Final answer:
The term "stat" in a medical context means that something needs to be done immediately. It is commonly used when urgent blood tests or treatments are required for a patient.
Step-by-step explanation:
When Dr. Berry orders blood tests to be done "stat," it means that the tests must be performed immediately. The term stat is derived from the Latin word statim, which means 'immediately' or 'on the spot'. In a medical context, it is often used to prioritize patient tests and treatments that are considered urgent. Factors such as checking levels of various metabolites in plasma, or distinguishing and counting blood cells using automated methods, can be critical for assessing a patient's health promptly in emergencies or when quick medical decisions are needed.