Questions, Board Review

Board Review Questions: August 2022

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1. A 9-year-old boy presents with progressive facial swelling. His features are distorted from swollen eyelids and generalized edema. Examination of his abdomen is consistent with mild ascites. He has not had any recent infections. Urinalysis reveals 4+ protein and no hematuria. What is the physiologic cause of this patient's edema?

A. Decreased excretion of free water due to decreased glomerular filtration in the kidney
B. Decreased production of albumin and other proteins in the liver
C. Release of nitric oxide, histamine, and other inflammatory mediators from mast cells
D. Urinary excretion of protein leading to decreased oncotic pressure in the plasma

The correct answer is D, Urinary excretion of protein leading to decreased oncotic pressure in the plasma.

Why is this the correct answer?

This boy is presenting with a nephrotic syndrome, which could be induced by a number of different pathological changes in the glomerulus. These processes lead to increased permeability of the glomerulus to proteins and the excretion of proteins in the urine, hence the large amount of protein detected on urinalysis. This leads to decreased serum albumin and hypoproteinemia, with a loss of oncotic pressure in the plasma and resulting generalized edema. The kidney also retains salt and water in response to increased aldosterone secretion, and the edema worsens. The liver attempts to counter the loss of albumin by increasing protein production of all kinds, including lipoproteins, leading to hyperlipidemia and hypercoagulability.

In this patient, the most likely renal pathology is minimal change disease. It is the most common primary glomerulonephritis in children and one of the few that is unlikely to have concomitant hematuria. A similar complaint with a recent URI is a typical presentation for post-Streptococcus glomerulonephritis. Other causes of glomerulonephritis include Henoch-Schönlein purpura, focal segmental glomerulonephritis, and membranous glomerulonephritis (as seen in systemic lupus erythematosus).

Why are the other choices wrong?

  • When faced with decreased blood flow to the glomerulus, the kidney responds appropriately by decreasing filtration and retaining sodium and free water as much as possible. This decreased filtration leads to the uremia seen in acute kidney injury from shock or severe dehydration. This patient has increased filtration, which has become less selective, and he is losing proteins from the plasma.
  • In the nephrotic syndrome, the liver increases production of albumin and other proteins to compensate for the loss in the urine. This results in hyperlipidemia and hypercoagulability.
  • Anaphylaxis is the result of sudden degranulation of mast cells in response to an antigen. These granules contain preformed vasoactive substances, including histamine and nitric oxide that lead to increased vascular permeability and edema. This patient is suffering from the gradual onset of nephrotic syndrome rather than the sudden and immediate effects of anaphylaxis.

REFERENCES

Wolfson AB. Renal failure. In: Walls RM, Hockberger RS, Gausche-Hill M, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Vol 1. 9th ed. Elsevier; 2018:1179-1196.

Dixon A, Stauffer B. Renal emergencies in children. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill; 2020:881-888.


2. A 52-year-old man presents with severe chest pain radiating to his neck. The pain started acutely 2 hours ago, has been unrelenting, and is worse with deep breathing and swallowing. According to his wife, he "smoked a joint before that and then threw up so hard he vomited blood." The patient confirms this, and his voice is notably hoarse. On examination, he appears distressed due to pain, and his skin is sweaty. His vital signs are BP 124/89, P 112, R 24, and T 37.4°C (99.3°F); SpO2 is 98% on room air. What is the most likely cause of this patient's symptoms?

A. Acute myocardial infarction
B. Boerhaave syndrome
C. Peptic ulcer disease
D. Spontaneous pneumothorax

The correct answer is B, Boerhaave syndrome.

Why is this the correct answer?

Boerhaave syndrome is a life-threatening, full-thickness perforation of the esophagus from a rapid rise in esophageal pressure. It can result from any straining valsalva maneuver or weakening of the esophageal mucosa (eg, forceful vomiting, coughing, heavy lifting, childbirth, foreign body or caustic ingestion, esophagitis, cancer, or trauma). The patient’s history of marijuana use with several episodes of vomiting is consistent with cannabinoid hyperemesis syndrome. Boerhaave syndrome classically results in sudden, severe, and unrelenting chest pain that may radiate to the neck, back, shoulders, and abdomen. Thirty percent of patients develop emphysema in the mediastinal or cervical areas, resulting in crepitus on palpation or a Hamman crunch on auscultation. It is important to note that mediastinal emphysema can take time to develop; its absence does not necessarily rule out perforation. Although Boerhaave syndrome is often the cause of esophageal perforation, it is no longer the most common cause. In this era, iatrogenic causes are more common, resulting from upper endoscopy, esophageal dilatation, transesophageal echocardiography, variceal treatment, and a variety of injuries.

Why are the other choices wrong?

  • The presentation of Boerhaave syndrome can be clinically challenging and can mimic other conditions. Although acute myocardial infarction should be considered in a patient who presents with chest pain, it is unlikely given the other aspects of the complaint. 
  • This patient has a trigger for powerful emesis with evidence for laryngeal involvement. Peptic ulcer disease can produce vomiting with bloody emesis but usually has a relationship with food and body position. Perforation caused by an ulcer can produce severe pain, but this would usually not ascend into the neck or shoulders. 
  • Pain from pulmonary embolism is not associated with episodes of forceful vomiting. Perforation of the lower esophagus can cause a pneumothorax, but this would not be a primary presentation of a spontaneous pneumothorax.

REFERENCES

Raja AS. Thoracic 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; 2018:382-403.

Lee AW, 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. 9th ed. Elsevier; 2018:1067-082.

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; 2020:500-505.


3. What is the treatment of choice for Rocky Mountain spotted fever in pediatric patients?

A. Chloramphenicol
B. Doxycycline
C. Supportive care
D. Trimethoprim-sulfamethoxazole

The correct answer is B, Doxycycline.

Why is this the correct answer?

Rocky Mountain spotted fever (RMSF) is a tick-borne illness caused by Rickettsia rickettsii. Doxycycline is the treatment of choice for all age groups and should be initiated within 5 days of symptom onset without waiting for confirmatory testing. Although tetracyclines are typically avoided in children younger than 8 years, new studies have shown a lack of permanent dental staining that was previously thought to occur with use in pediatric patients. Additionally, doxycycline has been shown to be superior to other antibiotics for the treatment of RMSF and should be given as soon as clinically suspected. Doxycycline should be given for at least 3 days after fever subsides, often 7 to 14 days. Contrary to its name, most cases (60%) are reported in the following five states: Arkansas, Missouri, North Carolina, Oklahoma, and Tennessee. Common symptoms of RMSF include fever, rash, headache, myalgias, abdominal pain, and vomiting. The rash is described as small macules starting on extremities, including palms or soles (or both), and spreading to the torso and later becoming petechial. In severe cases, the illness can cause a vasculitis, multi–organ system failure, and even death. Early treatment improves outcomes, especially in pediatric patients, who are five times more likely to die from RMSF than adults are.

Why are the other choices wrong?

  • Chloramphenicol is sometimes used to treat RMSF in pregnant patients with a mild course of illness or in patients with life-threatening allergies to doxycycline. Chloramphenicol should not be given routinely, however, as there is an increased mortality rate compared to doxycycline. Additionally, there is no oral form available in the United States, and chloramphenicol has some severe side effects, including aplastic anemia and gray baby syndrome.
  • Supportive care is encouraged in RMSF, especially for patients with severe illness and multi–organ system failure. However, supportive care alone is insufficient for the treatment of RMSF. Doxycycline must be given as soon as clinically suspected because a delay in treatment leads to increased morbidity and mortality rates.
  • Trimethoprim-sulfamethoxazole should not be used to treatment RMSF because it is less effective than doxycycline. Furthermore, sulfa drugs can worsen infection.

REFERENCES

Kitch BB, Meredith JT. Zoonotic infections. Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill; 2020:1070-1079.

Todd SR, Dahlgren FS, Traeger MS, et al. No visible dental staining in children treated with doxycycline for suspected Rocky Mountain Spotted Fever. J Pediatr. 2015 May;166(5):1246-1251.

CDC information about Rocky Mountain spotted fever
https://www.cdc.gov/rmsf/index.html

CDC article about research on doxycycline
https://www.cdc.gov/rmsf/doxycycline/


4. An 80-year-old woman presents with pressure in her pelvis that is worsened by standing up or bearing down. She has not had any surgeries and has four grown children. She is otherwise asymptomatic; she denies dysuria, urinary dribbling, vaginal bleeding, and abdominal pain. A descending soft circular mass is discovered within the vagina on pelvic examination. What is the most likely diagnosis?

A. Cystocele
B. Prolapsed fibroid
C. Rectocele
D. Uterine prolapse

The correct answer is D, Uterine prolapse.

Why is this the correct answer?

Patients with uterine prolapse typically complain of pelvic pressure that is worse with standing up or bearing down. The symptoms get better when the patient lies down. On pelvic examination, the uterus is seen coming down into the center of the vagina. Risk factors include increased age, parity, obesity, and past surgery. For mild symptoms, patients are treated as outpatients with nonoperative techniques, such as pelvic exercises, weight loss, and pelvic pessaries. More severe symptoms may require surgical repair.

Why are the other choices wrong?

  • A cystocele is a form of pelvic relaxation in which the bladder wall prolapses down through the anterior wall of the vagina. Symptoms include urinary incontinence or difficulty emptying the bladder.
  • A prolapsed fibroid or leiomyoma is a firm mass that can prolapse through the cervix into the vagina. It usually requires visualization with a speculum.
  • Rectoceles occur when the rectum herniates into the posterior aspect of the vaginal vault. It occurs especially when the patient bears down to have a bowel movement. Symptoms include fecal incontinence and discharge or drainage with protruding rectum.

REFERENCES

Dooley-Hash S, Herrman NWC. Uterine prolapse. In: Knoop KJ, Stack LB, Storrow AB, Thurman RJ, eds. The Atlas of Emergency Medicine. 5th ed. McGraw-Hill; 2021:279-280.

Pour TR, Tibbles CD. Selected gynecologic disorders. 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: 1232-1239.


5. Which method is most reliable for confirming the correct tube placement after endotracheal intubation?

A. 5-point auscultation
B. Chest x-ray
C. End-tidal capnography
D. Endotracheal tube condensation

The correct answer is C, End-tidal capnography.

Why is this the correct answer?

There are multiple methods of assessing correct placement of the endotracheal tube after intubation. No technique is infallible, but the most reliable methods include direct visualization and end-tidal capnography. End-tidal capnography involves the use of a CO2 monitor, which displays CO2 concentration in real time. Capnometry is a similar though slightly less accurate method; it involves the use of a small adaptor with pH paper that changes colors in the presence of different concentrations of CO2. Typically, the paper remains purple when exposed to low CO2 concentrations (<4 mm Hg PCO2) and changes to yellow when exposed to higher CO2 concentrations (15 to 38 mm Hg PCO2), indicating correct endotracheal location. It is important to note that no method is 100% accurate, and even end-tidal capnography can be rendered less accurate by cardiac arrest, hypopharyngeal placement, and recent ingestion of a carbonated beverage.

Why are the other choices wrong?

  • The 5-point auscultation method involves listening with a stethoscope at four separate locations on the chest (typically, the bilateral axillae and bilateral anterolateral chest areas) and once near the epigastrium. Proper endotracheal placement is supported by bilateral breath sounds and the absence of gastric inflation. However, this has been shown to be much less reliable than capnography.
  • Chest x-ray is used to identify mainstem bronchus intubation or a tube that is too high (not far enough into the trachea). A chest x-ray does not distinguish endotracheal versus esophageal placement. 
  • Endotracheal tube condensation is an unreliable finding and can be seen with hypopharyngeal placement as well as with gastric distention. This finding should not be relied on as sole confirmation of correct endotracheal tube placement.

REFERENCES

Brown CA, Walls RM. Airway. In: Walls RM, Hockberger RS, Gausche-Hill M, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. Vol 1. 9th ed. Elsevier; 2018:3-24.

Wang HE, Carlson JN. Tracheal intubation. In: Tintinalli JE, Ma OJ, Yealy DM, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 9th ed. McGraw-Hill; 2020:179-190.

ACEP Clinical Policy on verifying endotracheal tube placement
https://www.acep.org/patient-care/policy-statements/verification-of-endotracheal-tube-placement/

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