2 - PHLEBOTOMY

• The circulatory system is made up of four main components: the heart, blood vessels, blood, and lymph
• Arteries carry oxygen-rich blood away from the heart to all of the body's tissues
• Capillaries are small, thin blood vessels that connect the arteries and the veins, allowing the exchange of water and chemicals between the blood and the tissues
• Both veins and arteries are composed of three major layers: tunica intima, tunica media, and tunica externa
• Vasoconstriction is the narrowing of blood vessels by contracting the vascular smooth muscle in the vessel walls
• Vasodilation is the widening of blood vessels, a process mediated by antagonistically acting mediators, with nitric oxide being a prominent vasodilator
• The antecubital fossa is a triangular area on the anterior of the elbow, a site of major veins and the first choice for routine venipuncture
• In the antecubital fossa, the basilic vein runs along the medial side of the elbow, the median cubital vein is a branch of the basilic vein that runs across the elbow crease, and the cephalic vein runs along the radial side of the elbow
• The median cubital vein is the preferred venipuncture site as it is easiest to access and least painful for the patient
• The cephalic vein is the second choice for venipuncture, although harder to palpate, but is usually better when drawing blood from an obese patient
• The basilic vein is the last choice for venipuncture as it is not well anchored and punctures are more painful
• The intermediate antebrachial veins in the arm include the median, median cephalic, and median basilic veins, with the median vein being the first choice vein for venipuncture
• Veins at the back of the hand can be used for venipuncture if the antecubital veins are not accessible, but they are smaller and thus more painful
• Leg, ankle, and foot veins must not be used in venipuncture without the permission of a physician due to complications such as thrombosis
• Arteries are not used for routine blood collection and are limited to the collection of arterial blood gas, requiring special training and posing risks for the patient
• Phlebotomy is the act of drawing or removing blood from the circulatory system through a cut or puncture to obtain a sample for analysis and diagnosis
• Phlebotomy is also done as part of the patient’s treatment for certain blood disorders
• Historically, phlebotomy was a standard treatment in the 18th century for various conditions like fever, hypertension, and inflammation of the lungs
• George Washington's last illness involved the removal of 2365 mL of blood over 12 hours, reflecting dehydration and hypovolemia
• Phlebotomy is used every day to diagnose health problems, introduce medication intravenously, and in life-saving procedures like blood transfusions
• Phlebotomists play a crucial role in specimen collection, with errors in the process potentially causing serious harm to patients
• Specimen Collection is the first step in most laboratory analysis

  
• Test results are said to be as good as sample collection and handling
• Quality assessment in phlebotomy includes preparation of a patient for any specimens to be collected, collection of valid samples, and proper specimen transport
• The phlebotomist is the only laboratory staff member that a patient sees and is expected to deliver unexcelled customer satisfaction
• Patient identification procedures:

  • Conscious In-patients: verbally ask their full names, verify it using the identification bracelet
  • Sleeping patients: must be awakened before blood collection, identified same as conscious patients
  • Unconscious patients/Mentally incompetent patients: identified by asking the attending nurse or relative; ID bracelet
  • Infants and Children: nurse or relative may identify the patient or by ID bracelet
  • Outpatient patient: verbally ask their full name, DOB and countercheck with driver’s license or ID with photo
• When obtaining a blood specimen from an adolescent, it is important to be relaxed and perceptive about any anxiety that he or she may have
• Treat geriatric patients with dignity and respect, addressing them with a formal title such as Mrs., Ms., or Mr. rather than by their first name
• Categories of additives used in blood collection:

  • Antiglycolytic agent: inhibits the use of glucose by blood cells
  • Anticoagulant agent: prevents blood from clotting
  • Clot activator: helps initiate or enhance the clotting mechanism
  • Thixotropic Gel Separator: serves as a separation barrier between the liquid (serum and plasma) and cells
• Color coding for tube caps:

  • Red: No additive
  • Orange: Coagulant
  • Yellow: Coagulant and Separation Gel
  • Green: Heparin Sodium
  • Light Green: Heparin Lithium
  • Purple: EDTA
  • Light Blue: Sodium Citrate 1:9
  • Black: Sodium Citrate 1:4
  • Grey: Potassium Oxalate Monohydrate and Sodium Fluoride
• Order of draw for evacuated tube:

  • Blood Culture or sterile tubes
  • Coagulation tube
  • Serum tube with or without clot activator or gel
  • Heparin Tube
  • EDTA tube
  • Oxalate/fluoride tube
• Special capillary puncture procedures:

  • Capillary blood gases: less desirable for blood gas analysis, warming the site for 5-10 minutes is necessary
  • Neonatal bilirubin collection: done to newborns to detect and monitor increased bilirubin levels
• The circulatory system consists of four main components: the heart, blood vessels, blood, and lymph

  
• The structure of blood vessels includes three layers of the blood vessel wall: the tunica intima, the tunica media, and the tunica externa

  
• Vasodilation is the widening of blood vessels, while vasoconstriction is the narrowing of blood vessels

  
• The antecubital fossa contains veins like the basilic vein, median cubital vein, and cephalic vein, along with nerves like the lateral cutaneous nerve of the forearm and the medial cutaneous nerve of the forearm

  
• Special capillary puncture procedures include:

  • Neonatal bilirubin collection: done to detect and monitor increased bilirubin levels in newborns
  • Newborn/Neonatal screening: testing for genetic, metabolic, hormonal, and functional disorders in newborns
  • Finger puncture precautions: guidelines for finger puncture in infants and children under 1 year of age
• Complications encountered in blood collection:

  • Ecchymosis (bruise) and syncope (fainting) are common complications
  • Hematoma, failure to draw blood, and petechiae are other complications
  • Edema, obesity, and hemoconcentration are additional complications
• Physiologic factors affecting test results:

  • Posture, diurnal rhythm, exercise, stress, diet, and smoking can influence test results
• Poor collection techniques:

  • Venous stasis, hemodilution, hemolysis, clotted sample, and partially filled tubes are examples of poor collection techniques