CHAPTER 17 PHLEBOTOMY.

CHAPTER 17 PHLEBOTOMY

PRETEST True or False An individual who collects blood specimens is known as a vampire. The purpose of applying a tourniquet when performing venipuncture is to make the patient's veins stand out. The tourniquet should be left on the patient's arm for at least 2 minutes before performing a venipuncture Serum is obtained from whole blood that has been centrifuged. A 25-gauge needle is recommended for performing venipuncture.

PRETEST, CONT. True or False
The size of the evacuated tube used to obtain a venous blood specimen depends on the size of the patient's veins. A correct order of draw for the vacuum-tube method of venipuncture is red, lavender, gray, and green. Veins are most likely to collapse in patients with large veins and thick walls. Hemolysis of a blood specimen results in inaccurate test results. When obtaining a capillary specimen, the first drop of blood should be used for the test.

Content Outline Introduction to Phlebotomy
Purpose of phlebotomy: collect blood for laboratory analysis Phlebotomy: Incision of a vein for the removal of blood Phlebotomist: individual collecting the blood sample

Introduction to Phlebotomy, cont.
Specimen may be: Tested at office Taken to an outside laboratory for testing Must be placed in a biohazard specimen bag

Needs to be accompanied by a laboratory request Informs laboratory what tests to run MA completes laboratory request On computer Manually (by hand)

Types of blood collections: Arterial puncture: performed in a hospital setting Venipuncture Skin puncture

Venipuncture (VP) Venipuncture (VP): Puncturing of a vein for the removal of a venous blood sample 2. Performed when a large blood specimen is needed for testing What is the difference between an artery and a vein?

Venipuncture (VP), cont.
Methods Vacuum tube: use of evacuated tube (glass or plastic tube containing a vacuum) Fastest Most convenient Most often used Where would you obtain vacuum tubes? 9

Venipuncture (VP), cont.
Butterfly and syringe: for difficult draws Small veins Sclerosed (hardened veins) What would be a reason a patient may have sclerosed veins?

General Guidelines for Venipuncture
Patient Preparation for Venipuncture Provide patient with advance preparation (if required) Most tests require no preparation If the test required preparation, what would it be? 11

Patient Preparation for Venipuncture, cont.
Most common preparation Fasting: Abstaining from food or fluid (except water) for a specified amount of time Usually 12 to 14 hours Avoidance of medication

Patient preparation listed in reference sources Outside laboratory: Laboratory directory Tech support Physician’s Office Laboratory (POL) Instructions included with blood analyzers and testing kits Where would you obtain a laboratory directory?

Ask patient if he has prepared properly before performing VP If patient has not prepared: do not collect specimen Unless directed by physician If VP is rescheduled: review preparation requirements with patient Why would we not want to obtain a specimen on a patient who has not followed the preparation instructions?

Explain VP procedure in an unhurried and confident manner Helps reduce patient fears Relaxes veins Makes procedure easier to perform Less pain for patient How would reducing patient fears relax the veins?

Identification of the patient Avoids collecting specimen on wrong patient Could lead to inaccurate diagnosis and wrong treatment Ask patient to state full name and date of birth Compare with information in patient's chart The MA should always identify himself or herself to the patient. Why is this important?

Instruct patient to remain still Tell patient that a small amount of pain is associated with procedure NEVER tell the patient the VP will not hurt Why would you not want to tell the patient the procedure will not hurt?

Just before inserting needle: Tell patient he will "feel a small stick" Avoids startling patient: could cause patient to move Movement causes pain Could damage VP site If a patient asks what tests are being run, how would the MA respond?

Patient Position of Venipuncture
Important to a successful collection Proper positioning: Allows easy access to vein More comfortable for patient Position depends on vein being used Fainting can occur. How can you help prevent injury? 19

Patient Position of Venipuncture, cont.
Most common VP site: antecubital space Patient should be seated in chair Arm extended in downward position To form straight line from shoulder to wrist With palm facing up Arm should not bend at elbow Where would you find the antecubital space? 20

Antecubital Space

Arm should be well supported on armrest: By rolled towel By patient placing fist of the other hand under elbow Why is it important to support the arm?

Never have patient on stool or standing Fainting could occur: patient may be injured If patient has fainted in the past from VP or is nervous: Place in semireclining position on examining table Why might a patient faint during this procedure?

Venous reflux: blood flows from evacuated tube back into patient's vein during procedure Could cause patient to have adverse reaction to a tube additive Particularly ethylenediaminetetraacetic acid (EDTA) To prevent: keep patient's arm in a downward position Evacuated tube remains below the VP site Fills from the bottom up What are some symptoms of venous reflux? 24

Application of the Tourniquet
Purpose: makes patient's veins stand out so they are easier to palpate Causes venous blood to slow down and pool in veins in front of tourniquet Makes veins more prominent More visible Can be palpated Tourniquets can be made of latex. Make sure the patient is not allergic to latex. Use latex-free tourniquet.

Application of the Tourniquet, cont.
When applying: important to obtain correct tension Should slow venous flow without affecting arterial flow Too tight: obstructs both arterial and venous flow May produce inaccurate test results How would you know if the tourniquet is too tight?

Too loose: veins will not stand out enough to be palpated Correct tension: Should fit snugly Not pinch skin If the tourniquet is too loose, what would you do?

Guidelines for Applying the Tourniquet Do not apply over sores or burned skin Place 3 to 4 inches above bend in elbow Allows adequate room for: Cleansing site Performing VP Why would you not want to apply over areas with sores or burned skin?

Apply tourniquet so that it is snug Should not pinch patient's skin Should not be painful to patient Ask patient to clinch fist: pushes blood from lower arm into veins for easier palpation Ask patient to clench and unclench fist a few times Avoid vigorous pumping: could lead to hemoconcentration What is hemoconcentration?

Never leave on for more than 1 minute Uncomfortable for patient Causes venous blood to stagnate: venous stasis Plasma filters into tissues: causes hemoconcentration

Hemoconcentration: An increase in the concentration of blood components Caused by a decrease in fluid content of the blood Can alter test results

Remove tourniquet when good blood flow is established When first learning venipuncture: best to remove tourniquet just before removing needle May move needle No more blood flow Must redraw Make sure the ends of the tourniquet are not touching the site. 32

Always remove tourniquet before removing needle If needle removed first: blood forced out of puncture site causing a hematoma Hematoma: A swelling or mass of coagulated blood caused by a break in a blood vessel Wipe tourniquet with a disinfectant (alcohol) if reusable Throw away if disposable Have the patient unclench his or her fist before removing the needle. 33

Remove Tourniquet Before Removing Needle

Types of Tourniquets Rubber Tourniquet: flat, soft band of rubber 1 inch wide 15 to 18 inches long Advantage: easily removed with one hand The MA should make sure the tourniquet end is accessible for easy removal. 35

Position: 3 to 4 inches above bend in elbow Should lie flat against' patient's skin Flaps must be directed upward so do not dangle in working area 36

Application of Tourniquet

Velcro-Closure Tourniquet Band of rubber or elastic with Velcro attached at ends Advantage Easier to apply than rubber tourniquet More comfortable for patient Are these types of tourniquets disposable? 38

Disadvantage: More difficult to remove May not fit around arm of obese patients 39

Velcro-Closure Tourniquet

Site Selection for Venipuncture
Best site for most patients: veins in antecubital space Easy to draw blood Patient with large visible veins Difficult to draw blood Small veins Veins that cannot be palpated If a vein cannot be palpated, should the MA still draw blood? 41

Site Selection for Venipuncture, cont.
Antecubital space: surface of arm in front of elbow 42

Antecubital veins: Usually have wide lumen Close to surface of skin Makes them easily accessible 43

Usually have thick walls: Less likely to collapse Skin is less sensitive: less pain for patient Do not use small spidery veins on surface of skin Not suitable for VP Antecubital veins lie beneath these veins Why would a small spidery vein not be suitable for VP? 44

Veins to use in antecubital space: Median cubital: best vein Large vein: does not roll Located in middle of antecubital space Cannot be used: When it lies deep in the tissues: cannot be palpated Is scarred from repeated VPs What does it mean if a vein rolls? 45

Basilic and cephalic: located on opposite sides of antecubital space Use: when median cubital cannot be used Cephalic: located on thumb side of hand Basilic: located on little-finger side of hand Disadvantage: may roll and escape puncture To prevent: Apply firm pressure below vein to stabilize it Locate these sites on your arm. 46

Antecubital Veins

Brachial artery: also located in antecubital space (used to measure blood pressure) Lies deeper in the tissues Artery pulsates, is more elastic, and has a thicker wall than a vein If punctured: patient feels more pain and blood is bright red and comes out pulsing If occurs: Remove tourniquet and then needle Apply pressure with gauze pad for 4 to 5 minutes Why would we not want to use the brachial artery as a site? 48

Guidelines for Site Selection
Guidelines for Site Selection: Facilitates selection of a good vein Ensure adequate lighting Facilitates selection of vein What would happen if you could not find a good vein on a patient for venipuncture? 49

Guidelines for Site Selection, cont.
Ensure that veins "stand out" as much as possible Apply tourniquet Ask patient to clench fist 50

Examine antecubital veins of both arms Patient may have larger veins in one arm than in other Ask patient which vein was previously used for VP Why would the MA want to know which vein was previously used? 51

Use inspection and particularly palpation to select vein Vein does not have to be seen in order to be a good selection Palpation alone can be used to locate a vein Vein feels like an elastic tube Gives under the pressure of the fingertips Follow the vein direction with your fingertip. 52

Palpate for median cubital vein first Advantages over other antecubital veins: Usually bigger Anchored better Bruises less Poses smallest risk of injuring underlying structures (nerves) Define median. (middle) 53

If median cubital cannot be seen but can still be palpated: Use as a first choice If median cubital is good in both arms Select the one that is the fullest 54

Cephalic: second choice Does not roll and bruise as easily as basilic Basilic: last choice May cause injury to underlying structures: In some individuals: branches of median nerve lie close to basilic Lie in close proximity to brachial artery What are the nerves that lie close to these veins? 55

Thoroughly assess vein Place one or two fingertips over vein Index and middle finger Press lightly: then release pressure Do not use thumb to palpate (not as sensitive) Suitable vein: feels round, firm, elastic, and engorged When an engorged vein is depressed and released: Springs back in a rounded, filled state Should the tourniquet be on when assessing the veins? 56

Determine size, depth, and direction of vein Thoroughly palpate vein 57

Trace the path of the vein By rolling index finger back and forth over vein Inspect and palpate vein for problems (a) Small (b) Hard (c) Bumpy (d) Flat Why would you not want to use the areas listed on the slide? 58

Mentally "map" puncture site on patient's arm with skin marks Site may be near freckle, wrinkle, pigmented area Helpful in making stick when vein cannot be seen and can only be palpated Do not leave tourniquet on for more than 1 minute Causes: Patient discomfort Hemoconcentration If you are unsure of the puncture site, what should you do? 59

Techniques to make veins more prominent: Remove tourniquet and have patient dangle arm over side of chair 1 to 2 minutes Tap vein site sharply with index finger and second finger Gently massage arm from wrist to elbow Apply warm, moist washcloth for 5 minutes Why do these techniques make the vein more prominent? 60

Alternative Venipuncture Sites
Alternative sites Inner forearm Wrist area above thumb Back of hand See slide 62 for sites. 61

Alternative Venipuncture Sites

Alternative Venipuncture Sites, cont.
Alternative veins: Smaller than antecubital veins Have thinner walls Use alternative veins when all possibilities at antecubital site have been considered Example: May be able to use butterfly on a small antecubital vein Where would the tourniquet be applied for these sights? 63

Use veins in hands as a last resort: Have a tendency to roll because: Not supported by much tissue Close to the surface of the skin Makes them more difficult to stick Would a patient still make a fist for this site? 64

Abundant supply of nerves in hand Makes procedure uncomfortable for patient Thin walls Make them susceptible to: Collapsing Bruising Phlebitis What is phlebitis and how is it treated? 65

In some patients: hand veins may be only accessible site Examples: Obese patients Elderly patients Do not stick at the junction of a vein. 66

What Would You Do? What Would You Not Do?

Types of Blood Specimens
Type of blood specimen required: depends on type of test to be performed Examples: Serum: required for most blood chemistry studies Whole blood: required for a complete blood count (CBC) What is the difference between serum and whole blood? (See next slides for answers.) 69

Types of Blood Specimens, cont.
Clotted blood: obtained from tube with no anticoagulant Causes blood cells to clot 3. Serum: obtained from clotted blood Allow specimen to stand and then centrifuge it Because tube does not contain an anticoagulant, separates into: Top layer: Serum Bottom layer: Clotted blood cells How does anticoagulant keep the blood from clotting? 70

Whole blood: Obtained from tube containing an anticoagulant to prevent clotting of blood cells Tube must be gently rotated 8 to 10 times after collection To mix anticoagulant with blood Do not shake the tube. 72

Plasma: obtained from whole blood that has been centrifuged Because tube contains an anticoagulant, separates into: Top layer: plasma Middle layer: buffy coat (white blood cells and platelets) Bottom layer: red blood cells (RBCs) What does centrifuging mean? 73

OSHA Safety Precautions
To avoid exposure to bloodborne pathogens during VP Wear gloves. Wear a face shield (or mask and eye protection): Whenever splashes, spray, splatter, or droplets of blood may be generated. Where would you dispose of your gloves if soiled with blood? 75

OSHA Safety Precautions
Perform all procedures involving blood in a manner to minimize splashing, spraying, splattering, and generating droplets of blood. Bandage cuts before gloving. Sanitize hands after removing gloves. If hands or other skin surface comes in contact with blood: Wash with soap and water immediately. Why is it important to bandage cuts before gloving? 76

OSHA Safety Precautions, cont.
If mucous membranes come in contact with blood Flush with water immediately Do not break, bend, or shear contaminated venipuncture needles. Do not recap contaminated venipuncture needle. Why would you not want to recap venipuncture needles? 77

Locate the sharps container as close as possible to the area of use Immediately after use: discard VP setup in biohazard sharps container Why should the sharps container be located close to your workstation? 78

Place blood specimens in containers that prevent leakage during collection, handling, processing, storage, transport, and shipping. If exposed to blood: report incident immediately to your physician-employer An incident report needs to be filled out if exposed to blood. 79

Vacuum Tube Method of Venipuncture
Frequently used to collect venous blood specimens Ideal for collecting blood from antecubital veins that are of adequate size To withstand the pressure of the vacuum in the evacuated tube What happens if a vein cannot stand the pressure of the vacuum tube? 80

Vacuum Tube Method of Venipuncture, cont.
Vacuum tube system: Collection needle Plastic needle holder Evacuated tube 81

Vacuum Tube Method of Venipuncture, cont.
Commercially available system: Vacutainer 82

Needle Double-pointed needle with threaded hub
Screws into plastic holder Packaged in sealed twist-apart container Do not use if seal is broken Printed on paper seal: Needle gauge Needle length Why would you not use if seal is broken? 83

Needle, cont. 3. Needle consists of:
Anterior needle: Is longer and has a beveled point Bevel: Facilitate entry into skin and vein Locate a bevel on the needle. 84

Needle, cont. Posterior needle: pierces rubber stopper of evacuated tube Needle has a rubber sleeve: functions as a valve When needle pushed into rubber stopper: sleeve compresses Exposes needle opening Allows blood to enter tube 85

Needle, cont. When tube removed: sleeve slides back over needle opening Closes off opening Stops flow of blood Why is it important for the flow to stop? 86

Needle, cont. 4. Gauge sizes for VP: 20 to 22
21 gauge: most commonly used Length of needle: 1 inch and 1½ inches 87

Needle, cont. Length used: based on individual preference 1 inch:
Less intimidating to patient Offers more control during stick 1½ inch: Allows more room for stabilizing vein 88

Gauge and Length of Needle

Safety-Engineered Venipuncture Devices
OSHA stipulates requirements To reduce needlestick and other sharps injuries among healthcare workers Employers must evaluate and implement safer medical devices Includes safety-engineered VP devices Proper use of the medical device allows for safer surroundings for the MA. 90

Safety-Engineered Venipuncture Devices, cont.
Have a built-in safety features To reduce risk of needlestick injuries The MA should hear a click when this safety feature is activated. 91

Plastic Holder Consists of plastic cylinder with two openings
Small opening: used to secure needle Large opening: holds evacuated tube 92

Plastic Holder, cont. Flange: extension on large opening
Assists in insertion and removal of tubes Prevents holder from rolling when placed on a flat surface Why is it important to use the flange when inserting and removing tubes? 93

Plastic Holder, cont. Indention on holder
Marks point at which posterior needle starts to enter rubber stopper of tube Do not insert tube stopper past this point before entering vein Causes tube to fill with air Blood is not able to enter the tube The tube should lay in plastic holder until the needle enters the vein. 94

Evacuated Tubes Glass tube with rubber stopper
Contains vacuum that creates suction Pulls blood specimen into tube Tube additive must not: Alter blood components Affect laboratory test 95

Evacuated Tubes, cont. Color-coded for easy identification of additive
Red: does not contain an anticoagulant Used to obtain clotted blood or serum Serum required for: Serologic tests Most blood chemistries 96

Evacuated Tubes, cont. Lavender: EDTA (anticoagulant)
Used to obtain whole blood or plasma Most common use: collect a blood specimen for a CBC What does CBC stand for? 97

Evacuated Tubes, cont. Light blue: sodium citrate (anticoagulant)
Used to obtain whole blood or plasma Most common use: coagulation tests (e.g., prothrombin time) What is prothrombin time? 98

Evacuated Tubes, cont. Green: heparin (anticoagulant)
Used for blood gas determinations and pH assays Gray: sodium fluoride/potassium oxalate (anticoagulant) Used to obtain whole blood or plasma Most common use: glucose tolerance test Why is a blood gas obtained? What is a glucose tolerance test used for? 99

Evacuated Tubes, cont. Dark blue: heparin or no additive
Made of refined glass and special stopper Used to detect trace elements (e.g., lead, arsenic) Define heparin. 100

Evacuated Tubes

Evacuated Tubes, cont. 5. Additive tube used depends on type of test performed MA must determine correct stopper color Example: CBC requires lavender stoppered tube Do not substitute one additive tube for another Leads to inaccurate results How would the MA determine the correct tube to use? 102

6. Tubes available in different sizes: 2, 3, 5, 7, 10, and 15 ml
Size selected: depends on the amount of specimen required for the test Information on amount of specimen and stopper color required Outside laboratory: indicated in laboratory directory POL: indicated in instructions accompanying blood analyzer or testing kit

Evacuated Tubes, cont. 8. Label of tube and vacuum tube box indicates:
Additive content Expiration date Tube capacity Fill indicator -To indicate when vacuum has been exhausted: tube is full Why is it important to fill the tube to its capacity? Why is it important to check the expiration date? 104

Hemogard Closure Tubes
Newer type of evacuated tube Consists of: Plastic closure that fits over a rubber stopper and overhangs outside of tube When top removed: Reduces likelihood of contacting contents of tube Reduces splattering of blood See slide 107. 105

Hemogard Closure Tubes, cont.
Regular evacuated tube: pops as top is removed May result in splattering of blood Tube made of plastic: reduces possibility of tube breakage Color coding is similar to rubber-stoppered tubes See slide 107. 106

Hemogard Closure Tubes

Order of Draw for Multiple Tubes
Blood culture tube Drawn first to prevent contamination by other tubes How would other tubes contaminate a blood culture tube? 108

Order of Draw for Multiple Tubes, cont.
Coagulation tubes (light blue) Prevents additives from other tubes from getting into tube If butterfly used to collect specimen: modification in technique required Butterfly tubing: contains air If blue tube is first or only tube drawn Must draw 5-ml red tube first and discard What would the MA do with the tube that is meant to be discarded? 109

Some of tube's vacuum: exhausted by air in tubing Results in underfilling tube Underfilled tube: results in incorrect anticoagulant to blood ratio When performing coagulation test Causes inaccurate result a) To prevent: draw a red tube first and discard 110

Serum tubes Includes: Tubes with or without a clot activator (red-stoppered) Serum separator tubes (SST) (red/slate gray stoppered) Prevents contamination of nonadditive tubes by tubes with an anticoagulant Why do we need to centrifuge a serum separator tube? 111

Anticoagulant tubes in this order: Green Lavender Gray Prevents cross-contamination between different types of anticoagulants Cross-contamination: may lead to inaccurate test results Tubes should be lined up for order of draw when the MA is performing venipuncture. 112

What Would You Do? What Would You Not Do?

Evacuated Tube Guidelines
Select proper tubes According to tests being performed Amount of specimen required 115

Evacuated Tube Guidelines, cont.
Check tubes for cracks: will no longer have a vacuum Check expiration date: outdated tube may not have a vacuum 116

Label tube with: Patient's name, date, MA's initials Avoids mixing up specimens Office may use bar codes to identify specimens 117

Powdered additive tubes (gray-stoppered tube) Gently tap tube just below stopper Dislodges additive from stopper If additive is trapped in stopper - Could cause erroneous test results 118

6. Take precautions to avoid premature loss of vacuum Can be caused by: Dropping tube Pushing posterior needle through stopper before puncturing vein Partially pulling needle out of patient's arm during VP Should the MA have extra tubes available in case of premature loss of vacuum?

7. To make puncture: Use a continuous steady motion At a 15-degree angle to patient's skin The bevel must be facing up. 120

Do not use: Slow timid motion Painful to patient Rapid, jabbing motion Could cause needle to go through vein resulting in: 1) Failure to obtain blood 2) Hematoma 121

Follow proper order of draw to prevent: Contamination of nonadditive tubes with additive tubes Cross-contamination between different types of additive tubes Leads to inaccurate test results 122

Fill tubes until vacuum is exhausted Blood ceases to flow into tube Tube will be almost, but not quite full If tube removed before vacuum exhausted Rush of air enters tube Damages RBCs Tube with anticoagulant: ensures proper ratio of additive to blood What would you do if the blood stopped flowing before the tube was full? 123

Remove last tube from plastic holder before removing needle from vein Prevents blood from dripping out of needle after withdrawing it Use the flange to withdraw the tube. Why is this important? 124

Mix tubes containing anticoagulant immediately after drawing Rotate tube gently 8 to 10 times Provides adequate mixing without causing hemolysis Hemolysis: the breakdown of blood cells Shaking tube: can result in hemolysis 125

Rotate Tube with Anticoagulant

Clotting of blood can be caused by: Not mixing tubes immediately Inadequate mixing May cause inaccurate test results 127

After VP: top of stopper may contain residual blood Follow OSHA standard when handling tubes How would you handle a tube that has blood on the stopper? 128

Butterfly Method of Venipuncture
Also called winged infusion method Winged infusion set: used to perform the procedure Term 'butterfly': derived from plastic wings located between needle and tubing 129

Butterfly Method of Venipuncture
Advantages: Provides better control when making puncture Less pressure exerted on vein from evacuated tube Pressure must travel through a length of tubing Minimizes pressure on vein Describe why you have better control.

Butterfly Method of Venipuncture, cont.
4. Recommended for: Adult patients with small antecubital veins Children: typically have small antecubital veins When antecubital veins not available Alternative site is used (e.g., hand) May occur with elderly or obese patients 131

Butterfly Method of Venipuncture, cont
5. Alternative sites Veins are smaller Have a thin wall More likely to collapse

6. Gauge of needle: 21 to 23 7. Length of needle: ½ to ¾ inch Needle: short and sharp Makes it easier to stick difficult veins 133

8. For an extremely small vein: Use a 23-gauge needle To prevent rupture of vein Use smaller volume tube (2 ml) Large tube: too much vacuum pressure on vein Vein may collapse Show difference in gauges. 134

9. Needle attached to tubing Tubing lengths: 6 inch 12 inch Tubing must be extended to prevent kinks. 135

10. Adapters for winged infusion sets: Luer adapter: attached to posterior needle Plastic holder screwed onto Luer adapter Hub adapter: used to attach a syringe 136

Adapters for Winged Infusion Set

11. Safety needles available Shield that covers contaminated needle In the pictures on the slide, the yellow cover is pushed forward over the needle. 138

Guidelines for the Butterfly Method
Patient position Antecubital, wrist, and forearm veins Arm in straight line from shoulder to wrist 139

Guidelines for the Butterfly Method, cont.
Hand veins Hand on armrest Have patient make a loose fist or grasp a rolled towel Causes hand veins to stand out Locate vein between knuckles and wrist bones 140

Position of tourniquet Forearm or wrist: 3 inches above site Hand: just above wrist bone 141

Compress plastic wings together Insert with bevel up At 15-degree angle to skin After entering vein: decrease angle to 5 degrees Why compress the plastic wings together? Why decrease to 5 degrees? 142

Insertion of Needle

Slowly thread needle inside vein an additional ¼ inch Anchors (seats) needle in center of vein Can use both hands to change tubes To prevent venous reflux: Keep tube and holder in a downward position Ensures that tube fills from bottom up When holding the holder down, make sure not to pull the needle out of the vein. 144

Follow proper order of draw (same as for vacuum tube method) 145

Syringe Method of Venipuncture
Least used method a. Amount of blood collected limited by size of syringe b. Blood specimen must be transferred from syringe to evacuated tube Requires an additional step 2. Used to obtain blood from small veins May collapse if vacuum tube method used Explain the transfer process to the class. 146

Syringe Method of Venipuncture, cont.
Offers more control than other methods Rate of blood flow not dictated by tube vacuum 147

Once vein is entered: specimen obtained by pulling back on plunger of syringe Pull plunger slowly: minimizes pressure against vein Vein is less likely to collapse It is important to stabilize hand holding the syringe to prevent pulling the needle out of the vein while pulling back on the plunger. 148

Set Up: Disposable needle and syringe Needle gauge: 21 to 23 Needle length: 1 to 1½ inches 149

Capacity of syringe depends on amount of specimen required Ranges from 5 ml to 20 ml (cc) If more than 20 ml needed: must perform a second VP 150

After collection: transfer specimen to evacuated tube OSHA requires a needleless device for the transfer Order of fill: Same as order of draw for vacuum tube method Tubes with additives: gently rotate 8 to 10 times immediately after filling 151

Problems Encountered with Venipuncture
Failure to Obtain Blood May occur with: Obese patients: May have small superficial veins Suitable vein: buried deep in adipose tissue What is adipose tissue? 152

Failure To Obtain Blood, cont.
Elderly patients with arteriosclerosis: May have thick and hard veins Difficult to puncture Small or thin-walled veins: May collapse What is arteriosclerosis? 153

After two unsuccessful attempts: Ask for assistance in obtaining blood specimen 154

Failure to obtain blood once needle has been inserted: Not inserting needle far enough Prevents needle from entering the vein 155

Inserting needle too far: causes needle to go through vein Bevel opening becoming lodged against wall of vein 156

Remove needle if blood not obtained Do not probe vein Uncomfortable for patient May affect integrity of blood specimen - Leads to inaccurate test results 157

Occasionally: evacuated tube may lose its vacuum Cause: Manufacturing defect Improper handling of tube Action: Remove tube and insert another one Have extra tubes available. 158

Inappropriate Puncture Sites
Patient complains of pain or soreness at a potential site Avoid site Do not use areas that are: Scarred Bruised Burned Adjacent to areas of infection What other conditions might a patient have that require avoidance of the site? 159

Inappropriate Puncture Sites, cont.
Avoid an arm with edema Makes it difficult to locate a vein Takes longer for puncture to heal Avoid arm to which a cast is applied Avoid arm on the same side of a radical mastectomy 160

Scarred and Sclerosed Veins
Caused by: Many venipunctures over period of years Scar tissue: develops in wall of vein Elderly patients with arteriosclerosis Veins become thickened 161

Scarred and Sclerosed Veins, cont.
Veins feel stiff and hard Difficult to stick Blood return may be poor Caused by narrowed lumen 162

Scarred and Sclerosed Veins, cont.
Recommended: use another vein If not possible: Insert needle with careful pressure To avoid going through vein 163

Rolling Veins Side veins have a tendency to roll Cephalic Basilic
2. To prevent rolling: Apply firm pressure with thumb: Apply the pressure to the side of the vein and below vein Stabilizes the vein Keeps thumb out of the way when making puncture Why is it important to keep the thumb out of the way when making the puncture? 164

Apply firm pressure below vein:

Collapsing Veins Most likely to collapse: Small veins
Veins with thin walls 166

Collapsing Veins, cont. Most likely to occur with vacuum tube method
Sucking action of vacuum: causes vein to collapse Blocks flow of blood into tube Result: Small amount of blood enters tube and then stops What would you do if a vein collapsed? 167

Collapsing Veins, cont. Use butterfly or syringe method on patients with small veins Better control Less pressure on vein

Collapsed Vein

Premature Needle Withdrawal
Needle comes out of vein prematurely Caused by Patient movement Improper VP technique 170

Premature Needle Withdrawal, cont.
Blood is forced out of puncture site from pressure of tourniquet Immediate action is required to prevent a hematoma Remove tourniquet immediately Place a gauze pad on site Apply pressure with gauze until bleeding stops Why should the tourniquet be removed immediately? 171

Hematoma Blood leaks from puncture site of the vein into surrounding tissue Results in a bruise 172

Hematoma, cont. Cause: Needle inserted too far and goes through vein
Bevel opening is partially in vein and partially out of vein Applying insufficient pressure after needle removal 173

Cause of a Hematoma

Hematoma, cont. First sign of hematoma: sudden swelling in area around puncture site Remove tourniquet and needle immediately (if needle still in vein) Apply pressure until bleeding stops What would the MA say to a patient who has developed a hematoma? 175

Hemolysis Hemolysis: breakdown of blood cells Blood cells are fragile
Rough handling may cause hemolysis Produces inaccurate test results 176

Hemolysis, cont. To prevent hemolysis: Store tubes at room temperature
Chilled tubes: can result in hemolysis Allow alcohol to air dry completely Alcohol entering specimen: can cause hemolysis Why would you allow the alcohol to air dry instead of drying it with a gauze pad? 177

Hemolysis, cont. Do not use a small-gauge needle to collect specimen
Causes RBCs to rupture as they pass through needle lumen Practice good technique in collecting specimen Always handle blood specimen tube carefully Do not shake or handle roughly How do we mix a specimen that has an additive? 178

Fainting VP may cause dizziness or fainting
May occur during or after VP If a patient has fainted previously during venipuncture, what should the MA do before performing the procedure? (lay the patient down) 179

Fainting, cont. What to do Protect patient from injury
Example: prevent patient from falling Place patient in position that promotes blood flow to brain Notify physician for further treatment 180

Treatment for Fainting

Obtaining a Serum Specimen
Serum: plasma from which the clotting factor fibrinogen has been removed Serum contains dissolved substances: Glucose Cholesterol Lipids Sodium What are lipids? 182

Serum, cont. Potassium Chloride Antibodies Hormones Enzymes 183

Serum, cont . Many laboratory tests require a serum specimen
To determine if substances are within normal range To detect any substances that are not normally present Give an example of a lab test that requires a serum specimen. 184

Tube Selection To collect serum
Tube with no anticoagulants (red-stoppered) 185

Tube Selection, cont. Serum recovered: only part of total blood specimen Must use a tube that is 2½ times amount required for test Example: To obtain 2 ml of serum, must use a 5-ml tube Must use a 5-ml red-stoppered tube (2 x 2½) 186

Serum in Red Tube

Preparation of the Specimen
Allow tube to stand upright at room temperature for 30 to 45 minutes Allows clot formation: yields more serum Where would you have the specimen in the office during this time? 188

Preparation of the Specimen, cont.
If centrifuged immediately: Clotting factors do not have time to settle into cell layer Result: formation of a fibrin clot in serum layer Spongy substance that occupies space Interferes with adequate serum collection 189

Preparation of the Specimen, cont.
Do not let blood stand for more than 1 hour Leaching of substances from cell layer into serum Leads to inaccurate test results What exactly does leaching mean? 190

Removal of Serum After allowing specimen to stand: centrifuge specimen
191

Removal of Serum, cont. Remove serum with a pipette and place in transfer tube Do not disturb cell layer of the clot Draws RBCs into serum layer If cells enter serum: recentrifuge specimen What PPE would the MA need for this procedure? What is a pipette? 192

Removing Serum

Removal of Serum, cont. Hold serum up to light to:
Inspect for presence of: Intact RBCs Hemolyzed blood Describe what you would see if intact RBCs were present. 194

Inspect Serum

Removal of Serum, cont. After centrifuging intact RBCs:
If present: specimen has a reddish appearance Must recentrifuge After centrifuging intact RBCs: Cells settle to bottom of tube Serum can be removed 196

Removal of Serum, cont. After centrifuging hemolyzed blood:
Serum will still have a reddish appearance RBCs have ruptured Releases hemoglobin into serum Not suitable for laboratory tests: inaccurate test results Must collect another specimen What would you say to a patient who had to be retested? 197

Serum Separator Evacuated Tubes (SST)
Facilitates collection of serum specimen Identified by red and slate-gray stopper 198

Serum Separator Evacuated Tubes (SST)
Used for collection and separation of blood Thixotropic gel in bottom of tube 199

Serum Separator Evacuated Tubes (SST), cont.
Blood collected and placed upright for 30 to 45 minutes: allow for clot formation During centrifugation: Gel temporarily becomes fluid Moves to dividing point between serum and clotted cells Re-forms into a solid gel Serves as a barrier between serum and clot Why is it important to centrifuge a specimen for the proper length of time? 200

Gel Forms a Barrier

Serum Separator Evacuated Tubes (SST), cont.
Serum can be transported in SST Inspect tube carefully To make sure gel barrier firmly attached to glass wall If a complete barrier has not formed: Remove serum: place in transfer tube Prevents leaching of substances from cell layer into serum (leads to inaccurate test results) How would you transfer the serum to the transfer tube? 202

Obtaining a Plasma Specimen
Plasma: The liquid portion of blood Consists of a straw colored fluid Makes up 55% of the blood volume 203

Obtaining a Plasma Specimen, cont.
Transports substances through body Blood cells are suspended in plasma Are circulated through the body 204

Plasma, cont. Composition of plasma: Carried to and from tissues
Water: 92% Dissolved solid substances: 8% Carried to and from tissues 205

Plasma, cont. Solutes present in plasma
Plasma proteins: serum albumin, globulins fibrinogen, prothrombin Serum albumin: regulates volume of plasma in the blood vessels Globulins: play role in immunity mechanism of body Fibrinogen and prothrombin: needed for proper blood clotting 206

Plasma, cont. Electrolytes: sodium, chloride, potassium, calcium, phosphate, bicarbonate, magnesium For normal cell functioning Maintenance of normal fluid and acid-base balance 207

Plasma, cont. Nutrients from breakdown of food substances: glucose, amino acids, lipids Nourish body tissues Waste products: urea, uric acid, lactic acid, and creatinine Are excreted from body 208

Plasma, cont. Respiratory gases: carbon dioxide and small amount of oxygen Substances that regulate and control body functions Hormones Antibodies Enzymes Vitamins 209

Tube Selection To obtain a plasma specimen
Must use a tube with an anticoagulant Check laboratory directory: to determine color of stopper Separating plasma from whole blood Use same procedure as for separating serum from whole blood Label transfer tube: plasma What would you write on the label? 210

Preparation and Removal of the Specimen
Collect 2½ times amount required for test Tap tube with powdered anticoagulant just below stopper: Releases anticoagulant from stopper Allow specimen to fill to exhaustion of vacuum Ensures proper ratio of anticoagulant to blood Ensures accurate test results Why collect 2½ times as much? 211

Preparation and Removal of the Specimen, cont.
Gently rotate tube 8 to 10 times immediately after drawing To mix anticoagulant with blood Centrifuge 10 to 15 minutes (does not need to stand) Packs cells and causes separation of blood into: Plasma Buffy coat RBCs What is the buffy coat? 212

Preparation and Removal of the Specimen, cont.
6. Separating plasma from blood Use same procedure as for serum 213

Skin Puncture Used to obtain capillary blood specimen
Also called capillary puncture A capillary is a minute blood vessel that is finer than hair. 214

Skin Puncture, cont. Testing done at medical office Examples of tests
Hemoglobin Hematocrit Blood glucose Mononucleosis Prothrombin time Why are these tests performed? 215

Skin Puncture, cont. Skin puncture performed when:
Test requires small amount of blood Preferred for infants and young children Venipuncture is difficult to perform on these age groups Adult has no acceptable veins (as a last resort) PKU is performed on infants. What is PKU for? 216

Skin Puncture, cont. Before collecting specimen: Select puncture site
Select skin puncture device Obtain proper microcollection device 217

Puncture Site Fingertip: preferred for adult Third or fourth finger
Earlobe is no longer recommended Blood in earlobe contains a higher concentration of hemoglobin than fingertip Slower flow of blood: makes it harder to collect specimen Why is it not recommended to use other fingers than the third and fourth? 218

Puncture Site, cont. Plantar surface of heel: infant (birth to 1 year)
Never perform finger puncture on an infant Amount of tissue between skin and bone is small Injury to bone is likely After child is walking Can perform on fingertip Where is the plantar surface of the heel located? 219

Skin Puncture Devices Types Depth of puncture
Disposable semiautomatic retractable lancet device Reusable semiautomatic retractable lancet device Depth of puncture Adults: must not be deeper than 3.1 mm Infants and children: must not be deeper than 2.4 mm How would you cleanse the reusable device? 220

Skin Puncture Devices, cont.
If puncture is too deep: may penetrate bone Could result in: Osteochondritis: inflammation of bone and cartilage Osteomyelitis: inflammation of bone due to bacterial infection To prevent: Use spring-loaded blade available in different lengths To control the depth of the puncture How are these conditions treated? 221

4. Blade length selected Based on: Size of patient’s fingers Amount of blood specimen required 222

Shorter blade Adults with thin fingers Children When only a drop of blood required b. Longer blade To obtain enough blood to fill a microcollection device

5. OSHA recommends: retractable lancets To reduce sharps injuries Where would these devices be disposed of?

Disposable Semiautomatic Lancet
Spring-loaded plastic holder Metal blade is inside holder 225

Disposable Semiautomatic Lancet, cont.
Different length blades available: To control depth of the puncture Plastic holder conceals blade: Protects MA from accidental needlestick Patient cannot see blade during puncture Results in less apprehension Should you let the patient know how this will feel and the sound that will be heard? Why or why not? 226

Disposable Semiautomatic Lancet, cont.
To perform puncture: Lancet device placed on patient's skin Device is activated Blade is forced into skin by spring Blade retracts into the holder Lancet device is discarded into biohazard sharps container Place lancet firmly against the skin for proper puncture. 227

Disposable Lancet

Reusable Semiautomatic Lancet
Wide variety available Not all appropriate for use in medical office Safest type: the part that may become contaminated is retractable and disposed of easily Reduces risk of sharps injuries 229

Reusable Semiautomatic Lancet, cont.
Glucolet II: plastic, spring-loaded holder and a lancet/endcap Plastic holder is reusable Lancet is disposable How would you load the lancet? 230

Reusable Semiautomatic Lancet, cont.
To perform puncture: Lancet/endcap placed on skin Release button depressed Blade is forced into skin by spring Blade retracts into the endcap Lancet/endcap removed: discarded into biohazard sharps container How would you remove? 231

Reusable Lancet Device

Microcollection Devices
Specimen may be placed directly onto a reagent strip Example: blood glucose monitors May be collected with microcollection device Device used depends on laboratory equipment being used Examples: Capillary tubes Microcollection tubes If placing on a strip, why should you not touch the finger to the strip? 233

Capillary Tubes Consists of disposable glass or plastic tube
Depending on size: can hold 5 to 75 microliters of blood Used for hematocrit determination 234

Microcollection Tubes
Small plastic tube with removable blood collector tip Tip designed to collect capillary blood from skin puncture After collecting specimen: Collector tip removed, discarded and replaced by plastic plug See tube in slide Describe how tip is used to collect blood specimen. 235

Microcollection Tubes, cont.
Available with or without additives Plugs color-coded to correspond with evacuated tube VP system 236

Guidelines for Performing a Finger Puncture
If laboratory test requires advance preparation: Verify that patient prepared properly Patient should be seated comfortably in a chair Arm firmly supported Palm facing up Why is the palm facing up? 237

Guidelines for Performing a Finger Puncture, cont.
Instruct patient to remain still Just before making puncture: Tell patient a small stick will be felt Avoids startling patient: may cause patient to move The MA should secure the finger in case the patient flinches. 238

Use lateral part of tip of third or fourth finger of nondominant hand Capillary bed is large Skin is easy to penetrate Puncture site should be free of: Lesions Scars Bruises Edema Why should the nondominant hand be used? 239

Do not use index finger Skin is more callused: harder to penetrate Patient uses index finger more: will notice pain longer Do not use little finger Amount of tissue between skin surface and bone is small -Could result in injury to bone Which finger is considered the index finger? 240

Site may be warmed: increases blood flow Gently massage finger from base to tip Place hand in warm water Chemical packs are also available to warm puncture sites. 241

Cleanse site with antiseptic wipe and allow it to dry thoroughly If alcohol is not dry: Round drop of blood does not form on the finger Blood leaches out on patient's skin: difficult to collect Alcohol can enter blood specimen Leads to inaccurate test results Patient experiences a stinging sensation during puncture Why would you not fan the site? 242

Firmly grasp finger in front of most distal knuckle joint Apply enough pressure to cause fingertip to become hard and red Ensures adequate penetration and depth of puncture Select the site Make puncture in fleshy portion of fingertip Slightly to the side of center 243

Guidelines for Performing a Finger Puncture
Do not puncture side or very tip of finger To prevent injury to the bone Position blade perpendicular to lines of fingerprint (not parallel) Facilitates formation of well-formed drop of blood that is easy to collect If not perpendicular Blood flow follows lines of fingerprint: runs down finger a) Difficult to collect 244

Fingertip Puncture Sites

Perform the puncture Firmly press lancet device against puncture site Activate spring-loaded device If not enough pressure applied Puncture not deep enough - Poor blood flow results May need to puncture patient again Where is the activation button located? 246

d. With a good puncture: blood flows freely e. Deep puncture hurts no more than superficial one

Wipe away first drop of blood with gauze pad Diluted with alcohol and tissue fluid Not a suitable specimen: could cause inaccurate test results Where would you discard the gauze after wiping away the blood? 248

Allow large drop to form by applying gentle pressure near puncture Can massage the tissue surrounding the puncture site to promote blood flow Do not squeeze excessively: causes dilution of specimen with tissue fluid May lead to inaccurate test results Collect specimen Using appropriate microcollection device Describe massaging the site. 249

Check site to make sure bleeding has stopped Apply adhesive bandage if needed What instructions would you give to the patient regarding lab results? 250

POSTTEST True or False Venous reflux can be prevented by filling the evacuated tube to the exhaustion of the vacuum. If the tourniquet is applied too tightly, inaccurate test results may occur. The median cubital vein is the best vein to use for venipuncture. Upon standing, a blood specimen to which an anticoagulant has been added separates into plasma, buffy coat, and blood cells. Whole blood is obtained by using a tube containing an anticoagulant. 251

POSTTEST, CONT. True or False
An evacuated glass tube with a lavender stopper contains EDTA. A red stoppered tube is used to collect a blood specimen for most blood chemistries. Not filling a tube to the exhaustion of the vacuum can result in hemolysis of the blood specimen. If the needle is removed from the arm before removing the tourniquet, the evacuated tube will not fill completely. If a fibrin clot forms in the serum layer of a blood specimen, it will lead to inaccurate test results. 252

CHAPTER 17 PHLEBOTOMY.

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CHAPTER 17 PHLEBOTOMY.

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