Which of the following criteria is acceptable in determining the quality of a peripheral blood smear?

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.

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.