MAP 105 CLO 1 Mastery Review

How should you clean the venipuncture site?

• Wipe back and forth with alcohol wipe

• Blow on it and call it good

• Wave dry with hand

• Let the alcohol air dry before inserting the needle.

Answer explanation

Proper preparation for venipuncture requires that the site be cleansed (70% isopropyl alcohol or other antiseptic agent as indicated by the manufacturer’s instructions). The antiseptic should be allowed to air dry, allowing ample time for the antiseptic action to take effect. Residual (undried) alcohol could lead to hemolysis of the specimen and could create a burning sensation for the patient upon needle insertion.

If you apply pressure to the venipuncture site and after a couple of minutes it still won't stop bleeding, what should you do?

• Call for help

• Elevate the arm while applying pressure.

• Wrap the arm extra tight

• Keep applying pressure and have patient bending the arm at the elbow.

Answer explanation

Elevating the arm reduces the pressure from the flow of blood, i.e., the blood is flowing down the arm. The venipuncture wound will heal more easily without the pressure from the blood flow.

Which of the following needle gauges is most commonly used for venipuncture?

• 16-17

• 18-20

• 21-23

• 24-25

Answer explanation

The gauge of a needle refers to its outer diameter or lumen (smaller numbers= larger diameters and vice versa). The most commonly used needle for venipuncture is a 21-23 gauge. The needle size must be large enough to prevent hemolysis (break down of blood cells).

During a capillary puncture, why do I wipe away the first drop of blood?

• The first drop of blood contains more platelets and clots faster.

• The first drop of blood may be contaminated by the lancet.

• The first drop of blood contains too much oxygen.

• The first drop of blood may contain traces of alcohol.

Answer explanation

The first drop of blood should be wiped off the finger after the lancet puncture to remove any excess alcohol. The excess alcohol could compromise laboratory results.

What does the color of an evacuated collection tube represent?

• The type or absence of an additive.

• The minimum volume of blood to be obtained.

• A visual identifier for tests expected to be above or below normal range.

• The personal protective equipment required for collection.

Answer explanation

The colors of the caps indicate the presence or absence of additive. Particular laboratory tests may require a specific additive. For instance, if a test requires serum, a red top tube that allows the blood to clot would suffice. Other tubes contain different additives such as anticoagulants that will keep blood from clotting, allowing for whole blood testing.

A patient shares with the medical assistant that the last time he was in the clinic to have his blood drawn, he “became very dizzy and felt like the room was spinning.” Which of the following actions should the medical assistant take?

• Encourage the patient to lie down during the venipuncture.

• Encourage the patient to look away during the venipuncture.

• Reassure the patient the procedure will be over before dizziness occurs.

• Ask the patient to lean slightly forward during the venipuncture.

Answer explanation

The medical assistant should encourage the patient to lie down during the venipuncture. This will help to prevent syncope (fainting) and maintain safety for the patient.

What's the longest time that I can leave the tourniquet on the patient?

• 525, 600 minutes

• 1 minute

• 30 seconds

• 2 minute

Answer explanation

The advised time limit for having a tourniquet applied to an arm is one minute. This limit is in place to prevent flow constriction and increased risk of clotting during the venipuncture. Hemoconcentration, which may affect test results, can occur if the tourniquet is left on for more than one minute.