Board Review Questions: October 2015

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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 VIII. To learn more about PEER VIII, or to order it, go to www.acep.org/bookstore.

  1. Which of the following is a risk factor for the development of cellulitis?
    A.    Arterial insufficiency
    B.    History of cancer
    C.    Lymphedema
    D.    Tobacco use
  2. Which of the following agents in overdose most closely mimic opioid poisoning?
    A.    Clonidine
    B.    Diphenhydramine
    C.    LSD
    D.    Yohimbine
  3. A 6-year-old boy is brought in by his father 1 hour after sustaining a head injury. He was riding his bicycle down a hill and fell off after it struck a tree branch; he was not wearing a helmet. Medical history is significant for hemophilia A. Which of the following is the first step in management?
    A.    Blood transfusion using O-negative whole blood
    B.    CT
    C.    Factor VIII therapy to 100% activity
    D.    Factor IX therapy to 50% activity
  4. An emergent lumbar puncture is performed on a woman with fever, headache, and a stiff neck. Her past medical history is notable only for hypertension and chronic atrial fibrillation. The procedure is successful, with minimal trauma, but later she begins to complain of local back pain at the site of the procedure, lower extremity dysesthesias, and urinary incontinence. What should be the primary concern?
    A.    Diabetic neuropathy
    B.    Epidural hematoma
    C.    Nerve damage
    D.    Spine abscess
  5. Which of the following patients can be appropriately discharged without imaging after an afebrile first-time seizure?
    A.    18-month-old black child with sickle-cell disease who is now acting normally
    B.    2-year-old white child with a ventriculoperitoneal shunt for hydrocephalus who is now acting normally
    C.    3-year-old Chinese child with a family history of seizure disorder who is now acting normally
    D.    4-year-old Mexican child who recently immigrated to the United States who is now acting normally

Answers

  1. The answer is C, Lymphedema.
    (Marx, 1836-1837; Tintinalli, 1015-1016)
    Cellulitis is an infection of the skin and soft tissue caused by blood or lymph system dissemination or more commonly by direct inoculation of bacteria through skin trauma. Recent studies have shown that the clinical risk factors for the development of cellulitis include lymphedema, portal of entry, venous insufficiency, and obesity. The portal of entry can include chronic fungal infection of the feet, particularly between the toes. Remarkably, studies have not supported that cancer, tobacco use, and diabetes mellitus are risk factors for cellulitis. Interestingly, bacteria are often cleared from the site of the infection within 12 hours, and the remainder of the symptoms are the result of infiltration of inflammatory cells and the production of cytokines. Arterial insufficiency is not an independent risk factor for the development of cellulitis. Typical signs and symptoms of cellulitis include local erythema, increased warmth, localized swelling, and pain. Skin flora (Staphylococcus aureus, Streptococcus pyogenes) are the most common bacterial organisms.
  1. The answer is A, Clonidine.
    (Nelson, 198, 753, 915, 1066, 1171-1172; Wolfson, 1450-1451)
    Clonidine is an alpha2-adrenergic agonist that, in overdose, can cause a depressed level of consciousness, hypoventilation (often responsive to tactile stimulation), and miosis. The presentation can closely mimic an opioid poisoning. Although initial hypertension and reflex bradycardia can occur and are attributed to nonspecific activation of peripheral alpha1 receptors, sympatholytic hypotension and bradycardia are typical. Naloxone was likely first used in clonidine poisoning due to the similarity to opioid poisoning; occasionally, it reverses some of the effects of toxicity. Treatment of clonidine poisoning is supportive, and naloxone use can be considered. Poisoning with other alpha2 agonists such as tetrahydrozyline (in eye drops) and xylazine (a veterinary anesthetic) present similar to clonidine. Poisoning with diphenhydramine, lysergic acid (LSD), and yohimbine typically result in mydriasis, not miosis. Diphenhydramine has antimuscarinic properties and can present with all of the typical signs of antimuscarinic (anticholinergic) poisoning such as tachycardia, mild hyperthermia, delirium, mydriasis, and dry skin. Diphenhydramine also has sodium-channel blocking activity, which can manifest as QRS complex prolongation and convulsions. Presentations related to LSD are uncommon but mydriasis, tachycardia, and hallucinations are typical symptoms. Yohimbine is an alpha2 antagonist (opposite of clonidine). Manifestations of poisoning include sympathomimetic symptoms and signs of tachycardia, hypertension, agitation, diaphoresis, and mydriasis.
  1. The answer is C, Factor VIII therapy to 100% activity.
    (Fleisher, 878-883; Marx, 1578-1587)
    Head trauma can be life-threatening in hemophilia patients, and bleeds involving the CNS are the major cause of complications. With these injuries, treatment consists of replacement therapy to at least 50% activity before the child is sent for CT. If an injury is diagnosed, 100% activity should be achieved giving 50 units/kg of factor VIII. Lower percentages of activity are used for less severe injuries. Hemophilia is usually an X-linked recessive disorder causing a variation in factor VIII, which diminishes clot promotion in the clotting cascade. Emergency department treatment of bleeding events was once common, but most of the replacement therapy is now performed at the patient’s home. Replacement therapy for hemophilia A includes cryoprecipitate or factor VIII:C concentrate. The infusion of 1 unit of factor VIII/kg increases the level by approximately 2%. The screening for antihemophilia antibodies should be done in all hemophiliac patients, but especially in those who are not responding to factor repletion. Treatment for a bleeding issue depends on the specific location, but the emergency physician should institute therapy as soon as possible in patients with obvious signs of bleeding or those patients who indicate that they are bleeding. Hospitalization is likely after a head injury in a patient with hemophilia A, and observation alone is not enough therapy, as factor replacement is required. Communication with a hematologist is helpful to guide therapy further. Factor IX therapy is used for treatment of hemophilia B. Blood transfusion is often required for a patient suffering from hemorrhagic shock but not part of the management of hemophilia A.
  1. The answer is B, Epidural hematoma.
    (Roberts, 1108-1117; Straus, 2013)
    An epidural hematoma can develop as a result of lumbar puncture in a patient who is taking anticoagulant agents, even with minimal trauma. When lumbar puncture must be performed emergently prior to infusing clotting factor in a hemophiliac patient or before correcting the INR with fresh frozen plasma in an anticoagulated patient (like this one with chronic atrial fibrillation), the patient should be watched closely for weakness or numbness in the legs, incontinence, and worsening local pain. A spine abscess would not likely develop from the tap itself. If an unrecognized brain abscess exists, lumbar puncture can induce herniation. A brain abscess can also rupture, spill into the ventricular system, and cause ventriculitis and meningitis. If a lumbar puncture must be performed in a patient who is anticoagulated or has a coagulopathy, the most experienced clinician should perform the procedure and correct the coagulopathy if possible. In children with leukemia and low platelet counts, studies have shown that prophylactic platelet transfusions were not required when the platelet count was higher than 10,000/mcL. The incidence of spinal epidural hematoma is 0.1/100,000; it usually is related to lumbar puncture or epidural anesthesia but can rarely occur spontaneously. Spinal epidural abscess typically extends over four to five spinal vertebral segments. Symptoms include progressive back pain, focal tenderness to percussion, fever, sweats, and chills. Changes in bowel or bladder function and focal weakness are late symptoms and are unlikely to present immediately after lumbar puncture. Classic signs of peripheral diabetic neuropathy include tingling, numbness, nocturnal burning, and pain. A diabetic autonomic neuropathy can present with bladder dysfunction and paralysis but not with an acute presentation as described in this question. If lumbar puncture is performed in or near the correct vertebral space, damage to the spinal cord is unlikely. Minor nerve irritation can occur, which usually causes a tingling or an electric shock sensation, but nerve damage caused by direct needle trauma is not likely. Although the most common complication of lumbar puncture is a headache, occurring in up to 70% of patients, fever and stiff neck are not typical symptoms. The classic postspinal headache is much more severe when the patient is upright and improves or resolves when the patient lies down.
  1. The answer is C, 3-year-old Chinese child with a family history of seizure disorder who is now acting normally.
    (Hirtz, 618-623; Wolfson, 1171-1174)
    Following an afebrile first-time seizure, a healthy child older than 12 months can be safely discharged without emergent imaging when there is no concern for an underlying structural, traumatic, or infectious etiology that might require intervention. In the emergency department, CT scanning or MRI can be obtained to evaluate for any of these findings. Nonemergent MRI is the indicated test for outpatient imaging. Neuroimaging is preferred in children younger than 12 months in the setting of first-time seizure. Patients who are at higher risk for a focal finding include those with recurrent or persistent seizures and those who are from areas endemic for cysticercosis, such as Mexico. Children who are immunocompromised, have hypercoagulable states such as sickle cell disease, or have sustained trauma should be imaged. Children with ventriculoperitoneal shunts or other conditions that put them at higher risk for having elevated intracerebral pressure should also be imaged. Other tests that might be indicated based on history and physical examination include serum glucose and electrolytes, urine toxicology, and lumbar puncture. In general, children with isolated first-time seizures without any identifiable etiology are not started on antiepileptic agents. Expeditious followup with a specialist for outpatient MRI and EEG is indicated.
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