Board Review Questions: December 2017

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NEW! PEER IX QUESTIONS NOW AVAILABLE! 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. To order PEER IX, go to to www.acep.org/bookstore.

  1. A 33-year-old woman presents with a tight, band-like pain around her head. Although she is uncertain when it started, she says it “came on slowly maybe a week ago.” She denies fever, photophobia, phonophobia, nausea, and vomiting. What is the most likely diagnosis?
    A.     Cluster headache
    B.     Migraine headache
    C.     Tension headache
    D.     Trigeminal neuralgia
  2. A 56-year-old man presents with a severe headache and nausea with vomiting; his wife says he “started to act really confused.” Vital signs include BP 201/135, P 102, T 37°C (98.6°F); Spo2 is 99% on room air. Computed tomography of the brain reveals bilateral white matter hypodensities in the occipital and parietal regions consistent with vasogenic edema. What is the most appropriate treatment?
    A.     Hydralazine titrated to a target BP of 140/80
    B.     Metoprolol titrated to a target P of 60
    C.     Nicardipine titrated to a MAP of 126
    D.     Nitroprusside titrated to a diastolic BP less than 100
  3. What is the most common presenting symptom in PE?
    A.     Chest pain
    B.     Dyspnea
    C.     Hypotension
    D.     Hypoxia
  4. A 37-year-old man presents with ataxia, headache, and nausea. He says he was using a gas-powered generator indoors “and passed out cold.” Vital signs are normal. Carboxyhemoglobin level is 26%. What is the best first step in management?
    A.     Arrange for exchange blood transfusion
    B.     Perform serial carboxyhemoglobin measurements
    C.     Provide supplemental oxygen
    D.     Transport to the nearest hyperbaric oxygen facility
  5. At which of the following levels is a unilateral facet dislocation most likely to occur?
    A.     C1-C2
    B.     C3-C7
    C.     L1-L5
    D.     T1-T12

Answers

1. The correct answer is C, Tension headache.
Why is this the correct answer?
A tension headache is the most common of the primary headache syndromes but also the least distinct. It is characterized by a gradual onset of pain, usually described as bandlike, and often associated with tightness in the muscles of the neck and shoulders. Because the pain from tension headaches usually does not interfere with the activities of daily living, patients can have symptoms for several days or weeks before seeking treatment. The pain in tension headaches does not increase with activity and is not affected by light and sound. Patients do not typically report nausea, vomiting, or neurologic symptoms. Tension headaches are, however, often associated with chronic conditions such as depression and anxiety. Besides screening for depression, clinicians evaluating patients with tension-type headaches should also consider other possible causes, including idiopathic intracranial hypertension, sinus disease, and intracranial mass. Nonsteroidal anti-inflammatory drugs or acetaminophen is usually sufficient to manage the pain of tension headaches, but most patients have tried this before seeking care in the emergency department and request a different approach. The antiemetic dopamine agonists used for migraine therapy can be helpful, and many clinicians favor muscle relaxants such as cyclobenzaprine. Another approach is to use trigger point injections into the tense muscles of the shoulder or neck. For patients with chronic symptoms, it is important to address the underlying stress and depression that are contributing to the headache syndrome. Nonpharmacologic approaches such as massage, meditation, and acupuncture can help some patients.

Why are the other choices wrong?
A cluster headache is a sharp, stabbing pain in one eye lasting 15 minutes to several hours and occurs in clusters throughout the week.
A migraine headache is abrupt-onset severe throbbing or pounding pain that is frequently associated with neurologic symptoms such as vision changes, photophobia, phonophobia, nausea, and even limb weakness or numbness.
Trigeminal neuralgia is an episodic, shooting, electrical type of pain that occurs in one or more branches of the trigeminal nerve. These debilitating attacks can be brought on by stimulation of the nerve with talking, brushing teeth, or even a cold wind blowing on the face.

PEER REVIEW
What are the primary headache syndromes? Cluster, migraine, and tension — and tension headaches are the most common.
Tension headaches present with the gradual onset of bandlike, nondebilitating pain.
Tension headaches can be managed with NSAIDs, acetaminophen, muscle relaxants, trigger point injections, or nonpharmacologic therapies.

REFERENCES
Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier;2014:1386-1397.
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: 1077-1085.

2. The correct answer is C, Nicardipine titrated to a MAP of 126.
Why is this the correct answer?
Severe headache, vomiting, and altered mental status in a patient with severe hypertension suggest hypertensive encephalopathy, a true hypertensive emergency. In this patient, the CT findings are consistent with the diagnosis as well. Goals for therapy include lowering the MAP back into a range where cerebral autoregulation can occur. Nicardipine, a peripherally acting calcium channel blocker given intravenously, has consistent effects on dilating vascular beds and is considered first-line therapy for hypertensive encephalopathy. Generally, the MAP should be lowered by 20% in the first hour but by no more than 25% in the first day. This formula can be used to estimate MAP: MAP = Diastolic BP + 1/3(Systolic – Diastolic pressure). Lowering the blood pressure too rapidly can provoke cerebral ischemia in a brain that is accustomed to higher blood pressures.

Why are the other choices wrong?
Hydralazine is not considered first-line therapy for hypertensive encephalopathy. It can unpredictably lower cerebral perfusion pressure, precipitating ischemia in the brain.
Metoprolol is a beta-1 selective adrenergic receptor blocker. It primarily affects the heart rate with no vasodilatory properties. Although metoprolol can lower blood pressure, direct-acting vasodilatory agents are considered better options. In addition, therapy for hypertensive encephalopathy does not normally focus on heart rate.
Nitroprusside, like hydralazine, can unpredictably lower cerebral perfusion pressure and paradoxically elevate intracranial pressure. It can be considered as second-line or third-line therapy but should not be used as a first-line agent.

PEER REVIEW
What defines hypertensive encephalopathy? Central nervous system findings consistent with end-organ damage — not absolute blood pressure.
Remember that lowering blood pressure too aggressively can result in ischemic symptoms in a chronically hypertensive patient.

REFERENCES
Manning L, Robinson TG, Anderson CS. Control of Blood Pressure in Hypertensive Neurological Emergencies. Curr Hypertens Rep. 2014;16:436.
Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier; 2014: 1113-1123.

3. The correct answer is B, Dyspnea.
Why is this the correct answer?
Although patients with PE can present in many ways, the most common uniting feature among them is dyspnea. It is present in more than 90% of patients with PE without infarction. Patients might present with dyspnea while at rest, but most have exertional dyspnea, both of which are due to irregular pulmonary blood flow from the occluded vessel. Pleuritic chest pain is a common presenting symptom as well but not as common as dyspnea. The Pulmonary Embolism Ruleout criteria (the PERC rule) are used to exclude the diagnosis of PE and avoid additional testing. These criteria rule out any patient with an oxygen saturation level above 94% on room air.

Why are the other choices wrong?
Chest pain is more likely with distal pulmonary emboli and is the second most common symptom, after dyspnea, for PE.
Hypotension is a physical examination finding, not a symptom. It is not likely to occur except in patients with very large hemodynamically compromising pulmonary emboli.
Hypoxia can occur, but it is not considered the most common finding. It is a sign, not a symptom.

PEER REVIEW
Pulmonary Embolism Ruleout Criteria (PERC Rule)
Can be applied to patients whom the treating physician believes are otherwise at low risk for PE based on clinical impression:
Age younger than 50 years
No exogenous hormone use
No unilateral leg swelling
Oxygen saturation above 94% on room air
Pulse rate less than 100 beats per minute
No prior history of PE or DVT
No recent major surgery
No hemoptysis

PEER REVIEW
Symptoms are presenting complaints. Signs are found on physical examination.
Hypoxia and hypotension can be present in large pulmonary emboli, but most pulmonary emboli are small and wouldn’t cause these to occur.
Dyspnea is the most common symptom found in patients presenting with PE.

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

4. The correct answer is C, Provide supplemental oxygen.
Why is this the correct answer?
The mainstay of treatment for CO poisoning is removing the patient from the source of CO and delivering maximal oxygen as soon as possible. This patient has symptoms of acute CO poisoning with a corresponding elevated carboxyhemoglobin percentage. Providing the maximal amount of supplemental oxygen by nonrebreather facemask or endotracheal tube (if indicated for airway control) is the next best step in this scenario. The half-life of carboxyhemoglobin is drastically reduced from an average of 5 hours for patients breathing room air to roughly 1 hour when breathing 100% oxygen.

Why are the other choices wrong?
Exchange transfusion has no known role in the management of CO toxicity. It does have a role in the management of sickle cell disease, thrombotic thrombocytopenic purpura, and hemolytic disease of the newborn.
For inhalational CO exposures, serial measurements of carboxyhemoglobin are not necessary and do not change management. After the patient is removed from the CO source, the carboxyhemoglobin level predictably decreases, and oxygen therapy accelerates this.
Hyperbaric oxygen (HBO) therapy is a suitable treatment for this patient, but the most important first step is to supply maximal oxygen by nonrebreather mask or endotracheal tube. Providing HBO therapy for CO poisoning remains controversial. The primary goal of using it is to decrease the risk of persistent or delayed neurologic sequelae. The patient in this case does meet several suggested criteria for HBO treatment (syncope, coma, seizure, altered mental status or confusion, carboxyhemoglobin >25%, abnormal cerebellar function, age ≥36, prolonged CO exposure [≥24 hours], fetal distress in pregnancy). Transferring him to a facility for HBO treatment might certainly be considered — while he is already receiving supplemental oxygen.

PEER REVIEW
Remember the mainstays of CO poisoning treatment: identify it, remove the victim from the source, and give oxygen.
The primary goal of HBO therapy in CO poisoning is to decrease the risk of persistent or delayed neurologic sequelae.

REFERENCES
Hoffman RS, Howland MA, Lewin NA, et al. Goldfrank’s Toxicologic Emergencies. 10th ed. New York, NY: McGraw-Hill; 2010: 1584-1588.
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: 1439.

5. The correct answer is B, C3-C7.
Why is this the correct answer?
Unilateral facet dislocations most commonly occur at the level of C3-C7 due to the relatively flat articular processes in this region. These dislocations occur secondary to flexion-rotation forces causing anterior rotation of the inferior facet of one vertebra over the superior facet of the vertebra below. Typically, unilateral facet dislocations are stable injuries and might not present with any neurologic compromise. In the thoracic and lumbar spine, bilateral facet dislocations are much more common due to the relatively larger articular processes. Bilateral facet dislocations are unstable and typically present with neurologic deficits. Significant flexion-rotation forces at C1-C2 most commonly cause atlantoaxial dislocation, a highly unstable lesion.

Why are the other choices wrong?
Atlantoaxial dislocation, not unilateral facet dislocation, is the most common lesion that occurs at C1-C2 secondary to flexion-rotation forces. These lesions are extremely unstable and require emergent neurosurgical consultation.
Unilateral facet dislocations are even more rare in the lumbar spine than in the thoracic spine. Bilateral facet dislocations in the lumbar region are typically not associated with spinal cord deficits because the adult cord terminates at L1 into the cauda equina.
Flexion-rotation forces in the thoracic spine are more likely to cause bilateral facet dislocations, particularly at the thoracolumbar junction. A bilateral facet dislocation in the thoracic spine should raise significant concern for associated intrathoracic injuries.

PEER REVIEW
Unilateral facet injuries are stable and most commonly occur at C3-C7.
The prevalence of flexion-rotation injuries of the spine differs based on vertebral level.

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