How can a phlebotomist distinguish whether a collection tube contains serum or plasma?

Choice A reason:
The BUN test measures the amount of urea nitrogen in the blood, which can indicate kidney function. Fasting is not typically required for a BUN test unless it is being conducted alongside other tests that may require fasting.

Choice B reason:
An HDL test is part of a lipid profile that measures the levels of good cholesterol in the blood. Fasting before a cholesterol test, including HDL, is often recommended to ensure accuracy, although recent guidelines have changed, allowing for nonfasting cholesterol testing in certain individuals.

Choice C reason:
An ABG test measures oxygen and carbon dioxide levels in the blood and assesses the body's acid-base balance. Preparation for an ABG test does not typically require fasting, but patients may need to stop supplemental oxygen before the test to get accurate measurements.

Choice D reason:
A CBC test, or complete blood count, does not require fasting. It measures various factors of the blood, including red and white blood cells and platelets. Fasting is not necessary unless the CBC is part of a panel of tests that includes tests requiring fasting.

Choice A Reason:
Contacting the physician by paging or calling right away is the most appropriate action when critical values are confirmed on a laboratory test. Critical values are defined as those that indicate the patient is in danger of death unless treatment is initiated immediately. Immediate notification of the responsible licensed caregiver is required so that appropriate clinical action can be taken for the patient. This is a standard procedure compliant with CLIA regulation 493.1109(f) and is essential for patient safety.

Choice B Reason:
Leaving a message at the physician's office number is not an adequate response to confirmed critical values. Messages can be overlooked or not checked until the next business day, which could delay necessary urgent medical interventions.

Choice C Reason:
Calling the physician's office on the next business day is not acceptable when dealing with critical values. The urgency of critical results requires immediate action, and waiting until the next business day could result in significant harm or death to the patient.

Choice D Reason:
Faxing the results to the physician's office with a stat fax cover is not sufficient for immediate communication of critical values. While the fax may indicate urgency, there is no guarantee that the fax will be seen immediately by the physician or their staff. Direct communication through paging or calling ensures that the critical information is relayed without delay.