The document provides information about FAST (Focused Assessment with Sonography in Trauma) scans. It begins with an overview of what a FAST scan is used for - to identify fluid in the abdomen or pelvis where it is not normally found, which can indicate injury. It then details the anatomy visualized in a standard FAST scan and describes the technique. Examples are provided of free fluid appearing in different locations like Morrison's pouch or the pelvis. The document discusses interpreting FAST scans and explores limitations and advantages of the procedure. In under 3 sentences, the document provides an overview of the FAST scan for trauma patients to quickly identify free fluid that could indicate internal injury.
3. What does it Mean?
FAST
Focused
Abdominal (Assessment
with)
Sonography in
Trauma
4. Fast Application
• Indications:
– Acute blunt or penetrating torso trauma (stable or
unstable patient )
– Trauma in pregnancy
– Pediatric trauma
– Subacute torso trauma(unexplained hypotension)
• Goal: To identify fluid in a location where it does not
normally belong and detect visceral injury.
5. FAST USG SCAN
• ANATOMY
• TECHNIQUE
• FAST DEMO
• FREE FLUID
• ABDOMINAL ORGAN INJURY
6. Where can I see FF?
• Free fluid usually appears anechoic by US
(black )
• Accumulation in area of injury
• Overflows into dependent areas (pouch of
Douglas, Morrison’s pouch) via rivers
(paracolic gutters) and into thoracic cavity
7. FAST: Anatomy
7 Dependent Sites
1. Right Supramesocolic
(Morison’s pouch)
2. Left Supramesocolic
(Splenorenal recess)
3. Right Pericolic gutter
4. Right Inframesocolic
5. Left Inframesocolic
6. Left Pericolic gutter
7. Pelvic cul-de-sac
8. FAST: Technical Considerations
Standard Views
• The Right Upper Quadrant View (Also Known as the
Perihepatic, Morison Pouch, or Right Flank View)
• The Left Upper Quadrant View (Also Known as the
Perisplenic or Left Flank View)
• The Pelvic View (Also Known as the
Retrovesical, Rectrouterine, or Pouch of Douglas View)
• The Pericardial View (Also Known as the Subcostal or
Subxiphoid View)
• The Right and Left Pericolic Gutter Views
12. FAST: Subxiphoid exam
• Normal Anatomy
• Liver at very top of screen
• Epicardial fat vs. effusion
– Thin layer anterior to RV
– Not present posterior to
LV
15. FAST: RUQ exam
• Probe placed
– Perpendicular
– Mid-coronal plane
– Just superior to the iliac
crest
• Probe facing
– Toward patient’s head
Evaluating
– Hepatorenal interface
– Possibility of fluid in
Morison’s pouch ( Right
Supramesocolic space)
16. FAST: RUQ exam
• Normal Anatomy
• In the supine patient,
the hepatorenal space
(Morison’s Pouch) is
the most dependent
space
Morison’
s
Pouch
17. FAST: Pelvis exam
• Pelvis: Longitudinal Axis
– Normal Anatomy
– In the erect patient, the pouch of
Douglas (Retrovesical space ) is
the most dependent space
18. FAST: Pelvis exam
• Pelvis: Longitudinally and Transvers Axis.
• Probe placed
– Transversally than Longitudinally
– Midline 2 cm superior to the symphysis
pubis
– “aimed” caudally into the pelvis
(prostate )
• Probe facing
– Toward patient’s head and right side.
• Best with some urine in bladder(acoustic
window)
• Evaluating
– Bladder ,Uterus in female ,and
Prostate in male
– The potential spaces are Pouch of
Douglas (Cul de sac ) in female and
Retrovesical space in male
– ‘
20. FAST: LUQ Exam
• Normal Anatomy
• More difficult to evaluate than
RUQ (do not have liver as acoustic
window)
• Left kidney more superior than
right
• Splenorenal Recess , Potential
space between kidney and spleen
• Presplenic /subphrenic space
between spleen and diaphragm (
most common space for fluid
collection in LUQ)
21. FAST: LUQ Exam
• Probe placed
– Perpendicular
– Mid - coronal plane
– Just superior to the iliac crest
• Probe facing
– Towards patient’s head
• Evaluating
– Spleno-renal interface
– Possibility of fluid in Splenorenal
recess and presplenic /subphrenic
space( most common space for
fluid collection in LUQ)
22. FAST: LUQ Exam
• Probe placed
– Perpendicular
– Mid - coronal plane
– Just superior to the iliac crest
• Probe facing
– Towards patient’s head
• Evaluating
– Spleno-renal interface
– Possibility of fluid in Splenorenal
recess and presplenic /subphrenic
space( most common space for
fluid collection in LUQ)
24. Extended FAST (E-FAST)
RUQ, LUQ views:
• Check above diaphragm for hemothorax
– CXR < US in detection of hemothorax
– 50-175cc vs. 20cc or less
• US does not replace CXR
Suprapubic view:
– Check uterus for pregnancy
26. FAST
Focused Abdominal Sonography In
Trauma
Reliability
• accuracy 86 - 97 %
• sensitivity 88 - 91.7 %
• specificity 94.7 - 99 %
Can detect 70 ml fluid (by linear probe can
detect as little as 10 ml or less)
27. How To Interpret FAST
–Positive:
• Fluid in pericardium or any 1 of 4 abdominal
windows
–Negative:
• No fluid in any windows
–Indeterminate:
• If any one of the 4 windows is inadequately
visualized
28. Scoring System of Fluid
• In lower volumes, fluid accumulates in the pelvis
or near the site of injury.
• It is not until there are larger intraperitoneal fluid
volumes (>500 mL) that fluid is detectable in the
perihepatic and perisplenic spaces.
• Recent studies show that FAST scan can detect
fluid ranges from approximately 250 mL to 620
ml.
Abrams BJ, Sukumvanich P, Seibel R, Moscati R, Joelle D. Ultrasound for the detection of
intraperitoneal fluid: Am J Emerg Med 1999;17(2):117–20.
29. Scoring System of Fluid
• One point is assigned to each anatomic site in which free fluid is
detected during the FAST scan, with a score ranging from 0 to 8.
• Fluid of more than 2 mm in depth in the hepatorenal or the
splenorenal space was given 2 points instead of 1.
• Floating loops of bowel were given 1 point.
• 96% of patients with scores 3 required exploratory laparotomy;
however, 38% of patients with scores <3 still required surgery.
• 84% sensitive and 71% specific for quantifying hemoperitoneum
greater or less than 1 L.
Huang and associates 1994
30. Modified Scoring System
• Revaluated scoring system measures the
depth of fluid in the deepest pocket, and 1
point is added for fluid in each of the other
areas (four areas maximum.)
• 85% of patients with a score[3 required a
therapeutic laparotomy, whereas 15% of
patients with a score of 2 required surgery.
McKenney et al
31. Does FAST Make a Difference In Trauma
Management?
• During primary or secondary survey
FAST
Positive NegativeIndeterminate
unstable stable
OR CT
unstable stable
OR
DPL
CT
DPL
Serial exam
Repeat US/ CT
Adapted from: Rozycki GS, et al. J Trauma, 1996
32. Pearls
• Lack of FF ≠ no injury
– Not enough to see (?too early)
– You missed it
– Hard-to-see places
• FF may not be blood
– Urine, lavage fluid, ascites,
amniotic fluid, bowel contents, ruptured cyst
33. Advantages of FAST
Easy & Early to Diagnose in
Resuscitation/Emergency room
Rapid(1 – 2.5 min)
Repeatable
Non-invasive
Low cost.
34. Difficult to distinguish
Type of fluid
Site of bleeding ,
Solid organ injury
Cannot evaluate retroperitoneum
Difficult in the obese patient ,
subcutaneous emphysema
Examiner Dependent.
Bowel gas interposition
False –Negative : retroperitoneal &
Hollow viscus injury
Disadvantages of FAST
36. Pearls
• The scan should be repeated during the secondary
survey and also if the patient demonstrates clinical
deterioration, since free fluid may have accumulated
in the intervening time .
• The quality of images obtained may also be a limiting
factor with patient obesity , gas in the bowel leading
to degradation in image quality , subcutaneous
emphysema , non-mobile patient and penetrating
injury.
37. Does FAST replace CT?
• Unstable patient, (+) FAST OR
• Stable patient, low force injury, (-) FAST consider observing patient.
CT is far more sensitive than FAST for detecting and characterizing abdominal injury in
trauma. The gold standard for characterizing intraparenchymal injury.
“Death begins with a CT.” Never send an unstable patient to CT. FAST, however, can be
performed during resuscitation.
FAST
Positive NegativeIndeterminate
unstable stable
OR CT
unstable stable
OR
DPL
CT
DPL
Serial exam
Repeat US/ CT
59. Solid-Organ Injuries (sonographic
patterns)
I. Contusion : patchy ill defined non-linear echogenic area .
II. Subcapsular hematoma : under capsule.
III. Intra-parenchymal hematoma : well defined rounded
hyperechoic area .
IV. Laceration : linear well defined hper / hypoechoic area.
V. Multiple lacerations/vascular injury (organic fracture,
disorganization )
71. References
• Vicki E Nobil , Manual of emergency and critical care ultrasound , Cabridge university 2007
• Rosen, C. Ultrasound in Emergency Medicine. Emergency Medicine Clinics of North America. August
2004. Volume 22. Number 3.
• O. John Ma and James R. Mateer. Emergency Ultrasound. McGraw-Hill. Medical Publishing Division.
2003.
• Simon, B. Ultrasound in Emergency and Ambulatory Medicine. Mosby. 1997
• Temkin, BB. Ultrasound Scanning: Principles and Protocols. WB Saunders. 1993.
• AIUM Practice Guideline for the Performance of the Focused Assessment With Sonography for Trauma
(FAST) Examination
• Wolfang Dahnert
• Ppt by Dr. Derhim Alfaqeeh Radiologist Consultant HO The Radiology Dept University Of
Science And Technology Hospital - Sana’a December 17, 2013