Nursing practice questions with comprehensive rationales
NurseDive Free Nursing Practice Question
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.
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:
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.
Similar Questions
A phlebotomist is planning to collect a specimen to measure a patient's serum cortisol level. Which of the following factors should the phlebotomist consider?
A. Body temperature
Body temperature does not significantly affect serum cortisol levels and is not a factor that needs to be considered when planning to collect a cortisol specimen. Cortisol levels are regulated by the hypothalamic-pituitary-adrenal axis and not by body temperature.
B. Time of day
Time of day is a critical factor to consider when collecting a specimen for serum cortisol level measurement. Cortisol levels follow a diurnal pattern, peaking in the early morning hours and declining throughout the day, with the lowest levels typically occurring around midnight¹². This variation is known as the cortisol awakening response (CAR) and is important for accurately interpreting the results of the test.
C. Alcohol consumption
Alcohol consumption can affect cortisol levels; however, it is not typically a factor that a phlebotomist needs to consider immediately before specimen collection unless the patient is under the influence at the time of the test. Chronic alcohol use can lead to alterations in cortisol levels, but this is more of a consideration for the healthcare provider interpreting the results rather than the phlebotomist collecting the specimen.
D. Prandial status
Prandial status, or the fed or fasting state of the patient, can influence cortisol levels, but it is not as significant a factor as the time of day. Cortisol levels can be slightly higher after eating, but this effect is generally considered minimal. The primary concern for prandial status would be if the cortisol test is being conducted alongside other tests that require fasting.
Full Explanation
Choice A Reason:
Body temperature does not significantly affect serum cortisol levels and is not a factor that needs to be considered when planning to collect a cortisol specimen. Cortisol levels are regulated by the hypothalamic-pituitary-adrenal axis and not by body temperature.
Choice B Reason:
Time of day is a critical factor to consider when collecting a specimen for serum cortisol level measurement. Cortisol levels follow a diurnal pattern, peaking in the early morning hours and declining throughout the day, with the lowest levels typically occurring around midnight¹². This variation is known as the cortisol awakening response (CAR) and is important for accurately interpreting the results of the test.
Choice C Reason:
Alcohol consumption can affect cortisol levels; however, it is not typically a factor that a phlebotomist needs to consider immediately before specimen collection unless the patient is under the influence at the time of the test. Chronic alcohol use can lead to alterations in cortisol levels, but this is more of a consideration for the healthcare provider interpreting the results rather than the phlebotomist collecting the specimen.
Choice D Reason:
Prandial status, or the fed or fasting state of the patient, can influence cortisol levels, but it is not as significant a factor as the time of day. Cortisol levels can be slightly higher after eating, but this effect is generally considered minimal. The primary concern for prandial status would be if the cortisol test is being conducted alongside other tests that require fasting.
How many times should an EDTA tube be inverted after blood collection?
A. 5 to 7
Inverting the tube 5 to 7 times may not be sufficient to mix the blood thoroughly with the EDTA. This could lead to partial clotting and potentially inaccurate test results. The EDTA anticoagulant works by binding calcium ions, which are necessary for blood clotting. Without adequate mixing, the EDTA may not be evenly distributed, leaving some areas of the blood sample able to clot.
B. 2 to 4
Inverting the tube only 2 to 4 times is inadequate for proper mixing. This minimal agitation would likely result in clot formation because the anticoagulant would not be sufficiently mixed with the blood. Clots can interfere with the accuracy of hematological tests by trapping cells and altering the specimen's composition.
C. 1 to 3
Inverting the tube 1 to 3 times is clearly insufficient and would almost certainly lead to clotting. The purpose of inverting the tube is to ensure that the EDTA coats all the blood cells, preventing coagulation. Such a low number of inversions would not allow for the anticoagulant to perform its function effectively.
D. 8 to 10
Inverting the tube 8 to 10 times is the recommended practice. This number of inversions ensures that the blood is fully mixed with the EDTA, preventing clot formation and preserving the integrity of the sample for accurate laboratory analysis. It is important to perform these inversions gently to avoid hemolysis, which can also affect test results. Hemolysis occurs when red blood cells are damaged and their contents leak out, which can happen if the blood is shaken too vigorously.
Full Explanation
Choice A Reason:
Inverting the tube 5 to 7 times may not be sufficient to mix the blood thoroughly with the EDTA. This could lead to partial clotting and potentially inaccurate test results. The EDTA anticoagulant works by binding calcium ions, which are necessary for blood clotting. Without adequate mixing, the EDTA may not be evenly distributed, leaving some areas of the blood sample able to clot.
Choice B Reason:
Inverting the tube only 2 to 4 times is inadequate for proper mixing. This minimal agitation would likely result in clot formation because the anticoagulant would not be sufficiently mixed with the blood. Clots can interfere with the accuracy of hematological tests by trapping cells and altering the specimen's composition.
Choice C Reason:
Inverting the tube 1 to 3 times is clearly insufficient and would almost certainly lead to clotting. The purpose of inverting the tube is to ensure that the EDTA coats all the blood cells, preventing coagulation. Such a low number of inversions would not allow for the anticoagulant to perform its function effectively.
Choice D Reason:
Inverting the tube 8 to 10 times is the recommended practice. This number of inversions ensures that the blood is fully mixed with the EDTA, preventing clot formation and preserving the integrity of the sample for accurate laboratory analysis. It is important to perform these inversions gently to avoid hemolysis, which can also affect test results. Hemolysis occurs when red blood cells are damaged and their contents leak out, which can happen if the blood is shaken too vigorously.
Which of the following is the correct angle of insertion when performing venipuncture using the evacuated tube method?
A. 50°
An angle of 50° is too steep for venipuncture and increases the risk of going through the vein and causing injury to structures beneath it. A steeper angle can also make it more difficult to control the depth of the needle, leading to an increased chance of puncturing the posterior wall of the vein.
B. 30°
An angle of 30° is the recommended angle for venipuncture as it allows for a smooth entry into the vein without going too deep. This angle helps to ensure that the needle enters the vein in a controlled manner and minimizes the risk of injury to the patient. It also provides a good balance between ease of entry and control over the needle's depth.
C. 90°
An angle of 90° is not recommended for venipuncture because it is perpendicular to the skin, which greatly increases the risk of passing through the vein entirely and causing injury. This angle does not allow for any control over the depth of the needle and is likely to cause discomfort or pain to the patient.
D. 75°
An angle of 75° is also too steep for safe venipuncture. Similar to a 50° angle, it increases the risk of penetrating the posterior wall of the vein and potentially damaging surrounding tissues or arteries. It is important to use a lower angle to ensure the safety and comfort of the patient during the procedure.
Full Explanation
Choice A Reason:
An angle of 50° is too steep for venipuncture and increases the risk of going through the vein and causing injury to structures beneath it. A steeper angle can also make it more difficult to control the depth of the needle, leading to an increased chance of puncturing the posterior wall of the vein.
Choice B Reason:
An angle of 30° is the recommended angle for venipuncture as it allows for a smooth entry into the vein without going too deep. This angle helps to ensure that the needle enters the vein in a controlled manner and minimizes the risk of injury to the patient. It also provides a good balance between ease of entry and control over the needle's depth.
Choice C Reason:
An angle of 90° is not recommended for venipuncture because it is perpendicular to the skin, which greatly increases the risk of passing through the vein entirely and causing injury. This angle does not allow for any control over the depth of the needle and is likely to cause discomfort or pain to the patient.
Choice D Reason:
An angle of 75° is also too steep for safe venipuncture. Similar to a 50° angle, it increases the risk of penetrating the posterior wall of the vein and potentially damaging surrounding tissues or arteries. It is important to use a lower angle to ensure the safety and comfort of the patient during the procedure.