Questions, Board Review

Board Review Questions: October 2020

PEER (Physician’s Evaluation and Educational Review in Emergency Medicine) is ACEP’s gold standard in self-assessment and educational review. These questions are from PEER, updated continually on its digital platform. Order PEER to prepare!

1. An ill-appearing 6-year-old boy presents with a high fever, inspiratory stridor, accessory muscle use, and a barky cough that has worsened over the past hour. His mother says he had a positive flu test 10 days ago and that he can breathe better when he is flat on his back. Nebulized racemic epinephrine is administered, after which the stridor is unchanged. His SpO2 is 90% on room air. What is the best next step in management?
A. Administer dexamethasone and repeat nebulized racemic epinephrine
B. Prepare for intubation and administer intravenous antibiotics
C. Provide suctioning and supplemental oxygen only
D. Start intravenous antibiotics and order a chest x-ray


2. A 58-year-old woman presents with sharp chest pain. Her medical history includes chronic uncontrolled hypertension, and her blood pressure is 190/100. Which diagnostic test is most likely to help rule out aortic dissection?
A. ABG
B. Chest x-ray
C. D-dimer
D. ECG


3. A mother brings in her 2-year-old son after he choked on a peanut. Which symptom would indicate that the foreign body is in his bronchus?
A. Drooling
B. Hoarseness
C. Stridor
D. Wheezing


4. In the setting of a benzodiazepine overdose, flumazenil administration is contraindicated with which coingestant?
A. Bupropion
B. Carisoprodol
C. Gabapentin
D. Phenobarbital


5. Which facial bone fracture is associated with the lowest rate of infection?
A. Frontal
B. Mandibular
C. Orbital
D. Zygomatic

ANSWERS 

1. The correct answer is B, Prepare for intubation and administer intravenous antibiotics.

Why is this the correct answer?
Bacterial tracheitis is a rare condition that can cause severe upper-airway obstruction in children. In cases with signs of near-total airway obstruction, airway control takes priority over diagnostic evaluation. This patient requires intubation followed by intravenous administration of antibiotics, preferably vancomycin and a third-generation cephalosporin such as ceftriaxone. Bacterial tracheitis generally occurs in the first 8 years of life. It is characterized by purulent secretions of the tracheal mucosa below the vocal cords caused by a bacterial infection. Staphylococcus aureus is the most common cause, but Streptococcus pneumoniae, Streptococcus pyogenes, Moraxella catarrhalis, and Haemophilus influenzae are other known causes. Bacterial tracheitis often occurs following damage to the airway mucosa or inflammation that accompanies viral URIs.

Clinical features of bacterial tracheitis include signs of airway obstruction, such as stridor, cough, and respiratory distress. Fever is common, but drooling is uncommon. Patients appear toxic with a high fever and a rapidly progressing croup-like syndrome, and they often prefer to lie flat. Nebulized epinephrine and steroids are ineffective. Overall, bacterial tracheitis can appear very similar to croup. Imaging classically shows the steeple sign, which is a narrowing of the subglottic trachea that is indistinguishable from croup on plain films. Neck x-rays are not needed to make the diagnosis. Laboratory analysis is unhelpful; WBC count and C-reactive protein results vary widely in bacterial tracheitis and are not prognostic.

Why are the other choices wrong?

  • Giving dexamethasone and repeated doses of nebulized racemic epinephrine is usually sufficient to improve the condition of a patient with severe croup. However, this patient’s clinical picture (ie, toxic appearance, high fever) suggests a disease more severe than croup. Bacterial tracheitis or epiglottitis should be considered, and airway control is essential.
  • Guidelines from the American Academy of Pediatrics indicate that bronchodilators, steroids, and antibiotics are ineffective in treating bronchiolitis and that only supportive care is recommended. If this patient had bronchiolitis, suctioning and supplemental oxygen would be the correct management; however, this patient is older and has a more severe presentation than is expected for bronchiolitis. Intervention with airway management and antibiotics is indicated.
  • The development of bacterial pneumonia is common following influenza. Intravenous antibiotic therapy and a chest x-ray are indicated, but control of this patient’s impending respiratory failure is more urgent.

REFERENCES
Ralston SL, Lieberthal AS, Meissner HC, et al. Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis. Pediatrics. 2014 Nov;134(5):e1474-e1502.

Lucia D, Glenn J. Pediatric emergencies. In: Stone CK, Humphries RL, eds. CURRENT Diagnosis & Treatment Emergency Medicine. 8th ed. McGraw-Hill Education; 2017:964-1016.

Parikh RR, Huang CJ. Stridor and drooling in children. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill; 2020:789-798.

2. The correct answer is C, D-dimer.

Why is this the correct answer?
When chest pain and acute neurologic or vascular deficits are present, aortic dissection is the most likely diagnosis. Recently, D-dimer has been shown to be a sensitive biomarker for ruling out aortic dissection in those with a low pretest probability. Using a risk score (eg, the Aortic Dissection Detection Risk Score) to identify low-risk patients with D-dimer has been shown to be accurate and effective in a large cohort. Aortic dissection is deadly and difficult to diagnose. The classic presentation is sudden, severe, unrelenting pain in the chest or back. Longitudinal cleavage of the aortic wall by blood creates and can propagate a false lumen. CT angiography is the diagnostic test of choice.

Why are the other choices wrong?

  • An ABG analysis has no diagnostic utility in suspected acute aortic dissection. However, hypotension can lead to acidosis, which can be seen with ABG testing.
  • Chest x-ray is always obtained in suspected aortic dissection. Assessing for widening of the mediastinum is classically taught; however, this is a poor diagnostic tool with low sensitivity. A tortuous aorta — which is quite common in hypertensive patients — causes a widened mediastinum as well as many other etiologies, including tumor, adenopathy, lymphoma, and enlarged thyroid.
  • ECG is not diagnostic for aortic dissection, but approximately two-thirds of ECGs are abnormal in patients with dissection. Abnormal ECG findings that can be seen include left ventricular hypertrophy from hypertension, ST-segment elevation from dissections involving a coronary artery, or nonspecific changes from generalized coronary artery disease.

REFERENCES
Afshar N. Aortic dissection. In: Adams JG, Barton ED, Collings JC, DeBlieux PMC, Gisondi MA, Nadel ES, eds. Emergency Medicine Clinical Essentials. 2nd ed. Elsevier Saunders; 2013:561-570.

Asha SE, Miers JW. A systemic review and meta-analysis of D-dimer as a rule-out test for suspected acute aortic dissection. Ann Emerg Med. 2015 Oct;66(4):368-378.

Ankel FK, Stanfield SC. Aortic dissection. In: Walls RM, Hockberger RS, Gausche-Hill M, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Vol 1. 9th ed. Elsevier; 2018:1021-1026.

Shimony A, Filion KB, Mottillo S, Dourian T, Eisenberg MJ. Meta-analysis of usefulness of D-dimer to diagnose acute aortic dissection. Am J Cardiol. 2011 Apr 15;107(8):1227-1234.

3. The correct answer is D, Wheezing.

Why is this the correct answer?
Foreign bodies can lodge in any of the anatomic structures in a toddler’s pharynx, airway, or esophagus. The presenting symptoms can provide a clue to the location of the foreign body and the urgency of treatment; for instance, a wheezing sound comes from the narrowing of the airways at the level of the bronchus. Most foreign bodies, especially in children, become obstructed at this level because the larynx and trachea are generally larger than the bronchus. A child who is wheezing because of foreign body aspiration but is not cyanotic can be watched in the emergency department or admitted for urgent bronchoscopy.

Chest x-rays are generally unhelpful because most foreign bodies are nonopaque food particles; peanuts are the most frequently identified food culprit. Indirect evidence of a foreign body can be seen on a chest x-ray with unilateral air trapping or atelectasis on the affected side. Unobserved foreign body aspiration should be considered a possible etiology in any child with unilateral wheezing. If a foreign body is opaque and flat, the location can be determined based on the direction of the item; a flat foreign body appears on edge if in the trachea on an anteroposterior image or in the esophagus on a lateral view.

Why are the other choices wrong?

  • Drooling can occur from a foreign body obstructing the esophagus or the pharynx. Although there may be no airway obstruction, young children drool rather than spit (as adults do) if they cannot swallow their own secretions due to an esophageal obstruction. If a drooling pediatric patient has no respiratory symptoms, including stridor or tachypnea, then the foreign body is likely in the esophagus, and a pediatric gastroenterologist should be consulted.
  • Hoarseness occurs in patients with an obstructing foreign body in the pharynx or larynx generally at or above the level of the vocal cords. An aspirated foreign body can be asymptomatic initially but then lead to increasing swelling or tissue granulation, resulting in interference with the vocal cords and worsening hoarseness over time. In this situation, an otolaryngologist should be consulted.
  • Stridor is generally noted with foreign bodies obstructing at the level of the vocal cords or just below in the trachea. This is a much more alarming indication of obstruction, and emergent evaluation — including involvement by a pediatric pulmonologist or otolaryngologist — should be obtained. If the patient is in extremis, the emergency physician can carefully use a laryngoscope to view the larynx and remove a foreign body if it is seen above the vocal cords. If not, intubation can be performed, with the attempt to push the tracheal foreign body into one bronchus. Because children generally have larger trachea distally, the foreign body generally does not get stuck again until it reaches the bronchus.

REFERENCES
Freire G, Shefrin AE, Zemek R. Wheezing in infants and children. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill; 2020:798-810.

Young T, Brown L. Foreign bodies. In: Wolfson AB, Cloutier RL, Hendey GW, Ling LJ, Rosen CL, Schaider JJ, eds. Harwood-Nuss’ Clinical Practice of Emergency Medicine. 6th ed. Wolters Kluwer; 2015:1247-1249.

4. The correct answer is A, Bupropion.

Why is this the correct answer?
Flumazenil remains a controversial antidote, but it can be used safely both diagnostically and therapeutically in a very select group of patients. Contraindications to the use of flumazenil include the coingestion of a proconvulsant drug (such as bupropion) and a history of convulsions. Bupropion, both therapeutically and in overdose, can cause convulsions. In the setting of an ingestion of both a benzodiazepine and a proconvulsant drug, flumazenil can reverse the benzodiazepine’s protective effect on seizure prevention and is thus contraindicated. In the setting of an overdose of unknown medications, the presence of findings that are inconsistent with a pure benzodiazepine overdose or are suggestive of a proconvulsant coingestant (such as convulsions, mydriasis, tachycardia, and QRS width prolongation) contraindicates flumazenil administration.

Why are the other choices wrong?

  • Carisoprodol does not cause convulsions in overdose, so the coingestion of it with a benzodiazepine is not a contraindication for flumazenil administration. However, carisoprodol can be associated with myoclonic jerking in overdose, which can mimic convulsions. There is some evidence that carisoprodol’s sedative effects can be reversed with flumazenil.
  • Gabapentin does not cause convulsions in overdose. Thus, the coingestion of gabapentin with a benzodiazepine does not contraindicate flumazenil administration.
  • Phenobarbital overdose does not cause convulsions and is not a contraindication for flumazenil administration in the setting of a benzodiazepine overdose. Notably, some patients take phenobarbital for seizure disorders; although the seizure disorder itself is a contraindication to the use of flumazenil, the medication as a coingestant with benzodiazepines is not a contraindication.

REFERENCES
Howland MA. Flumazenil. In: Nelson LS, Howland MA, Lewin NA, Smith SW, Goldfrank LR, Hoffman RS, eds. Goldfrank’s Toxicologic Emergencies. 11th ed. McGraw-Hill Education; 2019:1094-1098.

Quan D. Benzodiazepines. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill; 2020:1215-1218.

5. The correct answer is D, Zygomatic.

Why is this the correct answer?
Because the zygomatic bone does not lie directly over a sinus or the oropharynx, the risk of infection following fracture is lower than it is with the other fractures listed. The zygoma can be fractured as the result of a direct blow, which can indent the cheek and cause cosmetic deformity. Although isolated fractures of the zygomatic bone are fairly uncommon, these fractures often require surgical repair due to the resulting deformity of the face. Patients with zygoma fractures can also present with hypesthesia in the distribution of the infraorbital nerve.

Why are the other choices wrong?

  • Frontal bone fractures often involve the frontal sinus, placing them at higher risk for infection. Antibiotic prophylaxis is indicated if the frontal sinus is involved. In general, coverage for sinus infections is similar to that for oral infections: A beta-lactam antibiotic (such as penicillin) or an extended-spectrum beta-lactam antibiotic (such as amoxicillin-clavulanic acid) is appropriate. Clindamycin should be used, however, if the patient is allergic to penicillin.
  • Mandibular fractures often involve the teeth and gingiva hidden in the interdental spaces. An open fracture can be difficult to detect without a careful examination; for this reason, a high risk of infection is associated with these fractures. Antibiotic prophylaxis is indicated if the fracture is open. In general, coverage with a beta-lactam antibiotic (such as penicillin) or an extended-spectrum beta-lactam antibiotic (such as amoxicillin-clavulanic acid) is appropriate, but clindamycin should be used if the patient is allergic to penicillin.
  • Orbital fractures often communicate with the frontal, maxillary, or ethmoidal sinuses. They are consequently prone to infection, and antibiotic prophylaxis is indicated if the sinuses are involved. Patients should also be instructed regarding nose-blowing precautions.

REFERENCES
Mayersak RJ. Facial trauma. In: Walls RM, Hockberger RS, Gausche-Hill M, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Vol 1. 9th ed. Elsevier; 2018:330-344.

Hedayati T, Amin DP. Trauma to the face. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill; 2020:1714-1722.

Sprinkel K, Colucciello C. Maxillofacial injuries. In: Wolfson AB, Cloutier RL, Hendey GW, Ling LJ, Rosen CL, Schaider JJ, eds. Harwood-Nuss’ Clinical Practice of Emergency Medicine. 6th ed. Wolters Kluwer; 2015:158-166.

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