Board Review Questions: August 2016

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Provided by PEER VIII. 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 the latest edition of PEER VIIITo learn more about PEER VIII, or to order it, go to www.acep.org/bookstore.

  1. A 77-year-old man presents with abdominal pain. Compared with a younger patient, he is more likely to:
    A .     Complain of well-localized pain
    B.      Develop a fever
    C.      Present with peritoneal signs
    D.      Require a surgical procedure
  2. A patient who is taking linezolid presents with symptoms of an upper respiratory tract infection. Which of the following agents should the patient avoid?
    A.      Benzonatate
    B.      Diphenhydramine
    C.      Oxymetazoline
    D.     Pseudoephedrine
  3. A 5-month-old girl presents by ambulance after a seizure. The mother says her daughter has never had a seizure before, and that she had been well until that morning when she developed a small cough and a runny nose. She describes the seizure as a shaking and tensing of her entire body, with her eyes rolling up into her head, that lasted about 10 minutes. On examination, the patient is healthy appearing and progressively improving to baseline without a focus of illness. Vital signs are blood pressure 75/40, pulse 120, respirations 40, and temperature 40°C (104°F). Which of the following elements of her history supports the diagnosis of complex febrile seizure as opposed to simple febrile seizure?
    A.      Age
    B.      Length of seizure
    C.      Number of previous seizures
    D.     Temperature
  4. Which of the following statements regarding the evaluation for compartment syndrome is correct?
    A.      Compartment pressure measurement is generally painless and does not require anesthesia
    B.      Compartment pressure readings indicate the need for fasciotomy even in the absence of significant clinical findings
    C.      Local infection is rare as a result of compartment pressure measurement, and sterile technique is not required
    D.     Pain out of proportion to clinical findings is commonly the earliest finding of compartment syndrome
  5. A 65-year-old man with lung cancer presents with pain in his low thoracic spine of 2 weeks’ duration, as well as tingling in his legs. Examination reveals a thin man with grade 2/5 motor strength in his bilateral lower extremities and decreased sensation starting at the T10 level. Which of the following statements characterizes this patient’s condition?
    A.      Only 25% of patients have motor weakness at the time of diagnosis
    B.      Reflexes below the affected level are usually preserved as the disease progresses
    C.      Symptoms are often made worse by coughing or sneezing
    D.     The lumbar spine is the most commonly affected site

Answers

  1. The answer is D, Require a surgical procedure.
    (Marx, 2348-2352; Tintinalli, 526)

Abdominal pain in elderly patients is more likely to reflect a serious abdominal pathology, with up to 60% of elderly patients having a surgical pathology. Nearly 20% of elderly patients with abdominal pain go directly to the operating room. The mortality rate for abdominal pain pathology in older patients is significantly elevated when compared with that for younger patients. For example, the mortality rate associated with appendicitis is about 0.02% in younger patients. In the elderly, it ranges from 3% to 8%. The presentation of an elderly patient with serious abdominal pathology might not initially reflect the magnitude of the pathology. Elderly patients are less likely to develop a fever in response to a serious intraabdominal pathology than are younger patients. Elderly patients are often not able to localize the pain and complain only of vague abdominal pain. They usually present later in the course of the illness, and they rarely present with peritoneal signs, as they lack the abdominal musculature to produce guarding and rebound. The prevalence of atherosclerosis makes the development of necrotic complications of otherwise simple pathologies such as cholecystitis more likely.

  1. The answer is D, Pseudoephedrine.
    (Nelson, 1029-1031; Wolfson, 1504-1509)

Linezolid (marketed in the United States as Zyvox) is an antibiotic that can be used orally to treat methicillin-resistant Staphylococcus aureus infections. It has monoamine oxidase inhibitor (MAOI) activity, so the addition of pseudoephedrine could potentially lead to a life-threatening drug-drug interaction of catecholamine excess. Patients who are prescribed linezolid should be warned that eating foods rich in tyramine, such as aged, mature cheeses and red wines, can trigger significant stored norepinephrine release and a severe hyperadrenergic crisis. The current use of MAOIs for depression is uncommon due to newer, safer drugs. However, occasionally patients are still prescribed MAOIs for depression, and drugs used for other purposes, such as selegiline for Parkinson disease and linezolid, have MAOI activity. The major problems with MAOIs include overdose and adverse food-drug and drug-drug interactions. The MAOIs inhibit the breakdown of the monoamines dopamine, norepinephrine, and serotonin and lead to their accumulation in nerve terminals. Amphetamines, including over-the-counter pseudoephedrine, act by releasing preformed norepinephrine, which in the setting of MAOI use can be excessive and dangerous. Another significant adverse MAOI drug-drug interaction is serotonin toxicity that can occur with the coadministration of a serotonergic drug and other medications such as meperidine and dextromethorphan. Treatment of catecholamine excess associated with all of the various MAOI interactions is supportive and also involves the use of agents such as nitroprusside or phentolamine to counteract the potentially severe hypertension. The other drugs listed do not need to be avoided in patients on MAOIs. Diphenhydramine is an antihistamine with antimuscarinic activity. Oxymetazoline is an imidazoline that acts as a local vasoconstrictor, and benzonatate (found in Tessalon Perles) acts as an oropharyngeal anesthetic.

  1. The answer is A, Age.
    (Fleisher, 564, 569-570; Marx, 2101)

Febrile seizure is the most common convulsive condition among pediatric patients. The National Institutes of Health defines febrile seizure as “a seizure occurring in patients aged 6 months to 5 years that is associated with a fever (temperature greater than 38°C) but without any signs of intracranial

infection or other neurologic disease.” Febrile seizures are classified into two basic categories: simple and complex. A simple febrile seizure is defined as follows: first episode with age between 6 months and 5 years, short duration less than 15 minutes, generalized without any focality, and single episode within a 24-hour period. A complex febrile seizure is defined as follows: first episode with age younger than 6 months and older than 5 years, duration greater than 15 minutes, focality of seizure or a Jacksonian march with the focal area then leading to a generalized seizure, and more than one seizure within a 24-hour period. An estimated 2% to 5% of the population has seizures related to fever, and although they are terrifying to watch, they are not typically life-threatening events. A prolonged seizure can lead to brain injury, and steps must be taken to stabilize the patient’s airway, breathing, and circulation while also treating the seizure with benzodiazepines with or without the addition of antiepileptic agents. The patient should be placed in the recovery position during the episode so that, if emesis occurs, there will not be aspiration. An extensive diagnostic workup is not needed in the emergency department after a simple febrile seizure if the child has a normal-for-age neurologic examination (although the patient might have a short postictal stage and be initially hyperreflexic) and no signs of CNS infection. But in a patient who has had a complex febrile seizure, lumbar puncture is recommended to rule out meningitis. It is important to communicate to families that up to one-third of patients can have another seizure, and three-fourths will do so within the first year. The likelihood of repeated episodes is higher among younger patients with higher temperatures.

  1. The answer is D, Pain out of proportion to clinical findings is commonly the earliest finding of compartment syndrome.
    (Marx, 477-479; Roberts, 989)

Pain out of proportion to clinical findings, also seen with early bacterial fasciitis, is an important early finding for compartment syndrome. The classic symptoms of compartment syndrome—pallor, pulse deficit, paresis/ paralysis, paresthesias, and pain on passive stretching—are typically late findings and are often unreliable, especially in children. The lower extremities are the most frequently affected, with the anterior compartment most frequently involved and the posterior compartment most frequently missed. Strict sterile technique must be used to prevent infection when measuring compartment syndromes. This procedure can be so painful as to require procedural sedation or local anesthesia at a minimum. If local anesthesia is used, care should be taken to avoid injection into the compartment itself, as this can falsely elevate the pressure. A combination of clinical findings and pressure measurements should be used to determine the need for intervention. Normal compartment pressure is less than 12 mm Hg; clinically significant impairment of blood flow can occur at pressures greater than 20 mm Hg; and fasciotomy is recommended at values greater than 30 mm Hg. Actions to prevent falsely elevating the pressure in the compartment include providing adequate pain control to prevent movement, using ultrasound to guide the placement of the needle and decrease the number of attempts, and placing the extremity at the level of the heart in an appropriate position for insertion of the needle.

  1. The answer is B, Negative inspiratory force less than 30 cm H2O.
    (Marx, 1400-1401; Wolfson, 779-780)

The patient in this question has Guillain-Barre syndrome, a demyelinating polyneuropathy that often presents 1 to 2 weeks after an infectious illness. These patients are at risk for respiratory failure related to respiratory muscle weakness, which is best predicted by a negative inspiratory force less than 30 cm H2O. An alternative measurement that can be used is forced vital capacity (FVC). An FVC less than 20 mL/kg is predictive of possible impending respiratory failure; intubation is not usually needed if FVC is greater than 40 mL/kg. Arterial blood gas measurements can be used to evaluate for respiratory function by measuring Pco2. Elevations in Pco2 are indicative of alveolar hypoventilation and are associated with respiratory failure. There is no absolute Po2 that is predictive of respiratory failure. Peak flow measurements are typically used to evaluate patients with obstructive lung disease such as asthma. A PEFR of 100% predictive for age and sex would be a reassuring finding; however, there is no absolute measurement that is predictive of respiratory failure. On physical examination, patients with Guillain-Barre syndrome usually present with bilateral lower extremity weakness, greater distally than proximally, often with sparing of the anal sphincter. Deep tendon reflexes are often diminished or absent, and the sensory changes can vary. Recommended treatment includes plasma exchange or intravenous immunoglobulin. Steroids are no longer indicated.

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