The document discusses Focused Abdominal Sonography for Trauma (FAST), which is a 2-5 minute ultrasound examination performed on victims of torso trauma. It searches for free fluid in the pericardial sac, both upper abdominal quadrants, and the intraperitoneal recesses near the bladder. FAST can detect hemothoraces and pneumothoraces. It is accurate for detecting moderate or large volumes of intraperitoneal fluid but can miss some isolated solid organ injuries with minimal bleeding. Small isolated lesions with under 250mL of blood rarely require intervention. False positives can occur from various anatomical structures or fluid collections.

2. Evaluación por Ecografía Focalizada en Trauma
(FAST)

3. • Focused Abdominal Sonography
• for Trauma (FAST)
• FAST is performed as part of the secondary survey in victims of
• torso trauma (see Chapter 16 ). It is a temporally (2–5 minutes)
• and anatomically limited real-time sonographic examination
• whose core components include a direct sonographic search for
• free fluid in the pericardial sac, both upper abdominal quadrants,
• and the intraperitoneal recesses adjacent to the urinary
• bladder. Scanning is optimally performed in two orthogonal
• planes (e.g., longitudinal and transverse), and intraparenchymal
• and retroperitoneal injuries are generally not sought but are
• sometimes seen. FAST may be extended to detect a hemothorax
• and pneumothorax. Commercially available, portable handheld
• real-time imaging devices are technically adequate to
• perform FAST.
• FAST is uniformly accurate for the detection of intraperitoneal
• fluid with moderately large volumes 400 cm 3 (at smaller
• volumes, accuracy varies with user experience). 3 – 5 Unfortunately,
• isolated hepatosplenic injuries with minimal or no hemoperitoneum
• represent as many as one third of solid organ injuries.
• 6 , 7 Fortunately, small isolated intraparenchymal lesions
• with less than 250 mL of intraperitoneal blood rarely require
• endovascular or surgical intervention (liver 1%, spleen
• 5%). 8 False-positive interpretation of FAST images can
• result from improper machine settings (gain), sonolucent perinephric
• fat (which is rarely sonolucent in both axial and coronal
• scanning planes), fluid-filled loops of bowel, bladder,
• various types of fluid-filled intra-abdominal cysts, and physiological

5. • SURGEON-PERFORMED
• ULTRASOUND IN TRAUMA
• ■ FAST
• Developed for the evaluation of injured patients, the F ocused
• A ssessment for the S onographic Examination of the T rauma
• Patient (FAST) is a rapid diagnostic examination to assess
• patients with potential injuries to the torso. The test sequentially
• surveys for the presence or absence of fluid in the pericardial
• sac and in the dependent abdominal regions, including Morison’s pouch region in the right upper quadrant (RUQ),
• the left upper quadrant (LUQ) behind the spleen and between
• the spleen and kidney, and the pelvis posterior to the bladder.
• Surgeons can perform the FAST during the primary
• or secondary survey of the American College of Surgeons
• Advanced Trauma Life Support 19 algorithm and, although
• minimal patient preparation is needed, a full urinary bladder is
• ideal to provide an acoustic window for visualization of blood
• in the pelvis.
• Blood, as any fluid, will accumulate in dependent regions of