Final answer:
The blood test that requires immediate refrigeration on ice is the blood urea nitrogen (BUN) test. In emergencies with no time for blood typing, type O negative blood is transfused. Agglutination in both anti-A and anti-B wells indicates type AB blood.
Step-by-step explanation:
The type of test that must be placed on ice immediately after being drawn to prevent changes in the blood chemistry is the blood urea nitrogen (BUN) test. The BUN test measures the amount of urea nitrogen in the blood, which can be affected by factors such as temperature. Placing the drawn blood sample on ice preserves its integrity until the analysis can be performed.
Regarding emergency blood transfusions, in the case of critical situations where there is no time to determine the patient's blood type, type O negative blood is used. It is considered the universal donor type and does not cause adverse reactions related to blood type incompatibility.
If a lab technician observes agglutination in both the anti-A and anti-B wells, this indicates that the patient has type AB blood. This is not an error but a normal response for individuals with type AB blood, which means they have both A and B antigens on the surface of their red blood cells.