Trauma Ultrasound and E-Fast Examination



Trauma Ultrasound and E-Fast Examination


Morgan J. Crigger

Vicki Sein





1. A 25-year-old man presents after a high-speed motorcycle crash. His BP is 85/50 mm Hg, HR 120 bpm, and SpO2 90% on a non-rebreather mask. To prioritize operative versus diagnostic procedures, a Focused Assessment with Sonography in Trauma (FAST) examination is performed. Which of the following views/windows are included in this examination?


A. Hepatorenal, splenorenal, anterior left chest, anterior right chest


B. Hepatorenal, parasternal, splenorenal, subxiphoid


C. Hepatorenal, splenorenal, suprapubic, subxiphoid


D. Hepatorenal, anterior left chest, anterior right chest, subxiphoid

View Answer

1. Correct Answer: C. Hepatorenal, splenorenal, suprapubic, subxiphoid

Rationale: The FAST examination is indicated in patients who are hemodynamically unstable following blunt trauma. The examination allows for rapid assessment for hemoperitoneum and hemopericardium as the cause of hypotension. In addition, solid organ injury may be identified, but the sensitivity is inadequate to exclude these injuries on the basis of ultrasound alone. The FAST examination includes views of the pericardium from the subxiphoid window and the abdomen from the right upper quadrant (hepatorenal), left upper quadrant (splenorenal), and suprapubic (pelvic) windows. Views of the left and right chest are obtained in the eFAST examination to evaluate for pneumothorax and hemothorax. Additional views can be pursued for additional information (e.g., parasternal), but are not part of the traditional FAST examination.

Selected Reference

1. Rozyck GS, Oschner MG, Schmidt JA, et al. A prospective study of surgeon performed ultrasound as the primary adjuvant modality for the injured patient assessment. J Trauma. 1995;39(3):492-498.



2. A 55-year-old man is brought to the Emergency Department after being struck by a car while crossing a residential street. His BP is 90/55 mm Hg, HR 105 bpm, respiratory rate (RR) 18/min, and SpO2 95% on 2 L nasal cannula. A FAST examination reveals hypoechoic fluid in the pelvis, and his BP improves and stabilizes after 1 L intravenous (IV) lactated Ringer’s solution. What is the minimum volume needed in the peritoneal cavity to result in a positive FAST examination?


A. 100 mL


B. 200 mL


C. 500 mL


D. 1000 mL

View Answer

2. Correct Answer: B. 200 mL

Rationale: It takes approximately 200 mL of free fluid to be reliably detected on ultrasound. A volume smaller than this may be occasionally visible, but is unlikely to be the cause of hemodynamic instability. That said, one should repeat the FAST examination if ongoing bleeding is suspected, as an initial examination may be negative because of a small fluid volume. Also, a positive FAST does not necessarily mean that a patient needs an intervention, since many injuries can be managed nonoperatively.

Selected Reference

1. Branney SW, Wolfe RE, Moore EE, et al. Quantitative sensitivity of ultrasound in detecting free intraperitoneal fluid. J Trauma. 1995;39:375-380.



3. A 45-year-old man is brought to the Emergency Department after falling about 10 feet from a roof and striking a concrete driveway. The paramedics report that they initially had clear breath sounds bilaterally. Focused ultrasound of the lung is performed to evaluate for pneumothorax, and the following M-mode image is seen in Figure 60.1.







Which of the following is the most appropriate probe position to assess for pneumothorax?


A. Second-third intercostal space, midclavicular line


B. Fourth-fifth intercostal space, midclavicular line


C. Second-third intercostal space, midaxillary line


D. Fourth-fifth intercostal space, midaxillary line

View Answer

3. Correct Answer: A. Second-third intercostal space, midclavicular line

Rationale: Pneumothoraces tend to be “antidependent,” because the lung tissue is heavier than the pleural airspace. Therefore, evaluation for pneumothorax generally starts anteriorly and apically, at approximately the second or third intercostal space, in the midclavicular line, where a small pneumothorax is most likely to be detected. However, localized pleural disease is possible, so a more thorough examination of the chest is warranted if clinical suspicion is high.

Selected Reference

1. Kirkpatrick AW, Sirois M, Laupland K, et al. Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the extended focused assessment with sonography for trauma (EFAST). J Trauma Inj Infect Crit Care. 2004;57(2):288-295.



4. After Figure 60.1 is obtained, the trauma surgeon questions the diagnosis and requests that a chest x-ray be performed. What is the sensitivity of the extended FAST (eFAST) examination for diagnosing pneumothorax?


A. 0% to 25%


B. 26% to 50%


C. 50% to 85%


D. 86% to 100%

View Answer

4. Correct Answer: D. 86% to 100%

Rationale: The eFAST is composed of the traditional FAST examination with added views of the chest to identify and diagnose pneumothorax and hemothorax. The sensitivity for pneumothorax with this examination approaches 86% to 100%, in contrast with chest x-ray, which has a sensitivity 30% to 80%.

Selected Reference

1. Schellenberg M, Inaba K, Bardes JM, et al. The combined utility of extended focused assessment with sonography for trauma and chest x-ray in blunt thoracic trauma. J Trauma Acute Care Surg. 2018;85(1):113-117.



5. A patient presents to the Emergency Department after sustaining a gunshot wound to the chest. An eFAST examination is performed, demonstrating hypoechoic fluid in the pleural space. A chest tube is placed, and 300 mL of blood is drained. What is the approximate sensitivity of the eFAST examination for diagnosing hemothorax?


A. 25%


B. 50%


C. 75%


D. >90%

View Answer

5. Correct Answer: D. >90%

Rationale: Ultrasound is an excellent tool for detecting hemothorax in the trauma patient with blunt and penetrating chest injury. Multiple studies have assessed the utility of ultrasound to detect clinically significant hemothorax and they have shown 100% sensitivity and specificity with no false-negative or false-positive findings.

Selected Reference

1. Governatori NJ, Saul T, Siadecki SD, Lewis RE. Ultrasound in the evaluation of penetrating thoraco-abdominal trauma: a review of the literature. Med Ultrason. 2015;17(4):528-534.



6. A 45-year-old woman presents to the Emergency Department after a motor vehicle collision (MVC). Her BP is 120/65 mm Hg, HR 90 bpm, RR 14/min, and SpO2 99% on room air. An eFAST examination is performed and is noted to be positive in the right upper quadrant and in the pelvis. What is the sensitivity of eFAST for diagnosing hemoperitoneum in a patient without a hemodynamically significant amount of blood loss?


A. 15% to 20%


B. 30% to 40%


C. 60% to 70%


D. 90% to 100%

View Answer

6. Correct Answer: C. 60% to 70%

Rationale: An eFAST examination can be used to detect intra-abdominal injury in the blunt and penetrating trauma patient, but the sensitivity for solid organ injury and small-volume hemoperitoneum is significantly less than that for CT scan. With a small volume of fluid (<200 mL), the sensitivity is 60% to 70%, which has been shown over multiple trials. Fortunately, the sensitivity increases with increasing blood volume and is excellent when a hemodynamically significant amount of blood is present in the peritoneum. For this reason, serial reassessment is important if ongoing bleeding is suspected.

The moderate sensitivity may argue against performing eFAST in a hemodynamically stable patient. But, it is important to note that even though the sensitivity is low, the specificity of a positive eFAST is quite high (>90%) in most studies. Hence, a positive eFAST after an abdominal trauma identifies at-risk patients, though it cannot rule out solid organ injury.

Selected References

1. Branney SW, Wolfe RE, Moore EE, et al. Quantitative sensitivity of ultrasound in detecting free intraperitoneal fluid. J Trauma Inj Infect Crit Care. 1995;39(2):375-380.

2. Dolich MO, McKenney MG, Varela JE, et al. 2,576 Ultrasounds for blunt abdominal trauma. J Trauma Inj Infect Crit Care. 2001; 50(1):108-112.

3. Natarajan B, Gupta PK, Cemaj S, Sorensen M, Hatzoudis GI, Forse RA. FAST scan: is it worth doing in hemodynamically stable blunt trauma patients? Surgery. 2010;148(4):695-701.



7. In which of the following scenarios is the use of eFAST most appropriate?


A. A 95-year-old man with BP 110/65 mm Hg after an MVC


B. A 45-year-old woman with BP 85/50 mm Hg after an MVC


C. A 35-year-old man with BP 120/65 mm Hg after a gunshot wound to the abdomen


D. A 25-year-old woman with BP 80/40 mm Hg after a gunshot wound to the abdomen

View Answer

7. Correct Answer: B. A 45-year-old woman with BP 85/50 mm Hg after an MVC

Rationale: The FAST and eFAST examinations are noninvasive tests that can be performed concomitantly with resuscitation. The use of ultrasound evaluation is most indicated in a blunt trauma patient who is not stable to transport to CT, to evaluate for intraperitoneal fluid and determine the need for immediate operative intervention. CT is the preferred method of imaging for a stable patient and may provide information about other organ injuries as well. Penetrating trauma patients would be expected to have some degree of fluid in the chest or abdomen (depending on the site of injury), and a negative eFAST examination would not provide adequate reassurance; thus, it would not help clinical decision-making.

Selected Reference

1. EAST Practice Management Guidelines Work Group. J Trauma. 2002;53(3):602-615.



8. What is the most appropriate transducer to use for the abdominal portion of the eFAST examination?


A. 2 to 5 MHz curvilinear probe


B. 1 to 5 MHz phased array probe


C. 5 to 12 MHz linear probe


D. 8 to 13 MHz intracavitary probe

View Answer

8. Correct Answer: A. 2 to 5 MHz curvilinear probe

Rationale: Ultrasound probes penetrate tissue levels according to the frequency (MHz) of the transducer. Higher frequency probes have less penetration, but greater resolution at shallow depths. Lower frequency probes have greater penetration and allow for visualization of deeper structures. The 2 to 5 MHz curvilinear or convex array probe is best used to evaluate deep abdominal structures for injury. The 1 to 5 MHz phased array probe has a smaller footprint and allows for more advanced manipulation of the ultrasound beam, which is best used for pediatric examinations and echocardiography, although it would be a reasonable alternative if the curvilinear array probe was unavailable. The 5 to 12 MHz linear transducer probe is best used for superficial structures and vascular access, as well as evaluation of pneumothorax. The 8 to 13 MHz intracavitary probe is best used for transvaginal and oral evaluations due to its high-resolution images and the shape, which allows it to image from within a body cavity.

Selected Reference

1. Enriquez JL, Wu TS. An introduction to ultrasound equipment and knobology. Crit Care Clin. 2014;30(1):25-45.




9. A 35-year-old woman presents to the Emergency Department after an MVC. Her BP is 110/60 mm Hg, HR 90 bpm, RR 22/min, and SpO2 90% on room air. An eFAST examination is performed. Which of the following images is most consistent with a pneumothorax?







A. Figure 60.2A


B. Figure 60.2B


C. Figure 60.2C


D. Figure 60.2D

View Answer

9. Correct Answer: B. Figure 60.2B

Rationale: In addition to lung sliding seen on real-time B-mode ultrasound, M-mode can be used to detect motion. In normal lung ultrasound, a “seashore sign” is seen, indicating motion of the pleural layers below the chest wall, as seen in Figure 60.2D. The “barcode” or “stratosphere” sign indicates no motion of the pleura or lung, as seen in Figure 60.2B, and is indicative of pneumothorax. B-lines are seen with pulmonary interstitial fluid (Figure 60.2A), and their presence excludes pneumothorax at that location. A dark stripe around the lung can be seen with a pleural effusion or hemothorax (Figure 60.2C).

Selected Reference

1. Lichtenstein DA. Lung ultrasound in the critically ill. Ann Intensive Care. 2014;4(1). doi:10.1186/2110-5820-4-1.



10. A 45-year-old man with a history of hepatitis C cirrhosis arrives in the Emergency Department after an MVC. His BP is 90/55 mm Hg, HR 102 bpm, RR 18/min, and SpO2 95% on room air. Which of the following is true regarding the eFAST examination in a patient with ascites?


A. Blood appears more dense or with visible cells compared to ascites


B. The peritoneal fluid echogenicity can be compared to the pleural fluid echogenicity to distinguish blood from ascites


C. The eFAST examination has little diagnostic value for hemoperitoneum in this setting


D. Only the thoracic views of the eFAST should be performed in a patient with known ascites

View Answer

10. Correct Answer: C. The eFAST examination has little diagnostic value for hemoperitoneum in this setting

Rationale: The eFAST will detect intra-abdominal or intrathoracic fluid, but is unable to reliably differentiate between types of fluid. Although a hematocrit level may be apparent after blood cells have settled, in the acute setting, blood cannot be reliably differentiated from other fluids. Because of this, the abdominal and posterior thoracic views of the examination may be confounding, and additional clinical information may be necessary to guide management.

Selected Reference

1. Maitra S, Jarman R, Halford N, Richards S. When FAST is a FAFF: is FAST scanning useful in non-trauma patients? Ultrasound. 2008;16(3):165-168.

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Jun 9, 2022 | Posted by in CARDIOLOGY | Comments Off on Trauma Ultrasound and E-Fast Examination
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