consequently, a 5-mL discard tube should be drawn first when blood specimens are collected from a heparin lock or from a saline lock that has been flushed with heparin. Drawing coagulation specimens from them is also not recommended because traces of heparin or dilution with saline can negatively affect test results.
• Never collect blood specimens from known previous IV sites within 24 to 48 hours of the time the IV was discontinued. Follow facility protocol.
• Arterial Line


  A catheter that is placed in an artery, most commonly located in the radial artery of the wrist, typically used to provide accurate and continuous measurement of a patient's blood pressure, may also be used to collect blood gas and other blood specimens and for the administration of drugs such as dopamine
• Arteriovenous Shunt, Fistula, or Graft

  An arteriovenous (AV) shunt is the permanent surgical connection of an artery and vein, bypassing the capillaries and forcing arterial blood directly into a vein. A dialysis shunt created by direct permanent fusion of the artery and vein is called an AV fistula and is visible as a large bulging section of vein. A fistula has become the most common type of shunt used for dialysis. If the shunt was created using a piece of vein or tubing to form a loop from the artery to the vein that is visible, it is called an AV graft.
• Geriatric Venipuncture


  Relating to old age, involving physical, psychological, and social changes leading to conditions, behaviors, and habits that may seem unusual to those unaccustomed to working with elderly patients
• It is important to remember that elderly patients are unique individuals with special needs who deserve to be treated with compassion, kindness, patience, and respect.
• Challenges in Geriatric Venipuncture

  • Skin Changes
  • Hearing Impairment
  • Visual Impairment
  • Mental Impairment
• Effects of Disease in Geriatric Venipuncture

  • Arthritis
  • Coagulation problems
  • Diabetes
  • Parkinson Disease and Stroke
  • Pulmonary Function Problems
• Other Problems in Geriatric Venipuncture


  • Decreased sense of smell and taste
  • Poor nutrition
• Geriatric Patients


  • Dialysis patients
  • Long-Term Care Patients
  • Home Care Patients
  • Hospice Patients