The target view is an image showing the relevant structures

The diaphragm is displayed on the left side of the screen, when the OM correctly points towards the head in the coronal plane and the OI is on the left side of the screen

The structures identified in the RUQ view:
– Diaphragm – white hyperechoic (white) curved line above the homogenous liver tissue
– Liver – observe the many hypoechoic structures in the liver representing liver veins and bile ducts
– The right kidney – characteristic “kidney bean form” with hyperechoic calyces and kidney pelvis
– The hepatorenal recess – Morrison’s pouch
– The subdiaphragmatic space between the diaphragm and the liver

The target view is a 4 chamber image of the heart

Using the liver as an “acoustic window” makes it easier to visualise the beating heart
The apex of the heart is displayed on the right side of the screen

The structures identified in the the subcostal view:
– Liver
– Apex and base of the heart
– RA: Right atrium
– RV: Right ventricle
– LA: Left atrium
– LV: Left ventricle

Free fluid will collect between the heart and the pericardium, and is often seen as a black shadow between the liver and the heart

The cardiac views are reviewed in detail in the FATE e-learning course. For the FAST examination only the subcostal view is used

The subcostal view is obtained by placing the transducer in the subcostal position

According to convention, the apex of the heart should always point towards the right side of the screen

When an abdominal transducer is used the orientation marker should be directed towards the patient’s right shoulder. When a cardiac transducer is used, the OM should be directed towards the patient’s left shoulder

The FAST protocol includes 4 views:

– Position 1 – Subcostal view (Pos 1 – SC view)
– Position 2 – Right upper quadrant view (Pos 2 – RUQ view) – perihepatic view
– Position 3 – Left upper quadrant view (Pos 3 – LUQ view) – perisplenic view
– Position 4 – Pelvic longitudinal and transverse view (Pos 4 – P view)

The regions and organs pertinent to the FAST examination are:

– The subcostal part of the heart covered by the caudal part of the sternum

– The liver in the right upper quadrant (RUQ) of the abdomen and its relationship
to the diaphragm and the right kidney

– The spleen in the left upper quadrant (LUQ) of the abdomen, and its relationship
to the diaphragm and the left kidney

– The urinary bladder behind the pubic symphysis and its relationship to the uterus
in the female and the rectum in the male

Free fluid collects in these locations, which are examined by the FAST operator:

Pericardial cavity
– The space between the parietal and visceral pericardial layers; the pericardial cavity surrounds the heart

Right upper quadrant
– The hepatorenal recess (Morison’s pouch) between the liver and the right kidney
– The space between the liver and right diaphragm

Left upper quadrant
– The splenorenal recess between the spleen and the left kidney
– The space between the spleen and left diaphragm

Pelvis
– The rectouterine pouch in the female and the rectovesical pouch in the male

This lesson describes the anatomy and sonoanatomy relevant for performing the FAST protocol

This includes:
– Anatomy of relevant organs in the abdomen and location of the heart in thorax
– The 4 FAST views
– Placement and orientation of the transducer for the FAST views
– Orientation of the image on the ultrasound screen
– Identifying an appropriate reference point and anatomical structures
– Recognising diaphragm, liver/spleen, kidneys and urinary bladder on the ultrasound images

Focused Assessment with Sonography for Trauma (FAST) is a limited point-of-care ultrasound examination directed solely at identifying the presence of free intraperitoneal or pericardial fluid

In the context of traumatic injury, free fluid is usually due to haemorrhage and contributes to the assessment of the circulation, and the use of FAST in thoracoabdominal trauma expedites time to definitive care, because it can help determine whether emergent interventions such as chest tube thoracotomy or surgery are warranted