Why do I need to Fast for my Lower Extremity Arterial Study?
Frequently when performing a Lower Extremity Arterial Study, the exam's findings indicate a need to evaluate blood vessels that are further upstream than the legs. This means the technologist then needs to include an Abdominal Vascular Study to determine if blockages might be present in the abdominal aorta or the iliac arteries which provide the main circulation to the legs. Planning ahead by having patients fast for Lower Extremity Arterial Studies allows the same technologist performing the test to continue examining up into the abdomen during the same appointment. Using this protocol is much more efficient because that technologist often has information that suggests where to evaluate in the abdomen making the exam more focused and confluent with the Lower Extremity Arterial Study. Without fasting, the exam would likely require the patient return for a second appointment after fasting which adds obvious inconvenience for the patient not to mention additional time required since scheduling doesn't always allow the same technologist to complete the exam. Please read the column to the right to learn what fasting accomplishes.
Why do I need to Fast for my Abdominal Vascular Study?
When a person eats, drinks, smokes, or chews gum, small amounts of air are swallowed repeatedly. In addition, after eating, the digestive system also produces gas. Air (or gas) prohibits ultrasound used for this test from penetrating the body adequately to obtain the pictures needed. 12 hours of fasting typically allows the body enough time to clear most air (or gas) from the body. This nearly invariably allows for a much improved and a more complete ultrasound exam. Without fasting, it is, in fact, impossible to perform an Abdominal Vascular Study on many people.
Fasting, for the purpose of this test, includes: