Medical Education, Board Review, Questions

Board Review Questions: June 2018

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 IX, which made its print debut in June 2017. Order PEER to prepare!

1. A 23-year-old woman presents with anxiety of 30 minutes’ duration. She has no medical history and is not taking any medications. She feels short of breath, reports palpitations, and feels tingling around her mouth and in both hands. Vital signs include BP 112/76, P 90, R 20; Spo2 is 97%. Results of her physical examination are within normal limits. What is the correct approach to evaluating this patient for PE?
   A. Draw a D-dimer and proceed if positive
   B. No further evaluation is necessary
   C. Order CT angiography of the chest
   D. Order Doppler ultrasonography of the lower extremities

2. A 32-year-old man presents after passing out in his living room. Vital signs are stable, and he is asymptomatic. Physical examination is unremarkable. An ECG is obtained. What is the underlying diagnosis?
   A. Brugada syndrome
   B. Prolonged QT syndrome
   C. Third-degree AV block
   D. Wolff-Parkinson-White syndrome

3. A mother brings in her 3-year-old son for evaluation of a 2-day progressive nonproductive cough, runny nose, and fever. Vital signs include P 105, R 26, T 37.6°C (99.7°F); Spo2 is 95% on room air. He has inspiratory stridor, moderate intercostal retractions, and a seal-like barky cough. After treatment with systemic corticosteroids and nebulized racemic epinephrine, he has no further stridor, retractions, or cough. What is the best next step in management?
   A. Arrange admission to the hospital
   B. Discharge home
   C. Monitor for 3 hours in the emergency department
   D. Start nebulized albuterol treatment

4. A 21-year-old woman presents with frequent recurrent seizures soon after ingesting a large quantity of isoniazid. Blood glucose level is normal. Which of the following should be administered intravenously?
   A. Niacin
   B. Phytonadione
   C. Pyridoxine
   D. Thiamine

5. Which of the following features of fingertip amputations warrants hand surgery consultation?
   A. Exposed bone
   B. Involvement of the fingernail
   C. Pediatric patient
   D. Visible volar fat pad

ANSWERS 1. B; 2. A; 3. C; 4. C; 5. A

1. The correct answer is B, No further evaluation is necessary.

Why is this the correct answer?
Based on the pulmonary embolism rule-out criteria—the PERC rule—this patient with anxiety has a pretest probability of having PE that is less than 1.8%. Ordering a D-dimer is more likely to result in a false-positive result, leading to more testingand unnecessary radiation exposure. The absence of tachycardia or hypoxia in a patient younger than 50 years is reassuring; patients with anxiety or panic attacks often present with tachycardia and tachypnea. She is further at low risk for PE because she has no symptoms of DVT, no history of thromboembolic disease, no use of oral hormones, no hemoptysis, and no history of surgery, trauma, or prolonged immobilization.

Why are the other choices wrong?
A D-dimer is useful for ruling out thrombosis when it is negative, but unfortunately a positive result is very nonspecific: its sensitivity in venothrombotic disease is 94% to 98%, and specificity is only 50% to 60%. When used in the lowest-risk patients, it leads to unnecessary testing and therefore unnecessary radiation exposure and expense.

Overall, the best test for ruling in PE is CT angiography of the chest. It has a sensitivity of 83% to 86% and a specificity of 96%. But it is not necessary in this patient because she has a low pretest probability.

Doppler ultrasonographic imaging of the lower extremity is a good alternative for identifying thromboembolic disease in a patient with suspected PE. If a DVT is found, the treatment for the DVT is identical to that for PE. It can be done at the bedside and does not involve radiation. Unfortunately, negative Doppler ultrasonography does not effectively rule out PE.

REFERENCES
Adams JG, Barton ED, Collings JL, et al, eds. Emergency Medicine: Clinical Essentials. 2nd ed. Philadelphia, PA: Elsevier; 2013: 602-610.e1.

Kline JA, Mitchell AM, Kabrhel C, Richman PB, Courtney DM. Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism. J Thromb Haemost. 2004;2(8):1247–1255.

Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier; 2014: 1157-1169.e1.

Tintinalli JE, Stapczynski JS, Ma OJ, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill; 2012:388-399.

 

2. The correct answer is A, Brugada syndrome.

Why is this the correct answer?
Brugada syndrome is a genetic disorder that causes abnormal sodium channel function. The classic ECG findings with Brugada syndrome, which appear on this patient’s ECG, include an incomplete RBBB pattern and ST-segment elevations in leads V1 and V2. Death resulting from Brugada syndrome is related to subsequent polymorphic ventricular tachycardia or ventricular fibrillation. Patients commonly have a family history of sudden death or cardiac syncope without structural heart disease. Management in the emergency department includes cardiac monitoring with admission for further monitoring and cardiology consultation; Brugada syndrome is associated with a high risk of death. Ultimate treatment includes placement of an automatic implanted cardiac cardioverter-defibrillator. The ECG findings can often be normal at the time of evaluation in the emergency department, so any patient with a family history of sudden death should be referred for further evaluation and provocative testing.

Why are the other choices wrong?
The ECG findings in prolonged QT syndrome are notable for significant prolongation of the QT interval. The syndrome causes increased susceptibility to polymorphic ventricular tachycardia. The QT interval in this patient’s ECG is normal.

Third-degree AV block (complete heart block) is noted with dissociation of P waves from QRS complexes. A ventricular rate of less than 60 is noted; the specific rate and QRS complex morphologies are dependent on the level of the block (nodal versus infranodal). The PR intervals are normal and regular on this ECG and show no evidence of heart block.

Wolff-Parkinson-White syndrome can also lead to syncope and, extremely rarely, sudden cardiac death. The associated ECG changes, while the patient is in normal sinus rhythm, are classically shortened PR interval, delta wave, and minimally widened QRS complex — none of which is present in this patient.

REFERENCES

Mattu A, Brady WJ, et al (eds). Cardiovascular Emergencies. Dallas, TX: American College of Emergency Physicians Publishing; 2014: 11-35.

Tintinalli JE, Stapczynski JS, Ma OJ, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY:McGraw-Hill; 2012: 112-134.

 3. The correct answer is C, Monitor for 3 hours in the emergency department.

Why is this the correct answer?
Emergency department treatment of laryngotracheobronchitis, or croup, as described in the case, includes administration of nebulized epinephrine and corticosteroids. Discharge home after treatment has been demonstrated to be safe in well-appearing patients with normal vital signs and no stridor, no retractions, no hypoxia, and access to close follow-up. But because the effects of inhaled epinephrine on respiratory vasoconstriction persist for 2 to 3 hours, investigators recommend at least 3 hours of observation to ensure no recurrence of stridor. Use of racemic epinephrine or L-epinephrine is safe and efficacious.

Why are the other choices wrong?
Hospitalization for treatment of croup is infrequently needed. After administration of corticosteroids and inhaled epinephrine in the emergency department, factors that support the need for admission include persistence of stridor at rest, persistence of respiratory distress, hypoxia, young age (<6 months), high fever, and poor access

Discharge home immediately following inhaled epinephrine therapy is inappropriate: its effects last for about 2 hours, so monitoring the patient for at least this long — 3 hours is often recommended — is necessary to ensure no recurrence of symptoms. Discharge home after corticosteroids, inhaled epinephrine, and an appropriate emergency department monitoring period is appropriate in a well-appearing patient with none of the following: hypoxia, tachycardia, tachypnea, retractions, or stridor.

Albuterol has no role in the treatment of croup and can worsen airway edema through its beta-mediated vasodilatory effects on the respiratory mucosa.

REFERENCES

Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier; 2014: 2112-2114.

Tintinalli JE, Stapczynski JS, Ma OJ, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY:McGraw-Hill; 2012: 793-802.

4. The correct answer is C, Pyridoxine.

Why is this the correct answer?
The primary manifestations of acute isoniazid poisoning are convulsions refractory to conventional therapy, coma, and metabolic acidosis. The principal treatment is the administration of pyridoxine (vitamin B6). Glutamate, the main excitatory neurotransmitter in the CNS is converted by a pyridoxine-dependent pathway to GABA, the main inhibitor neurotransmitter in the CNS. An overdose of isoniazid depletes pyridoxine by increasing excretion and causes inactivation of the active form of pyridoxine needed to convert glutamate to GABA. The combination of too much excitatory glutamate and not enough inhibitory GABA leads to convulsions that can be refractory to benzodiazepines (benzodiazepines require the presence of GABA to work). In this scenario, pyridoxine administration is required. Metabolic acidosis (lactic acidosis) predominantly occurs from the presence of convulsions.

Why are the other choices wrong?
Niacin (vitamin B3) is an essential dietary component. Deficiency causes pellagra characterized by the 3 Ds: dermatitis, diarrhea, and dementia. It does not have a role in the treatment of acute isoniazid poisoning.

Phytonadione (vitamin K1) is an essential fat-soluble vitamin. Its primary medical use is for the reversal of the effects of warfarin in the setting of bleeding or supratherapeutic effects. It does not have a role in the treatment of acute isoniazid poisoning.

Thiamine (vitamin B1) is water-soluble vitamin. Deficiency is responsible for wet beriberi, characterized by congestive heart failure, and dry beriberi, consisting of nervous system pathology such as Wernicke encephalopathy (triad of ataxia, altered mental status, and ophthalmoplegia) and Wernicke-Korsakoff syndrome. It does not have a role in the treatment of acute isoniazid poisoning.

REFERENCES

Hoffman RS, Howland MA, Lewin NA, et al. Goldfrank’s Toxicologic Emergencies. 10th ed. New York, NY: McGraw-Hill; 2010:787-791.

Tintinalli JE, Stapczynski JS, Ma OJ, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY:McGraw-Hill; 2012: 1342-1343, 1347.

5. The correct answer is A, Exposed bone.

Why is this the correct answer?
Exposed bone in a fingertip amputation indicates that the injury can lead to significant complications and even death. The thumb and index finger are the most important digits in terms of hand function. Fingertip amputations are very common, and emergency physicians should understand what is within their scope of practice and when a hand surgery consultation is advised. An injury with enough tissue loss to reveal exposed bone can lead to osteomyelitis, poor sensation, cold intolerance, and even poor function. Significant tissue loss of the volar aspect of the digit is high risk. These patients often require surgical repair with a flap or skin graft performed by a hand surgeon, although outcomes are improved when patients undergo primary flap or closure.

Why are the other choices wrong?
Involvement of the fingernail is not necessarily a reason for hand surgeon consultation. If an avulsion is small and involves the distal tip of the nail, a good cosmetic outcome is usually achievable. These wounds can be cleansed and dressed with a nonadherent dressing in the emergency department and allowed to heal by secondary intention with close follow-up.

Pediatric patients do particularly well with fingertip avulsions and generally have better outcomes than adults, especially if only the tip of the digit is involved. Even when the wound approximates the bone, these patients have good regenerative capacity and can heal by secondary intention.

Injury to the volar aspect of the digit is more serious than a dorsal injury. However, these patients generally do well healing by secondary intention even if the volar fat pad is exposed as long as the injury is small (1 cm or less) and does not involve a large amount of soft tissue loss.

REFERENCES

Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier;2014: 561-562.

Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss’ Clinical Practice of Emergency Medicine. 6th ed. Philadelphia, PA:Lippincott, Williams & Wilkins; 2014: 274-275.

 

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