Lesson 1-7

• Venipuncture


  The process of collecting or "drawing" blood from a vein and the most common way to collect blood specimens for laboratory testing
• Venipuncture Procedures

  1. I. PATIENT IDENTIFICATION AND REQUISITION SLIPS

  2. II. PATIENT PREPARATION

  3. III. SITE SELECTION

  4. IV. PERFORMING THE VENIPUNCTURE

  5. V. VENIPUNCTURE COMPLICATIONS AND PRE EXAMINATION VARIABLES

  6. VI. PATIENT COMPLICATIONS

  7. VII. COMMON DIFFICULTIES ENCOUNTERED DURING COLLECTION AND PROCESSING OF BLOOD

  8. VIII. PHLEBOTOMY IN PEDIATRICS PATIENTS

  9. IX. GERIATRIC PATIENTS

  10. X. ARTERIAL BLOOD GAS COLLECTION

  11. XI. Common Reasons for Specimen Rejection
• Test Requisition


  The form on which test orders are entered
• Test Requisitions


  • They become part of a patient's medical record and require specific information to ensure that the right patient is tested, the physician's orders are met, the correct tests are performed at the proper time under the required conditions, and the patient is billed properly
• Manual Requisitions

  • Test request written on a prescription pad by a physician
  • Special form issued by a reference laboratory
• Computer Requisitions/ Bar–code Requisitions


  • They contain a bar code, a series of black stripes and white spaces of varying widths that correspond to letters and numbers to represent patient names, identification numbers, or laboratory tests
  • They normally contain the actual labels that are placed on the specimen tubes immediately after collection
• Reviewing the Requisition

  1. Check to see that all required information is present and complete

  2. Verify the tests to be collected and time and date of collection

  3. Identify diet restrictions or other special circumstances that must be met prior to collection

  4. Determine test status or collection priority
• Patient Preparation

  • Always ask the patient if he or she is allergic to latex
  • It may be necessary to move a hospitalized patient slightly to make the arm more accessible
  • Place a pillow or towel under the patient's arm for better support and to position the arm in a straight line downward
• Explaining the Procedure

  • Most patients have had a blood test before, so a statement of your intent to collect a specimen for a blood test is usually sufficient for them to understand what is about to occur
  • A patient who has never had a blood test may require a more detailed explanation
  • If a patient does not speak or understand English, you may have to use sign language or other nonverbal means to demonstrate what is to occur
• Gloves and Tourniquet Application

  • Gloves must be worn when performing a venipuncture procedure (OSHA Mandate)
  • Gloves must remain intact throughout the procedure (e.g., do not remove the fingertips)
  • The tourniquet serves two functions: 1) Impedes venous blood flow, causing blood to accumulate in the veins making them more easily located, 2) Provides a larger amount of blood for collection
• Tourniquet Application and Fist Clenching

  Tourniquet Application and Fist Clenching
• Site Selection

  • The preferred venipuncture site is the AC area of the arm, where a number of veins lie fairly close to the surface
  • The median cubital and median veins are normally closer to the surface, more stationary, and in an area where nerve injury is least likely, so they are the first choices for venipuncture
  • The basilic and median basilic veins are the last-choice veins because they are near the median nerve and brachial artery, which could be punctured accidentally
• 3 Veins

  • Median Cephalic Vein - located near the center; preferred vein for venipuncture because it is large, stationary, least painful due to less nociceptor & bruises less easily
  • Basilic Vein - medial side; not well anchored & rolls easily, ↑ risk of puncturing median cutaneous nerve or the brachial artery
  • Cephalic Vein - lateral aspect; second choice; hard to palpate but fairly well anchored & the only vein can be felt in obese
• Other Sites

  • Veins on the underside of the wrist should never be used for venipuncture
  • Leg, ankle, and foot veins are sometimes used but not without permission of the patient's physician
  • Vein of the longitudinal sinus or sagittal sinus, Femoral vein, Wrist vein, Saphenous vein, Veins on the dorsal portion of the hand
• Cleansing the Site

  1. The venipuncture site must be cleaned with an antiseptic prior to venipuncture

  2. The recommended antiseptic is 70% isopropyl alcohol, typically available in sterile, prepackaged pads referred to as alcohol prep pads
• Assembly of Equipment

  1. Check equipment for defects

  2. Check needle and syringe if properly screwed

  3. Extra tubes should be near at hand

  4. Do not place collection tray on patient's bed
• Evacuated Tube System


  • The most common and most efficient method of performing venipuncture
  • Blood is collected directly into an evacuated tube through a needle that has two pointed ends
• Winged Infusion or Butterfly Method


  • Made up of a beveled needle attached to a length of tubing with a luer adapter
  • Often used for venipuncture in patients having very fragile veins, such as those in the hands, for many pediatric blood draws, small fragile veins in areas other than the hand, and sometimes for uncooperative patients
• Syringe


  • Use of a syringe to withdraw blood allows for more control of the vacuum used to withdraw blood from the vein
  • Syringe draws also allow the person performing the venipuncture to see the blood in the hub of the needle as the vein is entered, which can be reassuring when attempting a blood draw on a vein that is difficult to palpate or locate
• Performing the Venipuncture

  1. Examine Needle – BEVEL UP

  2. Anchoring Vein

  3. Insertion of Needle

  4. Filling tubes

  5. Removal of Needle

  6. Disposal of Needle

  7. Labelling Tubes

  8. Bandaging Patient's Arm

  9. Disposing Used Supplies

  10. 10. Leaving Patient
• Sleeping Patients and Unconscious Patients

  • Sleeping patients should be gently awakened
  • Unconscious Patients should be greeted in the same manner as conscious ones
  • Nursing personnel can assist patient
• Unavailable Patient


  • Seek assistance from attending nurse/ nurse station to locate patient
• Young and Cognitively Impaired Patients


  • Ask the patient's nurse, relative, or a friend to identify the patient
• Basal State


  The ideal time to collect blood from a patient, defined as the body's state after 8 to 12 hours of fasting and abstention from strenuous exercise
• Timed Specimens


  Taken to determine changes in the level of some substance of interest over time, most often used to monitor medication levels, changes in the patient's condition, and normal diurnal variation in blood levels at different times of the day
• 1. Hour Postprandial Test


  Used to test for diabetes mellitus, compares the fasting glucose level with the level 2 hours after consuming glucose
• Oral Glucose Tolerance test (OGTT)


  Tests for both diabetes mellitus and other disorders of carbohydrate metabolism, still widely used in pregnant women to diagnose gestational diabetes
• Immediate Local Complications

  • Fainting (Syncope)
  • Failure Of Blood To Enter The Syringe
  • Hemoconcentration Or Venous Stasis
  • Seizures
  • Petechiae
  • Vomiting
  • Nerve Injury
• Delayed Local Complications

  • Delayed Local Complications
• Immediate Local Complications

  • Petechiae
  • Vomiting
  • Nerve Injury
• Petechiae


  • Small, nonraised red hemorrhagic spots
  • May have prolonged bleeding following venipuncture
  • Additional pressure should be applied to the puncture site following needle removal
• Handling vomiting

  1. If the patient is nauseated, instruct the patient to breathe deeply and slowly

  2. Apply cold compresses to the patient's forehead

  3. If the patient vomits, stop the blood collection and provide an emesis basin or wastebasket and tissues

  4. Notify the patient's nurse or designated firstaid personnel
• Nerve Injury


  • May result in loss of movement to the arm or hand
  • Permanent injury in the venipuncture procedure is damage to the median antebrachial cutaneous nerve
• Signs of nerve injury

  • Shooting pain
  • Electric-like tingling/numbness running up or down the arm or in the fingers of the arm
• Delayed Local Complications

  • Thrombosis of veins
  • Thrombophlebitis
  • Hematomas
• Thrombosis of veins

  Formation of blood clots inside the lumen of the vein due to trauma
• Thrombophlebitis

  Inflammation of the vein caused by thrombus
• Hematomas


  Blue or black skin discoloration commonly due to repeated trauma or puncture of the veins
• Areas to avoid

  • Damaged Veins
  • Hematoma
  • Edema
  • Burns, Scars, and Tattoos
  • Arm on the same side of a Mastectomy
  • IV Therapy
• Common difficulties encountered during collection and processing of blood

  • Hemolysis
  • Lipemia or Lactescence