Abdominal Emergencies
Hassan Mashbari
Ahmed Al Hazmi
Brittany K. Bankhead-Kendall
Christopher R. Tainter
1. A 45-year-old woman presents complaining of acute-onset right upper quadrant (RUQ) abdominal pain associated with fever and vomiting. Her vital signs show a temperature of 38.6°C, HR 115 bpm, and her examination reveals tenderness in the RUQ. Based on Figure 69.1, which of the following additional sonographic findings would be most consistent with the suspected diagnosis?
 Figure 69.1 |
A. Gallbladder wall diameter is 3 mm
B. Contracted gallbladder
C. Pericholecystic fluid
D. Sludge visualized in the gallbladder
View Answer
1. Correct Answer: C. Pericholecystic fluid
Rationale: Acute calculous cholecystitis is inflammation of the gallbladder wall caused by a gallstone obstructing the cystic duct. RUQ ultrasound is the diagnostic test of choice due to its wide availability, portability, and efficiency. The overall sensitivity of ultrasound for acute cholecystitis is 90% to 95%, although the specificity is 78% to 80%. The sonographic findings of acute cholecystitis are well-described and include: the presence of gallstones (often seen at the gallbladder neck or cystic duct), gallbladder wall thickening (>3 mm), pericholecystic fluid, and a positive sonographic Murphy’s sign. The presence of two of these is diagnostic, although each has its own sensitivity and specificity (see Table 69.1).
Table 69.1 Screening Performance Characteristics of Emergency Department Bedside Sonography for Four Sonographic Findings of Acute Cholecystitis | |||||||||||||||||||||||||
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Selected References
1. Bennett GL, Balthazar EJ. Ultrasound and CT evaluation of emergent gallbladder pathology. Radiol Clin North Am. 2003; 41(6):1203-1216. doi:10.1016/S0033-8389(03)00097-6.
2. Cosby KS, Kendall JL. Right upper quadrant: liver, gallbladder, and biliary tree. In: Cosby KS, Kendall JL, eds. Practical Guide to Emergency Ultrasound. 2nd ed. Wolters Kluwer; 2014:133-155.
3. Kiewiet JJS, Leeuwenburgh MMN, Bipat S, Bossuyt PMM, Stoker J, Boermeester MA. A systematic review and meta-analysis of diagnostic performance of imaging in acute cholecystitis. Radiology. 2012;264(3):708-720. doi:10.1148/radiol.12111561.
4. Shekarchi B, Rafsanjani SZH, Fomani NSR, Chahardoli M. Emergency department bedside ultrasonography for diagnosis of acute cholecystitis; a diagnostic accuracy study. Emerg (Tehran). 2018;6(1):e11.
5. Strasberg SM. Acute calculous cholecystitis. N Engl J Med. 2008;358(26):2804-2811. doi:10.1056/NEJMcp0800929.
2. A 65-year-old man who presents for evaluation of flank pain and hematuria suddenly becomes hypotensive. His past medical history is significant for hypertension and a 30-pack-year smoking history. His initial BP was 160/90 mm Hg with a HR of 65 bpm. Repeat vital signs now show a BP of 85/45 mm Hg and HR 130 bpm. Which of the following ultrasound findings best correlates with this scenario and Figure 69.2?
 Figure 69.2 |
A. Calcifications of proximal abdominal aorta
B. Distal aorta diameter 6.5 cm
C. Dilated bowel with “target sign”
D. Bilateral grade 4 hydronephrosis
View Answer
2. Correct Answer: B. Distal aorta diameter 6.5 cm
Rationale: This presentation is concerning for a ruptured AAA. The classic presentation of AAA is the triad of abdominal or flank pain, palpable abdominal mass, and hypotension. Most aneurysms are asymptomatic and are usually found incidentally, but the diagnosis must be considered in any patient with risk factors (family history, hypertension, peripheral vascular disease, and history of tobacco use). The size of the AAA portends the risk of rupture, which carries a mortality rate of ˜70%. A normal abdominal aortic diameter is < 3 cm on the transverse view. An aneurysm <5 cm in size does not require immediate operative repair unless it is symptomatic, but aneurysms >5 cm are usually repaired even in asymptomatic patients.
POCUS can rapidly identify AAA and both the sensitivity and specificity are nearly 100% for the detection of AAAs. The presence of a dilated aorta or a periaortic fluid collection or hematoma on ultrasound should prompt emergent management for presumed rupture. Aortic calcification may warrant additional evaluation in the proper scenario, but does not itself raise concern for AAA rupture. A dilated bowel with a “target sign” is suggestive of intussusception, which is less likely in this case. Hydronephrosis due to ureteral obstruction from an aneurysm may occur, but this is not the most likely scenario in this case.
Selected References
1. Dean AJ. Abdominal Aorta. In: Cosby KS, Kendall JL, eds. Practical Guide to Emergency Ultrasound. 2nd ed. Wolters Kluwer; 2014:156-171.
2. Lech C, Swaminathan A. Abdominal aortic emergencies. Emerg Med Clin North Am. 2017;35(4):847-867. doi:10.1016/j.emc.2017.07.003.
3. Mellnick VM, Heiken JP. The acute abdominal aorta. Radiol Clin North Am. 2015;53(6):1209-1224. doi:10.1016/j.rcl.2015.06.007.
3. A 25-year-old man is brought to the Emergency Department (ED) after being involved in a high-speed motor vehicle collision. His initial vital signs showed a BP of 85/50 mm Hg and HR of 125 bpm after 2 L Lactated Ringer’s fluid resuscitation. He has generalized abdominal tenderness. A Focused Assessment with Sonography in Trauma (FAST) examination is performed and is shown in Figure 69.3.
 Figure 69.3 |
Which of the following is the most appropriate next step in his management?
A. Immediate operative intervention
B. Computed tomography (CT) to evaluate for intraperitoneal bleeding
C. Additional volume resuscitation for inferior vena cava (IVC) diameter <1.5 cm
D. Diagnostic peritoneal lavage
View Answer
3. Correct Answer: A. Immediate operative intervention
Rationale: A hypoechoic stripe visualized in the hepatorenal recess (Morison’s pouch) represents hemoperitoneum in this scenario. Given the hemodynamic instability, the most appropriate intervention is to proceed directly to exploratory laparotomy. Going to the CT scanner may be unsafe and would delay a necessary operative intervention. The IVC is not visualized in this image. Diagnostic peritoneal lavage may be considered if there is diagnostic uncertainty, if unable to obtain adequate views, or if there is an alternative explanation for the intra-abdominal fluid such as ascites (not the case in this scenario).
Selected References
1. Bailitz J. A problem-based approach to resuscitation of acute illness or injury. In: Cosby KS, Kendall JL, eds. Practical Guide to Emergency Ultrasound. 2nd ed. Wolters Kluwer; 2014:96-107.
2. Lobo V, Hunter-Behrend M, Cullnan E, et al. Caudal edge of the liver in the right upper quadrant (RUQ) view is the most sensitive area for free fluid on the FAST exam. West J Emerg Med. 2017;18(2):270-280. doi:10.5811/westjem.2016.11.30435.
3. Richards JR, McGahan JP. Focused assessment with sonography in trauma (FAST) in 2017: what radiologists can learn. Radiology. 2017;283(1):30-48. doi:10.1148/radiol.2017160107.
4. Richards JR, McGahan JP, Pali MJ, Bohnen PA. Sonographic detection of blunt hepatic trauma: hemoperitoneum and parenchymal patterns of injury. J Trauma Inj Infect Crit Care. 1999;47(6):1092. doi:10.1097/00005373-199912000-00019.
4. A 21-year-old woman presents to the ED with 2 days of periumbilical abdominal pain and nausea. The pain has migrated to the right lower quadrant (RLQ) and is now associated with fever and vomiting. Her physical examination demonstrates RLQ tenderness. A point-of-care ultrasound (POCUS) is performed, and a representative image is displayed in Figure 69.4.
 Figure 69.4 |
Which of the following findings would be most expected?
A. Free fluid visualized in the pouch of Douglas
B. Dilated loops of small bowel
C. Collapsed lumen of the colon
D. Target sign in the RLQ
View Answer
4. Correct Answer: D. Target sign in the RLQ
Rationale: Abdominal pain is one of the most common complaints in the ED and there is a concern for the overuse of ionizing radiation with CT scans. For this reason, the American College of Emergency Physicians and American College of Radiology recommend ultrasonography (US) as the initial radiologic modality for evaluation of acute appendicitis (AA), especially in the pediatric population. Ultrasound is less sensitive than CT (˜86%), but the specificity is high (˜95%).
The diagnosis of AA can be achieved by direct visualization of the appendix or indirectly by observing signs of local inflammation. Direct signs include noncompressibility of the appendix (except in the case of perforation), a diameter >6 mm, wall thickness ≥3 mm, visualized appendicolith (hyperechoic structure with posterior shadowing), enhanced vascularity (seen in early stages of AA) or decreased/absent vascularity (seen with abscess and necrosis), or the presence of a “target sign.” The target sign is described as a hypoechoic fluid-filled center surrounded by hyperechoic mucosa/submucosa, surrounded by a hypoechoic muscularis ring. Indirect signs of AA are free fluid surrounding the appendix, local abscess formation, increased echogenicity of adjacent mesenteric fat, enlarged mesenteric lymph nodes, thickening or hyperechogenicity of the peritoneum, and signs of secondary SBO.
Selected References
1. Benabbas R, Hanna M, Shah J, Sinert R. Diagnostic accuracy of history, physical examination, laboratory tests, and point-of-care ultrasound for pediatric acute appendicitis in the emergency department: a systematic review and meta-analysis. Acad Emerg Med. 2017;24(5):523-551. doi:10.1111/acem.13181.
2. Mostbeck G, Adam EJ, Nielsen MB, et al. How to diagnose acute appendicitis: ultrasound first. Insights Imaging. 2016;7(2):255-263. doi:10.1007/s13244-016-0469-6.
3. Noguchi T, Yoshimitsu K, Yoshida M. Periappendiceal hyperechoic structure on sonography. J Ultrasound Med. 2005;24(3):323-327. doi:10.7863/jum.2005.24.3.323.
4. Quigley AJ, Stafrace S. Ultrasound assessment of acute appendicitis in paediatric patients: methodology and pictorial overview of findings seen. Insights Imaging. 2013;4(6):741-751. doi:10.1007/s13244-013-0275-3.
5. Smith EA, Smith WL. Pediatric imaging. In: Farrell TA, ed. Radiology 101. Wolters Kluwer; 2020:144-174.
5. A 62-year-old woman presents with abdominal pain and fever for the last 4 days. Her vital signs are notable for a temperature of 39°C, HR 122 bpm, BP 115/90 mm Hg, RR 16/min, and SpO2 95% on room air. Her physical examination reveals RUQ tenderness and jaundice. A POCUS reveals Figure 69.5.
 Figure 69.5 |
Which of the following ultrasound findings is most supportive of the diagnosis?
A. Gallbladder wall diameter > 3 mm
B. IVC diameter > 2.5 cm
C. Common bile duct diameter > 8 mm
D. Gallstones visualized within the gallbladder
View Answer
5. Correct Answer: C. Common bile duct diameter >8 mm
Rationale: Acute cholangitis is a potentially fatal biliary infection caused by obstruction of the common bile duct, usually by a gallstone. The sonographic findings of acute ascending cholangitis include bile duct wall thickening and intraductal debris, often with associated biliary ductal dilatation >7 mm. While gallbladder wall thickness >3 mm and the presence of gallstones support the diagnosis of cholecystitis, this is not the most likely diagnosis in this case. A dilated IVC may suggest elevated central venous pressure, which may contribute to hepatic dysfunction, but again, this is not the most likely diagnosis.
Selected References
1. Cosby KS, Kendall JL. Right upper quadrant: liver, gallbladder, and biliary tree. In: Cosby KS, Kendall JL, eds. Practical Guide to Emergency Ultrasound. 2nd ed. Wolters Kluwer; 2014:133-155.
2. Oppenheimer DC, Rubens DJ. Sonography of acute cholecystitis and its mimics. Radiol Clin North Am. 2019;57(3):535-548. doi:10.1016/j.rcl.2019.01.002.
3. Parulekar SG. Ultrasound evaluation of common bile duct size. Radiology. 1979;133(3):703-707. doi:10.1148/133.3.703.
4. Sokal A, Sauvanet A, Fantin B, de Lastours V. Acute cholangitis: diagnosis and management. J Visc Surg. June 2019. Article in press. doi:10.1016/j.jviscsurg.2019.05.007.
6. A 45-year-old man presents to the ED with right flank pain. The pain is episodic and is associated with nausea and vomiting. His past medical history is significant for Crohn’s disease. His vital signs are normal except for HR 100 bpm, and his physical examination is only remarkable for left flank tenderness. Which of the following sonographic findings is most consistent with the tentative diagnosis and Figure 69.6?
 Figure 69.6 |
A. Increased echogenicity of the liver
B. Hyperechoic pancreatic tissue
C. Increased echodensity of the renal parenchyma
D. Dilatation of urinary collecting ducts
View Answer
6. Correct Answer: D. Dilatation of urinary collecting ducts
Rationale: The presentation and imaging shown in Figure 69.6 are most consistent with ureteral obstruction by a kidney stone. Nephrolithiasis can occasionally be visualized with POCUS but typically the only evidence supporting the clinical suspicion is the presence of hydronephrosis. Hydronephrosis can be identified as dilatation of the renal collecting ducts, which appears as a hypoechoic structure within the renal parenchyma (severity is graded by its sonographic appearance). If urolithiasis can be identified, it will appear as a hyperechoic structure within the ureter or renal pelvis.
Selected References
1. Favus MJ, Feingold KR. Kidney stone emergencies. 2018 Sep 13. In: Feingold KR, Anawalt B, Boyce A, et al., eds. Endotext [Internet]. MDText.com, Inc.; 2000. https://www.ncbi.nlm.nih.gov/books/NBK278956/.
2. Graham A, Luber S, Wolfson AB. Urolithiasis in the emergency department. Emerg Med Clin North Am. 2011;29(3):519-538. doi:10.1016/j.emc.2011.04.007.
3. Jendeberg J, Geijer H, Alshamari M, Cierzniak B, Lidén M. Size matters: the width and location of a ureteral stone accurately predict the chance of spontaneous passage. Eur Radiol. 2017;27(11):4775-4785. doi:10.1007/s00330-017-4852-6.
4. Laselle BT, Kendall JL. Trauma. In: Cosby KS, Kendall JL, eds. Practical Guide to Emergency Ultrasound. 2nd ed. Wolters Kluwer; 2014:21-25.
5. Ma OJ, Mateer JR, Reardon RF, Joing SA. Emergency Ultrasound. 3rd ed. McGraw-Hill Education; 2014.
7. A 67-year-old man presents with diffuse abdominal pain, abdominal distention, and vomiting. His past medical history is significant for hypertension and previous abdominal surgery after a gunshot wound. His vital signs show HR 127 bpm and BP 110/80 mm Hg, and he has diffuse abdominal tenderness on physical examination. An image from a point-of care ultrasound is shown in Figure 69.7.
 Figure 69.7 |
Which of the following ultrasound findings is most consistent with the presumptive diagnosis?
A. Free fluid in the peritoneum
B. Multiple hyperechogenic structures in the epigastrium
C. Bowel loop diameter 3.1 cm
D. Gallbladder diameter 3.1 cm
View Answer
7. Correct Answer: C. Bowel loop diameter 3.1 cm
Rationale: Figure 69.7 shows dilated loops of fluid-filled bowel, suggesting a small bowel obstruction (SBO). The most common cause for SBO is previous surgery resulting in adhesions. POCUS for SBO has a sensitivity over 97% and specificity of approximately 93%. Ultrasound findings of SBO include:
Bowel diameter >25 mm in three or more bowel loops
Bowel wall thickness >2 mm (caused by bowel wall edema)
Swirling motion of bowel content within the loops
Increased (to and from) or decreased peristaltic movements
Visible valvulae conniventes (plicae circulares) >2 mm (keyboard sign)
Noncompressible bowel close to collapsed, compressible small bowel (represents a transition point)
The presence of two or more of these findings in a critically ill patient is diagnostic for SBO and should prompt aggressive resuscitation, decompression of the bowel, and surgical evaluation.
Selected References
1. Abu-Zidan FM, Cevik AA. Diagnostic point-of-care ultrasound (POCUS) for gastrointestinal pathology: state of the art from basics to advanced. World J Emerg Surg. 2018;13(1):1-14. doi:10.1186/s13017-018-0209-y.
2. Frasure S. Accuracy of abdominal ultrasound for the diagnosis of small bowel obstruction in the emergency department. World J Emerg Med. 2018;9(4):267. doi:10.5847/wjem.j.1920-8642.2018.04.005.
3. Hefny AF, Corr P, Abu-Zidan FM. The role of ultrasound in the management of intestinal obstruction. J Emerg Trauma Shock. 2012;5(1):84-86. doi:10.4103/0974-2700.93109.
4. Schmutz GR, Benko A, Fournier L, Peron JM, Morel E, Chiche L. Small bowel obstruction: role and contribution of sonography. Eur Radiol. 1997;7(7):1054-1058. doi:10.1007/s003300050251.
5. Tayal VS, Lewis MR. Does the patient have a bowel obstruction? In: Bornemann P, ed. Ultrasound for Primary Care. Wolters Kluwer; 2021:158-16.
6. Ünlüer EE, Yavasi Ö, Eroglu O, Yilmaz C, Akarca FK. Ultrasonography by emergency medicine and radiology residents for the diagnosis of small bowel obstruction. Eur J Emerg Med. 2010;17(5):260-264. doi:10.1097/MEJ.0b013e328336c736.
8. A 39-year-old woman presents with a 3-day history of fever, malaise, and right-sided back pain. She has been on antibiotics for a urinary tract infection (UTI) since last week. Her vital signs show a temperature of 39.1°C, HR 125 bpm, BP 110/70 mm Hg, RR 18/min, and SpO2 97% on room air. Her physical examination is notable only for right costovertebral angle (CVA) tenderness. What finding is demonstrated in her ultrasound shown in Figure 69.8?
 Figure 69.8 |
A. A complex renal abscess
B. Grade 3 hydronephrosis with an obstructing stone
C. Multiple gallstones within a thickened gallbladder wall
D. A hepatic mass medial to the gallbladder
View Answer
8. Correct Answer: A. A complex renal abscess
Rationale: Perinephric and renal abscesses are rare complications of untreated UTIs, but the mortality rate approaches 50%. Due to the vague presentation and insidious onset, it can be difficult to make this diagnosis by examination alone. Symptoms can easily be mistaken for pyelonephritis. POCUS can help identify a perinephric or renal abscess as a fluid-filled mass with mixed echogenicity extending from the renal cortex into the perinephric fat. The presence of complicating factors includes prior stenting, urolithiasis, nephrolithiasis, and external compression.
Figure 69.8 shows a dual-image sonogram depicting a sagittal and transverse views of a complex renal abscess (arrows). Small air bubbles are seen as an echogenic focus.
Selected References
1. Bogler DM. Possible renal mass. In Sanders RC, eds. Clinical Sonography: A Practical Guide. 5th ed. Wolters Kluwer; 2015:575-587.
2. Coelho RF, Schneider-Monteiro ED, Mesquita JLB, Mazzucchi E, Marmo Lucon A, Srougi M. Renal and perinephric abscesses: analysis of 65 consecutive cases. World J Surg. 2007;31(2):431-436. doi:10.1007/s00268-006-0162-x.
3. Gardiner RA, Gwynne RA, Roberts SA. Perinephric abscess. BJU Int. 2011;107(Suppl. 3):20-23. doi:10.1111/j.1464-410X.2011.10050.x.
4. Liu X-Q. Renal and perinephric abscesses in West China Hospital: 10-year retrospective-descriptive study. World J Nephrol. 2016;5(1):108. doi:10.5527/wjn.v5.i1.108.
5. Shu T, Green JM, Orihuela E. Renal and perirenal abscesses in patients with otherwise anatomically normal urinary tracts. J Urol. 2004;172(1):148-150. doi:10.1097/01.ju.0000132140.48587.b8.
9. A 35-year-old man is admitted to the intensive care unit (ICU) because of a fever and new-onset hypotension. He had a splenectomy 4 days ago following a motor vehicle collision. On examination, he has tenderness in the RUQ. Which of the following sonographic findings is demonstrated in Figure 69.9?
 Figure 69.9 |
A. Hydronephrosis of the right kidney
B. Dilated loop of bowel
C. Distended gallbladder without gallstones
D. Intraparenchymal liver hematoma
View Answer
9. Correct Answer: C. Distended gallbladder without gallstones
Rationale: Figure 69.9 shows a thickened gallbladder wall, sludge, and pericholecystic fluid (arrow) suggesting acute acalculous cholecystitis. Acute acalculous cholecystitis results from bile stasis within the gallbladder and remains an elusive diagnosis due to the complex clinical setting in which it occurs.
Ultrasound is the diagnostic test of choice given its availability, portability, and diagnostic accuracy. Ultrasound findings consistent with acalculous cholecystitis include gallbladder wall thickening >3 mm, pericholecystic fluid, sludge within the gallbladder, distention of the gallbladder, pneumobilia (intramural gas), and the absence of gallstones.
Selected References
1. Balmadrid B. Recent advances in management of acalculous cholecystitis. F1000Research. 2018;7:1-8. doi:10.12688/f1000research.14886.1.
2. Bieker TM. The gallbladder and biliary system. In: Kawamura D, Nolan T, eds. Abdomen and Superficial Structures. 4th ed. Wolters Kluwer; 2018:171-211.
3. Huffman JL, Schenker S. Acute acalculous cholecystitis: a review. Clin Gastroenterol Hepatol. 2010;8(1):15-22. doi:10.1016/j.cgh.2009.08.034.
4. Tana M, Tana C, Cocco G, Iannetti G, Romano M, Schiavone C. Acute acalculous cholecystitis and cardiovascular disease: a land of confusion. J Ultrasound. 2015;18(4):317-320. doi:10.1007/s40477-015-0176-z.
10. A 72-year-old man presents to the ED with 2 days of fever, mental status changes, and RUQ abdominal pain. His temperature is 35°C, HR 130 bpm, BP 95/60 mm Hg, RR 20/min, and SpO2 89% on room air. His white blood cell (WBC) count is 17,000/mm3, his alanine aminotransferase (ALT) is 350 U/L (10-55 U/L), and total bilirubin is 0.7 mg/dL (0.0-1.0 mg/dL). A POCUS is performed and reveals Figure 69.10.
 Figure 69.10 |
What is the most likely diagnosis?
A. Air within the gallbladder
B. Hypoechoic hepatic mass medial to the gallbladder
C. An obstructing gallstone in the common bile duct
D. Calcifications with the gallbladder wall
View Answer
10. Correct Answer: A. Air within the gallbladder
Rationale/Critique: Figure 69.10 shows a highly echogenic reflection within the gallbladder wall, with posterior shadowing and reverberation artifact, representing intraluminal air (arrows). Emphysematous cholecystitis is a rare but rapidly progressing and life-threatening form of cholecystitis, with a mortality rate of up to 15%. Ultrasound will show signs of cholecystitis with a thickened gallbladder wall, pericholecystic fluid, and sonographic Murphy’s sign. Gas within the lumen causes a sonographic reverberation artifact, which can be seen in any portion of the gallbladder. In some cases, there may be small echogenic foci floating within the gallbladder lumen.
Selected References
1. Aherne A, Ozaki R, Tobey N, Secko M. Diagnosis of emphysematous cholecystitis with bedside ultrasound in a septic elderly female with no source of infection. J Emerg Trauma Shock. 2017;10(2):85-86. doi:10.4103/JETS.JETS_75_16.
2. Bieker TM. The gallbladder and biliary system. In: Kawamura D, Nolan T, eds. Abdomen and Superficial Structures. 4th ed. Wolters Kluwer; 2018:171-211.
3. Bloom RA, Libson E, Lebensart PD, et al. The ultrasound spectrum of emphysematous cholecystitis. J Clin Ultrasound. 1989;17(4):251-256. doi:10.1002/jcu.1870170404.
4. Oyedeji FO, Voci S. Emphysematous cholecystitis. Ultrasound Q. 2014;30(3):246-248. doi:10.1097/RUQ.0000000000000101.
5. Parulekar SG. Sonographic findings in acute emphysematous cholecystitis. Radiology. 1982;145(1):117-119. doi:10.1148/radiology.145.1.7122865.
6. Wexler BB, Panebianco NL. The effervescent gallbladder: an emergency medicine bedside ultrasound diagnosis of emphysematous cholecystitis. Cureus. 2017;7(7):5-9. doi:10.7759/cureus.1520.
11. A 53-year-old man is brought to the ED following a motor vehicle collision. His HR is 125 bpm, BP is 98/55 mm Hg, and he has bruises over the left upper abdomen. Which of the following statements is most true about the FAST examination?
A. An empty bladder does not affect the ability to detect free fluid.
B. Up to 10% of FAST examinations may be indeterminate.
C. Peritoneal blood is hyperechoic when compared to ascites or urine.
D. A FAST examination is not indicated in this patient.
View Answer
11. Correct Answer: B. Up to 10% of FAST examinations may be indeterminate
Rationale: The FAST examination has been established as a reliable method to rapidly evaluate for intra-abdominal blood in a trauma patient. However, its test characteristics are operator-dependent, and even in the hands of an experienced sonographer, up to 10% of scans can have a false negative. Small-volume hemorrhage can be missed and the presence of clot may be misinterpreted. Repeating the examination over time (or with a worsening clinical situation) can improve the sensitivity of the examination. An empty bladder decreases the acoustic window available for imaging the pelvis, which may decrease the sensitivity to a small blood volume. Fresh blood generally appears anechoic and is difficult to distinguish from urine or ascites. Because this patient shows signs of hemodynamic instability and has a suspected intra-abdominal injury, a FAST examination would be appropriate in his evaluation.
Selected Reference
1. Panebianco N. Ultrasound in acute trauma. In: Carmody KA, Moore CL, Feller-Kopman D, eds. Handbook of Critical Care and Emergency Ultrasound. McGraw-Hill; 2011: Chapter 24. Accessed November 13, 2019. http://accessanesthesiology.mhmedical.com/content.aspx?bookid=517§ionid=41066810.
12. An 85-year-old man with a past medical history of hypertension and a 65-pack-year smoking history presents to the ED with epigastric pain. His temperature is 37°C, HR 81 bpm, BP 167/85 mm Hg, RR 14/min, and SpO2 95% on room air. His abdominal examination reveals a pulsatile, nontender abdominal mass but no other significant findings. Which of the following is most correct regarding the ultrasound shown in Figure 69.11?
 Figure 69.11 |
A. The calipers provide an accurate measurement of the aortic diameter.
B. The presence of abdominal gas helps with the ultrasound identification of an abdominal aortic aneurysm (AAA).
C. The cylinder-tangent effect may overestimate the size of an AAA.
D. The measured diameter of the aorta should include the outer walls.
View Answer
12. Correct Answer: D. The measured diameter of the aorta should include the outer walls.
Rationale: The correct measurement of a AAA includes the outer walls. Measurement of the interior hypoechoic portion underestimates the size of the aneurysm, as does the cylinder-tangent effect, which can be mitigated by measuring in two planes. The use of ultrasonography in the ED to detect an AAA has a pooled sensitivity of 99% (95% confidence interval [CI] 96%-100%) and specificity of 98% (95% CI 97%-99%). The presence of abdominal gas may impair the ability to visualize the aorta.
Selected References
1. Carmody K, Moore CL. Ultrasound of the aorta. In: Carmody KA, Moore CL, Feller-Kopman D, eds. Handbook of Critical Care and Emergency Ultrasound. McGraw-Hill; 2011: Chapter 5. Accessed November 13, 2019. http://accessanesthesiology.mhmedical.com/content.aspx?bookid=517§ionid=41066791.
2. Daffner RH, Hartman M. Abdominal radiographs. In: Daffner RH, Hartman M, eds. Clinical Radiology. 4th ed. Wolters Kluwer; 2014:215-251.
13. A 21-year-old woman presents to the ED with sudden-onset RLQ abdominal pain and vomiting. She is sexually active and does not recall her last menstrual cycle. Her physical examination reveals mild tachycardia, focal tenderness in the RLQ, and right adnexal tenderness but no cervical discharge. Her urine beta human chorionic gonadotropin (BhCG) is positive. Which of the following is demonstrated in Figure 69.12?
 Figure 69.12 |
A. Free fluid in Morrison’s pouch
B. A hypoechoic stripe in the pouch of Douglas
C. An intrauterine pregnancy
D. A double decidual sac
View Answer
13. Correct Answer: B. A hypoechoic stripe in the pouch of Douglas
Rationale/Critique: Figure 69.12 shows an 8-week living ectopic pregnancy (with cardiac activity, not visualized in this image) in the cul-de-sac with an empty uterus and free pelvic fluid in the pouch of Douglas. POCUS can help diagnose an ectopic pregnancy using either the transabdominal or transvaginal approach, but the transabdominal approach should be attempted initially. A full bladder may facilitate visualization but is not required.
A definitive extrauterine pregnancy is diagnosed when a gestational sac with a yolk sac or fetal pole is seen outside the uterus. Findings suggestive of ectopic pregnancy include an empty uterus, pelvic free fluid (typically in the pouch of Douglas), an adnexal mass, or tubal rings.
Selected References
1. Hsu S, Euerle BD. Ultrasound in pregnancy. Emerg Med Clin North Am. 2012;30(4):849-867. doi:10.1016/j.emc.2012.08.001.
2. Mukul LV, Teal SB. Current management of ectopic pregnancy. Obstet Gynecol Clin North Am. 2007;34(3):403-419. doi:10.1016/j.ogc.2007.07.001.
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