EFASTRimon Bengiamin, MD, RDMS, FACEP

Objectives

• Discuss what the EFAST is and its utility in the setting of trauma

• Become familiar with the components/windows of the EFAST

• Review strategies to obtain the windows of the EFAST

• Recognize pathology and abnormal windows

Trauma 2 STAT• 26 year old male was at a family barbecue when

his girlfriend’s ex-boyfriend showed up and grabbed the barbecue fork and stabbed him

• BP 70/45 P 130 R 28 O2Sat 92%

• What do you want to know?

• What’s your differential?

Focused Assessment with Sonography in Trauma

• Abdominal sonography can detect as little as 50 cc of free fluid but generally you need about 200-250cc on average for a positive view

• An analysis of 62 publications with 18,167 patients revealed an overall sensitivity of 79% and a specificity of 99.2% for detecting free fluid, organ damage, or both. (1)

• Another study of emergency physicians showed a sensitivity of 90% and specificity of 99%. (2)

• Sensitivity increases with a repeat exam at 30 minutes. (3)

• Sensitivity is nearly 100 percent in the setting of hypotension and trauma

• What does this mean?

• It’s a good screening tool

• Not a good definitive test if your suspicion is high and the test is negative

Pros and Cons• Pros

• Rapid - the average time to perform a complete FAST examination of the thoracic and abdominal cavities is 2.1 to 4.0 minutes. (4,2)

• Noninvasive - less risk of infection/bleeding/other complications

• Repeatable - increases the sensitivity of the study

• Portable - convenient in unstable patients

• No contrast or radiation - renal failure and pregnant patients

• Cons

• Inability to determine the exact etiology in some cases

• Technically difficult in cases of obesity or bowel gas

• Cannot evaluate the retroperitoneum as well as CT

Focused Assessment With Sonography In Trauma (FAST)

• When should it be done?

• Part of the primary survey, particularly when evaluating circulation

• What does ATLS say?

• It is supported. Doesn’t really say when. Maybe after the primary survey? Some say after x rays.

• Practice management guidelines from the Eastern Association for the Surgery of Trauma recommend it be considered the initial diagnostic modality to exclude hemoperitoneum. (5)

• Why wait?

• CXR less sensitive than thoracic ultrasound.

• What will guide your treatment more than knowing the cause of instability?

• FAST can be performed simultaneously as other things are being done!

Focused Assessment With Sonography In Trauma (FAST)

• What about cases when there isn’t trauma?

• AAA

• Ruptured ectopic pregnancy

What Is The Extended FAST Exam?

• Also known as the EFAST

• The traditional FAST exam with the addition of evaluation of the thorax

• Thoracic exam includes looking for:

• Pneumothoraces

• Hemothoraces

Right Upper Quadrant• Evaluate three areas:

• Morison’s Pouch

• Most sensitive for detecting free fluid particularly if the patient is in Trendelenburg (6,7)

• Tip of the liver and pericolic gutter

• Slide the probe caudally

• Diaphragm

• Slide the probe cephalad and it may help to rotate the probe tip posteriorly (counterclockwise) to get through the ribs

Right Upper Quadrant -Probe Orientation-

Right Upper Quadrant -Morison’s Pouch-

Right Upper Quadrant -Positive Free Fluid-

Text

RUQ Diaphragm -Probe Orientation-

Right Upper Quadrant -Diaphragm-

Pelvic View

• The traditional view in ATLS is the transverse view

• However, evaluation of the pelvis in the saggital view, with the probe dot toward the head, can be more helpful

• Better delineation of the anatomy

• Helps with differentiation of free fluid

Pelvic View -Probe Orientation-

Pelvic View -Tips-

• If the bladder is empty you can use a bag of IV fluids and scan through it

• If the foley is in, it may help to instill fluid into the foley and clamp it to obtain a sonographic window

Pelvic View -Normal Female-

Pelvic View -Normal Male-

What is this?

Pelvic View -Free Fluid-

Left Upper Quadrant

• Unlike Morison’s view, evaluation of the interface between the kidney and spleen is not as important

• Free fluid does not commonly collect in this space because of the phrenicocolic ligament running in this area

• Fluid commonly collects around the tip of the spleen, base of the spleen, or between the spleen and diaphragm

Left Upper Quadrant -Probe Orientation-

Left Upper Quadrant

• Need to have the probe oriented more cephalad and posterior than with Morison’s view

• Also may help to rotate the probe tip posteriorly (counterclockwise) to get through the ribs

Left Upper Quadrant -Normal View-

Left Upper Quadrant -Free Fluid-

Left Upper Quadrant -Free Fluid-

Cardiac

• Looking mainly for pericardial effusion

• Classic view is the subxiphoid window

• If too difficult to obtain you may use the long axis parasternal window

• Can also evaluate contractility and the IVC (more to come in another lecture)

Cardiac (Subxiphoid) -Probe Orientation-

Cardiac Subxiphoid -Normal-

Cardiac Subxiphoid -Pericardial Effusion-

Cardiac (Parasternal) -Probe Orientation-

Cardiac -Parasternal Long Axis-

Cardiac Parasternal -Effusion with Clot-

Thoracic Ultrasound• What does it add?

• Evaluation for pnuemothorax

• Sliding lung sign

• Leading edge

• Comet tail artifact

• Evaluation for hemothorax

• RUQ and LUQ windows

Thoracic Ultrasound -Kirkpatrick et al. (8)-

• “EFAST has comparable specificity to CXR but is more sensitive for the detection of occult pneumothorax after trauma”

• Study of 225 patients

• EFAST more sensitive than CXR

• Picked up 63% of pneumothoraces missed on CXR

Thoracic Ultrasound -Comparison to CXR-

• Makes sense that it would be more sensitive particularly in the supine patient since the air will be anterior

• Can be life saving in the case of the unstable patient

• Zhang et al. (9)

• 135 trauma patients, 83 mech. ventilated

• 29 had a pneumothorax

• US: sensitivity 86%, NPV 96%

• CXR: sensitivity 28%, NPV 84%

• US: 2.3 minutes CXR:10.3 minutes

Sliding Lung Sign• Curvilinear (abdominal) or vascular probe

• The vascular probe tends to provide better quality images

• Position the probe:

• with the dot toward the head

• at the 2nd intercostal space

• at the midclavicular line

• Can use M mode to confirm - “waves crashing on a beach”

• Should see pleural lines

Thoracic Ultrasound -Probe Position-

Thoracic Ultrasound -Sliding Lung Sign-

Sliding Lung Sign -M Mode-

Thoracic Ultrasound -Sliding Lung-

• Can use sliding lung to estimate the size of a pneumothorax

• Actually need to map out the lung by evaluating for sliding lung at each of the intercostal spaces

Comet Tail Artifact

• Artifact perpendicular to the pleura casting a hyperechoic line into the lung parenchyma

• Normally seen in fully expanded lung

• Can also be seen in pathologic states such as pulmonary edema or consolidation

Thoracic Ultrasound -Comet Tail Artifact-

Thoracic Ultrasound -Pathologic Comet Tail-

Atelectasis

Consolidation

Kerley B Lines

Normal

Lung Point

Thoracic Ultrasound -Hemothorax-

• Upright CXR - 100 cc

• Supine CXR - 200-300 cc

• CXR can miss large effusions

• US can pick up as little as 20 cc of effusion

Thoracic ultrasound -Hemothorax-

EFAST -A Case-

EFAST -A Case-

EFAST -A Case-

EFAST -A Case-

EFAST -A Case-

EFAST -A Case-

EFAST

Questions?