What is the purpose of the FAST exam in trauma assessment?

• A. To evaluate airway patency and ventilation.
• B. To assess spine alignment during transfer.
• C. To determine ongoing fluid resuscitation needs.
• D. To rapidly detect free intraperitoneal fluid or pericardial fluid suggesting bleeding.

Answer: (D)

The FAST exam is a rapid bedside ultrasound used in trauma to quickly detect free fluid in the abdomen or around the heart, which signals internal bleeding. In a trauma patient, finding free intraperitoneal fluid or pericardial fluid suggests hemorrhage and helps guide urgent decisions about operative intervention or escalation of resuscitation. It’s especially valuable when the patient is unstable and transferring for CT isn’t safe. This tool isn’t used to evaluate airway patency or ventilation, nor spine alignment; those tasks are addressed by airway management and immobilization assessments. While FAST findings inform how aggressively to resuscitate, its primary purpose is to identify fluid from bleeding as fast as possible.