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Chapter 15 Specimen Collection And Laboratory Procedures

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Title: Chapter 15 Specimen Collection And Laboratory Procedures


1
Chapter 15 Specimen Collection And Laboratory
Procedures
2
Microscope
  • One or more lense that makes an enlarged image of
    an object.

3
Compound Microscope
  • Lets light pass through an object and then
    through two or more lenses.

4
Oculars
  • The ocular lens, also known as the eyepiece lens,
    is the part of a compound microscope that a user
    looks into to see a magnified image. It is a
    see-through double convex lens curved to cause
    images to appear larger. 
  • Monocular microscope has one eyepiece
  • Binocular microscopes have two

5
Objectives
  • The objectives are screwed into a circular
    revolving nosepiece that is revolved by hand

6
Objectives
  • Objectives are the lens farthest from the eye and
    closest to the specimen
  • A microscope has 3 to 4 objectives
  • 4x, 10x, 40x, 100x
  • Always begin focusing a microscope on the lowest
    power and then move to the next higher power and
    refocus

7
Objectives
  • The 4X objective is used for scanning a slide
  • This is lung tissue(pneumonia) 4X

8
Objectives
  • The 10X objective is used to count cells and to
    scan urine sediment
  • This is the most common objective. ALWAYS START
    WITH THE LOW POWER OBJECTIVE! Low power
    lens gives the widest field of view and makes it
    easier to find the specimen when you look through
    the microscope

9
Objectives
  • The 40X objective is used for red and white blood
    cell counts
  • This is a WBC

10
Objective
  • The 100X has the greatest power and is use to
    identify characteristics for bacteria and blood
    smears
  • Finding the specimen at high power, without first
    centering it in the field of view at low power,
    is nearly impossible.

11
10X, 40X, 100X
12
Stage
  • The stage is the platform that holds the slide to
    be viewed
  • The hole on the stage allows light to enter from
    below, passing through the specimen to the lens
    system

13
Light
  • In order for the microscope to work, light must
    pass upward through the material being viewed and
    into the objective lens

14
How to use a microscope
  • Focusing the microscope is done by moving the
    objective up or down relative to the stage.
    Movement of the stage is controlled by the round
    knobs, on both sides of the microscope
  • This permits resting your arms on the table while
    focusing

15
Course and Fine Adjustments Knobs
  • The coarse adjustment focus knob moves the
    objective quickly(usually the larger knob)
  • It moves the tube and lenses closer and farther
    away from the specimen
  • This knob is used first to bring the specimen
    into focus

16
Course and Fine Adjustments Knobs
  • The fine adjustment knob is used to fine-tune the
    focus of your specimen after using the coarse
    adjustment knob.
  • It moves the objective much more slower with only
    a short distance. Focus slowly. It is easy
    to focus right past the correct focus point if
    you are going too fast. 

17
Eyepiece Adjustment
  • When using a binocular microscope, it is
    necessary to adjust the eyepieces to your own eye
    span and visual acuity. A gentle push inward or
    pull outward with adjust the distance between the
    eyepieces to accommodate your eye span

18
Light Adjustment
  • The right level of light is essential for a clear
    image.
  • Too little light will obscure details in
    darkness, while too much light will produce a
    blinding glare without the contrast necessary to
    distinguish features.

19
Putting It All Together
  • To focus the microscope for lab work using the
    10X objective
  • Maximum distance between the stage and objective
  • Clamp the slide on the stage
  • Turn on the light
  • Raise the condenser to its highest position
  • Look at the side not through the oculars, rotate
    the low-power-(10X) objective into position
  • Still looking for the side, use the coarse
    adjustment knob, lower the objective until it
    nears the stage or stops

20
Putting It All Together
  • Look through the eyepiece and reverse the
    direction of the course focus adjustment knob
    until the slide comes into focus
  • Adjust the fine focus until you attain the
    clearest possible image
  • Adjust the condenser(light source) until the
    image is clear
  • Slide the specimen with the mechanical knobs(left
    and right, toward or away from you)

21
Key Points
  • Start with the lowest power first
  • Always clip your objective(slide) in the center
    of the light source
  • Use the course adjustment knob(larger knob) to
    focus and move the stage(now you are done with
    this knob)
  • You can use the fine adjustment knob if
    needed(depending on your eyesight)
  • Then you can turn the nosepiece and use a higher
    power objective
  • Never use the course adjustment again(in the
    higher power) This will raise the stage and could
    crush the slide and break the microscope
  • Again only then will you use the fine adjustment
    knob to focus
  • Always put the objective back on the lowest
    power before you remove the slide and before you
    turn off the microscope
  • Cover the microscope

22
Microscope Care
  • The microscope is a delicate, expensive
    instrument that is easily damaged by dust, oil,
    light, and falls
  •  Arm-part of the microscope is the part that you
    carry the microscope with on hand
  • Base-always support the microscope with the other
    hand underneath the base

23
Cleaning the microscope
  • Only clean your microscope lenses when they are
    dirty and only use lens paper
  • Blow dust form the glass with a syringe
  • Clean only the outside surface of the lens
  • Never touch the lens
  • Never substitute the lens paper(this may scratch
    the lens

24
Skin Puncture
  • Dermal puncture or capillary puncture
    venipuncture is the most frequent performed
    phlebotomy procedure.
  • However, because current laboratory instruments
    and procedures enable us to use smaller and
    smaller amounts of blood, obtaining micro samples
    by capillary or dermal(skin) puncture is also
    popular
  • Always use the ring/middle finger

25
Fingerstick Sites
  • When performing a finger-stick, select a site on
    the central, fleshy portion of the ring or middle
    finger
  • The incision should be slightly off the middle of
    the finger and never to close to the nail bed
  • Avoid the index finger due to a large number of
    nerves(more painful)
  • The little(fifth) finger(decrease mass)
  • The thumb is too course
  • (harder to obtain blood)
  • Finger-sticks should not be performed on
  • infants younger than 6 months of age
  • due to the short distance between the
  • finger bone and the skin surface.

26
Skin Puncture
  • Lancets are designed to control the depth of the
    dermal puncture
  • Safety lancets must be used, so that the blade
    retracts after use to prevent needle- stick
    injuries

27
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28
Venipuncture
  • Venous  venipuncture surgical puncture of a
    vein
  • Phlebotomy Chair
  • For all blood collection procedures, the patient
    should be lying down or seated in a phlebotomy
    chair
  • In an outpatient setting, lock the arm mechanism,
    this prevents the patient from falling if the
    patient faints
  • It is critical to make the patient safe and
    comfortable during the procedure

29
Tourniquets
  • Tourniquets are used to help pool the blood in
    the veins, causing the veins to enlarge
  • In addition, the pooling of veins make it easier
    for the vein to tolerate the vacuum suction of
    the tubes withdrawing blood
  • Place the tourniquet on the patients upper arm,
    about 3 inches above the elbow
  • Ask about latex allergies
  • Disinfect the tourniquets with 70 alcohol after
    ever use
  • Never leave a tourniquet on longer than 1
    minute(this can also alter blood test results)
  • If it is necessary to wait longer than a minute,
    remove the tourniquet and reapply it when ready
  • ALWAYS remove the tourniquet before removing
  • the needle from the vein(this will cause a
  • hematoma)

30
Venipuncture
  • Venipuncture method as called phlebotomy, take
    blood directly from a vein, most commonly
  • in the antecubital area
  • of the arm
  • The inner arm at the
  • bend of the elbow

31
Venipuncture
  • The vein used most often are the
  • Median cubital vein
  • Cephalic vein
  • Basilic vein
  • Other sites
  • sometimes used
  • are the lower
  • forearm, back of
  • hand and wrist

32
Antiseptics
  • 70 percent alcohol wipes(most common)
  • Alcohol prevents the introduction of
    microorganisms into the body during venipunture
  • It is critical when using alcohol to allow the
    alcohol to completely air dry
  • Betadine is the other antiseptic commonly used
    for blood alcohol levels, blood cultures, and
    blood donations

33
Butterfly Winged Infusion Collection Set
  • The butterfly winged infusion device consists of
    needle with plastic wings,
  • plastic tubing, and an adapter
  • Its easy-to-grasp and flexible
  • It can be attached to either
  • a needle holder or a syringe
  • The needle gauge is usually 19 to 23 gauge and ¾
    of an inch long
  • This can be helpful when collecting a specimen
    from a neonate, child, elderly, cancer patient,
    or severely traumatized patient

34
Butterfly Winged Infusion Collection Set
  • The butterfly winged infusion device consists of
    needle with plastic wings, plastic tubing, and an
    adapter
  • Its easy-to-grasp and flexible
  • It can be attached to either
  • a needle holder or a syringe
  • The needle gauge is usually 19 to 23 gauge and ¾
    of an inch long
  • This can be helpful when collecting a specimen
    from a neonate, child, elderly, cancer patient,
    or severely traumatized patient

35
Butterfly Utilizing Tube System
  • When using a butterfly needle with an evacuated
    tube, use a 10 to 15 degree angle, this is
    slightly lower than the standard needle
  • With a butterfly set you can grasp the butterfly
    by the wings(easy to grasp)

36
Butterfly Winged Infusion Collection Set
  • When using a butterfly needle, you
  • will know when the needle has
  • entered the vein because you will
  • observe a flash of blood on the
  • shaft of the tubing
  • Patients may request the butterfly needle,
    because the length of the needle is shorter and
    looks smaller
  • Inform the patient that the gauge is about the
    same, therefore, there should no difference in
    pain with the two needles

37
Hematoma
  • Venipuncture must be always be done carefully to
    avoid causing an hematoma(collection of blood
    just under the skin)
  • To prevent a hematoma
  • Puncture only the uppermost wall of the vein
  • Remove the tourniquet before removing the needle
  • Use the major superficial veins
  • Make sure the needle fully penetrates the upper
    most wall of the vein. (Partial penetration may
    allow blood to leak into the soft tissue
    surrounding the vein by way of the needle bevel)
  • Apply pressure to the venipuncture site

38
Methods Of Performing A Venipuncture
  • There are two methods of performing this
    procedure
  • Syringe method
  • Needle and vacuum tube method

39
Syringe Draw
  • A syringe is a plastic barrel and plunger set
    that is manually pulled to control the flow of
    blood
  • Syringes come variety of sizes 10 mL an 20 mL
    are the most commonly used in the venipuncture
    procedure(do not use any larger or smaller
    syringe)
  • Prior to attaching the syringe it is important to
    prime the syringe. Pull the plunger in and out
    of the syringe to ensure it moves smoothly
  • It is critical that the plunger be pushed back
    into place before beginning the phlebotomy
    procedure to avoid injecting air into the
    patients vein
  • You can control the rate at which the blood is
    being withdrawn
  • You should observe the vein during the procedure
    and make any adjustments to the rate of
    collection as needed (collapsed vein)
  • Once the blood has been collected in the syringe,
    you must engage the needle safety mechanism,
    remove the needle, and replace it with a transfer
    device before transferring the blood to the
    tubes. Allow the tubes to fill without applying
    pressure(this will hemolysis the blood)

40
Hemolysis
  • Hemolysis is the breakdown of red blood cells.
  • This can cause alterations to blood test results
    and give an inaccurate reading
  • Hemolyzes blood samples are generally discarded
  • Causes
  • An improper choice in the venipuncture site
  • Prolonged tourniquet time
  • Cleansing the venipuncture site with alcohol and
    not allowing the site to dry
  • Pulling the plunger of a syringe back too fast
  • Transferring into a tube by pushing down on the
    syringe plunger in order to force blood into a
    tube
  • Vigorous mixing or shaking of a specimen
  • Having the patient pump their hand

41
Vacuum Method
  • This method is probably the most popular because
    it is so convenient

42
Gauge for Venipuncture
  • Gauge average size for venipuncture needles is 21
    or 22 gauge in size

43
Blood Collect Tubes
  • A variety of different tubes are required when
    performing venipuncture. Tubes vary in size,
    volume, and additives
  • The color of the rubber stopper located at the
    top of the tube indicates what additive is found
    in the tube
  • Many tubes contain an anticoagulant, a chemical
    that interferes with the clotting process and
    prevents a clot from being formed in the tube

44
Blood Collect Tubes
  • These tubes have a vacuum a specified amount of
    air has been taken out by the manufacturer so
    that when the tube is pierced by the needle, the
    tube will fill with a predetermined amount of
    blood
  • This ensures that only the proper amount of blood
    enters the tube

45
Order Of Draw
  • When several blood specimens are ordered, they
    should be drawn into the color-coded stopper
    tubes in the order to prevent contamination from
    the additives in the other tubes
  • Yellow(for blood cultures)
  • Red/red-gray(no additive or anticoagulant is
    used)
  • Blue(contains the anticoagulant sodium citrate)
  • Green (contains one of three different
    anticoagulants sodium heparin, lithium heparin,
    or ammonium heparin)
  • Lavender(contains the anticoagulant EDTA, which
    binds to calcium, preventing the formation of a
    clot)
  • Gray(contains two additives sodium fluoride and
    potassium oxalate)
  • Young red-headed boys greet little girls

46
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47
Explain What You Are Going To Do
  • It is important to explain what you are going to
    do
  • Ask the patient if they have any questions
  • Remember that you what the patient to feel
    comfortable and relaxed

48
Laboratory Classification And Regulation
  • POC physician's office laboratory
  • Waived test moderately complex tests(rapid
    strep's, UA)
  • Non-waived tests complex tests with multiple
    steps(HIV)
  • CLIA Clinical Laboratory Improvement Amendments
    Law passed in 1988, establishing quality
    standards for all non-research laboratory testing
    performed on specimens derived from humans for
    the purpose of providing information for the
    diagnosis, prevention, treatment of disease, or
    impairment of, or assessment of health.

49
Hemoglobin And Hematocrit
  • Hemoglobin is the protein molecule in red blood
    cells that carries oxygen from the lungs to the
    body's tissues and returns carbon dioxide from
    the tissues to the lungs
  • The HemoCue is one example of the instrument
    commonly used to measure hemoglobin with
    capillary blood

50
Hemoglobin
  • Hemoglobin is measured if anemia is suspected in
    the patient(usually along with hematocrit)
  • The normal range for females 12 to 16 g/dl
  • The normal range for males 14 to 18 g/dl

51
The Hematocrit
  • The hematocrit is a simple yet reliable test to
    measure the percent volume of red blood cells per
    volume of whole blood
  • Given as a percent, it is often used as an
    indirect measure of hemoglobin

52
Cellular Layers
  • To measure the volume of red blood cells, you
    first must separate them from other blood
    components by high-speed centrifugation
  • During centrifugation, the red blood cells are
    packed at the bottom of the tube
  • Packed cell volume, or PCV is another
  • name for hematocrit
  • On top of the red blood cells are white blood
    cells and platelets(whitish-tan layer)called the
    buffy coat
  • Plasma is at the top of the tube

53
The Microhematocrit Method
  • Capillary puncture or venipuncture can be used to
    obtain microhematocrit blood sample
  • Heparinized(red tip) capillary tubes should be
    used when collecting capillary blood samples
  • They are filled three-fourths full
  • (horizontally, avoid air bubbles)
  • The clean end is sealed with clay
  • A gloved index finger should be
  • placed over the open end to
  • prevent blood from flowing into
  • the sealing material(must be done)

54
How To Use A Hematocrit reader
  • 1.Place the bottom of the tube along the red
    line below the scale.
  • 2. Be sure that the place where the white
    hematocrit sealer meets the RBCs is on the line
    at the bottom of the scale itself.
  • 3. Move the tube along those lines until the top
    of the plasma intersects the top line of the
    scale. (If the tube is very full, you may need to
    use the scale on the right side.)
  • 4. The value of the hematocrit is read on the
    line where the RBCs meet the plasma.

55
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56
The Erythrocyte Sedimentation Rate(ESR)
  • The ERS(ESR and sed rate) is the rate at which
    red blood cells settle out of plasma when placed
    in a vertical tube
  • The ESR is calculated by measuring the distance
    the red blood cells travel through the plasma
    during a given interval of time

57
Erythrocyte Sedimentation Rate(ESR)
  • ERS is a test to indicate
  • Acute infections
  • Chronic infections
  • Rheumatoid arthritis
  • Monitoring inflammation
  • Page 791(normal values and how to perform an ESR)

58
Introduction
  • Measuring the blood level of glucose, a simple
    sugar, is probably the most commonly performed
    blood chemistry test in the lab

59
Blood Glucose And Disease
  • The normal glucose level in a random blood sample
    is 70 to 110 mg/dl
  • If the patient has fasted, before the test, the
    normal level is 70 to 120 mg/dl
  • Blood glucose levels outside the normal range may
    indicate pathology(diabetes)

60
DM Type 1
  • The more severe form of diabetes, type
    1(insulin-dependent or juvenile-onset) diabetes
  • Type 1 is comprises about 5 to 10 of all cases
    an usually strikes before age 25
  • Type 1 diabetes requires administration of
    insulin to manage the disease
  • This occurs when the pancreas does not produce
    enough insulin to properly control blood sugar
    levels.
  • Type 1 diabetics lack the insulin hormone

61
DM Type 2
  • Type 2 diabetes or adult-onset can usually be
    controlled by diet and oral hypoglycemic
    medications
  • It is the less severe form of the disease and the
    more common, comprising 90 to 95 of all cases if
    DM
  • It usually has a gradual onset and generally
    affects adults over age 40
  • Patients with this form of the disease often are
    obese

62
Glucose Tolerance Tests
  • When fasting blood glucose levels are not
    definitive for a diagnosis of diabetes or when
    there is unexplained glycosuria, a glucose
    tolerance test(GTT) may be ordered
  • Fast for 8 to 12 hours then you drink a liquid
    containing a certain amount of glucose. Your
    blood will be taken before you do this, and again
    every 30 to 60 minutes after you drink the
    solution
  • A GTT is done on pregnant women to determine
    gestational diabetes

63
Hemoglobin A1C
  • The hemoglobin A1C test, detects hyperglycemia
    that may be missed in type 1 patients who have
    wide swings in there blood glucose levels
  • This is a test over a three month period

64
Cholesterol Testing
  • Cholesterol is a steroid normally found in the
    body
  • Normal cholesterol should be under 200
  • LDL (low-density lipoprotein cholesterol, also
    called "bad" cholesterol lt 100)
  • HDL (high-density lipoprotein cholesterol, also
    called "good" cholesterol gt60)
  • Triglycerides (fats carried in the blood from the
    food we eat. Excess calories, alcohol, or sugar
    in the body are converted into triglycerides and
    stored in fat cells throughout the body lt150)

65
Infectious Mononucleosis
  • Also called mono
  • This serious disease most often affects teenagers
    and young adults(kissing disease)
  • It is caused by the Epstein-Barr virus, and it
    has flu-like symptoms, including fever, fatigue,
    weakness, swollen glands, sore throat, and
    headache(also effect liver, spleen)

66
Newborn Screening
  • This is a screening done with capillary blood
    from the heel of the foot
  • Done at birth and then at 14 day old
  • Tests for metabolic disorders inherited disorders
    can hinder an infant's normal physical and mental
    development in a variety of ways. And parents can
    pass along the gene for a certain disorder
    without even knowing that they're carriers
  • Some states test for 50 different disorders

67
Introduction
  • Urine specimens can provide a great deal of
    information about both the urinary tract system
    and other systems(DM,HBP,liver,drugs)
  • This is very useful test and can disclose
    evidence of disease, even some that have not
    caused signs or symptoms
  • The urine samples must be correctly collected and
    maintained

68
Urinalysis
  • Urine may be analyzed for its physical, chemical,
    or microscopic properties
  • When all three types of analysis are made, this
    is referred to as a urinalysis(UA)
  • Urine can also be tested for a just few
    tests(urine glucose level)
  • A urinalysis is performed for three general
    reasons
  • 1. Screening for urine glucose
  • 2. Diagnosis of suspected disease(bacteria UTI)
  • 3. Monitoring the course of treatment (UTI
    antibiotics)

69
First Morning/24 hour Urine Specimens
  • First Morning Specimen This is the specimen of
    choice for urinalysis and microscopic analysis,
    since the urine is generally more concentrated
    (due to the length of time the urine is allowed
    to remain in the bladder)
  • Urine for 24 hours
  • Purpose This procedure checks the function of
    your kidneys or measures certain products in your
    urine
  • A special container is used to collect the
    urine.
  • A preservative is in the container.
  • Refrigerate the container during
  • collection, the urine must be kept cold

70
Pediatric Collection System
  • These are available for infants to young children
  • Consists of a plastic bag with an adhesive
    backing around the opening
  • This system can under the childs diaper

71
Collecting The Sample
  • Some patient who are not able to follow the urine
    collection procedures may require urinary
    cauterization, which involves placing a tube
    called a catheter through the urethra into the
    bladder to obtain a urine specimen

72
Physical Examination
  • All routine urinalysis should begin with a
    physical examination of the urine sample. This
    examination includes assessment of volume, odor,
    and appearance (color and turbidity), and
    specific gravity
  • While odor is not generally recorded, it may be
    noted

73
  • The appearance of urine depends on its color and
    its turbidity or clarity(cloudiness)
  • Color- Urine color usually is determined by
    concentration, color can be yellow(light dark),
    amber, red, brown, orange, green, or blue
  • The amount of fluids an individual drinks is an
    important factor
  • The more fluids a person drinks, the more dilute
    the urine

74
Turbidity/Clarity
  • TurbidityNormally freshly voided urine is clear
    to hazy in appearance. A cloudiness, may be due
    to a number nonpathological causes or to a
    disease(blood, proteins, mucus, bacterial
    infection). The turbidity of urine should always
    be recorded and microscopically explained.

75
Specific Gravity
  • Shows how well the kidneys balance the amount of
    water in urine. The higher the specific gravity,
    the more solid material is in the urine. When you
    drink a lot of fluid, your kidneys make urine
    with a high amount of water in it which has a low
    specific gravity. When you do not drink fluids,
    your kidneys make urine with a small amount of
    water in it which has a high specific gravity.

76
Specific Gravity
77
Chemical Urinalysis
  • The chemical portion of the this test provides
    information regarding the presence or absence of
    several chemicals including glucose, ketones,
    protein, and blood

78
Chemical Urinalysis
  • Urine pH should be slightly acidic to fight off
    bacteria
  • Protein is normally not found in the urine(hard
    exercise, pregnancy, kidney disease)
  • Ketones when fat is broken down for energy,
    negative ketones is normal(DM, low carbohydrate
    diet)
  • Bilirubin and Urobilinogen negative is
    normal(liver problems or disease)
  • Hematuria(blood in the urine) a normal urine
    sample should not have any detectable
    blood(kidney or prostate problems)
  • Nitrite is normally not found in urine(positive
    means bacteria possibly UTI)
  • Glucose Negative is normal (when the blood
    sugar level is very high, as in uncontrolled
    diabetes, the sugar spills over into the urine)

79
Microscopic Properties of Urinalysis
80
Urine Sediment
  • Urine sediment is a centrifuged deposit suitable
    for microscopic examination for the presence of
    erythrocytes(RBC), leukocytes(WBC), casts,
    crystals, bacteria, fungi, parasites, mucous, and
    sperm(males)
  • Next to actual biopsies of kidney tissue,
    microscopic findings are the best indicators of
    renal disease
  • This is referred to liquid biopsy for this
    reason
  • Page 809

81
Pregnancy Testing
  • This is a test to determine the presence(or
    absence) of human chorionic gonadotropin hormone
    or HCG
  • This is a waived test with 3 drops of urine and
    timed for 3 minutes

82
Culture Media
  • A tentative diagnosis may be followed up with a
    lab test to confirm the diagnosis with a culture
  • A blood test may be done, or a specimen from the
    infected area may be examined directly

83
Throat Cultures
  • Strep throat is cause by Group A strep (GAS), a
    strain of streptococcus bacteria
  • The Group A Strep Test is easy to perform, but
    needs to be precisely followed(steps)
  • Without treatment(antibiotics) of the original
    strep infection, rheumatic fever may result

84
Strep Throat
  • First the throat is swabbed with a
  • sterile, nonabsorbent rayon-fiber swab
  • The swab is inserted into with the reagents to
    extract the Strep A antigen(If there is a strep A
    antigen the test will be positive)
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