Category: 4. eFAST Exam Protocol

eFAST Lung Views: Does my patient have a pneumothorax?

Recall, the parietal pleura covers the surface of the thorax and the visceral pleura covers the lungs. The presence of these moving against one another produces lung sliding on ultrasound.

Lung Probe Position and Hand Placement

• Point your indicator towards the patient’s head.
• Place your probe at the mid-clavicular line at the 2nd intercostal space of the right and left lungs respectively. This point is the most sensitive spot for looking for pneumothorax in the supine patient.
• Anchor your probe in the space between two ribs and set the ultrasound machine depth to 3-5cm.

Identify Two Rib Shadows (Batwing Sign)

• The first lung ultrasound finding to confirm you are in the correct position is to look for the two rib shadows or the “Batwing Sign.” This ensures that your probe is in between two ribs.

Identify Lung Sliding

• The next finding you will want to look for is lung sliding during respiration.
• Lung sliding is a normal finding where the visceral and parietal pleura slide back and forth on one another as the patient breathes. Some say this looks like tiny “ants marching on a line.”
• “Ants Marching” sign is produced from the visceral and parietal pleura moving against one another during respiration.
• This is a simple finding but extremely useful since lung sliding definitely means that the visceral and parietal pleura are next to each other, effectively ruling out a pneumothorax.

Although looking for lung sliding using B-Mode is usually sufficient, you can also consider assessing for a pneumothorax using M-mode.

Identify Lung Sliding using M-Mode (Optional)

• If lung sliding is not readily apparent, it can be further be evaluated using M-Mode. The goal of M-Mode is to see if the patient has a normal seashore sign.
• Place the ultrasound machine in M-Mode (M-Mode for motion)
• Place the ultrasound doppler indicator/cursor over the lung field (NOT over the rib).
• Look for the normal “Seashore Sign“: Sky = Skin/Subcutaneous Tissue, Ocean= Muscle, Beach = Lung sliding motion (sandy appearance). The Seashore Sign is a NORMAL finding.
• Contrast this with the Barcode sign (see in eFAST pathology section below).

eFAST Cardiac View: Does my patient have a pericardial effusion with cardiac tamponade?

The subxiphoid view is the preferred scan to evaluate the heart and assess for any pericardial fluid. However, the subxiphoid view can be difficult to obtain in some situations (e.g. patient body habitus or abdominal pain with trauma). If the subxiphoid view cannot be obtained, a parasternal long axis view is recommended.

*Editor’s Note: In this post, we will be pointing the indicator based on the abdominal/eFAST ultrasound preset. When you are in the dedicated cardiac mode preset the indicator will be pointing 180 degrees in the opposite direction.

Cardiac Subxiphoid View

• Hold the probe in the palm of your hand and use an overhand grip.
• Point the probe indicator towards the patient’s right with the ultrasound machine depth set to around 15-20 cm.
• Using the liver as the acoustic window, simultaneously press the probe into the patient’s abdomen while tilting the tail of the probe towards the patient’s feet
• Aim the ultrasound beam towards the patient’s left shoulder.

• Identify the liver, pericardium, right atrium, right ventricle, left atrium and left ventricle

Cardiac Parasternal Long Axis

Consider obtaining the parasternal long-axis view of the heart in a patient when you are unable to obtain the subxiphoid view. Otherwise, proceed to scanning the lungs.

• Grasp the linear probe between your thumb and first finger, like holding a pencil.
• Anchor your third and/or fourth finger(s) in the 2nd or 3rd left intercostal space, just lateral to the sternum.
• Probe indicator towards the patient’s left hip with the machine depth set approximately 10-15 cm

• Identify the pericardium, mitral valve, aortic valve, right ventricle, descending aorta, left atrium, and left ventricle
• You may have to move up or down a rib space to identify the structures

eFAST Pelvic View: Does my patient have free fluid in the abdomen or pelvis?

When looking for free fluid in the pelvis it’s important to consider the sex of your patient, as free fluid has a tendency to accumulate in different locations depending on the patient’s gender. Additionally, females may have a scant amount of normal physiologic fluid accumulation in the pelvis (pouch of Douglas).

• Ideally, scan your patient with a full bladder (so the bladder can be used as an acoustic window). Therefore, try to initiate the scan prior to foley catheter placement.
• Machine Depth: 10-15 cm

Pelvic Ultrasound – Longitudinal View

• Place the transducer with the indicator pointing towards the patient’s head in the patient’s midline, right above the pubic symphysis.
• Rock the probe so that it points down towards the pelvic cavity.

Tip: One of the most important things to remember when performing pelvic ultrasound in the eFAST scan is that the bladder is directly posterior to the pubic bone/symphysis. If you are unable to get proper images, most likely your ultrasound probe is placed too superiorly.

• In males, identify the bladder (immediately posterior to the symphysis), prostate/seminal vesicle, and rectovesical pouch in the longitudinal view.
• The rectovesical pouch is where free fluid will accumulate in the male pelvis.

• In Females, identify the bladder, uterus, and Rectouterine Pouch (also called the Pouch of Douglas).
• The Pouch of Douglas is where free fluid will accumulate in the female pelvis.

• In all patients (male or female), observe the lateral borders of the bladder to identify free fluid by tilting/fanning the probe left and right.

Pelvic Ultrasound – Transverse View

• Next, center the bladder and then rotate the transducer 90 degrees counterclockwise. The indicator should now point to the patient’s Right side.
• Make sure to tilt the ultrasound probe so it scans into the pelvic cavity.

• In the transverse view, identify the Bladder, Uterus (females), Prostate (males), and Rectum.

• Tilt/Fan the probe to examine the entire pelvis from superior to inferior.

eFAST LUQ View: Does my patient have free fluid in the abdomen or left thorax?

LUQ Probe Position and Hand Placement

• Grasp the linear probe between your thumb and first finger, like holding a pencil.
• Orientate the probe indicator towards the patient’s head.
• Anchor your probe in the posterior axillary line around the 8th intercostal space.
• You should have your “Knuckles to the bed” since the spleen is fairly posterior.

LUQ Normal View and Structures

• Using the spleen as an acoustic window, identify the spleen, perisplenic space, diaphragm, and the long-axis view of the left kidney.
• Free fluid in the LUQ is most frequently seen in the perisplenic space (between the spleen and the diaphragm). The reason is that there is a splenorenal ligament limiting the ability of fluid to track in between the spleen and left kidney
• A Mirror Image Artifact is a normal finding, similar to the RUQ, signifying there is an aerated lung above the diaphragm.
• You may have to move up or down a rib space to identify the structures.
  • Tip: these structures move as the diaphragm contracts and relaxes during the respiratory cycle. Consider asking your patient to hold their breath to keep the desired organs from moving. Also, consider slightly rotating the probe clockwise towards the bed, so that the probe fits better between the rib spaces.

For the right upper quadrant and left upper quadrant views. Remember to look free fluid both above (hemothorax) and below (hemoperitoneum) the diaphragm.

eFAST RUQ View: Does my patient have free fluid in the abdomen or right thorax?

Since the liver is the most commonly injured organ in blunt abdominal trauma, the right upper quadrant is usually the most sensitive view of the eFAST exam.

RUQ Probe Position and Hand Placement

• Orientate the probe indicator towards the patient’s head.
• Anchor your probe in the midaxillary line at the 10th intercostal space.

RUQ Normal View and Structures

• Using the liver as an acoustic window, identify the lung, liver, Morison’s Pouch, diaphragm, and the long-axis of the right kidney.
• Morison’s Pouch is where you usually identify free fluid in the RUQ view.
• A Mirror Image Artifact is a normal finding signifying there is an aerated lung above the diaphragm.
• You may have to slide up or down a rib space to identify the structures.
  • Tip: these structures move as the diaphragm contracts and relaxes during the respiratory cycle. Consider asking your patient to hold their breath to keep the desired organs from moving. Also, consider slightly rotating the probe counterclockwise towards the bed so that the probe fits better between the rib spaces.

The eFAST Exam serves to answer 4 questions:

1. Does my patient have free fluid in the Abdomen?
2. Does my patient have free fluid in the Thorax?
3. Does my patient have fluid in the Pericardium?
4. Does my patient have a Pneumothorax?

We will first introduce you to the 5 steps of how to perform the eFAST ultrasound exam and then in the following section we will give you examples of all of the major eFAST pathologies you may encounter.