A phlebotomist should verify that a patient has fasted for how long prior to obtaining a fasting specimen?
8 to 12 hours
1 to 2 hours
4 to 6 hours
24 hours
The Correct Answer is A
Choice A reason:
The standard recommendation for fasting before a blood specimen collection is typically between 8 to 12 hours¹²³. This duration is considered sufficient to ensure that food intake does not affect the blood test results, such as glucose or lipid levels.
Choice B reason:
A fasting period of 1 to 2 hours is too short and would not provide an accurate representation of the body's baseline levels for most tests that require fasting. It is important for certain levels, like blood sugar and lipids, to stabilize, which takes longer than 1 to 2 hours.
Choice C reason:
Fasting for 4 to 6 hours may be appropriate for some tests, but it is not the standard fasting duration for most blood tests that require fasting. The shorter time might not allow for the clearance of lipids and glucose from the bloodstream that can influence the test outcomes.
Choice D reason:
A 24-hour fast is generally not required for routine fasting blood tests and could be potentially harmful, as it may lead to hypoglycemia, especially in diabetic patients or those with metabolic disorders. It is excessive for the purposes of standard blood tests.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Choice A Reason:
Shaking the tubes vigorously can cause hemolysis, which is the rupture of red blood cells, leading to inaccurate test results. It is not recommended as it does not provide gentle mixing and can damage the blood cells.
Choice B Reason:
Moving the tubes in a figure-eight motion is not a standard practice for mixing blood samples. This method may not provide the consistent and gentle inversion needed to mix the anticoagulant with the blood effectively.
Choice C Reason:
Rolling the tubes between the palms of the hands 4 to 8 times after collection is the recommended method. This technique allows for gentle and thorough mixing of the blood with the anticoagulant, preventing clotting without causing hemolysis. The number of inversions ensures that the anticoagulant coats the inner surface of the tube and mixes with the blood, which is essential for accurate laboratory results.
Choice D Reason:
Passing the tubes from hand to hand is not an effective method for mixing blood samples. This action may not provide the necessary inversion and can lead to inadequate mixing, resulting in clotted specimens.
Correct Answer is A
Explanation
Choice A reason:
Expired tubes may lose their vacuum, which is necessary to draw the correct volume of blood into the tube. The vacuum in blood collection tubes ensures that the correct amount of blood is drawn. If the vacuum is lost, the blood will not be drawn into the tube properly, which can lead to underfilling and affect the test results.
Choice B reason:
Hemoconcentration refers to an increase in the concentration of cells and solids in the blood, usually because of a loss of plasma. While this can occur due to prolonged tourniquet application or dehydration, it is not directly caused by the use of expired tubes.
Choice C reason:
Hemolysis is the destruction of red blood cells, which can release hemoglobin and other intracellular components into the plasma. It can be caused by physical damage, such as from a needle during blood draw, but is not a consequence of using expired tubes. However, if an expired tube causes improper blood draw due to loss of vacuum, it could indirectly lead to hemolysis due to multiple attempts to draw blood.
Choice D reason:
An elevation of the red blood cell count would not be directly caused by using expired tubes. The red blood cell count is determined by the body's production and destruction of red blood cells, not by the collection method or equipment used.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.