5. Venipuncture Problems and Special Collections

Question 1

Define what is meant by routine precautions.

Answer 1

Blood and certain body fluids of all patients are considered potentially infectious,

therefore during blood collection gloves are worn.

Question 2

What type of isolation is used when a patient must be protected from acquiring an infection from a blood collector?

Answer 2

protective or reverse isolation

Question 3

What is the minimum age of children which should be considered for venipuncture? What is the maximum blood volume that should be taken at one time on a 40 pound child?

Answer 3

two years old

10 mL of blood

Question 4

List three common problems and their prevention when collecting from an elderly patient?

Answer 4

Veins collapse easily - use a syringe.

Veins roll - anchor firm and pull skin taut.

Bruise easily - put pressure on site for an extended period of time.

Question 5

List the two disinfectants commonly used for blood cultures.

Answer 5

70% alcohol povidone-iodine

Question 6

Which two groups are recognized by the Criminal Code as appropriate blood collectors for blood alcohol analyses?

Answer 6

6. qualified medical practitioners - usually physicians (also nurses)

qualified technicians - medical lab technologists, combined laboratory and x-ray technologists

Question 7

A blood specimen has been collected for a red blood count. When the specimen settles, the technologist notices that the supernatant is a clear red.

a. Is this specimen acceptable for analysis? 
b. What is the technical term to describe the specimen?
c. List seven preventative measures for this problem.

Answer 7

a. No
b. hemolysis
c. all surfaces that contact blood must be dry do not constrict vein excessively

use the correct anticoagulant: blood ratio do not shake the blood sample

do not freeze the whole blood sample

separate serum or plasma from the cellular elements in less than 4 hours do not force blood quickly through a needle

Question 8

What additional procedures are followed when you are collecting blood for a cross match?

Answer 8

The identification of the patient is done by a medical person (identifier) who knows the patient as well as the blood collector. A patient or specimen mix up could lead to the patient receiving the wrong donor blood and experiencing a transfusion reaction (which may be fatal). The medical person signs the requisition. An additional number (B.B. #) is put on the patient, blood specimen, requisition. The remainder of the numbers are returned to the Transfusion Lab where they are put on the units of bloods to be given to the patient. This number must match the arm band #, otherwise the blood is NOT given.

Question 9

How would you collect from an arm which has an IV running?

Answer 9

If at all possible, choose another site for the collection.

If you must collect from an arm which has an IV, then:

• Shut off the IV for a minimum of 2 minutes (10 for therapeutic drug monitoring).
• Draw below the site of the IV.
• Discard the first 5 to 7 mL of blood collected.
• Inform the lab of the contents of the IV.