Lecture 7: Pre-Analytical Considerations

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The pre-analytical phase of the testing process begins for the laboratory when a:

Test is ordered by a patient's physician.

Most reference ranges are based on normal laboratory test values for:

Healthy people.

Diurnal variations associated with some blood components are:

Normal fluctuations throughout the day.

A patient's arm is swollen. The term used to describe this condition is:

Edematous

Lipemia results from:

High fat content of the blood.

A patient with a high degree of jaundice typically has:

Yellow skin and sclerae.

Lymphostasis is:

Obstruction of the flow of lymph.

This is the medical term for a nervous system response to abrupt pain, stress, or drama:

Vasovagal syncope.

Small nonraised red spots appear on the patient's skin below where the tourniquet has just been tied. What are they and what causes them?

Petechiae due to capillary or platelet defects

Venous stasis is:

Stoppage of the normal venous blood flow.

A hematoma is a:

Swelling or mass of blood.

Mastectomy is the medical term for breast:

Removal.

Exsanguination is:

Life-threatening loss of blood.

Which of the following is a product of the breakdown of red blood cells (RBCs)?

Bilirubin

A vein that is thrombosed is:

Clotted.

A patient goes into convulsions while you are drawing his blood. The last tube has just started to fill. Which of the following is the wrong thing to do?

Complete the draw as quickly as you can.

The patient has an IV in the left forearm and a large hematoma in the antecubital area of the right arm. The best place to collect a specimen by venipuncture is the:

Right arm distal to the hematoma.

Figure 9-1 shows and arm with:

Remains of a hematoma that formed during a blood draw.

Hemoconcentration from prolonged tourniquet application increases:

Nonfilterable analytes.

Which of the following is the medical term for fainting?

Syncope

In which instance is the patient closest to basal state? The patient who:

Is awakened for a blood draw at 0600 after fasting since 0800 last night.

The best specimens to use for establishing inpatient reference ranges for blood tests are:

Basal-state specimens.

Which test requires the patient's age in calculating results?

Creatinine clearance

Which of the following tests is most affected by altitude?

RBC count

Persistent diarrhea in the absence of fluid replacement may cause:

Hemoconcentration.

The serum or plasma of a lipemic specimen appears:

Cloudy white.

A lipemic specimen is a clue that the patient was probably:

Not fasting.

A 12-hour fast is normally required in testing for this analyte:

Triglycerides.

This blood component exhibits diurnal variation, with peak levels occurring in the morning:

Cortisol.

Tests influenced by diurnal variation are typically ordered:

Timed.

A drug known to interfere with a blood test should be discontinued for this many hours before the test specimen is collected?

4-24

A test result can be falsely decreased if:

A drug competes with the test reagents for the test analyte.

Which of the following analytes can remain elevated for 24 hours or more after exercise?

CK

Which hormone is most affected by the presence of a fever?

Insulin

Which analyte has a higher reference range for males than for females?

Hematocrit

An icteric blood specimen indicates that:

Bilirubin test results could be elevated.

What changes occur in the bloodstream when a patient goes from supine to standing?

Nonfilterable elements increase.

Why do pregnant patients have lower reference ranges for RBC counts?

Increased body fluids result in the dilution of the RBC's.

Which of the following analytes is typically increased in chronic smokers?

Hemoglobin

It is not a good idea to collect a CBC from a screaming infant because the:

WBCs may be temporarily elevated.

Of the following factors known to affect basal state, which is automatically accounted for when reference ranges are established?

Geographic locale

Temperature and humidity control in a laboratory is important because it:

Maintains the integrity of specimens.

Scarred or burned areas should be avoided as blood collection sites because:

Circulation is typically impaired.

A vein that feels hard, cord-like, and lacks resiliency is most likely:

Sclerosed.

Drawing blood from an edematous extremity may cause:

Erroneous specimen results.

If you have no choice but to collect a specimen from an arm with a hematoma, collect the specimen:

Distal to it.

One reason collecting blood specimens from an arm on the same side as a mastectomy without permission from the patient's physician is prohibited is because:

Tourniquet application may injure it.

Which of the following veins is often the easiest to feel on obese patients?

Cephalic

You must collect a protime specimen from a patient with IVs in both arms. The best place to collect the specimen is:

Below one of the IVs.

A phlebotomist must collect a hemoglobin specimen from a patient in the ICU. There is an IV in the patients left wrist. There is no suitable antecubital vein or hand vein in the right arm. What should the phlebotomist do?

Perform a fingerstick on the right hand.

In selecting a venipuncture site, do not use an arm with:

And active AV shunt or fistula.

A type of line commonly used to monitor blood pressure and collect blood gas specimens is:

An A-line.

A vascular access pathway that is surgically created to provide access for dialysis is:

An AV shunt.

When a blood specimen is collected from a heparin lock, it is important to draw:

A 5 mL discard tube before the specimen tubes are filled.

Which of the following is a type of CVC?

Broviac

A subcutaneous vascular access device consisting of a small chamber attached to an indwelling line that is implanted under the skin and located by palpating the skin is:

An implanted port.

The way to bandage a venipuncture site when the patient is allergic to the glue in adhesive bandages is to:

Wrap it with self-adhering material.

You may have to be careful about what type of equipment is brought into the room if the patient is severely allergic to:

Latex.

What is the best thing to do if a venipuncture site continues to bleed after 5 minutes?

Report it to the patient's physician or nurse.

Which patient should be asked to lie down during a blood draw? A patient with a:

History of syncope.

During a blood draw, a patient says he feels faint. What should the phlebotomist do?

Discontinue the draw and lower his head.

An outpatient becomes weak and pale after a blood draw. What should the phlebotomist do?

Have the patient lie down until recovered.

If an outpatient tells you before a blood draw that she is feeling nauseated, you should:

Advise her to begin slow, deep breathing.

Pain associated with venipuncture can be minimized by:

Putting the patient at ease with a little small talk.

A site could potentially be used for venipuncture even if:

Petechiae appear below the tourniquet.

A vein with walls that have temporarily drawn together and shut off bloodflow during venipuncture is called a:

Collapsed vein.

You are in the process of collecting a blood specimen on a patient with difficult veins. You had to redirect the needle but it is now in the vein, and the first tube has just started to fill. The blood is filling the tube slowly. The skin around the venipuncture site starts to swell. You have several more tubes to fill. What should you do?

Stop the draw at once and apply pressure to the site.

Which of the following can cause a hematoma to form during venipuncture procedures?

Failing to apply adequate pressure after the draw

Which of the following is the best indication that you have accidentally punctured an artery?

Blood pulses into the tube.

Anemia brought on by the withdrawal of blood for testing purposes is described as:

Iatrogenic.

If you suspect that you have accidentally collected an arterial specimen instead of venous specimen:

See if the lab will accept it, and if so, label it as possibly an arterial specimen.

Infection of a venipuncture site can result from:

Touching the site after cleaning it.

Blind of deep probing for a vein can result in:

An arterial puncture.

A patient complains of marked pain when you insert the needle. The pain rotates down his arm and does not subside. What should you do?

Discontinue the venipuncture immediately.

A stinging sensation when the needle is first inserted is most likely the result of:

Not letting the alcohol dry thoroughly.

Which is the best way to avoid reflux?

Make certain that tubes fill from the bottom up.

Which of the following is least likely to impair vein patency?

Leaving a tourniquet on too long

Prolonged tourniquet application can affect blood composition because it causes:

Hemoconcentration.

The serum or plasma of a hemolyzed specimen appears:

Pink or reddish.

Which action is least likely to cause specimen hemolysis?

Transferring blood from a syringe to a tube

The ratio of blood to anticoagulant is most critical for which of the following tests?

Prothrombin time

A phlebotomist has tried twice to collect a light blue-top tube on a patient with difficult veins. Both times that phlebotomist has been able to collect only a partial tube. What should the phlebotomist do?

Have someone else collect the specimen.

Which of the following situations is least likely to cause contamination of the specimen?

Cleaning a finger stick site with isopropyl alcohol

You are collecting a blood specimen. The needle is in the vein and blood flow has been established. As the tube is feeling, you hear a hissing sound, there is a spurt of blood into the tube, and blood flow stops. What most likely happened is that the:

Bevel came out of the skin and the tube vacuum escaped.

A needle that has gone through the back wall of the vein may cause:

Blood to enter the tube slowly or not at all.

When a vein rolls, the needle typically:

Slips beside instead of in the vein.

You are in the process of collecting a blood specimen. The needle is inserted but the tube is filling very slowly. A hematoma starts to form rapidly. What has most likely happened is that the:

Needle is only partially in the vein.

You are performing a multitube blood draw. You collect the first tube without a problem. The second tube fails to fill with blood. You pull the needle back and nothing happens. You push the needle a little deeper and nothing happens. You remove the tube, pullback the needle a little, rotate the bevel, and reset the tube. Still nothing happens. Which of the following actions should you take next?

Try a new tube in case it is a vacuum issue.

You insert the needle during a venipuncture. You engage the tube in the tube holder but do not get blood flow. You determine that the needle is beside the vein. You redirect it two times and still do not get blood flow, even after trying a new tube. What should you do next?

Discontinue the draw and try again at a new site.

Which of the following is most apt to be the cause of vein collapse during venipuncture?

Tube vacuum is too great for the size of the vein.

True

True or False:
Blood collected for a patient's lithium level cannot be collected in a green-topped tube containing lithium heparin.

True

True or False:
Venipuncture should never be performed on the same side as that of a mastectomy.

A

When blood is to be collected for a glucose tolerance test, the patient should fast for:
a. 8-12 hours
b. 3-5 hours
c. 6-8 hours
d. 12-14 hours

True

True or False:
The required fasting time for the fasting glucose blood collection is 8-12 hours.

B

When hemoglobin is released from RBCs and serum becomes tinged as pink or red, this condition is referred to as:
a. hyperlipidemia
b. hemolysis
c. hemoconcentration
d. hemophilia

D

Which of the following is another term for fainting?
a. fomite
b. lymphostasis
c. thrombi
d. syncope

True

True or False:
Tylenol taken by a patient can cause the patient to have abnormal laboratory liver panel results.

B

What additive destroys the enzymes in the blood when the gray-topped tube is used to collect blood?
a. sodium citrate
b. sodium fluoride
c. sodium heparin
d. lithium heparin

True

True or False:
If the patient pumps his or her fist prior to blood collection, this action can lead to a falsely increased plasma phosphate concentrations.

False

True or False:
Basal state is approximately 16 hours after the last ingestion of food.