Board Review Questions: February 2018

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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 www.acep.org/bookstore.

  1. A 42-year-old man presents with lower back pain for the past 2 days after lifting some boxes. The pain is worse with movement and better with rest. He denies weakness, bowel or bladder incontinence, and fever but does say that he has a tingling feeling in his left leg every now and then. He also has hypertension. Physical examination is significant only for tenderness in the lower left paraspinal muscles. Neurologic examination findings are normal. What is the best next step?
    A.     Order CT of the lumbar spine
    B.     Order MRI of the lumbar spine
    C.     Recommend bed rest and physical therapy
    D.     Recommend light daily activities
  2. A 62-year-old man presents by ambulance with chest pain and nausea for the past 30 minutes. He told the paramedics he has high blood pressure. En route, he received aspirin 325 mg PO, morphine 2 mg IV, and 1 inch of nitroglycerin paste. An ECG demonstrates sinus tachycardia with new ST-segment elevation >2 mm in leads V1-V4. A STEMI alert is called, and the hospital cardiologist confirms that she will take the patient emergently for PCI in the next 20 to 25 minutes. Vital signs are BP 158/85, P 102, R 18, T 36.8°C (98.2°F); Spo2 is 99%. He rates his pain as 1 on a 10-point scale. What is the most appropriate pharmacotherapy while waiting for the cardiologist?
    A.     Intravenous alteplase bolus
    B.     Intravenous lorazepam and no beta blockers
    C.     Oral antiplatelet therapy and intravenous heparin bolus
    D.     Oral ibuprofen and intravenous heparin bolus
  3. Which of the following pathogens most commonly causes pneumonia in HIV-infected persons?
    A.     Pneumocystis jirovecii
    B.     Pseudomonas aeruginosa
    C.     Staphylococcus aureus
    D.     Streptococcus pneumoniae
  4. Which of the following best characterizes the presentation of patients in alcoholic ketoacidosis?
    A.     Abdominal pain and vomiting are common
    B.     Bradypnea is expected
    C.     Coma is common
    D.     Intoxication with ethanol is nearly universal
  5. Which of the following statements about perimortem cesarean delivery following trauma is correct?
    A.     Begins with a horizontal incision 3 cm above the pubic symphysis
    B.     Contraindicated when maternal survival is likely
    C.     Ideally performed within 20 minutes of maternal cardiac arrest
    D.     Indicated when the fetus is greater than 24 weeks of gestation

Answers

  1. The correct answer is D, Recommend light daily activities.

Why is this the correct answer?

Although back pain can be a symptom of a serious illness or injury, the patient in this case has a benign condition known as lumbago or idiopathic back pain. This is a clinical diagnosis and one that is not associated with any risk factors or neurologic deficits. Imaging is rarely needed, and the cost and radiation exposure can be avoided by conservative management. Symptoms of lumbago typically resolve on their own. Patients who resume light daily activities as they can tolerate them improve faster than those who go on bed rest. High-intensity exercise is not recommended. Because lumbago is a diagnosis of exclusion, the clinician should be on the lookout for signs of other diagnoses and ask all patients presenting with back pain questions to find out if the symptoms indicate more serious conditions. Some of those more concerning symptoms that warrant further workup and are cannot-miss diagnoses include midline back tenderness and trauma concerning for fracture; history of weight loss, fever, or night sweats concerning for cancer or infection; and bowel or bladder changes, weakness, or neurologic deficit concerning for cord compression.

Why are the other choices wrong?

Computed tomography is not indicated in acute lumbago because this disease process usually resolves on its own. It is mainly used to evaluate for trauma such as fractures involving the spine and does not visualize the spinal cord or canal as well as MRI.

Magnetic resonance imaging is not indicated in acute lumbago, again, because the condition is usually self-limiting and does not yield radiographic findings. But MRI is the diagnostic imaging modality of choice to diagnose the major back-related emergencies like neoplasms, infections, and cord compression.

Bed rest is not recommended as treatment for lumbago. Patients who go on bed rest have been shown to have a longer recovery times than those who resume light daily activities. Physical therapy has no proven benefit for acute lumbago.

PEER REVIEW

  • Your aftercare instructions for patients with lumbago should recommend light daily activities, not bed rest.
  • Lumbago resolves on its own; imaging isn’t needed in patients with nonspecific back pain.
  • Here are some “red flag” symptoms of a back pain presentation: fever, weight loss, night sweats, bowel or bladder changes, trauma, weakness, history of cancer. These warrant imaging to help make a diagnosis.

REFERENCES

Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier;2014:643-655.
Tintinalli JE, Stapczynski JS, Ma OJ, et al., eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill;2012:1887-1894.

  1. The correct answer is C, Oral antiplatelet therapy and intravenous heparin bolus.

Why is this the correct answer?

The diagnostic criteria for STEMI include the following:

  • Two contiguous leads with ST-segment elevation of more than 2 mm in leads V2 and V3, or
  • More than 1 mm in all other leads

The patient in this case is experiencing a STEMI and is waiting to undergo PCI. Before the procedure, the patient should ideally receive several medications, including an oral antiplatelet agent and anticoagulant therapy. Oral ticagrelor or prasugrel, the preferred antiplatelet agents, should be administered as a loading dose. Although not a specific choice in this scenario, aspirin is a highly effective antiplatelet agent in STEMI; it significantly reduces mortality rates. Intravenous heparin bolus is the preferred anticoagulant therapy when patients are treated with primary PCI.

Why are the other choices wrong?

Alteplase is a recombinant tissue plasminogen activator that acts as a fibrinolytic agent in the treatment of STEMI. Fibrinolysis would be preferred over PCI for this patient only if it were going to take more than 60 minutes for him to undergo PCI from first medical contact. But the time to therapy in this case is within the PCI window due to the patient’s early acute MI presentation: he is being prepared to undergo emergent PCI in the next 20 to 25 minutes, which makes PCI preferred over fibrinolytic therapy.

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.

Avoiding beta blockers and administering benzodiazepines might be appropriate if the patient were suspected of having cocaine-induced chest pain. In cocaine-induced MI, the cardiac ischemia is primarily via coronary spasm. Administering beta blockers might exacerbate coronary spasm and result in worsening ischemia. Furthermore, beta blockers can improve outcome, but the appropriate time to administration is within the initial 24 hours of infarction; postponing beta blocker administration to later in the first hospital day in most STEMI patients is appropriate due to the potential adverse effects seen early in the course of acute MI.

Although an intravenous heparin bolus is appropriate in this scenario, the oral ibuprofen is contraindicated. Ibuprofen is an NSAID, and with the exception of aspirin, NSAIDs have been associated with increased adverse cardiovascular events. They should be avoided in patients with acute MI.

PEER POINT

Fibrinolysis or PCI?
Fibrinolytic therapy is preferred over PCI in STEMI management only if PCI can’t be performed within an appropriate timeframe. That timeframe is based on the time from onset of infarction, as follows:

  • If the time from onset of infarction is less than 2 hours, PCI should be performed within 60 minutes.
  • If the time from onset of infarction is between 2 and 3 hours, PCI should be performed within 60 to 120 minutes.
  • If the time from onset of infarction is between 3 and 12 hours, PCI should be performed within 120 minutes. If PCI cannot be performed within this time frame and the patient is a candidate for fibrinolytic therapy, a fibrinolytic agent should be administrated.

PEER REVIEW

  • What should you give a patient with acute STEMI who is waiting for PCI? Aspirin, pain control, antiplatelet therapy, and anticoagulation.
  • Diagnostic ECG criteria for STEMI: two contiguous leads with ST-segment elevation of more than 2 mm in leads V2 and V3 or more than 1 mm in all other leads.

REFERENCES
Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier;2014:997-1033.
O’Connor RE, Al Ali AS, Brady WJ, et al: Part 9: Acute Coronary Syndromes—2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015;132:s483-500.

  1. The correct answer is D, Streptococcus pneumoniae.

Why is this the correct answer?
Although patients with HIV, because they are immunocompromised, are prone to contracting pneumonia caused by uncommon pathogens, they are also more likely to get the common types and have severe disease as a result. S. pneumoniae is the most common cause of community-acquired pneumonia among both immunocompetent and HIV-positive patients. Pulmonary infections are the most common cause of serious illness and death among patients with HIV, and while upper tract infections are most common, the incidence of lower tract infection increases as the CD4 count decreases.

Why are the other choices wrong?
Pneumocystis pneumonia (PCP) is caused by infection with P. jirovecii and is a serious cause of pneumonia for HIV-infected patients. But it is still less common than infection with S. pneumoniae and is usually present only when the CD4 count drops below 200. It is considered an AIDS-defining illness.

Pseudomonas infection is a concern among immunocompromised patients and recently hospitalized patients, particularly those who are in a hospital setting for more than 48 to 72 hours. But P. aeruginosa is decidedly less common than S. pneumoniae as a cause of community-acquired pneumonia.

  1. aureus can be a common cause of pneumonia; the illness can follow another infection, and it can be severe, but it is a less common cause of community-acquired pneumonia than S. pneumoniae.

PEER REVIEW

  • Pulmonary infections are the leading cause of morbidity and mortality among HIV-positive patients, and the incidence of lower tract disease increases as the CD4 count decreases.
  • What’s the most common source of pneumonia among persons who are HIV positive? pneumoniae, and opportunistic infections increase particularly when the CD4 count falls below 200.

REFERENCES
Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier; 2014:978-987;1751-1767.
Tintinalli JE, Stapczynski JS, Ma OJ, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill; 2012:445-456;1047-1057.

  1. The correct answer is A, Abdominal pain and vomiting are common.

Why is this the correct answer?
Alcoholic ketoacidosis typically occurs in undernourished alcoholics who have recently binged on alcohol and have had limited food intake. Abdominal pain and vomiting are common. These symptoms might be related to the condition, but a thorough evaluation for other etiologies such as pancreatitis is necessary. These patients characteristically have a normal mental status despite the presence of potentially severe acidosis, and this helps distinguish alcoholic ketoacidosis from poisoning with a toxic alcohol. The acidosis in alcoholic ketoacidosis predominantly results from the presence of beta-hydroxybutyrate (a ketoacid that is not typically detected as a ketone on urinalysis). As with most acidosis, tachypnea is expected. Treatment of alcoholic ketoacidosis involves hydration with glucose-containing solutions, thiamine, food intake, and treatment of any other underlying medical conditions.

Why are the other choices wrong?

As with other etiologies of metabolic acidosis such as diabetic ketoacidosis, tachypnea is expected as a normal compensatory mechanism, not bradypnea.

Preservation of mental status is characteristic of alcoholic ketoacidosis even when severe acidosis is present. This helps distinguish it from toxicity from toxic alcohols.

Although a not insignificant percentage of patients who present with alcoholic ketoacidosis have measurable ethanol levels, intoxication is not typical.

PEER REVIEW

  • Abdominal pain and vomiting are common in alcoholic ketoacidosis, but look carefully for other causes such as pancreatitis.
  • It’s characteristic of alcoholic ketoacidosis for a patient to have a normal mental status despite significant acidosis.

REFERENCES
McGuire LC, Cruickshank AM, Munro PT. Alcoholic ketoacidosis. Emerg Med J. 2006;23(6):417-420.
Tintinalli JE, Stapczynski JS, Ma OJ, et al, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw-Hill;2012:1464-1465.
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.

  1. The correct answer is D, Indicated when the fetus is greater than 24 weeks of gestation.

Why is this the correct answer?
Before 24 weeks of gestation, survival of a fetus is unlikely even under ideal circumstances. Therefore, perimortem cesarean delivery (more recently termed resuscitative hysterotomy) should be performed only when the gestational age is greater than 24 weeks. If the age of the fetus is unknown, the procedure should be performed only when the uterine fundus can be palpated above the umbilicus. The procedure should also only be performed when there are fetal heart tones present, as survival of the fetus is unlikely once fetal heart tones have been lost. Cardiopulmonary resuscitation of the mother should continue during the procedure whenever possible. An emergency physician may perform this procedure under extreme circumstances. Nevertheless, the most experienced clinician should perform the procedure when possible, especially if an obstetrician or surgeon is available.

Why are the other choices wrong?
A standard horizontal incision does not provide enough exposure to deliver the fetus quickly. Although a horizontal incision might be ideal for cosmesis in an elective procedure, in this emergent situation, the initial incision should be vertical and is historically described as made from the maternal epigastric area extending to the pubic symphysis. This allows the greatest exposure of the uterus and fetus and ease of delivery. Some find that an incision from the umbilicus to the pubic symphysis is large enough to accomplish fetal delivery. The uterine incision should be vertical as well.

Perimortem cesarean delivery might actually improve maternal circulation and is better performed early rather than too late. There have been reports of maternal survival after perimortem cesarean delivery even when the mother has been in cardiac arrest. Theoretically, delivery of the fetus can help restore maternal circulation and remove pressure from the inferior vena cava.

The procedure is ideally performed within 4 to 5 minutes of the loss of maternal circulation. Survival of the mother and the fetus is unlikely if the procedure is performed too late and is virtually futile if performed after 20 minutes of maternal cardiac arrest.

PEER REVIEW

  • Don’t perform a perimortem cesarean delivery unless fetal heart tones are present and the uterine fundus is above the umbilicus.
  • Make vertical skin and uterine incisions when performing a perimortem cesarean delivery.
  • Perimortem cesarean delivery is most successful when it’s performed early, ideally within 4 to 5 minutes of maternal arrest.

REFERENCES
Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 8th ed. St. Louis, MO: Elsevier;2014:303-304.
Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss’ Clinical Practice of Emergency Medicine. 6th ed. Philadelphia, PA: Lippincott, Williams & Wilkins;2014:324, 694.

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