Nursing practice questions with comprehensive rationales
NurseDive Free Nursing Practice Question
A phlebotomist should identify that a blood spot collection for inborn errors of metabolism requires which of the following?
A. The newborn must be at least 3 days old.
The age of the newborn is important for certain metabolic screenings, as some metabolites may not be present or at measurable levels immediately after birth. However, the requirement for the newborn to be at least 3 days old is not a standard for all blood spot collections for inborn errors of metabolism (IEM). Some screenings are performed within 24 to 48 hours after birth.
B. The circles on the filter paper must be at least half filled.
While it is important that the circles on the filter paper are adequately filled to ensure there is enough blood for the test, the requirement for them to be at least half filled is not specified in the guidelines. The focus is usually on ensuring the blood spot is of the right size and properly saturated through the filter paper.
C. The first drop of blood immediately following the puncture must be included.
The inclusion of the first drop of blood is not typically a requirement. In fact, the first drop is often wiped away to avoid contamination with tissue fluids that could affect the test results. Subsequent drops are used to fill the circles on the filter paper.
D. The specimen must be completely dried before the test can be processed.
The specimen must be completely dried before the test can be processed to prevent degradation or hemolysis of the blood sample. This is a critical step in the preparation of the sample for accurate testing of IEM. The drying process helps preserve the integrity of the metabolites to be analyzed.
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:
The age of the newborn is important for certain metabolic screenings, as some metabolites may not be present or at measurable levels immediately after birth. However, the requirement for the newborn to be at least 3 days old is not a standard for all blood spot collections for inborn errors of metabolism (IEM). Some screenings are performed within 24 to 48 hours after birth.
Choice B Reason:
While it is important that the circles on the filter paper are adequately filled to ensure there is enough blood for the test, the requirement for them to be at least half filled is not specified in the guidelines. The focus is usually on ensuring the blood spot is of the right size and properly saturated through the filter paper.
Choice C Reason:
The inclusion of the first drop of blood is not typically a requirement. In fact, the first drop is often wiped away to avoid contamination with tissue fluids that could affect the test results. Subsequent drops are used to fill the circles on the filter paper.
Choice D Reason:
The specimen must be completely dried before the test can be processed to prevent degradation or hemolysis of the blood sample. This is a critical step in the preparation of the sample for accurate testing of IEM. The drying process helps preserve the integrity of the metabolites to be analyzed.
Similar Questions
Which of the following is caused by excessive shaking of a tube?
A. Hemophilia
Hemophilia is a genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. This condition is not caused by shaking a blood collection tube; it is an inherited disorder typically caused by a mutation in one of the clotting factor genes.
B. Hemoconcentration
Hemoconcentration refers to an increase in the concentration of cells and solids in the blood, usually resulting from a loss of plasma. While this can occur due to various reasons, such as dehydration, it is not caused by shaking a blood collection tube. Shaking a tube does not change the ratio of cells to plasma in the blood.
C. Hemolysis
Hemolysis is the rupture of red blood cells, which can occur when a blood sample is handled roughly, such as by excessive shaking. This can cause the cells to break open and release their contents into the plasma, which can interfere with laboratory tests and lead to inaccurate results.
D. Hemostasis
Hemostasis is the process by which the body stops bleeding, which involves the clotting of blood. This process is not caused by shaking a blood collection tube. Hemostasis is a complex process that involves blood vessels, platelets, and clotting factors.
Full Explanation
Choice A Reason:
Hemophilia is a genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. This condition is not caused by shaking a blood collection tube; it is an inherited disorder typically caused by a mutation in one of the clotting factor genes.
Choice B Reason:
Hemoconcentration refers to an increase in the concentration of cells and solids in the blood, usually resulting from a loss of plasma. While this can occur due to various reasons, such as dehydration, it is not caused by shaking a blood collection tube. Shaking a tube does not change the ratio of cells to plasma in the blood.
Choice C Reason:
Hemolysis is the rupture of red blood cells, which can occur when a blood sample is handled roughly, such as by excessive shaking. This can cause the cells to break open and release their contents into the plasma, which can interfere with laboratory tests and lead to inaccurate results.
Choice D Reason:
Hemostasis is the process by which the body stops bleeding, which involves the clotting of blood. This process is not caused by shaking a blood collection tube. Hemostasis is a complex process that involves blood vessels, platelets, and clotting factors.
A phlebotomist is performing a venipuncture on a patient who is allergic to alcohol. Which of the following is an appropriate antiseptic to use in place of alcohol?
A. Sterile water
Sterile water is not an antiseptic; it does not contain antimicrobial agents. While it can be used to rinse a site, it will not disinfect the area before a venipuncture procedure. Therefore, it is not an appropriate substitute for alcohol in this context.
B. Antiseptic foam
Antiseptic foam may contain alcohol or other disinfectants. If it is alcohol-free, it could be a suitable alternative. However, without specific information about the ingredients, it cannot be assumed to be an appropriate choice for a patient allergic to alcohol.
C. Chlorhexidine
Chlorhexidine is a commonly used antiseptic for skin preparation before medical procedures, including venipuncture. It is effective against a broad spectrum of bacteria and is an appropriate alternative for patients who have an allergy to alcohol-based antiseptics.
D. Saline
Saline solution is not an antiseptic. It is a sterile solution of sodium chloride in water and does not have antimicrobial properties. Like sterile water, it is not suitable for disinfecting the venipuncture site.
Full Explanation
Choice A Reason:
Sterile water is not an antiseptic; it does not contain antimicrobial agents. While it can be used to rinse a site, it will not disinfect the area before a venipuncture procedure. Therefore, it is not an appropriate substitute for alcohol in this context.
Choice B Reason:
Antiseptic foam may contain alcohol or other disinfectants. If it is alcohol-free, it could be a suitable alternative. However, without specific information about the ingredients, it cannot be assumed to be an appropriate choice for a patient allergic to alcohol.
Choice C Reason:
Chlorhexidine is a commonly used antiseptic for skin preparation before medical procedures, including venipuncture. It is effective against a broad spectrum of bacteria and is an appropriate alternative for patients who have an allergy to alcohol-based antiseptics.
Choice D Reason:
Saline solution is not an antiseptic. It is a sterile solution of sodium chloride in water and does not have antimicrobial properties. Like sterile water, it is not suitable for disinfecting the venipuncture site.
Which of the following specimens requires a chain of custody form?
A. Blood for HIV testing
Blood for HIV testing does not typically require a chain of custody form. HIV testing is a confidential medical test, but the results are not usually used for legal purposes, which is when a chain of custody would be necessary.
B. Sputum for tuberculosis testing
Sputum for tuberculosis testing also does not require a chain of custody form. While the test is critical for diagnosing tuberculosis, the results are used for medical diagnosis and treatment rather than legal proceedings.
C. Blood for paternity testing
Blood for paternity testing requires a chain of custody form because the results can have legal implications, such as establishing paternity for child support or custody cases. The chain of custody ensures that the sample is properly handled and tracked from collection to analysis, preventing tampering or misidentification.
D. Swab for chlamydia testing
A swab for chlamydia testing, like HIV testing, is a confidential medical test that does not usually require a chain of custody form. The results are used for medical purposes, such as diagnosis and treatment, rather than legal proceedings.
Full Explanation
Choice A Reason:
Blood for HIV testing does not typically require a chain of custody form. HIV testing is a confidential medical test, but the results are not usually used for legal purposes, which is when a chain of custody would be necessary.
Choice B Reason:
Sputum for tuberculosis testing also does not require a chain of custody form. While the test is critical for diagnosing tuberculosis, the results are used for medical diagnosis and treatment rather than legal proceedings.
Choice C Reason:
Blood for paternity testing requires a chain of custody form because the results can have legal implications, such as establishing paternity for child support or custody cases. The chain of custody ensures that the sample is properly handled and tracked from collection to analysis, preventing tampering or misidentification.
Choice D Reason:
A swab for chlamydia testing, like HIV testing, is a confidential medical test that does not usually require a chain of custody form. The results are used for medical purposes, such as diagnosis and treatment, rather than legal proceedings.