6. Variables Affecting Blood Specimen Results

Question 1

Define the following terms:

2 hour pc glucose

Answer 1

the specimen is collected 2 hours after the patient has had a balanced meal.

Question 2

Define the following terms:

diurnal variation

Answer 2

there is a normal variation of certain substance in a patient’s bloodstream during the day.

Question 3

Define the following terms:

fasting

Answer 3

usually means that the patient has had no food or beverage (except water) for 8 to 16 hours prior to blood collection.

Question 4

Define the following terms:

NPO

Answer 4

nothing by mouth.

Question 5

Explain the diet restrictions for a glucose tolerance test.

Answer 5

The patient requires an adequate carbohydrate intake for 3 days, followed by an 8 to 16 hour fast, then 100 g. of glucose. Only water is permitted. No gum or cigarettes.

Question 6

List 7 patient variables which may affect blood constituent levels.

Answer 6

diet

diurnal variation posture

exercise

stress

medication (drugs)

age/gender

Question 7

For which types of specimens in the time of collection critical?

Answer 7

2 hour pc glucose

glucose tolerance test (GTT)

those substances that exhibit a diurnal variation

when the specimen is for therapeutic drug monitoring.