Nursing practice questions with comprehensive rationales
NurseDive Free Nursing Practice Question
Which of the following methods should a phlebotomist use to invert tubes to prevent clotting?
A. Shaking the tubes 4 to 8 times after collection.
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.
B. Moving the tubes in a figure-eight motion 4 to 8 times after collection.
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.
C. Rolling the tubes between the palms of the hands 4 to 8 times after collection.
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.
D. Passing the tubes from hand to hand 4 to 8 times after collection.
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.
This question is an excerpt from Nurse Dive's nursing test bank - Phlebotomy Certification Proctored Exam 130. Take the full exam now
Full 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.
Similar Questions
When a phlebotomist performs a heel stick for the purposes of obtaining a PKU test, it is important to:
A. Wrap the site with a heel warmer for 30 minutes.
Wrapping the site with a heel warmer for 30 minutes is a preparatory step before the heel stick procedure. It is used to increase blood flow to the area to make the collection easier. However, it is not the action to take after the blood has been collected. The heel warmer should be removed before performing the heel stick.
B. Wipe away the first drop of blood.
Wiping away the first drop of blood is the correct procedure. The initial drop may be contaminated with tissue fluids or alcohol if the site was cleaned prior to the stick, which can affect the accuracy of the test results. Therefore, the first drop should be wiped away, and subsequent blood should be used for the PKU test.
C. Keep a pressure dressing on the site for the day.
Keeping a pressure dressing on the site for the entire day is not necessary and is not part of the standard heel stick procedure. After the blood is collected, a small bandage is typically applied to stop any bleeding. The site should be monitored for a short time for any signs of continued bleeding or bruising, but a pressure dressing for the day is excessive.
D. Target the central arch area of the foot for the least amount of discomfort.
Targeting the central arch area of the foot for the heel stick is incorrect and can be harmful. The recommended area for a heel stick is the lateral portions of the heel to minimize discomfort and avoid injury to the bone or nerves. The central arch area should be avoided to prevent potential harm.
Full Explanation
Choice A Reason:
Wrapping the site with a heel warmer for 30 minutes is a preparatory step before the heel stick procedure. It is used to increase blood flow to the area to make the collection easier. However, it is not the action to take after the blood has been collected. The heel warmer should be removed before performing the heel stick.
Choice B Reason:
Wiping away the first drop of blood is the correct procedure. The initial drop may be contaminated with tissue fluids or alcohol if the site was cleaned prior to the stick, which can affect the accuracy of the test results. Therefore, the first drop should be wiped away, and subsequent blood should be used for the PKU test.
Choice C Reason:
Keeping a pressure dressing on the site for the entire day is not necessary and is not part of the standard heel stick procedure. After the blood is collected, a small bandage is typically applied to stop any bleeding. The site should be monitored for a short time for any signs of continued bleeding or bruising, but a pressure dressing for the day is excessive.
Choice D Reason:
Targeting the central arch area of the foot for the heel stick is incorrect and can be harmful. The recommended area for a heel stick is the lateral portions of the heel to minimize discomfort and avoid injury to the bone or nerves. The central arch area should be avoided to prevent potential harm.
Drawing more than the recommended amount of an infant's blood volume may result in which of the following conditions?
A. Pernicious anemia
Pernicious anemia is a type of anemia caused by a deficiency of vitamin B12, which is not directly related to the volume of blood drawn. It is typically associated with the inability to absorb vitamin B12 from the gastrointestinal tract and is not a consequence of drawing blood.
B. Iatrogenic anemia
Iatrogenic anemia is the correct answer. It is a condition that can occur when too much blood is drawn from an infant, leading to anemia caused by medical intervention. Infants have a limited blood volume, and removing more than the recommended amount can significantly decrease their red blood cell count, resulting in anemia.
C. Hyperthermia
Hyperthermia refers to an abnormally high body temperature, which is not a direct result of drawing blood. It is more commonly associated with environmental factors, infections, or other medical conditions that cause the body's temperature regulation to fail.
D. Hypothermia
Hypothermia is a condition where the body temperature drops below the normal range, which is also not a direct consequence of drawing blood. It is typically caused by prolonged exposure to cold temperatures and is unrelated to the volume of blood drawn from an infant.
Full Explanation
Choice A Reason:
Pernicious anemia is a type of anemia caused by a deficiency of vitamin B12, which is not directly related to the volume of blood drawn. It is typically associated with the inability to absorb vitamin B12 from the gastrointestinal tract and is not a consequence of drawing blood.
Choice B Reason:
Iatrogenic anemia is the correct answer. It is a condition that can occur when too much blood is drawn from an infant, leading to anemia caused by medical intervention. Infants have a limited blood volume, and removing more than the recommended amount can significantly decrease their red blood cell count, resulting in anemia.
Choice C Reason:
Hyperthermia refers to an abnormally high body temperature, which is not a direct result of drawing blood. It is more commonly associated with environmental factors, infections, or other medical conditions that cause the body's temperature regulation to fail.
Choice D Reason:
Hypothermia is a condition where the body temperature drops below the normal range, which is also not a direct consequence of drawing blood. It is typically caused by prolonged exposure to cold temperatures and is unrelated to the volume of blood drawn from an infant.
A phlebotomist is collecting a urine drug screen from a Department of Transportation employee. The phlebotomist should take the specimen temperature at which of the following times following collection?
A. Before 4 minutes.
Taking the specimen temperature before 4 minutes is the correct procedure according to the Department of Transportation (DOT) guidelines. The DOT Rule 49 CFR Part 40 Section 40.65 states that the temperature of the specimen must be checked no later than four minutes after the employee has given the specimen. The acceptable temperature range is 32–38 °C/90–100 °F, which helps to verify the validity of the specimen.
B. At 5 minutes.
Taking the specimen temperature at 5 minutes is not within the DOT guidelines. The temperature must be taken before 4 minutes have passed to ensure the specimen's integrity and to comply with the regulatory requirements.
C. At 15 minutes.
At 15 minutes, the temperature check would be too late. The DOT guidelines specify that the temperature should be checked no later than four minutes after collection to ensure the specimen has not been tampered with and is within the acceptable temperature range.
D. After 30 minutes.
After 30 minutes, the temperature of the urine specimen would not reflect the body temperature at the time of collection, which is necessary for the validity of the test. This delay could allow for the temperature to fall outside of the acceptable range, potentially invalidating the specimen.
Full Explanation
Choice A Reason:
Taking the specimen temperature before 4 minutes is the correct procedure according to the Department of Transportation (DOT) guidelines. The DOT Rule 49 CFR Part 40 Section 40.65 states that the temperature of the specimen must be checked no later than four minutes after the employee has given the specimen. The acceptable temperature range is 32–38 °C/90–100 °F, which helps to verify the validity of the specimen.
Choice B Reason:
Taking the specimen temperature at 5 minutes is not within the DOT guidelines. The temperature must be taken before 4 minutes have passed to ensure the specimen's integrity and to comply with the regulatory requirements.
Choice C Reason:
At 15 minutes, the temperature check would be too late. The DOT guidelines specify that the temperature should be checked no later than four minutes after collection to ensure the specimen has not been tampered with and is within the acceptable temperature range.
Choice D Reason:
After 30 minutes, the temperature of the urine specimen would not reflect the body temperature at the time of collection, which is necessary for the validity of the test. This delay could allow for the temperature to fall outside of the acceptable range, potentially invalidating the specimen.