A haemodynamically stable adult undergoes FAST after blunt abdominal trauma. In the supine position, free intraperitoneal fluid first accumulates in which one of the following spaces?

• A Right subphrenic space
• B Subphrenic space between liver and diaphragm
• C Left paracolic gutter
• D Rectovesical pouch (pouch of Douglas) ✓

Explanation

In the supine patient the pelvis is the most dependent part of the peritoneal cavity, so small volumes of free fluid layer into the rectovesical pouch in males and the rectouterine pouch (pouch of Douglas) in females. This is why the pelvic view is an integral part of FAST and adds sensitivity to the right upper quadrant view. The right subphrenic space and paracolic gutters only fill once larger volumes are present, so they are less sensitive for minor haemoperitoneum.

Reference: Grainger and Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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