Board Review Questions: January 2023

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1. An 8-month-old boy is brought in because he has been crying inconsolably for 2 hours. He has no history of excessive crying, recent illness, or injury. His vital signs include P 110, R 34, and T 37.4°C (99.3°F); SpO₂ is 99% on room air. Examination of the exposed infant reveals that he is well-developed and well-nourished. Skin and coloring are normal without rash or bruising. He has no obvious musculoskeletal abnormalities and does not cry more with palpation. The chest is clear of rales and rhonchi, but a cardiac examination is notable for a vibratory systolic ejection murmur grade 2/6 he has had since birth. Which diagnostic test should be performed?

1. CBC
2. Chest x-ray
3. Echocardiogram
4. Fluorescein staining of corneas

The correct answer is D, Fluorescein staining of corneas.

Why is this the correct answer?
When evaluating a crying infant, it is important to differentiate between emergent and benign causes of persistent crying. In this case, corneal abrasion should be considered since the patient appears well; fluorescein staining of the corneas is easily done and should be performed after more serious causes have been eliminated. Normal infant crying is characterized as crying that lasts less than 3 hours per day and is typically present in the afternoon to evening (around 3 pm to 11 pm). There is a long differential that includes life-threatening causes (eg, cardiac arrhythmia, nonaccidental trauma, and traumatic brain injury), limb-threatening causes (eg, fracture, hair tourniquets, and wounds), and more benign causes. The crying infant should be evaluated for fractures, skin injury (eg, lacerations, abrasions, and hair tourniquets), and nonaccidental trauma. It is important to ensure that the examination rules out the life- and limb-threatening causes of persistent crying, but benign causes are more common. The examination should be conducted with the infant completely undressed, including the diaper, and it should focus on conditions that are known culprits in persistent crying.

Why are the other choices wrong?

• A CBC provides no relevant information in the evaluation of a child who has no signs or symptoms of infection or anemia. Murmur is a common finding in younger children and is a normal variation in most.
• A chest x-ray is unwarranted in a child with a normal chest examination and no history of illness or trauma. After more serious causes of persistent crying have been eliminated, corneal abrasion should be considered and ruled out with fluorescein staining of the corneas.

An echocardiogram is excessive in the evaluation of an otherwise healthy infant with an innocent murmur. After more serious causes of persistent crying have been eliminated, corneal abrasion should be considered and ruled out with fluorescein staining of the corneas.

REFERENCES

Wilner EL, Patel S. Crying. In: Shaw KN, Bachur EG, Chamberlain J, Lavelle J, Nagler J, Shook JE, eds. Fleisher & Ludwig's Textbook of Pediatric Emergency Medicine. 8th ed. Wolters Kluwer; 2021:138-140.

Khan NS. The crying infant. In: Wolfson AB, Cloutier RL, Hendey GW, Ling LJ, Rosen CL, Schaider JJ, eds. Harwood-Nuss’ Clinical Practice of Emergency Medicine. 7th ed. Wolters Kluwer; 2021:1165-1167.

Pediatric EM Morsels article on the inconsolable infant
https://pedemmorsels.com/inconsolable-infant/

2. A 37-year-old woman presents with complaints of a large piece of steak stuck in her throat. She is able to swallow her own secretions but has not attempted to drink or eat. She has had impactions and episodic symptoms of heartburn before despite regular use of a proton pump inhibitor. After a few minutes, her symptoms resolve, and she can drink water. What is the most appropriate disposition?

A. Admit for close observation for complications
B. Arrange for urgent endoscopy in the emergency department
C. Discharge home with a referral for outpatient endoscopy
D. Observe for 6 hours and discharge if she remains asymptomatic

The correct answer is C, Discharge home with a referral for outpatient endoscopy.

Why is this the correct answer?
This patient has the typical symptoms of esophageal impaction. Because she could initially swallow her own secretions, watchful waiting is an appropriate treatment strategy, with endoscopy within 12 to 24 hours. With acute relief, she may be discharged home without further observation. Eosinophilic esophagitis should be considered in patients who present with recurrent esophageal food impaction and symptoms of gastroesophageal reflux disease despite the use of antacid medications. Patients are typically nonresponsive to high-dose proton pump inhibitors. Esophageal strictures are commonly seen in these patients, especially if the underlying condition is untreated, and can lead to recurrent impactions. Referral for outpatient endoscopy, for both diagnostic and therapeutic purposes, is the correct disposition.

Why are the other choices wrong?

• The patient's esophageal food impaction spontaneously passed on its own. Thus, admission is unnecessary if she remains asymptomatic.
• Although this patient does need to see a gastroenterologist for an endoscopy, biopsy, and further workup and management, she can safely do so as an outpatient. Indications for immediate endoscopy include significant distress, impactions that prevent handling of secretions, ingestion of sharp objects or button batteries, and impaction in the esophagus for longer than 24 hours.
• The food impaction resolved on its own, and the patient was able to drink water with no other symptoms. Thus, observation in the emergency department is unnecessary. Instead, this patient should be discharged home with an outpatient endoscopy referral.

REFERENCES

Nicholson AM, Hess JM. Esophagus, stomach, and duodenum. In: Walls RM, Hockberger RS, Gausche-Hill M, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Vol 1. 10th ed. Elsevier; 2023:1042-1057.

Bono MJ. Esophageal emergencies. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill Education; 2020:500-504.

3. A 28-year-old woman presents with abdominal bloating, diarrhea, and flatulence for the past week. She recently returned from a hiking trip and, when asked, admits to drinking water from a spring. Her vital signs include BP 110/68, P 82, R 18, and T 37.1°C (98.8°F). The physical examination is normal, and she is otherwise healthy. What is the best test to confirm the diagnosis of giardiasis?

A. Serum antibody
B. Stool antigen
C. Stool bacterial culture
D. Stool ova and parasite

The correct answer is B, Stool antigen.

Why is this the correct answer?
Giardiasis is caused by Giardia lamblia and is the most frequently diagnosed parasitic infection in the United States. Stool antigen is the test of choice for confirming the pathogen because it is consistently present in stool, regardless of Giardia cyst shedding (which is more variable). Giardiasis commonly affects hikers and campers who drink contaminated water, adults and children who spend time in child care centers, and people who engage in oral-anal sexual contact. Transmission can be waterborne, foodborne, or fecal-oral. Symptoms of giardiasis vary but generally include diarrhea, excessive flatulence, and abdominal bloating. In severe cases, steatorrhea (ie, excess fat in feces) can develop because saturation of the small bowel with organisms causes malabsorption. A patient experiencing fatty stools may describe them as greasy or sticky, pale, floating, or particularly bad smelling. Metronidazole, tinidazole, and nitazoxanide are among the appropriate therapies for giardiasis.

Why are the other choices wrong?

• Serum antibodies against Giardia lamblia can be detected; however, this test is generally unhelpful because it cannot differentiate between acute and prior infections.
• Giardia lamblia is a parasitic infection; thus, a stool bacterial culture will not be diagnostic.
• Giardia cysts are intermittently excreted in stool, leading to false-negative results with microscopy, and organisms quickly break down and become unrecognizable when voided. The sensitivity of the test increases with each repetition; although the CDC recommends assessing at least three different samples, this can be cumbersome, and results are dependent on technician expertise. One advantage of stool cultures and ova and parasite studies is their ability to rule out other potential infectious etiologies. However, if giardiasis is highly suspected, stool antigen remains the test of choice.

REFERENCES

Cahill JD, Becker BM. Parasites. In: Walls RM, Hockberger RS, Gausche-Hill M, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Vol 2. 10th ed. Elsevier; 2023:1654-1673.

Smith LM, Mahler SA. Food and waterborne illnesses. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill Education; 2020:1063-1069.

CDC information on diagnosing Giardia infections
https://www.cdc.gov/parasites/giardia/medical-professionals.html

4. A 20-year-old woman presents asking to be tested for an STI. She was recently with a new sexual partner and has noticed some mild discharge. The pelvic examination reveals no cervical motion tenderness. What is the most appropriate management at this time?

A. Confirmatory testing, then treatment only if positive
B. Single dose of both azithromycin and ceftriaxone
C. Single dose of ceftriaxone and 7 days of doxycycline
D. Single dose of ceftriaxone and 14 days of doxycycline and metronidazole

The correct answer is C, Single dose of ceftriaxone and 7 days of doxycycline.

Why is this the correct answer?
Cervicitis is inflammation of the cervix. Acute cervicitis is typically infectious, and Chlamydia trachomatis is the most commonly identified organism, followed by Neisseria gonorrhoeae. Coinfection is common, so CDC guidelines recommend treating for both without waiting for confirmatory testing, especially for women at increased risk. This category includes those younger than 25 years and those over 25 with a new sex partner, a sex partner with concurrent partners, or a sex partner who has an STI. Treatment consists of doxycycline 100 mg PO twice daily for 7 days for C. trachomatis and ceftriaxone 500 mg IM for N. gonorrhoeae; this is an update to previous guidelines as of 2021. Prompt treatment is essential to prevent the spread of infection to sexual partners, development of more significant infection (eg, pelvic inflammatory disease [PID], tubo-ovarian abscess, and endometritis), and development of long-term sequelae (eg, ectopic pregnancy and infertility). This is especially important for patients who present to emergency departments because follow-up is uncertain.

Why are the other choices wrong?

• Waiting for confirmatory test results may seem appropriate; however, many patients with chlamydial cervicitis are asymptomatic, so treatment without culture results is recommended. Annual screening for C. trachomatis is currently recommended for all sexually active women who are 25 years old or younger, older than 25 with new or multiple sexual partners, incarcerated, or pregnant. Annual screening for men is currently not recommended.
• A single dose of azithromycin and ceftriaxone was previously recommended by the CDC for treatment of cervicitis, but as of 2021, the CDC recommends a single dose of ceftriaxone and doxycycline for 7 days. Azithromycin alone was previously recommended for treatment of C. trachomatis, but it is no longer recommended as the first line of treatment; instead, doxycycline for 7 days is now recommended. Azithromycin is now listed as an alternative agent for C. trachomatis, but it is an inappropriate treatment for N. gonorrhoeae, which is a common coinfectant. Current CDC guidelines call for treating both C. trachomatis and N. gonorrhoeae without confirmatory testing.
• A single dose of ceftriaxone with 14 days of doxycycline and metronidazole is the appropriate treatment for PID, but this patient does not have signs or symptoms of PID. Pelvic examination in patients with PID commonly reveals cervical motion tenderness, cervical mucopus, and cervical erythema; these patients also typically have adnexal or uterine tenderness. Additionally, systemic symptoms are common, including malaise, nausea, vomiting, and fever. Unlike PID, presumed simple cervicitis can be treated with a single dose of ceftriaxone and doxycycline for 7 days rather than a 14-day course of antibiotics.

REFERENCES

Serrano KD. Sexually transmitted infections. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill Education; 2020:1013-1023.

2021 CDC treatment guidelines for chlamydial infections
https://www.cdc.gov/std/treatment-guidelines/chlamydia.htm

2021 CDC treatment guidelines for urethritis and cervicitis
https://www.cdc.gov/std/treatment-guidelines/urethritis-and-cervicitis.htm

5. When attempting transvenous pacing, what is the preferred site for access?

A. Right external jugular vein
B. Right femoral vein
C. Right internal jugular vein
D.Right subclavian vein

The correct answer is C, Right internal jugular vein.

Why is this the correct answer?
Emergency pacing is indicated for unstable bradycardias, unstable high-degree atrioventricular (AV) blockades, and overdrive pacing of torsade de pointes and ventricular tachycardia. Transvenous pacemakers are placed using specialized central line kits and are typically inserted through either the right internal jugular vein or the left subclavian vein because these are the more direct routes of passage to the heart. Inserting a transvenous pacemaker follows the same initial steps as central line insertion. After the catheter is in place, a special pacing wire is passed through the central line introducer and advanced approximately 10 cm. The distal balloon is inflated, and the wire is advanced until it reaches the apex of the right ventricle.

Proper placement can be confirmed by following ECG tracings, fluoroscopy, or cardiac ultrasonography. Once in place, the pacemaker should be set to demand mode at 80 to 100 bpm, and the output dial should be increased until capture. Once capture is obtained, the output dial should be lowered until capture is lost, and then it should be set at 1.5 to 2 times the minimal threshold output required for capture. In addition to known complications associated with central venous access, complications of transvenous pacing include cardiac dysrhythmias, myocardial perforation, catheter dislodgement, and circuit failure. Notably, the presence of a prosthetic tricuspid valve is an absolute contraindication to transvenous pacing.

Why are the other choices wrong?

• The right external jugular vein has a short course before joining the right internal jugular vein. It is often used for peripheral access, but it is not used for transvenous pacing.
• The right femoral vein may be used for transvenous pacing, but it is not preferred because it is difficult to access the right ventricle when entering the right atrium from the inferior vena cava. Instead, transvenous pacemakers are typically inserted through the right internal jugular vein or the left subclavian vein.
• The right subclavian vein can be used for transvenous pacing, but this involves entering the superior vena cava at a bifurcation, which significantly increases the risk of pacemaker wire misplacement. Thus, the left subclavian vein and right internal vein are preferred for access, when possible.

REFERENCES

Bessman ES. Emergency cardiac pacing. In: Roberts JR, Custalow CB, Thomsen TW, et al, eds. Roberts and Hedges’ Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Elsevier; 2019:288-308.

Lim SH, Teo WS, Anantharaman V. Cardiac pacing and implanted defibrillation. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill Education; 2020:216-222.