Board Review Questions: January 2017

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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 patient presents with peripheral cyanosis with no central cyanosis. Which of the following is the most likely etiology?
    A.     Dilated cardiomyopathy
    B.     Primary pulmonary hypertension
    C.     Tetralogy of Fallot
    D.     Tricuspid atresia
  2. A patient presents with tachycardia, mild hyperthermia, dry skin, delirium, and mydriasis after drinking a tea made from a plant. Which of the following plants was most likely used?
    A.     Dieffenbachia
    B.     Jimsonweed
    C.     Nicotiana tabacum
    D.     Oleander
  3. A 13-year-old boy presents with progressively worsening left knee pain of 2 weeks’ duration after he fell. The family’s primary care physician diagnosed growing pains, but the mother is concerned because he has also started to limp. Examination reveals no swelling or instability of the knee but pain with internal rotation, abduction, and flexion of the affected lower extremity. The patient is obese, but his vital signs are normal for age. What is the most likely injury?
    A.     Anterior cruciate ligament rupture
    B.     Slipped capital femoral epiphysis
    C.     Tibial spiral fracture
    D.     Toxic synovitis
  4. What is the best solution to resolve a Foley catheter balloon that does not deflate properly?
    A.     Instill a chemical such as toluene
    B.     Overextend the balloon
    C.     Pass a guidewire into the balloon port
    D.     Puncture the balloon with a suprapubic needle
  5. A 65-year-old man with hypertension and diabetes presents after a 20-minute episode of left arm and leg weakness and numbness. His symptoms have completely resolved. He had a similar episode the previous day that lasted between 5 and 10 minutes. He takes furosemide 40 mg daily, insulin, and aspirin 325 mg daily. Which of the following statements best summarizes his level of risk for future episodes?
    A.     High risk: symptoms occurred while he was taking a prophylactic antiplatelet agent
    B.     Low risk: symptoms did not involve dysphagia or dysarthria
    C.     Low risk: symptoms resolved in less than 30 minutes
    D.     Moderate risk: based on past medical history

Answers

  1. The answer is A, Dilated cardiomyopathy.
    (Marx, 211-216; Tintinalli, 470-471, 820-825)
    Peripheral cyanosis without associated central cyanosis is caused by five main events: low cardiac output states (including dilated cardiomyopathy), environmental exposure to cold with vasoconstriction, arterial or venous occlusion, and redistribution of blood flow. Peripheral cyanosis is seen in the peripheral vasculature (such as in the nail beds) when there is slowed flow of normally oxygenated blood, when more oxygen is extracted from the red blood cells with a resultant increase in the concentration of deoxyhemoglobin. In anemic patients, the concentrations of both oxyhemoglobin and deoxyhemoglobin are lowered, and it can be difficult to appreciate peripheral cyanosis. Central cyanosis is primarily a result of low arterial oxygen levels, anatomic shunts, or abnormal Hgb. Tetralogy of Fallot and tricuspid atresia are forms of cyanotic congenital heart disease and present with central cyanosis. Primary pulmonary hypertension causes ventilation-perfusion mismatch, leading to low arterial oxygen levels and central cyanosis.
  1. The answer is B, Jimsonweed.
    (Marx, 2062-2064; Wolfson, 1514-1516)
    Tachycardia, mild hyperthermia, dry skin, delirium, and mydriasis are classic signs of antimuscarinic or anticholinergic poisoning consistent with poisoning with jimsonweed (Datura stramonium). All parts of jimsonweed contain the antimuscarinic agents atropine, hyoscyamine, and scopolamine. Significant toxicity typically occurs in teenagers seeking hallucinogenic effects who will ingest, smoke, or make a tea from the plant. Other antimuscarinic or anticholinergic manifestations include picking behavior, diminished bowel sounds, and urinary retention. Treatment is supportive, although the short-acting acetylcholinesterase inhibitor physostigmine can be used both diagnostically and therapeutically. Oleander (Nerium oleander) is one of multiple plants that contain cardiac glycosides. Although small accidental exposures by children are typically without consequence, larger exposures such as from a suicide attempt from an oleander tea can be fatal. Manifestations and treatment are similar to those for digoxin poisoning. Dieffenbachia, also known as dumb cane, is a common household plant that causes local oral pain and swelling when ingested. The plant contains calcium oxalate crystals that cause this local reaction, which typically prevents further ingestion. Nicotiana tabacum is a plant used to make cigarette and cigar tobacco and contains nicotine. Most exposures to nicotine are from accidental ingestions of cigarette or cigar butts in children and are fortunately mostly benign, likely from vomiting that prevents absorption. Poisoning from nicotine can be confusing, as both sympathetic (tachycardia, hypertension, diaphoresis) and parasympathetic (salivation, lacrimation, vomiting, diarrhea) manifestations can occur. Muscular fasciculations and diaphragmatic paralysis can result from the agonism of nicotinic receptors on the neuromuscular junction. Seizures can also occur with significant toxicity. Management is supportive.
  1. The answer is B, Slipped capital femoral epiphysis.
    (Fleisher, 1361-1362, 1575-1576; Marx, 642-644, 660, 2254-2255)
    Slipped capital femoral epiphysis (SCFE) is a hip disorder in which the epiphysis of one or both femoral heads begins to slide off center. It occurs predominantly in males, with a 4:1 male-to-female ratio. There is a higher incidence among obese and African-American children and among patients 8 to 15 years old. A high index of suspicion for a hip injury is warranted in the examination of adolescent boys presenting with either hip or knee pain. In SCFE, physical examination elicits abnormal range of motion of the hip. The diagnosis can be verified with radiographs; AP views might not clearly show the SCFE, so frog-leg views should be obtained. Computed tomography, MRI, bone scintigraphy, or ultrasonography can be used if plain radiographs do not show the abnormality but clinical suspicion is high. In up to 10% to 25% of SCFE cases, the abnormality is bilateral, so both aspects of the femoral heads must be reviewed. This can be an issue if the clinician is using the “good” side as a comparison to the “bad.” Treatment requires case discussion with an orthopedic specialist and surgical pinning. Some orthopedists pin both heads even if the condition is unilateral as a prophylactic measure. An anterior cruciate ligament rupture is unlikely in a young adolescent boy without a significant injury who has normal findings on examination, as most of these injuries cause severe pain, instability, and effusion of the knee joint. Septic arthritis generally presents as a limp in a child with hip pain and is most common in children 3 to 10 years old. The four predictor diagnostics for this malady include fever, refusal to bear weight, an elevated sedimentation rate (>40 mm/hr), and an elevated systemic WBC count (>12,000/mm3). Septic arthritis is difficult to distinguish from toxic synovitis (nonbacterial inflammation of the hip joint); in both conditions, ultrasonography reveals joint effusion. A tibial spiral fracture (known as a toddler’s fracture) is a nondisplaced tibial spiral fracture that can be caused by minimal twisting trauma, which can occur when a toddler jumps down one stair. It is rarely seen in a child of this patient’s age.
  1. The answer is C, Pass a guidewire into the balloon port.
    (Roberts, 1024-1026; Tintinalli, 659)
    The most common cause of a nondeflating balloon on a catheter is trouble with the flap valve. A thin angiographic or central venous catheter can be inserted into the balloon port lumen to clear the flaplike defect in the canal. This procedure is effective and unlikely to result in balloon fragmentation. Cutting the inflation port might allow the balloon to deflate, but this is a less common site of obstruction. Another method to consider is instilling 50 to 100 mL of saline solution into the balloon, thereby increasing its size, which allows the balloon to be punctured using a suprapubic approach. Ultrasound guidance is very helpful in this approach. The thin needle may be passed suprapubically, transvaginally, transperineally, or transrectally. It is rare for fragmentation to occur with this method. Injection of a caustic material such as toluene, ether, acetone, or mineral oil ruptures the balloon but can allow it to fragment, requiring subsequent cystoscopic inspection of the bladder; this also can lead to a chemical cystitis. Overinflation of the balloon by injecting up to 200 mL of fluid or air is often successful but leads to balloon fragmentation as well.
  1. The answer is A, High risk: symptoms occurred while he was taking a prophylactic antiplatelet agent.
    (Cucchiara, S27-S39; Wolfson, 761-763)
    The patient in this question had a transient ischemic attack (TIA), the development of an acute ischemic neurologic deficit lasting less than 24 hours. A recently proposed change to the definition alters the time frame to less than 1 hour. Transient ischemic attacks that occur in patients while they are taking high-dose antiplatelet agents (325 mg aspirin or dipyridamole) indicate high risk for consequent stroke. Patients who experience TIA symptoms more than three times in a 72-hour period (crescendo TIAs) whose symptoms last longer than 10 minutes and who have symptoms of posterior circulation ischemia (vertebrobasilar system) or symptoms that suggest varied territories are being affected and would raise concern for a cardioembolic etiology are also at high risk. The ABCD score has been validated to predict the risk of future stroke in patients who have presented with a TIA. The score ranges from 0 to 6; patients with scores of 5 or 6 have an 8-fold increase in stroke risk for the immediate 30-day period compared with patients with scores of less than 5. The ABCD scoring system is as follows:
    A – Age 60 years or older, 1 point
    B – Systolic blood pressure greater than 140 mm Hg and/or diastolic blood pressure greater than 90 mm Hg, 1 point
    C – Clinical features of unilateral weakness, 2 points, or speech disturbance without weakness, 1 point
    D – Duration of symptoms 10 to 59 minutes, 1 point, or 60 minutes or longer, 2 pointsPatients with TIA symptoms that reflect a deficit in the anterior circulation should undergo carotid Doppler testing to evaluate for stenosis of greater than 50%, as well as CT or magnetic resonance angiography and echocardiogram, if it is indicated. The timing of these studies, whether inpatient, outpatient, or during an observation stay, should be based on the severity of the patient’s symptoms, ability to obtain these studies in an expeditious manner, and resources available to the provider. Patients with anterior circulation TIA symptoms and carotid stenosis of greater than 50% should be referred for carotid endarterectomy, which decreases the risk of subsequent stroke.
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