Prenalytical Considerations

Question 1

The ___ of the testing process begins
for the laboratory when a test is ordered and ends when testing begins.

Answer 1

preanalytical/pre-examination phase

Question 2

the results used for comparison become a range of values with high and low limits, commonly called as

Answer 2

reference range or reference interval

Question 3

refers to the resting metabolic state of the body early in the morning after fasting
for approximately 12 hours.

Answer 3

Basal state

Question 4

ideal for establishing reference ranges
on inpatients because the effects of diet, exercise, and other controllable factors on test results are minimized or eliminated.

Answer 4

basal-state specimen

Question 5

Values for some blood components vary considerably depending upon the age of the patient. For example, red blood cell (RBC) and white blood cell (WBC) values are normally higher in newborns than in adults.

Answer 5

AGE

Question 6

Test results for some blood analytes show signifi cant variation at higher elevations compared
with results at sea level.

Answer 6

ALTITUDE

Question 7

occurs, for example, with persistent vomit-
ing or diarrhea

Answer 7

DEHYDRATION

Question 8

dehydration causes ___, a condition in which blood components that
cannot easily leave the bloodstream become concentrated in the smaller plasma volume.

Answer 8

hemoconcentration

Question 9

Blood analyte composition can be altered by the ingestion of food and drink. As a result,
blood specimens collected soon after a meal or snack are unsuitable for many laboratory
tests.

Answer 9

DIET

Question 10

The following are examples of how some analytes can be signifi cantly affected by the con-
sumption of certain types of food or drink and the excess consumption of some fl uids.

Answer 10

• Ammonia, urea, and uric acid levels may be elevated in patients on high-protein diets.
• Cortisol and ACTH levels have been shown to increase with the consumption of bever-
ages containing caffeine.
• Glucose (blood sugar) levels increase dramatically with the ingestion of carbohydrates
or sugar-laden substances but return to normal within 2 hours if the patient has normal
glucose metabolism. Eating carbohydrates can also increase insulin levels.
• Hgb levels can decrease and electrolyte balance can be altered by drinking excessive
amounts of water and other fluids.
• Lipid levels increase with ingestion of foods such as butter or margarine, cheese, cream,
and some enteral (tube feeding) preparations.

Question 11

is a term meaning fat-soluble; it
is used to describe certain fatty substances of animal or vegetable origin.

Answer 11

Lipid

Question 12

Abnormally increased blood lipid content is called

Answer 12

lipemia

Question 13

Lipids do not dissolve in water and thus
high levels of lipids are visible in serum or plasma, causing it to appear milky (cloudy
white) or turbid, and the specimen is described as being

Answer 13

lipemic

Question 14

The levels of many blood components normally exhibit ___ variations or fluctuations. Factors that play a role in ___ variations include posture, activity, eating, daylight and darkness, and being awake or asleep.

Answer 14

diurnal (happening daily) or circadian (having a 24-hour cycle)

Question 15

Some drugs alter physiological functions, causing changes in the concentrations of certain
blood analytes. The effect may be desired or an unwanted side effect or sensitivity. Conse-
quently, it is not uncommon for physicians to monitor levels of specifi c blood analytes while
a patient is

Answer 15

DRUG THERAPY

Question 16

affects a number of blood components, raising levels of some and lowering levels
of others. Effects vary, depending on the patient’s physical condition and the duration and
intensity of the activity.

Answer 16

EXERCISE

Question 17

affects the levels of a number of hormones. also increases cortisol and may disrupt
its normal diurnal variation.

Answer 17

FEVER

Question 18

affects the concentration of a number of blood components. Most differences are apparent only after sexual maturity and are refl ected in separate normal values for males and females.

Answer 18

GENDER

Question 19

can increase levels of creatine kinase (CK) and the skeletal muscle fraction of LDH.

Answer 19

INTRAMUSCULAR INJECTION

Question 20

it is recommended that CK and LDH levels be drawn

Answer 20

before or at least 1 hr because it increases CK levels

Question 21

Going
from supine (lying down on the back) to an upright sitting or standing position causes blood
fluids to filter into the tissues, decreasing plasma volume in an adult up to 10%.

Answer 21

POSITION

Question 22

causes physiologic changes in many body systems. Consequently results of a num-
ber of laboratory tests must be compared with reference ranges established for pregnant
populations.

Answer 22

PREGNANCY

Question 23

The extent of these effects depends
upon the number of cigarettes smoked. Patients who smoke prior to specimen collection may
have increased cholesterol, cortisol, glucose, growth hormone, and triglyceride levels as well
as WBC counts.

Answer 23

PREGNANCY

Question 24

Environmental factors such as temperature and humidity can affect test values by infl uencing
the composition of body fl uids.

Answer 24

TEMPERATURE AND HUMIDITY

Question 25

Avoid burned, scarred, or tattooed areas. Veins are diffi cult to palpate or penetrate in these areas. Healed burn sites and other areas with extensive scarring may have impaired circula- tion and can therefore yield erroneous test results. Newly burned areas are painful and also susceptible to infection. Tattooed areas can have impaired circulation, may be more suscep- tible to infection, and contain dyes that can interfere with testing.

Answer 25

BURNS, SCARS, TATTOOS

Question 26

Some patients’ veins feel hard and cord-like and lack resiliency because they are occluded or obstructed.

Answer 26

DAMAGED VEINS

Question 27

veins may be __ or __ from the effects of infl ammation, disease, or chemotherapy drugs.

Answer 27

sclerosed (hardened) or thrombosed (clotted)

Question 28

is swelling caused by the abnormal accumulation of fluid in the tissues.

Answer 28

EDEMA

Question 29

is a swelling or mass of blood (often clotted) that can be caused by blood leaking from a blood vessel during or following venipuncture. A large bruise eventually spreads over the surrounding area.

Answer 29

HEMATOMA

Question 30

Blood should never be drawn from an arm on the same side as a __ without first consulting the patient’s physician.

Answer 30

MASECTOMY

Question 31

Lymph node removal, which is typically part of the procedure, causes __ (obstruction or stoppage of normal lymph fl ow)

Answer 31

lymphotasis

Question 32

Veins on obese patients may be deep and diffi cult to find. Proper tourniquet selection and application is the first step to a successful venipuncture.

Answer 32

OBESITY

Question 33

is a catheter that is placed in an artery. It is most commonly placed in a radial artery and is typically used to provide accurate and continuous measurement of a patient’s blood pressure.

Answer 33

ARTERIAL LINE (note: Never apply a tourniquet or perform venipuncture on an arm with an arterial line.)

Question 34

is the permanent surgical connection of an artery and vein by direct fusion (fistula), resulting in a bulging vein, or with a piece of vein or tubing (graft) that creates a loop under the skin.

Answer 34

ARTERIOVENOUS SHUNT, FISTULA, OR GRAFT

Question 35

A needleless closed blood sampling device is sometimes connected to an arterial or central venous catheter (see “Vascular-Access Devices”) for the purpose of collecting blood specimens. These devices are said to reduce the chance of infection, prevent needlesticks, and minimize waste associated with line draws.

Answer 35

BLOOD SAMPLING DEVICE

Question 36

is a catheter or cannula connected to a stopcock or a cap with a diaphragm (thin rubber-like cover) that provides access for administering medication or drawing blood. It is often placed in a vein in the lower arm above the wrist and can be left in place for up to 48 hours. To keep it from clotting, the device is flushed and fi lled with heparin or saline.

Answer 36

HEPARIN OR SALINE LOCK (note: Draw- ing coagulation specimens from either type is not recommended because traces of heparin or dilution with saline can negatively affect test results.)

Question 37

means “of, pertaining to, or within a vein.”

Answer 37

Intravenous (IV)

Question 38

is a catheter inserted in a vein to administer fluids.

Answer 38

Intravenous Line (note: preferred that blood specimens not be drawn from an arm with an IV)

Question 39

Blood specimens should not be collected from a known previous IV site within 24 to 48 hours of the time the IV was discontinued. Follow facility protocol.

Answer 39

PREVIOUSLY ACTIVE IV SITES

Question 40

consists of tubing inserted into a main vein or artery. CVADs are used primarily for administering fl uids and medications, monitoring pressures, and drawing blood.

Answer 40

central vascular access device (CVAD), also called an **indwelling line**

Question 42

Some patients are allergic to the glue used in adhesive bandages. One solution is to place a clean, folded gauze square over the site and wrap it with self adherent bandaging material such as Coban. many individuals are allergic to povidone–iodine. Increasing numbers of individuals are allergic to latex.

Answer 42

Adhesive Allergy, Antiseptic Allergy, Latex Allergy

Question 43

Normally, a patient will stop bleeding from the venipuncture site within a few minutes. Some patients, particularly those on aspirin or anticoagulant therapy, may take longer to stop bleeding. Pressure must be maintained over the site until the bleeding stops. If the bleeding continues after 5 minutes, the appropriate personnel should be notified.

Answer 43

EXCESSIVE BLEEDING

Question 44

described as a loss of consciousness and postural tone resulting from insufficient blood flow to the brain. It can last for as little as a few seconds or as long as half an hour.

Answer 44

Fainting or medical term - **syncope** (note: the patient should be asked to lie down)

Question 45

Sudden faintness or loss of consciousness due to a nervous system response to abrupt pain, stress, or trauma is

Answer 45

vasovagal syncope

Question 46

are tiny, nonraised red spots that appear on the patient’s skin when a tourniquet is applied. The spots are minute drops of blood that escape the capillaries and come to the surface of the skin below the tourniquet, most commonly as a result of capillary wall defects or platelet abnormalities.

Answer 46

PETECHIAE

Question 47

is the most common complication of venipuncture. It is caused by blood leaking into the tissues during or following venipuncture and is identified by rapid swelling at or near the venipuncture site.

Answer 47

Hematoma (notes: A rapidly forming hematoma may indicate that an artery has been inadvertently hit. Discontinue the draw immediately and apply direct forceful pressure to the puncture site for a minimum of 5 minutes until active bleeding ceases ; the phlebotomist should discontinue the draw immediately and hold pressure over the site for a minimum of 2 minutes.)

Question 48

is an adjective used to describe an adverse condition brought on by the effects of treatment.

Answer 48

Iatrogenic

Question 49

Blood loss to a point where life cannot be sustained

Answer 49

exsanguination

Question 50

stagnation of the normal venous blood flow. the trapping of blood in an extremity by compression of veins.

Answer 50

venous stasis (hemoconcentration)

Question 52

results when RBCs are damaged or destroyed and the hemoglobin they contain escapes into the fl uid portion of the specimen.

Answer 52

hemolysis